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Sample records for ash substituted cements

  1. High stenghth concrete with high cement substitution by adding fly ash, CaCO3, silica sand, and superplasticizer

    Science.gov (United States)

    Wicaksono, Muchammad Ridho Sigit; Qoly, Amelia; Hidayah, Annisaul; Pangestuti, Endah Kanti

    2017-03-01

    Concrete is a mixture of cement, fine aggregate, coarse aggregate and water with or without additives. Concrete can be made with substitution of cement with materials like Fly Ash, CaCO3 and silica sand that can increase the binding on pasta and also increase the compressive strength of concrete. The Superplasticizer on a mixture is used to reduce the high water content, improve concrete durability, low permeability concrete by making it more resilient, and improve the quality of concrete. The combination between Fly Ash (30% of cement required), CaCO3 (10% of cement required) and silica sand (5% of cement required) with added MasterGlenium ACE 8595 as much as 1,2% from total cement will produces compressive strength of up to 1080 kN/cm2 or 73,34 Mpa when the concrete is aged at 28 day. By using this technique and innovation, it proves that the cost reduction is calculated at 27%, which is much more efficient. While the strength of the concrete is increased at 5% compared with normal mixture.

  2. Use of Incineration Solid Waste Bottom Ash as Cement Mixture in Cement Production

    Science.gov (United States)

    Jun, N. H.; Abdullah, M. M. A. B.; Jin, T. S.; Kadir, A. A.; Tugui, C. A.; Sandu, A. V.

    2017-06-01

    Incineration solid waste bottom ash was use to examine the suitability as a substitution in cement production. This study enveloped an innovative technology option for designing new equivalent cement that contains incineration solid waste bottom ash. The compressive strength of the samples was determined at 7, 14, 28 and 90 days. The result was compared to control cement with cement mixture containing incineration waste bottom ash where the result proved that bottom ash cement mixture able achieve its equivalent performance compared to control cement which meeting the requirement of the standards according to EN 196-1. The pozzolanic activity index of bottom ash cement mixture reached 0.92 at 28 days and 0.95 at 90 and this values can be concluded as a pozzolanic material with positive pozzolanic activity. Calcium hydroxide in Portland cement decreasing with the increasing replacement of bottom ash where the reaction occur between Ca(OH)2 and active SiO2.

  3. Thermal properties of fly ash substituted slag cement waste forms for disposal of Savannah River Plant salt waste

    International Nuclear Information System (INIS)

    Roy, D.M.; Kaushal, S.; Licastro, P.H.; Langton, C.A.

    1985-01-01

    Waste processing at the Savannah River Plant will involve reconstitution of the salts (NaNO 3 , NaNO 2 , NaOH, etc.) into a concentrated solution (32 weight percent salts) followed by solidification in a cement-based waste form for burial. The stability and mechanical durability of such a 'saltstone monolith' will depend largely on the temperature reached due to heat of hydration and the thermal properties of the waste form. Fly ash has been used as an inexpensive constituent and to moderate the hydration and setting processes so as to avoid reaching prohibitively high temperatures which could cause thermal stresses. Both high-calcium and low-calcium fly ashes have been studied for this purpose. Other constituents of these mixes include granulated blast furnace slag and finely crushed limestone. Adiabatic temperature increase and thermal conductivity of these mixes have been studied and related x-ray diffraction and scanning electron microscopy studies carried out to understand the hydration process

  4. Formation of cement mortar with incineration municipal solid waste bottom ash

    Science.gov (United States)

    Jun, Ng Hooi; Abdullah, Mohd Mustafa Al Bakri; Hussin, Kamarudin; Jin, Tan Soo

    2017-04-01

    Product of incineration municipal solid waste bottom ash was substitute to Portland cement in construction industry. This study investigated the changes of bottom ash in Portland cement by chemical and mineralogical testing. Various substitution of bottom ash (10%, 20%, 30%, and 40%) to Portland cement was investigated. The main purpose was to clarify the mechanisms behind the formation of the cement mortar with bottom ash particles. The result indicated that the chemical and mineralogical of the cement mortar incorporating bottom ash was not significantly changed with the substitution of 10-40% bottom ash. However, the use of bottom ash minimizes the main composition of cement mortar. Overall, it was found that there is significant potential to increase the utilization of bottom ash.

  5. The effect of fly ash and coconut fibre ash as cement replacement materials on cement paste strength

    Science.gov (United States)

    Bayuaji, R.; Kurniawan, R. W.; Yasin, A. K.; Fatoni, H. AT; Lutfi, F. M. A.

    2016-04-01

    Concrete is the backbone material in the construction field. The main concept of the concrete material is composed of a binder and filler. Cement, concrete main binder highlighted by environmentalists as one of the industry are not environmentally friendly because of the burning of cement raw materials in the kiln requires energy up to a temperature of 1450° C and the output air waste CO2. On the other hand, the compound content of cement that can be utilized in innovation is Calcium Hydroxide (CaOH), this compound will react with pozzolan material and produces additional strength and durability of concrete, Calcium Silicate Hydrates (CSH). The objective of this research is to explore coconut fibers ash and fly ash. This material was used as cement replacement materials on cement paste. Experimental method was used in this study. SNI-03-1974-1990 is standard used to clarify the compressive strength of cement paste at the age of 7 days. The result of this study that the optimum composition of coconut fiber ash and fly ash to substitute 30% of cement with 25% and 5% for coconut fibers ash and fly ash with similar strength if to be compared normal cement paste.

  6. Processing of Sugarcane Bagasse ash and Reactivity of Ash-blended Cement Mortar

    Science.gov (United States)

    Ajay, Goyal; Hattori, Kunio; Ogata, Hidehiko; Ashraf, Muhammad

    Sugarcane bagasse ash (SCBA), a sugar-mill waste, has the potential of a partial cement replacement material if processed and obtained under controlled conditions. This paper discusses the reactivity of SCBA obtained by control burning of sugarcane bagasse procured from Punjab province of India. X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques were employed to ascertain the amorphousness and morphology of the minerals ash particles. Destructive and non-destructive tests were conducted on SCBA-blended mortar specimens. Ash-blended cement paste specimens were analyzed by XRD, thermal analysis, and SEM methods to evaluate the hydration reaction of SCBA with cement. Results showed that the SCBA processed at 600°C for 5 hours was reactive as ash-blended mortar specimens with up to 15% substitution of cement gave better strength than control specimens.

  7. Compressive Strength Of Rice Husk Ash-Cement Sandcrete Blocks ...

    African Journals Online (AJOL)

    There is growing demand for alternative, low-cost building material in developing countries. The effect of partial substitution of ordinary Portland cement with Rice Husk Ash (RHA) on the compressive strength of hollow sandcrete block was investigated through laboratory experimental procedures. The specific gravity, initial ...

  8. Incinerated sewage sludge ash as alternative binder in cement-based materials

    DEFF Research Database (Denmark)

    Krejcirikova, Barbora; Goltermann, Per; Hodicky, Kamil

    2013-01-01

    Sewage sludge ash is characterized by its pozzolanic properties, as cement is. This predetermines its use in a substitution of cement and cementitious materials. Utilization of sewage sludge ash does not only decrease the consumption of cement, one of the largest cause of CO2 emissions, but also...... it can minimize the need of ash landfill disposal. The objective of this study is to show potential use of incinerated sewage sludge ash (ISSA), an industrial byproduct, as possible binder in cement-based materials. Chemical and mechanical characteristics are presented and compared with results obtained...

  9. Expansion control for cementation of incinerated ash

    International Nuclear Information System (INIS)

    Nakayama, T.; Suzuki, S.; Hanada, K.; Tomioka, O.; Sato, J.; Irisawa, K.; Kato, J.; Kawato, Y.; Meguro, Y.

    2015-01-01

    A method, in which incinerated ash is solidified with a cement material, has been developed to dispose of radioactive incinerated ash waste. A small amount of metallic Al, which was not oxidized in the incineration, existed in the ash. When such ash was mixed with a cement material and water, alkaline components in the ash and the cement were dissolved in the mixing water and then metallic Al reaction with the alkaline compounds resulted in generation of H 2 . Because the H 2 generation began immediately just after the mixing, H 2 bubbles pushed up the mixed grout material and an expanded solidified form was obtained. The expansion leads to lowering the strength of the solidified form and making harmful void. In this study, we tried to control H 2 generation from the reaction of metallic Al in the cementation by means of following two methods, one was a method to let metallic Al react prior to the cementation and the other was a method to add an expansion inhibitor that made an oxide film on the surface of metallic Al. In the pre-treatment, the ash was soaked in water in order to let metallic Al react with it, and then the ash with the immersion solution was dried at 105 Celsius degrees. The pre-treated ash was mixed with an ordinary portland cement and water. The inhibitor of lithium nitrite, sodium nitrite, phosphoric acid, or potassium dihydrogen phosphate was added at the mixing process. The solidified forms prepared using the pre-treated ash and lithium nitrite were not expanded. Phosphoric acid and sodium nitrite were effective for expansion control, but potassium dihydrogen phosphate did not work. (authors)

  10. Coal Bottom Ash for Portland Cement Production

    Directory of Open Access Journals (Sweden)

    Cristina Argiz

    2017-01-01

    Full Text Available Because of industrialization growth, the amount of coal power plant wastes has increased very rapidly. Particularly, the disposal of coal bottom ash (CBA is becoming an increasing concern for many countries because of the increasing volume generated, the costs of operating landfill sites, and its potential hazardous effects. Therefore, new applications of coal bottom ash (CBA have become an interesting alternative to disposal. For instance, it could be used as a Portland cement constituent leading to more sustainable cement production by lowering energy consumption and raw material extracted from quarries. Coal fly and bottom ashes are formed together in the same boiler; however, the size and shape of these ashes are very different, and hence their effect on the chemical composition as well as on the mineralogical phases must be studied. Coal bottom ash was ground. Later, both ashes were compared from a physical, mechanical, and chemical point of view to evaluate the potential use of coal bottom ash as a new Portland cement constituent. Both ashes, produced by the same electrical power plant, generally present similar chemical composition and compressive strength and contribute to the refill of mortar capillary pores with the reaction products leading to a redistribution of the pore size.

  11. The Suitability of Lime Rice Husk Ash Cement as Construction ...

    African Journals Online (AJOL)

    However, by gradually increasing the percentage contents of silica, potassium oxide and sodium oxide in the Portland cement to the values found in the rice husk ash a new product, "Artificial Lime Rice Husk Ash" (ALRHA) cement was produced. The new product ALRHA cement compared favourably with the ordinary rice ...

  12. Alkali ash material: a novel fly ash-based cement

    Energy Technology Data Exchange (ETDEWEB)

    Hossein Rostami; William Brendley [Philadelphia University, Philadelphia, PA (United States)

    2003-08-01

    The United States generates 110 million t of coal ash annually. Approximately 70 million t of this coal ash is fly ash, of which 27% is recycled and the remaining 73% is landfilled. Disposal of such a huge quantity of ash poses a significant environmental problem. A new cementitious material has been developed, called alkali ash material (AAM), which is used to produce concrete for construction. AAM can be used to create a variety of concrete strengths and could revolutionize the concrete product manufacturing industry due to its economic advantage. AAM contains 40-95% Class F fly ash and is used as cement to bind sand, stone, and fibers creating concrete. AAM concrete has been tested for strength, durability, mechanical properties, and, most importantly, economic viability. AAM concrete is economically and technically viable for many construction applications. Some properties include rapid strength gain (90% of ultimate in 1 d), high ultimate strengths (110 MPa or 16 000 psi in 1 d), excellent acid resistance, and freeze-thaw durability. AAM's resistance to chemical attack, such as sulfuric (H{sub 2}SO{sub 4}), nitric (HNO{sub 3}), hydrochloric (HCl), and organic acids, is far better than portland cement concrete. AAM is resistant to freeze-thaw attack based on ASTM C-666 specifications. Potential immediate applications of AAM are blocks, pipe, median barriers, sound barriers, and overlaying materials. Eventual markets are high strength construction products, bridge beams, prestressed members, concrete tanks, highway appurtenances, and other concrete products. 28 refs., 7 figs., 2 tabs.

  13. Optimization of fly ash as sand replacement materials (SRM) in cement composites containing coconut fiber

    Science.gov (United States)

    Nadzri, N. I. M.; Jamaludin, S. B.; Mazlee, M. N.; Jamal, Z. A. Z.

    2016-07-01

    The need of utilizing industrial and agricultural wastes is very important to maintain sustainability. These wastes are often incorporated with cement composites to improve performances in term of physical and mechanical properties. This study presents the results of the investigation of the response of cement composites containing coconut fiber as reinforcement and fly ash use as substitution of sand at different hardening days. Hardening periods of time (7, 14 and 28 days) were selected to study the properties of cement composites. Optimization result showed that 20 wt. % of fly ash (FA) is a suitable material for sand replacement (SRM). Meanwhile 14 days of hardening period gave highest compressive strength (70.12 MPa) from the cement composite containing 9 wt. % of coconut fiber and fly ash. This strength was comparable with the cement without coconut fiber (74.19 MPa) after 28 days of curing.

  14. Scrap tire ashes in portland cement production

    Directory of Open Access Journals (Sweden)

    Mónica Adriana Trezza

    2009-01-01

    Full Text Available Scrap tires are not considered harmful waste, but their stocking and disposal are a potential health and environmental risk. Properly controlled calcinations at high temperatures make tire combustion an interesting alternative due to its high calorific power, comparable to that of fuel-oil. Consequently, using them as an alternative combustible material in cement kilns makes it possible to give it a valuable use. However, it remains to be assured whether the impurities added to the clinker through these fuels do not affect its structure or properties.This paper shows the studies carried out on different clinkers under laboratory conditions with different levels of addition of scrap tire ashes, added by partially replacing traditional fuel in cement kilns.

  15. Radioactive wastes dispersed in stabilized ash cements

    International Nuclear Information System (INIS)

    Rubin, J.B.; Taylor, C.M.V.; Sivils, L.D.; Carey, J.W.

    1997-01-01

    One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO 2 ) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO 2 to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO 2 to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms

  16. Radioactive wastes dispersed in stabilized ash cements

    Energy Technology Data Exchange (ETDEWEB)

    Rubin, J.B.; Taylor, C.M.V.; Sivils, L.D.; Carey, J.W.

    1997-12-31

    One of the most widely-used methods for the solidification/stabilization of low-level radwaste is by incorporation into Type-I/II ordinary portland cement (OPC). Treating of OPC with supercritical fluid carbon dioxide (SCCO{sub 2}) has been shown to significantly increase the density, while simultaneously decreasing porosity. In addition, the process significantly reduces the hydrogenous content, reducing the likelihood of radiolytic decomposition reactions. This, in turn, permits increased actinide loadings with a concomitant reduction in disposable waste volume. In this article, the authors discuss the combined use of fly-ash-modified OPC and its treatment with SCCO{sub 2} to further enhance immobilization properties. They begin with a brief summary of current cement immobilization technology in order to delineate the areas of concern. Next, supercritical fluids are described, as they relate to these areas of concern. In the subsequent section, they present an outline of results on the application of SCCO{sub 2} to OPC, and its effectiveness in addressing these problem areas. Lastly, in the final section, they proffer their thoughts on why they believe, based on the OPC results, that the incorporation of fly ash into OPC, followed by supercritical fluid treatment, can produce highly efficient wasteforms.

  17. Performance Evaluation of Steel Fibres in Rice Husk Ash Substituted Concretes

    Directory of Open Access Journals (Sweden)

    A. Sivakumar

    2013-12-01

    Full Text Available The potential use of supplementary cementitious materials in plain cement concrete for improving concrete properties has been a growing concern in recent years. In addition, the effective strengthening of the matrix by fibre reinforcements to avoid brittle failure is another requirement for plain concrete. This provided the motivation for exploring the benefits of rice husk ash (RHA as a cement replacement material and the addition of steel fibres for reducing brittleness in concrete. The rice husk ash used in this study was the residue of burnt raw rice husk sintered in a muffle furnace at 800 °C. The fine particle size of the rice husk ash provided an early pozzolanic reaction upon cement hydration and thus resulted in high cementing efficiency. This paper reports a systematic evaluation of the mechanical properties of rice husk ash substituted concrete mixtures containing RHA as a partial cement substitute at replacement levels of 10% and 20% by weight of cement, with different dosages of steel fibres. Our experimental results demonstrated that 10% RHA substitution led to improved compressive properties compared to plain concrete. The highest increase of split tensile and flexural strength was reported in the case of RHA substituted concrete with steel fibre added.

  18. Cementation and solidification of Rocky Flats Plant incinerator ash

    International Nuclear Information System (INIS)

    Phillips, J.A.; Semones, G.B.

    1994-01-01

    Cementation studies on various aqueous waste streams at Rocky Flats have shown this technology to be effective for immobilizing the RCRA constituents in the waste. Cementation is also being evaluated for encapsulation of incinerator ash. Experiments will initially evaluate a surrogate ash waste using a Taguchi experimental design to optimize the cement formulation and waste loading levels for this application. Variables of waste loading, fly ash additions, water/cement ratio, and cement type will be tested at three levels each during the course of this work. Tests will finally be conducted on actual waste using the optimized cement formulation developed from this testing. This progression of tests will evaluate the effectiveness of cement encapsulation for this waste stream without generating any additional wastes

  19. Application of sugarcane bagasse ash as a partial cement ...

    African Journals Online (AJOL)

    This study examined the potential use of sugarcane bagasse ash as a partial cement replacement material. In this study, bagasse ash sample was collected from Wonji sugar factory and its chemical properties were investigated. The bagasse ash was then ground until the particles passing the 63μm sieve size reach about ...

  20. Hydration kinetics and morphology of cement pastes with pozzolanic volcanic ash studied via synchrotron-based techniques

    Energy Technology Data Exchange (ETDEWEB)

    Kupwade-Patil, Kunal; Chin, Stephanie; Ilavsky, Jan; Andrews, Ross N.; Bumajdad, Ali; Büyüköztürk, Oral

    2017-10-13

    This study investigates the early ages of hydration behavior when basaltic volcanic ash was used as a partial substitute to ordinary Portland cement using ultra-small-angle X-ray scattering and wide-angle X-ray scattering (WAXS). The mix design consisted of 10, 30 and 50% substitution of Portland cement with two different-sized volcanic ashes. The data showed that substitution of volcanic ash above 30% results in excess unreacted volcanic ash, rather than additional pozzolanic reactions along longer length scales. WAXS studies revealed that addition of finely ground volcanic ash facilitated calcium-silicate-hydrate related phases, whereas inclusion of coarser volcanic ash caused domination by calcium-aluminum-silicate-hydrate and unreacted MgO phases, suggesting some volcanic ash remained unreacted throughout the hydration process. Addition of more than 30% volcanic ash leads to coarser morphology along with decreased surface area and higher intensity of scattering at early-age hydration. This suggests an abrupt dissolution indicated by changes in surface area due to the retarding gel formation that can have implication on early-age setting influencing the mechanical properties of the resulting cementitious matrix. The findings from this work show that the concentration of volcanic ash influences the specific surface area and morphology of hydration products during the early age of hydration. Hence, natural pozzolanic volcanic ashes can be a viable substitute to Portland cement by providing environmental benefits in terms of lower-carbon footprint along with long-term durability.

  1. Viability of Eggshells Ash Affecting the Setting Time of Cement

    OpenAIRE

    Fazeera Ujin; Kamran Shavarebi Ali; Zarina Yasmin Hanur Harith

    2016-01-01

    This research paper reports on the feasibility and viability of eggshells ash and its effects on the water content and setting time of cement. An experiment was carried out to determine the quantity of water required in order to follow standard cement paste of normal consistency in accordance with MS EN 196-3:2007. The eggshells ash passing the 90µm sieve was used in the investigation. Eggshells ash with percentage of 0%, 0.1%, 0.5%, 1.0%, 1.5% and 2.0% were constituted to replace the cement....

  2. The influence of sugarcane bagasse ash as fly ash on cement quality

    Science.gov (United States)

    Rauf, N.; Damayanti, M. C.; Pratama, S. W. I.

    2017-01-01

    Fly ash often is used as the third material for cement. The fly ash from sugarcane bagasse is usually considered as industrial waste material that can be added to the base material of cement (clinker, trash, gypsum and lime stone) for economic and environment reason. The amount of fly ash usually up to 30 % of cement material, but in this research the percentage of sugarcane bagasse ash (SBA) is added to cement material is up to 15% total weight. Then the x-rays fluorescence (XRF) was used to determine its chemical composition of raw material and cement samples. The physical properties of cement such as fineness, setting time, expansion, and compressive strength were measured using Automatic Blaine, Vicat, Autoclave, respectively. The result show that the percentage of sugarcane bagasse ash influences the quality of cement and concrete, and this is confirmed with Indonesia National Standard (SNI). It is showed that the sugarcane bagasse ash could be use as material to improve the quality of cement and will solve the environment waste material

  3. A review on seashells ash as partial cement replacement

    Science.gov (United States)

    Mohammad, Wan Ahmad Soffian Bin Wan; Hazurina Othman, Nor; Ibrahim, Mohd Haziman Wan; Rahim, Masazurah A.; Shahidan, Shahiron; Rahman, Raha Abd

    2017-11-01

    This review paper emphasis on various sea shells ash such as cockle, clam, oyster, mollusc, periwinkle, snail, and green mussel shell ash as partial cement replacement and its objective is to create sustainable environment and reduce problems of global warming. Cement production give huge impact to environment in every stage of its production. These include air pollution in form of dust and, gases, sound and vibration during quarry crushing and milling. One of the solutions to solve this problem is by using modified cement. The modified cement is a cementitious material that meets or exceeds the Portland cement performance by combining and optimizes the recycle and wasted materials. This will indirectly reduce the use of raw materials and then, become a sustain construction materials. Therefore, the replacement of cement in concrete by various sea shell ash may create tremendous saving of energy and also leads to important environmental benefits. This study includes previous investigation done on the properties of chemical and mechanical such as specific gravity, chemical composition, compressive strength, tensile strength and flexural strength of concrete produced using partial replacement of cement by seashells ash. Results show that the optimum percentage of seashells as cement replacement is between 4 - 5%.

  4. Effects of Groundnut Husk Ash-blended Cement on Chemical ...

    African Journals Online (AJOL)

    The empirical investigation reported the effects of chemicals on the properties of concrete with cement partially replaced with Groundnut Husk Ash (GHA). The principal characteristic measured was the compressive strength of Ordinary Portland Cement (OPC) concrete and OPC/GHA concrete after curing in three chemical ...

  5. A radoilogical evaluation of fly ash in cement

    International Nuclear Information System (INIS)

    Stranden, E.

    1981-01-01

    The radiological consequences of using fly ash as a component of cement are discussed. Measurements of the activity concentrations of emanation coefficients and exhalation rates. The radon exhalation rate was found to be significantly lower in concrete containing fly ash than in ordinary concrete. Dose calculations suggest that the fly ash will contribute to a reduction in effec- tive dose equivalent due to the reduced radon exhalation rate. (Auth)

  6. The analysis of mechanical properties of non autoclaved aerated concrete with the substitution of fly ash and bottom ash

    Science.gov (United States)

    Karolina, R.; Muhammad, F.

    2018-02-01

    Based on PP. No.85 of 1999 on the management of hazardous and toxic (B3), fly ash and bottom ash wastes are categorized into B3 waste because there are heavy metal oxide contents that can pollute the environment. One form of environmental rescue that can be applied is to utilize waste fly ash and bottom ash in the manufacture of concrete. In this research, fly ash and bottom ash waste are used as substitution of cement and fine aggregate to make lightweight concrete. The purpose of this research is to know the mechanical properties of non-autoclaved aerated lightweight concrete (NAAC) with FA and BA substitution to cement and fine aggregate which is expected to improve the quality of concrete. The NAAC lightweight concrete in this study is divided into 4 categories: normal NAAC lightweight concrete, NAAC lightweight NAAC substituted concrete with FA, NAAC lightweight concrete substituted with BA, and NAAC combined light weight from FA and BA with variations of 10%, 20% And 30%. The test specimen used in cylindrical shape, which was tested at the age of 28 days, amounted to 90 pieces and consisted of 10 variations. Each variation amounted to 9 samples. Based on the test results with FA and BA substitutions of 10%, 20%, and 30%, the highest compressive strength was achieved in samples with FA 30% of 12.687 MPa, maximum tensile strength achieved in samples with FA 30% of 1,540 MPa, The highest absorption was achieved in normal NAAC of 5.66%. Based on the weight of the contents of all samples, samples can be categorized in lightweight concrete, since the weight of the contents is less than 1900 kg / m3.

  7. The High Teperature Influence on Geopolymer Fly Ash Mixture’s Compressisive Strength with Insudtrial Waste Material Substitution

    Science.gov (United States)

    Bayuaji, R.; Wibowo, B.; Subekti, S.; Santoso, S. E.; Hardiyanto, E.; Kaelani, Y.; Mallu, L. L.

    2017-11-01

    This research aimed to figure out the influence of fly ash mixture from the industrial waste at the temperatures of 150°C, 450°C, 750°C viewed from the strength and resistance of geopolymer paste. As a result, cement will be substituted by industrial waste like fly ash. This experimental research was conducted on the mix design of geopolymer concrete which was made by dimension with 2.5 cm in diameter and 5 cm in height from four mixture composition of fly ash and industrial waste i.e. 100% fly ash, 50% fly ash+50% bottom ash, 50% fly ash+50% sandblast, and 50% fly ash+50% carbide waste. Each mixture was tested in terms of porosity and compressive strength. In conclusion, in the mixture of 50% fly ash+50% Sandblast and 50% fly ash+50% bottom ash in 12 molars, 1.5 activator comparison can be used to substitute fly ash at high temperature. Meanwhile, the mixture of 50% fly ash+50% carbide waste in 8 molars, 0.5 activator comparison has very small strength remaining if it is compared to the mixture of fly ash and other industrial waste (Bottom ash and Sandblast). The performance of mixture paste of 50% fly ash+50% carbide waste was very vulnerable after being burnt. Consequently, it cannot be used as the main structure at high temperature.

  8. Cementing Efficiency of Low Calcium Fly Ash in Fly Ash Concretes

    OpenAIRE

    T. D. Gunneswara Rao; Mudimby Andal

    2014-01-01

    Research on the utilization of fly ash will no longer refer the fly ash as a waste material of thermal power plants. Use of fly ash in concrete making, makes the concrete economical as well as durable. The fly ash is being added to the concrete in three ways namely, as partial replacement to cement, as partial replacement to fine aggregates and as admixture. Addition of fly ash to the concrete in any one of the form mentioned above, makes the concrete more workable and durable than the conven...

  9. Mercury release from fly ashes and hydrated fly ash cement pastes

    Science.gov (United States)

    Du, Wen; Zhang, Chao-yang; Kong, Xiang-ming; Zhuo, Yu-qun; Zhu, Zhen-wu

    2018-04-01

    The large-scale usage of fly ash in cement and concrete introduces mercury (Hg) into concrete structures and a risk of secondary emission of Hg from the structures during long-term service was evaluated. Three fly ashes were collected from coal-fired power plants and three blend cements were prepared by mixing Ordinary Portland cement (OPC) with the same amount of fly ash. The releasing behaviors of Hg0 from the fly ash and the powdered hydrated cement pastes (HCP) were measured by a self-developed Hg measurement system, where an air-blowing part and Hg collection part were involved. The Hg release of fly ashes at room temperature varied from 25.84 to 39.69 ng/g fly ash during 90-days period of air-blowing experiment. In contrast, the Hg release of the HCPs were in a range of 8.51-18.48 ng/g HCP. It is found that the Hg release ratios of HCPs were almost the same as those of the pure fly ashes, suggesting that the hydration products of the HCP have little immobilization effect on Hg0. Increasing temperature and moisture content markedly promote the Hg release.

  10. Radon exhalation study from cement, cement slabs and concrete slabs with variation in fly ash

    International Nuclear Information System (INIS)

    Sharma, Nisha; Singh, Jaspal

    2012-01-01

    Fly ash is a waste product from coal-fired power plants. Fly ash has become a subject of world-wide interest in recent years because of its diverse uses, e.g. in the manufacture of concrete for building purposes, for the filling of underground cavities, or as a component of building material. The fly ash may contain enhanced levels of the natural radionuclides in the uranium and thorium series and by using the fly ash in building materials, the radiation levels in houses may thus be technologically enhanced. Because of its relatively high radionuclide contents (including 226 Ra), fly ash may, however, present a potential hazard to the population through its radon emanation, which would be highly undesirable. Since fly ash is frequently used as a building material, the idea of the experiment was to mix fly ash in different proportions in the cement in the powder form, cemented slabs and concrete slabs to study the combined behaviors. Alpha sensitive LR-115 type II plastic track detector, commonly known as Solid State Nuclear Track Detectors (SSNTDs), were used to measure the radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The chemical etching in NaOH at 60°C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon concentrations were determined. In case of cement in the powder form and in cemented slab, starting from the pure cement, fly ash was added up to 70% by weight. In this case the radon exhalation rate has increased by addition of fly ash in the cement and in case of concrete slabs by the addition of fly ash in the cement the radon exhalation increases up to 60% and then decreases. Therefore, on the basis of our investigations we concluded that in general radon exhalation rate increases with the addition of fly ash. (author)

  11. Rice Husk Ash Cement – An alternative pozzolana cement for ...

    African Journals Online (AJOL)

    The engineering properties of the cement resulting from a mixture of OPC plus RHA and lime plus RHA were satisfactory with addition of up to 50% RHA. The RHA improved greatly the compressive strength of lime. The cost of producing RHA was considered in pricing the resulting binder and it showed that the use of RHA ...

  12. Effects of the addition of oil shale ash and coal ash on physic-chemical properties of CPJ45 cement

    Directory of Open Access Journals (Sweden)

    Nabih K.

    2014-04-01

    Full Text Available We focused our research on recycling industrial wastes, fly ash (F.A, bottom ash (B.A and oil shale ash (S.A in cement production. The study concerns physico-chemical characterization of these products and the influence of their addition on the mechanical proprieties of the CPJ45 cement. XRF allowed us to rank the three additives used according to their contents on major oxides. Coal ashes belong to the class F, and thus possess poozzolanic properties and oil shale ash belongs to the class C and possesses hydraulic and poozolanic properties. The crystalline phases constituting each ash were analysed by XRD. We observe in bottom ash the presence of quartz and mullite. The same crystals are found in fly ash with hematite and magnetite. Oil shale ash is composed of quartz, anhydrite, gehlenite, wollastonite and periclase. The microstructures of fly ash and bottom ash were studied using SEM. The bottom ash was composed respectively of fine particles that are generally irregularly shaped, their dimensions are between 5 and 28μm and of big particles(300 μm. The EDX analysis coupled with an electronic microscope provided some information about the major elements that constitute our samples. The dehydrations of anhydrous and three days hydrated cement were examined by DSC. For hydrated cements we noticed endothermic peaks related to the dehydration of CSH, CH and decomposition of carbonates. The study of the mechanical properties of CPJ45 cement by adding different proportions of fly ash, bottom ash and oil shale ash helped clarifying the percentage of ash that leaded to improve the 28 days mechanical strength. The results show that the cements studied have their maximum mechanical resistance with the addition at 7% of fly ash or 10% of oil shale ash.

  13. Assessment of Pb-slag, MSWI bottom ash and boiler and fly ash for using as a fine aggregate in cement mortar.

    Science.gov (United States)

    Saikia, Nabajyoti; Cornelis, Geert; Mertens, Gilles; Elsen, Jan; Van Balen, Koenraad; Van Gerven, Tom; Vandecasteele, Carlo

    2008-06-15

    Three types of wastes, metallurgical slag from Pb production (SLG), the sand-sized (0.1-2 mm) fraction of MSWI bottom ash from a grate furnace (SF), and boiler and fly ash from a fluidised bed incinerator (BFA), were characterized and used to replace the fine aggregate during preparation of cement mortar. The chemical and mineralogical behaviour of these wastes along with the reactivities of the wastes with lime and the hydration behaviour of ordinary Portland cement paste with and without these wastes added were evaluated by various chemical and instrumental techniques. The compressive strengths of the cement mortars containing waste as a partial substitution of fine aggregates were also assessed. Finally, leaching studies of the wastes and waste containing cement mortars were conducted. SLG addition does not show any adverse affect during the hydration of cement, or on the compressive strengths behaviours of mortars. Formation of expansive products like ettringite, aluminium hydroxide and H2 gas due to the reaction of some constituents of BFA and SF with alkali creates some cracks in the paste as well as in the cement mortars, which lower the compressive strength of the cement mortars. However, utilization of all materials in cement-based application significantly improves the leaching behaviour of the majority of the toxic elements compared to the waste as such.

  14. TECHNOLOGY AND EFFICIENCY OF PEAT ASH USAGE IN CEMENT CONCRETE

    Directory of Open Access Journals (Sweden)

    G. D. Liakhevich

    2015-01-01

    Full Text Available One of the main ways to improve physical and mechanical properties of cement concrete is an introduction of ash obtained due to burning of fossil fuels into concrete mix. The concrete mixes with ash are characterized by high cohesion, less water gain and disintegration. At the same time the concrete has high strength, density, water resistance, resistance to sulfate corrosion. The aim of this paper is to explore the possibility to use peat ash and slag of peat enterprises of the Republic of Belarus in the concrete for improvement of its physical and mechanical properties and characteristics of peat ash, slag, micro-silica, cement, superplasticizing agent. Compositions and technology for preparation of concrete mixes have been developed and concrete samples have been have been fabricated and tested in the paper. It has been shown that the concrete containing ash, slag obtained due to burning of peat in the industrial installations of the Usiazhsky and Lidsky Peat Briquette Plants and also MK-85-grade micro-silica NSPKSAUsF-1-grade superplasticizing agent have concrete tensile strength within 78–134 MPa under axial compression and 53 MPa – for the control composition. This index is 1.5–2.5 times more than for the sample containing no additives.The usage of peat ash, slag together with MK-85-grade micro-silica and NSPKSAUsF-1-grade superplasticizing agent for fabrication of concrete and reinforced bridge and tunnel structures will provide the following advantages: reduction of cross-sectional area of structures while maintaining their bearing capacity due to higher value of tensile strength in case of axial compression; higher density, waterand gas tightness due to low water cement ratio; high resistance to aggressive environment due to lower content of capillary pores that ensures bridge structure longevity; achievement of environmental and social impacts.

  15. the suitability of lime rice husk ash cement as construction material

    African Journals Online (AJOL)

    NIJOTECH

    the Lime Rice Husk Ash cement when used as a construction material would depend largely on the ... cement. However the proceedings from. UNIDO Conference [6] in 1979 recommended that the use of the rice husk ash cement would be mainly for mortar and plaster/ ... the greatest portion is dumped as a waste by-.

  16. Assessment of aggregates- cement paste border in concretes containing silica fume and fly ash

    Directory of Open Access Journals (Sweden)

    Ali Sademomtazi

    2017-12-01

    Full Text Available The bond between aggregate and cement paste, called the interfacial transition zone (ITZ is an important parameter that effect on the mechanical properties and durability of concrete. Transition zone microstructure and porosity (pores of cement paste or concrete are affected by the type and properties of materials used which evaluated in this research. On the other hand, the use of efficient, low-cost and reliable method is particularly important for evaluating of concrete performance against the chloride ion penetration and its relationships with transition zone as a suitable index to assess the durability. So far, various methods to approach the electrical Indices are presented. In this research, the effect of pozzolanic materials fly ash (10%, 20% and 30% and silica fume (5% and 10% as substitute of cement by weight in binary and ternary mixtures on the fresh and hardened concrete properties were investigated. To determine mechanical properties, the compressive strength, splitting tensile strength and modulus of elasticity tests were performed. Also, water penetration depth, porosity, water sorptivity, specific electrical resistivity, rapid chloride penetration test (RCPT and rapid chloride migration test (RCMT tests were applied to evaluate concrete durability. To examine the border of aggregate and cement paste morphology of concrete specimens, scanning electron microscope images (SEM was used. The fresh concrete results showed that the presence of silica fume in binary and ternary mixtures reduced workability and air content but fly ash increased them. Adding silica fume to mixtures of containing flay ash while increasing mechanical strength reduced the porosity and pores to 18%. The presence of pozzolanic materials in addition to increasing bond quality and uniformity of aggregate-cement matrix border a considerably positive effect on the transport properties of concrete.

  17. Characterization of cements and fly ashes from India : phase 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    Chevrier, R.L. [Natural Resources Canada, Ottawa, ON (Canada). CANMET International Centre for Sustainable Development of Cement and Concrete

    2004-03-15

    This paper provided details of fly ashes, cements, and admixtures received from India as part of a Canadian International Development Agency (CIDA) project. The materials for the first phase of the project included 2 cements and 19 fly ash samples. Specific gravity, Blaine Fineness, and fineness by the 45 {mu}m sieve were determined. Compressive strength tests were conducted on the cements and a strength activity index for the fly ashes was presented. Materials for the second phase of the project included 2 cements; 2 fly ashes; a water-reducing admixture; and a superplasticizer. Data were presented in tabular format and included details of their assigned laboratory reference numbers, and the original weight of the materials as received, and the collection origin of the fly ashes. The results of chemical analyses and physical property tests on the fly ashes and cements were presented. A strength activity index with Portland cement was also included. 10 tabs.

  18. Recycling MSWI bottom and fly ash as raw materials for Portland cement.

    Science.gov (United States)

    Pan, Jill R; Huang, Chihpin; Kuo, Jung-Jen; Lin, Sheng-Huan

    2008-01-01

    Municipal solid waste incineration (MSWI) ash is rich in heavy metals and salts. The disposal of MSWI ash without proper treatment may cause serious environmental problems. Recently, the local cement industry in Taiwan has played an important role in the management of solid wastes because it can utilize various kinds of wastes as either fuels or raw materials. The objective of this study is to assess the possibility of MSWI ash reuse as a raw material for cement production. The ash was first washed with water and acid to remove the chlorides, which could cause serious corrosion in the cement kiln. Various amounts of pre-washed ash were added to replace the clay component of the raw materials for cement production. The allowable limits of chloride in the fly ash and bottom ash were found to be 1.75% and 3.50% respectively. The results indicate that cement production can be a feasible alternative for MSWI ash management. It is also evident that the addition of either fly ash or bottom ash did not have any effect on the compressive strength of the clinker. Cement products conformed to the Chinese National Standard (CNS) of Type II Portland cement with one exception, the setting time of the clinker was much longer.

  19. Effect of fly and bottom ash mixture from combustion of biomass on strength of cement mortar

    Directory of Open Access Journals (Sweden)

    Ulewicz Małgorzata

    2017-01-01

    Full Text Available The preliminary results of fly and bottom ash mixture form combustion od biomass (80% of tree waste and 20% of palm kernel shells for the produce of ceramic mortars has been presented. Currently, bio- ash from fluidized bed are deposited in landfills. Use of this ash to production of cement mortar instead of sand will reduce the consumption of the mineral resources. The chemical composition of this waste materials was determined using X-ray fluorescence (spectrometer ARL Advant ‘XP. Cement mortar were made using CEM I 42.5 R. The ash were added in an amount 20% of cement weight (in different proportions of fly and bottom ash. The results showed, that the compressive strength (after 28 days of cement mortar containing ash is higher regardless of the type of ash mixture used. The highest compressive strength (increased by 7.0% compared to the control sample was found for cement mortars in which the ratio of fly ash to bottom ash was 10/90. This mortars also showed the highest frost resistance (after 150 cycles freezes and unfreeze. The largest decrease the compressive strength (over 18.7% after the frost resistance test. While cement mortars in which the ratio of fly ash to bottom ash was 90/10 showed the highest frost resistance (after 150 cycles freezes and unfreeze.

  20. Absorption Characteristics of Cement Combination Concrete Containing Portland Cement, fly ash, and Metakaolin

    Directory of Open Access Journals (Sweden)

    Folagbade S.O.

    2016-03-01

    Full Text Available The resistance to water penetration of cement combination concretes containing Portland cement (PC, fly ash (FA, and metakaolin (MK have been investigated at different water/cement (w/c ratios, 28-day strengths, and depths of water penetration using their material costs and embodied carbon-dioxide (eCO2 contents. Results revealed that, at equal w/c ratio, eCO2 content reduced with increasing content of FA and MK. MK contributed to the 28-day strengths more than FA. Compared with PC, FA reduced cost and increased the depth of water penetration, MK increased cost and reduced the depth of water penetration, and their ternary combinations become beneficial. At equal strengths and levels of resistance to water penetration, most of the cement combination concretes are more environmentally compatible and costlier than PC concrete. Only MK binary cement concretes with 10%MK content or more and ternary cement concretes at a total replacement level of 55% with 10%MK content or more have higher resistance to water penetration than PC concrete.

  1. Ground Nut Husk Ash (GHA) as a Partial Replacement of Cement in ...

    African Journals Online (AJOL)

    Ground Nut Husk Ash (GHA) as a Partial Replacement of Cement in Mortar. ... This paper examines some properties of Ordinary Portland Cement (OPC) and Groundnut Husk Ash (GHA) mortar. The GHA was used as a partial ... hot weather climate. Further research on the permeability and durability are also recommended.

  2. The fluidity of fly ash-cement paste containing naphthalene sulfonate superplasticizer

    Energy Technology Data Exchange (ETDEWEB)

    Pipat Termkhajornkit; Toyoharu Nawa [Hokkaido University, Sapporo (Japan). Division of Structural and Geotechnical Engineering, Graduate School of Engineering

    2004-06-01

    The zeta potential measurement indicated that the surface potential of fly ash was different from ordinary Portland cement (OPC) in both sign and value. Hence, the Derjaguin-Landau-Verway-Overbeek (DLVO) theory for dispersion-flocculation of heterogeneous particles with different surface potentials was applied to explain the influence of fly ash on the rheology of cement paste containing naphthalene sulfonate superplasticizer. For the fly ash-cement paste without superplasticizer, the sign of zeta potential of fly ash was different from OPC. Thus, the extent of the potential energy barrier between particles was small or even showed negative value, and the change in the rheology of the fly ash-cement paste was mainly dependent on the bulk solid volume of fly ash, which was related to available free water for fluidizing paste. For the fly ash-cement paste with naphthalene sulfonate superplasticizer, fly ash and cement had the same sign and dispersed well due to higher potential barrier. The extent of potential energy barrier depended on the absolute value of surface potential, which was represented by a function of the amount of adsorbed superplasticizer. The bulk solid volume of fly ash also affected the change in flow ability, but the effect of potential energy barrier between particles was superior to that of the bulk solid volume of fly ash.

  3. Study of effect of addition of fly ash on radon exhalation rate in cement samples

    International Nuclear Information System (INIS)

    Raj Kumari; Kant, Krishan; Garg, Maneesha

    2013-01-01

    Most of the building materials like cement and fly ash contain naturally occurring radioactive materials (NORM). Increased interest in measuring radon exhalation rate in building products is due to the concern about health hazards of NORM. This paper focuses on studying the effect of addition of fly ash on radon exhalation rate in cement samples. Ordinary Portland Cement (OPC) and coal fly ash were used for finding the exhalation rate of cement in this paper. To study the effect on exhalation rate of cement, fly ash is added in different proportions to cement samples. The measurement was conducted by CAN Technique using SSNTDs. A gradual increase has been observed in radon exhalation rate up to certain proportion and then start to decrease. (author)

  4. Novel Osteointegrative Sr-Substituted Apatitic Cements Enriched with Alginate

    Directory of Open Access Journals (Sweden)

    Simone Sprio

    2016-09-01

    Full Text Available The present work describes the synthesis of novel injectable, self-setting bone cements made of strontium-substituted hydroxyapatite (Sr-HA, obtained by single-phase calcium phosphate precursors doped with different amounts of strontium and enriched with alginate. The addition of alginate improved the injectability, cohesion, and compression strength of the cements, without affecting the hardening process. A Sr-HA cement exhibiting adequate hardening times and mechanical strength for clinical applications was further tested in vivo in a rabbit model, in comparison with a commercial calcium phosphate cement, revealing the maintenance of biomimetic composition and porous microstructure even after one month in vivo, as well as enhanced ability to induce new bone formation and penetration.

  5. Feasibility of backfilling mines using cement kiln dust, fly ash, and cement blends

    Directory of Open Access Journals (Sweden)

    Beltagui H.

    2018-01-01

    Full Text Available Cement kiln dust (CKD is an industrial by-product of the cement manufacturing process, the composition of which can vary widely. Recent years of using alternative fuels have resulted in higher chloride and alkali contents within CKDs; as such, this limits the applications in which CKDs can be utilised. Using a CKD containing a high free lime content of 29.5%, it is shown that this CKD is capable of activating pulverized fuel ash (PFA due to its high alkalinity, which can be utilised in low strength un-reinforced applications. One potential application involves the backfill of mines, reducing the need for continuous maintenance of the mine. This study focuses on the compressive strength achieved by various blends of CKD, PFA, and cement. Samples were hand mixed and compacted in 100 mm x 50 mm diameter cylinders, and unconfined compressive strength measurements taken at 28 and 56 days. The hydration products were assessed through the use of x-ray diffraction and thermogravimetric analysis. Aiming to maximise the use of CKD at a water to binder (w/b ratio of 0.2, it was found that the maximum CKD content possible to achieve the required strength was 90% CKD blended with 10% cement.

  6. Bonding material containing ashes after domestic waste incineration for cementation of radioactive waste

    International Nuclear Information System (INIS)

    Dmitriev, S.A.; Varlakov, A.P.; Gorbunova, O.A.; Arustamov, A.E.; Barinov, A.S.

    2007-01-01

    It is known that cement minerals hydration is accompanied with heat emission. Heat of hardening influences formation of a cement compound structure and its properties. It is important to reduce the heat quantity at continuous cementation of waste and filling of compartments of a repository or containers by a cement grout. For reduction of heating, it is necessary to use cement of mineral additives (fuel ashes, slag and hydraulic silica). Properties of ashes after domestic waste incineration can be similar to ones of fly fuel ashes. However, ash after domestic waste incineration is toxic industrial waste as it contains toxic elements (As, Cd, Hg, Pb, Sb, Zn). Utilization of secondary waste (slag and ash) of combustion plants is an important environmental approach to solving cities' issues. Results of the research have shown that ashes of combustion plants can be used for radioactive waste conditioning. Co-processing of toxic and radioactive waste is ecologically and economically effective. At SIA 'Radon', experimental batches of cement compositions are used for cementation of oil containing waste. (authors)

  7. Leachability of chelated ion-exchange resins solidified in cement or cement and fly ash

    International Nuclear Information System (INIS)

    McIsaac, C.V.

    1993-01-01

    Leach tests were conducted at the Idaho National Engineering Laboratory on six small-scale specimens of cement-solidified ion-exchange resin wastes. The ion-exchange resins had been used to process reagent solutions following chemical decontaminations of primary coolant systems at five commercial light water reactors. The decontaminations were performed using the AP/Citrox, Can-Decon, Dow NS-1, and Low Oxidation-State Transition-Metal ION (LOMI) processes. The ion-exchange resin wastes were loaded with radionuclides, transition metals, and organic chelating agents, and were solidified in either unmodified Portland Type 1 cement or in a mixture of Portland Type 1 cement and fly ash. Waste-form specimens were leach-tested in deionized water at 23C using the American National Standards Institute/American Nuclear Society (ANSI/ANS) Standard 16.1 procedure. Release rates, effective diffusivities, and leachability indexes of radionuclides, chelating agents, and stable metals were determined using ANS-16.1 diffusion release models. Releases of radionuclides, chelating agents, and metals from waste forms that degraded during leaching were similar to releases from waste forms that maintained their physical integrity during leaching. The presence of chelating agents in the waste forms did not adversely affect the leachability of the waste forms

  8. Geo-environmental application of municipal solid waste incinerator ash stabilized with cement

    Directory of Open Access Journals (Sweden)

    Davinder Singh

    2017-04-01

    Full Text Available The behavior of soluble salts contained in the municipal solid waste incinerator (MSWI ash significantly affects the strength development and hardening reaction when stabilized with cement. The present study focuses on the compaction and strength behavior of mixed specimens of cement and MSWI ash. A series of indices such as unconfined compressive strength, split tensile strength, California bearing ratio (CBR and pH value was examined. Prior to this, the specimens were cured for 7 d, 14 d, and 28 d. The test results depict that the maximum dry density (MDD decreases and the optimum moisture content (OMC increases with the addition of cement. The test results also reveal that the cement increases the strength of the mixed specimens. Thus, the combination of MSWI ash and cement can be used as a lightweight filling material in different structures like embankment and road construction.

  9. Hydraulic activity of belite cement from class C coal fly ash. Effect of curing and admixtures

    OpenAIRE

    Goñi, S., Guerrero, A.

    2006-01-01

    [EN] The effect of curing method and a water-reducing additive on the hydraulic activity of high lime content (ASTM type C) fly ash belite cement (FABC-2-W) is reported. A class C fly ash was subjected to hydrothermal treatment and subsequent calcination to synthesize FABC. Hydraulic activity was evaluated in the cement paste over 180 days from the physically bound water content as determined by thermogravimetric analysis and the degree of hydration, in turn found with...

  10. Ash cements stabilized by supercritical CO2 carbonation for tailings pond overlayer

    International Nuclear Information System (INIS)

    Rubin, J. B.; Taylor, C.M.V.; Paviet-Hartmann, P.; Hartmann, T.

    2000-01-01

    The article describes the general features of supercritical fluids, as well as the application of these fluids to the production of unmodified portland and portland cement modified by incorporation of industrial waste solids, such as oil shale ash. Suitably treated, pre-fabricated cement, incorporating spent oil shale ash, as well as some of the tailings pond waste, could be used as an overlayer for the Sillamaee tailings pond

  11. [Patterns of PCDD/Fs, PCBs and PCNs homologues in fly ash from cement kilns].

    Science.gov (United States)

    Zhang, Jing; Ni, Yu-Wen; Zhang, Hai-Jun; Zhang, Xue-Ping; Zhang, Qing; Chen, Ji-Ping

    2009-02-15

    The concentrations and toxic equivalent (TEQ) values of PCDD/Fs, PCBs and PCNs in fly ash collected from three types of cement kilns (vertical shaft kiln, wet-process rotary kiln and dry-process rotary kiln) and two types of waste incinerators were determined, and the patterns of homologues and congeners were compared. The results showed that the total TEQ of PCDD/Fs, PCBs and PCNs in cement kiln fly ash, which were in the range of 4.0-62, 0.069-3.9 and 0.47-2.8 ng x kg(-1) respectively, were much lower than that of fly ash from waste incinerators. In cement kiln fly ash, the predominating PCDD/Fs homologues were TCDFs, and the chief 2, 3, 7, 8-PCDD/Fs congeners were OCDD, 2, 3, 7, 8-TCDF and 1, 2, 3, 4, 6, 7, 8-HpCDF. The patterns of PCBs homologues in cement kiln fly ash were similar to those of waste incinerators in which TeCB were predominating homologues. PCB77, PCB105, PCB118 were at higher concentrations than other co-polar PCBs. Different types of cement kiln fly ash presented similar PCNs homologue patterns. The predominant homologues were TeCN, whereas OcCN were not detected. PCN 66/67 which has dioxin like toxity was the most abundant congener in all fly ash.

  12. Crushing strength of concrete using maize cob ash cement as binder

    African Journals Online (AJOL)

    Crushing strength of concrete using maize cob ash cement as binder. ... The dried product was burnt at temperature of 12500C. Four categories of MCC were prepared by ... consisting of one part maize cob ash and one part lime and this could be used for structural works in construction where low strength is required.

  13. Influence of fly ash fineness on water requirement and shrinkage of blended cement mortars

    Directory of Open Access Journals (Sweden)

    Vanissorn Vimonsatit

    2015-12-01

    Full Text Available In this paper, the influence of fly ash fineness on water requirement and shrinkage of blended cement mortar was studied. The results indicate that the water requirement and shrinkage characteristic of the blended cement mortar are dependent on fly ash fineness and replacement level. The use of coarse fly ash slightly reduces the water requirement but greatly reduced the drying and the autogenous shrinkage of the blended cement mortars and the reduction is more with an increase in the fly ash replacement level. The finer fly ashes further reduce the water requirement, but increase the drying and the autogenous shrinkages as compared with coarser fly ash. The incorporation of superplasticizer drastically reduces the water requirement, but the effect on the drying and autogenous shrinkages of the normal Portland cement mortar is small. However, for the fly ash mortar, the use of superplasticizer results in a decrease in drying shrinkage and in a substantial increase in the autogenous shrinkage particularly for the fine fly ash at a high replacement level.

  14. Performance evaluation of cement stabilized fly ash-GBFS mixes as a highway construction material.

    Science.gov (United States)

    Singh, S P; Tripathy, D P; Ranjith, P G

    2008-01-01

    Fly ash and granulated blast furnace slag (GBFS) are major by-products of thermal and steel plants, respectively. These materials often cause disposal problems and environmental pollution. Detailed laboratory investigations were carried out on cement stabilized fly ash-(GBFS) mixes in order to find out its suitability for road embankments, and for base and sub-base courses of highway pavements. Proctor compaction test, unconfined compressive strength (UCS) test and California Bearing Ratio (CBR) test were conducted on cement stabilized fly ash-GBFS mixes as per the Indian Standard Code of Practice. Cement content in the mix was varied from 0% to 8% at 2% intervals, whereas the slag content was varied as 0%, 10%, 20%, 30% and 40%. Test results show that an increase of either cement or GBFS content in the mixture, results in increase of maximum dry density (MDD) and decrease of optimum moisture content (OMC) of the compacted mixture. The MDD of the cement stabilized fly ash-GBFS mixture is comparably lower than that of similarly graded natural inorganic soil of sand to silt size. This is advantageous in constructing lightweight embankments over soft, compressible soils. An increase in percentage of cement in the fly ash-GBFS mix increases enormously the CBR value. Also an increase of the amount of GBFS in the fly ash sample with fixed cement content improves the CBR value of the stabilized mix. In the present study, the maximum CBR value of compacted fly ash-GBFS-cement (52:40:8) mixture obtained was 105%, indicating its suitability for use in base and sub-base courses in highway pavements with proper combinations of raw materials.

  15. Effects of Eggshells Ash (ESA) on the Setting Time of Cement ...

    African Journals Online (AJOL)

    Cement-eggshells ash (CESA) paste was constituted using 0%, 0.1%, 0.5%, 1%, 1.5%, 2.0% and 2.5% of ESA by weight of cement. Setting time test was conducted on the CESA paste in accordance to BS 12:1991 n[1]. Results show that the addition of ESA to the ordinary Portland cement (OPC) decreases the setting time ...

  16. The Stabilization of Weathered Dolerite Aggregates with Cement, Lime, and Lime Fly Ash for Pavement Construction

    OpenAIRE

    Okonta, Felix N.; Ojuri, Oluwapelumi O.

    2014-01-01

    An experimental program was performed on weathered dolerite specimens stabilized by adding varying percentages of cement (4, 8, 12, and 16) % and lime (6 and 12) % and a combination of lime and fly ash (6% lime + 12% Fly ash and 12% lime + 12% Fly ash) % by dry weight of soil. The strength was examined under three different curing methods, namely, membrane curing (MBC), alternate moist-air curing (MAC), and water curing (WAC), by conducting unconfined compressive strength (UCS) tests. Simple ...

  17. Recycling of bagasse ash in cement manufacturing and its impact on clinker potential and environmental pollution

    International Nuclear Information System (INIS)

    Amin, N.U.; Ali, K.

    2009-01-01

    In this investigation bagasse ash from sugar mills of North West Frontier Province (NWFP) has been used in the raw mix designing for high strength Portland cement as a raw material and subjected to clinkerization and cement formation. Different parameters of the resulting clinker and cement were studied and compared with the British and Pakistan standard specification. 5% bagasse ash was found as the optimal limit to be blended and pulverized with other raw material prior to clinkerization which decreased the emission of carbon dioxide to the environment up to 1.73%. Moreover it replaced 5% clay from the raw meal. (author)

  18. Properies of binder systems containing cement, fly ash, and limestone powder

    Directory of Open Access Journals (Sweden)

    Krittiya Kaewmanee

    2014-10-01

    Full Text Available Fly ash and limestone powder are two major widely available cement replacing materials in Thailand. However, the current utilization of these materials is still not optimized due to limited information on properties of multi-binder systems. This paper reports on the mechanical and durability properties of mixtures containing cement, fly ash, and limestone powder as single, binary, and ternary binder systems. The results showed that a single binder system consisting of only cement gave the best carbonation resistance. A binary binder system with fly ash exhibited superior performances in long-term compressive strength and many durability properties except carbonation and magnesium sulfate resistances, while early compressive strength of a binary binder system with limestone powder was excellent. The ternary binder system, taking the most benefit of selective cement replacing materials, yielded, though not the best, satisfactory performances in almost all properties. Thus, the optimization of binders can be achieved through a multi-binder system.

  19. Formulation of geopolymer cement using mixture of slag and class f fly ash for oil well cementing

    Science.gov (United States)

    Kanesan, Dinesh; Ridha, Syahrir; Rao, Prasath

    2017-05-01

    The increase in greenhouse gas emissions has been a factor for the increase in global temperature. Geopolymer cement has been intensively studied to replace conventional ordinary Portland cement, however the focus is limited to civil purposes under atmospheric conditions. This research focuses on the formulation of geopolymer cement to be used in oil well cementing application by taking account the effect of sodium hydroxide (NaoH) molarity, ratio of alkali binder and fly ash, amount of dispersant for oilwell operation under temperature ranging of 80°C and 90C° and pressure of 1000 and 3000psi. The formulated composition is tested for fluid loss where the standard has been from 60 to 80 ml. The cement slurry is cured in a 50mm x 50mm x 50mm mold for period of 24 hours. Four manipulating variables were set in formulating the cement slurry namely, the ratio between fly ash and slag to alkali binder, ratio of sodium hydroxide (NaoH) to sodium silicate, molarity of NaoH and amount of dispersant added. After running a set of 16 experiment, sample (12) was found to possess the best rheological properties and fluid loss according to API RP10B. It was found that as the curing temperature and pressure increase, the compressive strength of the formulated geopolymer cement also increased.

  20. Microstructure Development and Transport Properties of Portland Cement-fly Ash Binary Systems : In view of service life predictions

    NARCIS (Netherlands)

    Yu, Z.

    2015-01-01

    Fly ash is a by-product of burning coal in electric power generating plants. It is commonly known that owing to its pozzolanic properties fly ash is widely used as a partial replacement for Portland cement in concrete. The use of fly ash in concrete not only reduces the landfill costs of fly ash,

  1. Effect of amorphous silica ash used as a partial replacement for cement on the compressive and flexural strengths cement mortar.

    Science.gov (United States)

    Usman, Aliyu; Ibrahim, Muhammad B.; Bala, Nura

    2018-04-01

    This research is aimed at investigating the effect of using amorphous silica ash (ASA) obtained from rice husk as a partial replacement of ordinary Portland cement (OPC) on the compressive and flexural strength of mortar. ASA was used in partial replacement of ordinary Portland cement in the following percentages 2.5 percent, 5 percent, 7.5 percent and 10 percent. These partial replacements were used to produce Cement-ASA mortar. ASA was found to contain all major chemical compounds found in cement with the exception of alumina, which are SiO2 (91.5%), CaO (2.84%), Fe2O3 (1.96%), and loss on ignition (LOI) was found to be 9.18%. It also contains other minor oxides found in cement. The test on hardened mortar were destructive in nature which include flexural strength test on prismatic beam (40mm x 40mm x 160mm) and compressive strength test on the cube size (40mm x 40mm, by using the auxiliary steel plates) at 2,7,14 and 28 days curing. The Cement-ASA mortar flexural and compressive strengths were found to be increasing with curing time and decreases with cement replacement by ASA. It was observed that 5 percent replacement of cement with ASA attained the highest strength for all the curing ages and all the percentage replacements attained the targeted compressive strength of 6N/mm2 for 28 days for the cement mortar

  2. Self-degradable Slag/Class F Fly Ash-Blend Cements

    Energy Technology Data Exchange (ETDEWEB)

    Sugama, T.; Warren, J.; Butcher, T. (BNL); Lance Brothers (Halliburton); Bour, D. (AltaRock Energy, Inc.)

    2011-03-01

    Self-degradable slag/Class F fly ash blend pozzolana cements were formulated, assuming that they might serve well as alternative temporary fracture sealers in Enhanced Geothermal System (EGS) wells operating at temperatures of {ge} 200 C. Two candidate formulas were screened based upon material criteria including an initial setting time {ge} 60 min at 85 C, compressive strength {ge} 2000 psi for a 200 C autoclaved specimen, and the extent of self-degradation of cement heated at {ge} 200 C for it was contacted with water. The first screened dry mix formula consisted of 76.5 wt% slag-19.0 wt% Class F fly ash-3.8 wt% sodium silicate as alkali activator, and 0.7 wt% carboxymethyl cellulose (CMC) as the self-degradation promoting additive, and second formula comprised of 57.3 wt% slag, 38.2 wt% Class F fly ash, 3.8 wt% sodium silicate, and 0.7 wt% CMC. After mixing with water and autoclaving it at 200 C, the aluminum-substituted 1.1 nm tobermorite crystal phase was identified as hydrothermal reaction product responsible for the development of a compressive strength of 5983 psi. The 200 C-autoclaved cement made with the latter formula had the combined phases of tobermorite as its major reaction product and amorphous geopolymer as its minor one providing a compressive strength of 5271 psi. Sodium hydroxide derived from the hydrolysis of sodium silicate activator not only initiated the pozzolanic reaction of slag and fly ash, but also played an important role in generating in-situ exothermic heat that significantly contributed to promoting self-degradation of cementitious sealers. The source of this exothermic heat was the interactions between sodium hydroxide, and gaseous CO{sub 2} and CH{sub 3}COOH by-products generated from thermal decomposition of CMC at {ge} 200 C in an aqueous medium. Thus, the magnitude of this self-degradation depended on the exothermic temperature evolved in the sealer; a higher temperature led to a sever disintegration of sealer. The exothermic

  3. Chloride penetration and corrosion resistance of ground fly ash blended cement mortar

    Energy Technology Data Exchange (ETDEWEB)

    Rukzon, Sumrerng [Rajamangala Univ. of Technology (Thailand). Civil Engineering Dept.; Chindaprasirt, Prinya [Khon Kaen Univ. (Thailand). Sustainable Infrastructure Research and Development Center

    2011-03-15

    This research studies the potential for using ground fly ash from the Mae Moh power plant in Thailand as a pozzolanic material. Three different fly ash finenesses, viz., coarse original fly ash, ground medium fly ash, and ground fine fly ash, were used for the study. Ordinary Portland cement was partially replaced with fly ash at 20% and 40% by weight of the fly ash. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110 {+-} 5% with the aid of superplasticizer. Compressive strength, chloride penetration and corrosion resistance of mortars were determined. Fine fly ash has a high potential to be used as a good pozzolanic material. The resistance to chloride penetration and corrosion resistance of mortar improve substantially with partial replacement of Ordinary Portland cement with ground fly ash. The use of finer fly ash results in a stronger and denser mortar which is due to better dispersion and filling effect as well as an increase in the pozzolanic reaction. (orig.)

  4. Improvement of Shear Strength of Sandy Soil by Cement Grout with Fly Ash

    Directory of Open Access Journals (Sweden)

    Haifaa Abdulrasool Ali

    2018-12-01

    Full Text Available The effects of the permeation cement grout with fly ash on the sandy soil skeleton were studied in the present work in two phase; first phase the shear strength parameters, and the second phase effect of these grouted materials on volume grouted zone by injection (51 cm³ of slurry in sandy soil placed in steel cylinder model with dimension 15 cm in diameter and 30 cm in height. The soil sample was obtained from Karbala city and it is classified as poorly graded sand (SP according to USCS. The soil samples were improved by cement grout with three percentages weight of water cement ratio (w:c; (0.1w:0.9c, 0.8w:0.2c, and 0.7w:0.3c, while the soil samples were dehydrated for one day curing time. Fly ash class (F was used with cement grout as filler material; it was added to the mixture as a replacement material for cement in weight percentages; 10%, 25% and 40%. According to the results of tests, both shear strength and approximate volume of the effective grouted zone for treated samples soil with cement grout was increased when the water cement ratio decreased. Fly ash with cement grout needs to increase the water demand for the grout mixing to give best results in both shear strength and filling the soil voids.

  5. New methodology for assessing the environmental burden of cement mortars with partial replacement of coal bottom ash and fly ash.

    Science.gov (United States)

    Menéndez, E; Álvaro, A M; Hernández, M T; Parra, J L

    2014-01-15

    This paper assess the mechanical an environmental behaviour of cement mortars manufactured with addition of fly ash (FA) and bottom ash (BA), as partial cement replacement (10%, 25% and 35%). The environmental behaviour was studied by leaching tests, which were performed under several temperature (23 °C and 60 °C) and pH (5 and 10) conditions, and ages (1, 2, 4 and 7 days). Then, the accumulated amount of the different constituents leached was analysed. In order to obtain an environmental burden (EB) value of each cement mixture, a new methodology was developed. The EB value obtained is related to the amount leached and the hazardous level of each constituent. Finally, the integral study of compressive strength and EB values of cement mixtures allowed their classification. The results showed that mortars manufactured with ordinary Portland cement (OPC) and with coal BA had similar or even better environmental and mechanical behaviour than mortars with FA. Therefore, the partial replacement of cement by BA might be as suitable or even better as the replacement by FA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. INFLUENCE OF SILICEOUS AND CALCAREOUS FLY-ASHES ON PROPERTIES OF CEMENT MORTARS

    Directory of Open Access Journals (Sweden)

    Gabriela Monika Rutkowska

    2016-09-01

    Full Text Available Care of the environment in accordance with the principles of sustainable development introduces the possibility and need for waste recycling. Construction and building industries have the greatest potential for reuse of waste. The article presents the results of investigations of cement mortars – tests of compressive and tensile strength after 28 and 56 days of curing – for normative mortars and mortars containing fly ashes – calcareous and siliceous ash – in their composition. To make the samples, the Portland cement CEM I 32,5 R, 42,5R and natural aggregate with graining of 0–2 mm were used. Concrete with siliceous and calcareous admixtures was made in six lots where the ash was added in the quantity of 2%, 5%, 10% of the cement mass or the 2%, 5%, 10% of cement was replaced by ashes. After the tests, it was stated that the siliceous fly-ash admixture increases the compressive and bending strength in comparison to the mortars with the calcareous ash admixtures.

  7. Encapsulation of mixed radioactive and hazardous waste contaminated incinerator ash in modified sulfur cement

    International Nuclear Information System (INIS)

    Kalb, P.D.; Heiser, J.H. III; Colombo, P.

    1990-01-01

    Some of the process waste streams incinerated at various Department of Energy (DOE) facilities contain traces of both low-level radioactive (LLW) and hazardous constituents, thus yielding ash residues that are classified as mixed waste. Work is currently being performed at Brookhaven National Laboratory (BNL) to develop new and innovative materials for encapsulation of DOE mixed wastes including incinerator ash. One such material under investigation is modified sulfur cement, a thermoplastic developed by the US Bureau of Mines. Monolithic waste forms containing as much as 55 wt % incinerator fly ash from Idaho national Engineering Laboratory (INEL) have been formulated with modified sulfur cement, whereas maximum waste loading for this waste in hydraulic cement is 16 wt %. Compressive strength of these waste forms exceeded 27.6 MPa. Wet chemical and solid phase waste characterization analyses performed on this fly ash revealed high concentrations of soluble metal salts including Pb and Cd, identified by the Environmental Protection Agency (EPA) as toxic metals. Leach testing of the ash according to the EPA Toxicity Characteristic Leaching Procedure (TCLP) resulted in concentrations of Pb and Cd above allowable limits. Encapsulation of INEL fly ash in modified sulfur cement with a small quantity of sodium sulfide added to enhance retention of soluble metal salts reduced TCLP leachate concentrations of Pb and Cd well below EPA concentration criteria for delisting as a toxic hazardous waste. 12 refs., 4 figs., 2 tabs

  8. Cement substitution by a combination of metakaolin and limestone

    Energy Technology Data Exchange (ETDEWEB)

    Antoni, M., E-mail: mathieu.antoni@epfl.ch [EPFL-STI-IMX-Laboratoires des Materiaux de Construction, Station12, CH-1015 Lausanne (Switzerland); Rossen, J. [EPFL-STI-IMX-Laboratoires des Materiaux de Construction, Station12, CH-1015 Lausanne (Switzerland); Martirena, F. [CIDEM-UCLV, Universidad Las Villas, Santa Clara (Cuba); Scrivener, K. [EPFL-STI-IMX-Laboratoires des Materiaux de Construction, Station12, CH-1015 Lausanne (Switzerland)

    2012-12-15

    This study investigates the coupled substitution of metakaolin and limestone in Portland cement (PC). The mechanical properties were studied in mortars and the microstructural development in pastes by X-ray diffraction, thermogravimetry analysis, mercury intrusion porosimetry and isothermal calorimetry. We show that 45% of substitution by 30% of metakaolin and 15% of limestone gives better mechanical properties at 7 and 28 days than the 100% PC reference. Our results show that calcium carbonate reacts with alumina from the metakaolin, forming supplementary AFm phases and stabilizing ettringite. Using simple mass balance calculations derived from thermogravimetry results, we also present the thermodynamic simulation for the system, which agrees fairly well with the experimental observations. It is shown that gypsum addition should be carefully balanced when using calcined clays because it considerably influences the early age strength by controlling the very rapid reaction of aluminates.

  9. Post construction monitoring and performance evaluation of a cement stabilized fly ash base

    International Nuclear Information System (INIS)

    Gray, D.H.; Tons, E.; Berry, W.H.; Stoll, U.W.

    1991-01-01

    A compacted, aggregate-free, cement-stabilized fly ash base was placed under a 1,500-foot long test section of a road shoulder on either side of a four-lane, state highway in Michigan. The test section base was constructed in May 1987, using a high carbon, Class F, fly ash that was stabilized with 12% by weight Portland cement. A post construction monitoring and testing program was implemented to evaluate the performance of the base course. The results of monitoring tests conducted to date show that in general the fly ash test section has held up quite well. No widespread nor major problems have occurred during the 3-year period since construction. Any problems with heave and cracking of the pavement atop the fly ash have so far been restricted to a few local areas. Heaving and cracking in these areas occur primarily during the winter and are associated with frost effects. These localized problems appear to be the result of low density and strength in combination with a low cement content in the fly ash base and a thin asphalt cap or wearing surface. Laboratory leaching studies were performed on samples of cemented fly ash to ascertain the potential for groundwater contamination. Samples were leached according to the RCRA and ASTM procedures respectively; both these leaching protocols simulate worst case conditions. Results of these leaching tests showed that dissolved solids and heavy metals in the leachate were generally at or below allowable limits bases on the Safe Drinking Water Act (SWDA) standards. A field leachate collection system was installed beneath both the fly ash test section and adjacent control section. Groundwater monitoring wells were also installed in the vicinity of the fly ash and control sections. The results of field monitoring to date show no elevated levels of dissolved heavy metals in the groundwater nor significant differences in the leachate concentration between the fly ash and control sections

  10. Hydration mechanisms of ternary Portland cements containing limestone powder and fly ash

    International Nuclear Information System (INIS)

    De Weerdt, K.; Haha, M. Ben; Le Saout, G.; Kjellsen, K.O.; Justnes, H.; Lothenbach, B.

    2011-01-01

    The effect of minor additions of limestone powder on the properties of fly ash blended cements was investigated in this study using isothermal calorimetry, thermogravimetry (TGA), X-ray diffraction (XRD), scanning electron microscopy (SEM) techniques, and pore solution analysis. The presence of limestone powder led to the formation of hemi- and monocarbonate and to a stabilisation of ettringite compared to the limestone-free cements, where a part of the ettringite converted to monosulphate. Thus, the presence of 5% of limestone led to an increase of the volume of the hydrates, as visible in the increase in chemical shrinkage, and an increase in compressive strength. This effect was amplified for the fly ash/limestone blended cements due to the additional alumina provided by the fly ash reaction.

  11. Magnesium substitution in brushite cements for enhanced bone tissue regeneration

    Energy Technology Data Exchange (ETDEWEB)

    Cabrejos-Azama, Jatsue, E-mail: jacaza@farm.ucm.es [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); Alkhraisat, Mohammad Hamdan; Rueda, Carmen [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain); Torres, Jesús [Facultad de Ciencias de la salud URJC, Alcorcón, Madrid (Spain); Blanco, Luis [Departamento de Estomatología III, Facultad de Odontología UCM, Madrid (Spain); López-Cabarcos, Enrique [Departamento de Química-Física II, Facultad de Farmacia, UCM, Madrid (Spain)

    2014-10-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p < 0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations. - Highlights: • The Mg-CPCs promote higher new bone formation than the CPC. • The incorporation of magnesium ions in CPC improves osteoblasts proliferation. • Mg-CPC is a bone substitute with controllable biodegradable properties. • We suggest that the use of Mg ions could improve the clinical efficiency of CPCs.

  12. Magnesium substitution in brushite cements for enhanced bone tissue regeneration

    International Nuclear Information System (INIS)

    Cabrejos-Azama, Jatsue; Alkhraisat, Mohammad Hamdan; Rueda, Carmen; Torres, Jesús; Blanco, Luis; López-Cabarcos, Enrique

    2014-01-01

    We have synthesized calcium phosphate cements doped with different amounts of magnesium (Mg-CPC) with a twofold purpose: i) to evaluate in vitro the osteoblast cell response to this material, and ii) to compare the bone regeneration capacity of the doped material with a calcium cement prepared without magnesium (CPC). Cell proliferation and in vivo response increased in the Mg-CPCs in comparison with CPC. The Mg-CPCs have promoted higher new bone formation than the CPC (p < 0.05). The cytocompatibility and histomorfometric analysis performed in the rabbit calvaria showed that the incorporation of magnesium ions in CPC improves osteoblasts proliferation and provides higher new bone formation. The development of a bone substitute with controllable biodegradable properties and improved bone regeneration can be considered a step toward personalized therapy that can adapt to patient needs and clinical situations. - Highlights: • The Mg-CPCs promote higher new bone formation than the CPC. • The incorporation of magnesium ions in CPC improves osteoblasts proliferation. • Mg-CPC is a bone substitute with controllable biodegradable properties. • We suggest that the use of Mg ions could improve the clinical efficiency of CPCs

  13. Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures.

    Science.gov (United States)

    Glinicki, Michał A; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

    2016-01-02

    The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement-ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

  14. Wood ash used as partly sand and/or cement replacement in mortar

    DEFF Research Database (Denmark)

    Ottosen, Lisbeth M.; Hansen, Esben Østergaard; Jensen, Pernille Erland

    2016-01-01

    Wood ash (WA) is the residue generated during incineration of wood and wood products. The WAs in focus of this work are from incineration of virgin wood. Physical and chemical properties of WA vary significantly depending on many factors related to the wood species and the incineration process, a...... to use WA as partly cement replacement (percentages the workability was so low that extra water needed to be added and the results depended on the water:cement ratio rather than the ash mass.......Wood ash (WA) is the residue generated during incineration of wood and wood products. The WAs in focus of this work are from incineration of virgin wood. Physical and chemical properties of WA vary significantly depending on many factors related to the wood species and the incineration process...... from the differences in ash characteristics to the properties of the mortar samples. The characteristics of the ashes did vary considerably. For example, one ash had very high loss on ignition (LoI) of 14% compared to 3% for the other ashes. Ash solubility in water ranged from 18% to 28%. Two...

  15. Mössbauer, XRD, and Complex Thermal Analysis of the Hydration of Cement with Fly Ash

    Directory of Open Access Journals (Sweden)

    Vili Lilkov

    2013-01-01

    Full Text Available Hydration of cement with and without fly ash is studied with Mössbauer spectroscopy, XRD, and thermal analysis. Iron in cement is present as Fe3+-ions and occupies two octahedral positions, with close isomer shifts and quadrupole splittings. Iron in fly ash is present as Fe2+ and Fe3+, and the Mössbauer spectra display three doublets—two for Fe3+ in octahedral coordination and one for Fe2+. A third doublet was registered in the hydrating plain cement pastes after the 5th day, due to Fe3+ in tetrahedral coordination in the structure of the newly formed monosulphate aluminate. In cement pastes with fly ash, the doublet of tetrahedral iron is formed earlier because the quantity of ettringite and portlandite is low and more monosulphate crystallizes. No Fe(OH3 phase forms during hydration of C4AF. The fly ash displays pozzolanic properties, which lead to lowering of the portlandite quantity in the cement mixtures and increasing of the high temperature products.

  16. A study of radioactivity level of the cements containing fly ash of Soma power plant

    International Nuclear Information System (INIS)

    Aslan, A.; Oezer, N.; Suener, U.

    2009-01-01

    Cement is a product that is formed by grinding gypsum with clinkers resulted by burning the mixture that is obtained after mixing and grinding mainly silicium, calcium, alumina and iron oxides containing raw materials in certain proportions, to sintered degrees. When combined with water it posses binding properties. For portland cements, % 3-6 proportion gypsum (CaSO 4 .2H 2 O) in weight are added to clinkers at the grinding step in order to adjust the hydration degrees. By this way it prevents tricalcium aluminate (3CaO.Al 2 O 3 ) from rapid hardening. If ground without gypsum addition, clinkers when combined with water, harden rapidly. Additives such as fly ash, blast furnace slag, natural slag and trash possessing puzzolanic properties are also added to portland cement clinkers. At power plants, during the burning process of coals, light elements such as hydrogen and carbon are converted to their gaseous forms, and remaining ashes than become rich with uranium content. Thus fly ashes contain radioactive elements such as U-238 (Uranium), Th-232 (Thorium) and K-40 (Potassium). U-238 found in fly ash is not an intensively radioactive element at the beginning. It disintegrates naturally by losing its and particles and is transformed to some radio nuclides. Ra-226 (Radium) is the most active element among these radio nuclides and it is transformed to radon gas (Rn-222) by losing new particle. The rare gas radon and radioactive radium extremely jeopardize human health. Fly ashes when used in cements, it can lead to increase in the radioactivity level which is of prime public concern. It is therefore important to determine the radioactivity level formed in the cements and compare with the standard values. In this study, photon emissions and mechanical strength tests of C type fly ash of Soma power plant and portland cements containing this fly ash under laboratory conditions were measured. In that manner it has been examined whether fly ashes may cause some significant

  17. Effect of fly ash on the optimum sulfate of Portland Cement

    Science.gov (United States)

    Niemuth, Mark D.

    Calcium sulfate is typically added to ordinary portland cement (OPC) clinker during grinding to prevent flash set and to improve early-age strength development without causing volume instabilities. Recent changes to ASTM C150, Standard Specification for Portland Cement, have enabled greater flexibility in determining optimum sulfate levels in portland cement by not requiring ASTM C563, Approximation of Optimum SO3 in Hydraulic Cement Using Compressive Strength, to be used in setting sulfate target levels. ASTM C563 requires strength testing using only the hydraulic cement, which is not always indicative of the optimum sulfate for field use, since supplementary materials (e.g., fly ash) may be used by the concrete producer. Adding additional sulfate to account for the sulfate demand of fly ashes can enable an improvement in the early age strength for cement-fly ash systems and decrease in problems that may be attributed to OPC-admixture-fly ash incompatibility such as abnormal setting and slow strength gain. This thesis provides experimental data on the strength development and heat release during early hydration for cement-fly ash systems with different sulfate levels. The thesis focused on high calcium fly ashes, but low calcium fly ash was also tested. It is demonstrated that some fly ashes have their own sulfate demand and when these ashes are used in cement-fly ash blends there is effectively an increase in the optimal sulfate level that could be used for the OPC. It is also shown that optimum sulfate determined by heat of hydration measured with isothermal calorimetry is similar to the optimum sulfate determined by compressive strength at 1 day. Using isothermal calorimetry can result in substantial time and cost savings at plants for determining the optimal sulfate content. Theories for the mechanisms that drive the differences in sulfate demand in OPC are reviewed. These theories are adapted for OPC-fly ash blends and are outlined, tested and discussed. The

  18. Hydration of Hybrid Alkaline Cement Containing a Very Large Proportion of Fly Ash: A Descriptive Model

    Directory of Open Access Journals (Sweden)

    Inés Garcia-Lodeiro

    2016-07-01

    Full Text Available In hybrid alkaline fly ash cements, a new generation of binders, hydration, is characterized by features found in both ordinary portland cement (OPC hydration and the alkali activation of fly ash (AAFA. Hybrid alkaline fly ash cements typically have a high fly ash (70 wt % to 80 wt % and low clinker (20 wt % to 30 wt % content. The clinker component favors curing at ambient temperature. A hydration mechanism is proposed based on the authors’ research on these hybrid binders over the last five years. The mechanisms for OPC hydration and FA alkaline activation are summarized by way of reference. In hybrid systems, fly ash activity is visible at very early ages, when two types of gel are formed: C–S–H from the OPC and N–A–S–H from the fly ash. In their mutual presence, these gels tend to evolve, respectively, into C–A–S–H and (N,C–A–S–H. The use of activators with different degrees of alkalinity has a direct impact on reaction kinetics but does not modify the main final products, a mixture of C–A–S–H and (N,C–A–S–H gels. The proportion of each gel in the mix does, however, depend on the alkalinity generated in the medium.

  19. Hydration of Hybrid Alkaline Cement Containing a Very Large Proportion of Fly Ash: A Descriptive Model.

    Science.gov (United States)

    Garcia-Lodeiro, Inés; Donatello, Shane; Fernández-Jiménez, Ana; Palomo, Ángel

    2016-07-22

    In hybrid alkaline fly ash cements, a new generation of binders, hydration, is characterized by features found in both ordinary portland cement (OPC) hydration and the alkali activation of fly ash (AAFA). Hybrid alkaline fly ash cements typically have a high fly ash (70 wt % to 80 wt %) and low clinker (20 wt % to 30 wt %) content. The clinker component favors curing at ambient temperature. A hydration mechanism is proposed based on the authors' research on these hybrid binders over the last five years. The mechanisms for OPC hydration and FA alkaline activation are summarized by way of reference. In hybrid systems, fly ash activity is visible at very early ages, when two types of gel are formed: C-S-H from the OPC and N-A-S-H from the fly ash. In their mutual presence, these gels tend to evolve, respectively, into C-A-S-H and (N,C)-A-S-H. The use of activators with different degrees of alkalinity has a direct impact on reaction kinetics but does not modify the main final products, a mixture of C-A-S-H and (N,C)-A-S-H gels. The proportion of each gel in the mix does, however, depend on the alkalinity generated in the medium.

  20. Hydration of Hybrid Alkaline Cement Containing a Very Large Proportion of Fly Ash: A Descriptive Model

    Science.gov (United States)

    Garcia-Lodeiro, Inés; Donatello, Shane; Fernández-Jiménez, Ana; Palomo, Ángel

    2016-01-01

    In hybrid alkaline fly ash cements, a new generation of binders, hydration, is characterized by features found in both ordinary portland cement (OPC) hydration and the alkali activation of fly ash (AAFA). Hybrid alkaline fly ash cements typically have a high fly ash (70 wt % to 80 wt %) and low clinker (20 wt % to 30 wt %) content. The clinker component favors curing at ambient temperature. A hydration mechanism is proposed based on the authors’ research on these hybrid binders over the last five years. The mechanisms for OPC hydration and FA alkaline activation are summarized by way of reference. In hybrid systems, fly ash activity is visible at very early ages, when two types of gel are formed: C–S–H from the OPC and N–A–S–H from the fly ash. In their mutual presence, these gels tend to evolve, respectively, into C–A–S–H and (N,C)–A–S–H. The use of activators with different degrees of alkalinity has a direct impact on reaction kinetics but does not modify the main final products, a mixture of C–A–S–H and (N,C)–A–S–H gels. The proportion of each gel in the mix does, however, depend on the alkalinity generated in the medium. PMID:28773728

  1. Development of a Zero-Cement Binder Using Slag, Fly Ash, and Rice Husk Ash with Chemical Activator

    Directory of Open Access Journals (Sweden)

    M. R. Karim

    2015-01-01

    Full Text Available The increasing demand and consumption of cement have necessitated the use of slag, fly ash, rice husk ash (RHA, and so forth as a supplement of cement in concrete construction. The aim of the study is to develop a zero-cement binder (Z-Cem using slag, fly ash, and RHA combined with chemical activator. NaOH, Ca(OH2, and KOH were used in varying weights and molar concentrations. Z-Cem was tested for its consistency, setting time, flow, compressive strength, XRD, SEM, and FTIR. The consistency and setting time of the Z-Cem paste increase with increasing RHA content. The Z-Cem mortar requires more superplasticizer to maintain a constant flow of 110±5% compared with OPC. The compressive strength of the Z-Cem mortar is significantly influenced by the amounts, types, and molar concentration of the activators. The Z-Cem mortar achieves a compressive strength of 42–44 MPa at 28 days with 5% NaOH or at 2.5 molar concentrations. The FTIR results reveal that molecules in the Z-Cem mortar have a silica-hydrate (Si-H bond with sodium or other inorganic metals (i.e., sodium/calcium-silica-hydrate-alumina gel. Therefore, Z-Cem could be developed using the aforementioned materials with the chemical activator.

  2. Immobilization of Radioactive Waste in Different Fly Ash Zeolite Cement Blends

    International Nuclear Information System (INIS)

    Sami, N.M.

    2013-01-01

    The problem of radioactive waste management has been raised from the beginning use of nuclear energy for different purposes. The rad waste streams produced were sufficient to cause dangerous effects to man and its environment. The ordinary portland cement is the material more extensively used in the technologies of solidification and immobilization of the toxic wastes, low and medium level radioactive wastes. The production of portland cement is one of the most energy-intensive and polluting. The use of high energy in the production causes high emission due to the nature and processes of raw materials. The cement industry is responsible for 7% of the total CO 2 emission. Thus, the cement industry has a crucial role in the global warming. The formation of alite (Ca 3 SiO 5 ), which is the main component of the Portland cement clinker, produces a greater amount of CO 2 emission than the formation of belite (Ca 2 SiO 4 ). The proportion of alite to belite is about 3 in ordinary Portland clinker. Therefore, by decreasing this proportion less CO 2 would be emitted. Furthermore, if industrial byproducts such as fly ash from thermal power station or from incineration of municipal solid wastes have the potential to reduce CO 2 used as raw materials and alternative hydrothermal calcination routes are employed for belite clinker production, CO 2 emission can be strongly reduced or even totally avoided. The availability of fly ash will help in reducing the CO 2 emissions and will also help in resolving, to a great extent, the fly ash disposal problem. This thesis is based on focusing on the possibility of using fly ash as raw materials to prepare low cost innovation matrices for immobilization of radioactive wastes by synthesizing new kind of cement of low consuming energy. The synthesis process is based on the hydrothermal-calcination route of the fly ash without extra additions.

  3. Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

    Directory of Open Access Journals (Sweden)

    Michał A. Glinicki

    2016-01-01

    Full Text Available The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash.

  4. Influence of Blended Cements with Calcareous Fly Ash on Chloride Ion Migration and Carbonation Resistance of Concrete for Durable Structures

    Science.gov (United States)

    Glinicki, Michał A.; Jóźwiak-Niedźwiedzka, Daria; Gibas, Karolina; Dąbrowski, Mariusz

    2016-01-01

    The objective of this paper is to examine the possible use of new blended cements containing calcareous fly ash in structural concrete, potentially adequate for structural elements of nuclear power plants. The investigation included five new cements made with different contents of non-clinker constituents: calcareous fly ash, siliceous fly ash, ground granulated blastfurnace slag, and a reference cement—ordinary Portland cement. The influence of innovative cements on the resistance of concrete to chloride and carbonation exposure was studied. Additionally, an evaluation of the microstructure was performed using optical microscopy on concrete thin sections. Test results revealed a substantial improvement of the resistance to chloride ion penetration into concrete containing blended cements. The resistance was higher for increased clinker replacement levels and increased with curing time. However, concrete made with blended cements exhibited higher depth of carbonation than the Portland cement concrete, except the Portland-fly ash cement with 14.3% of calcareous fly ash. The thin sections analysis confirmed the values of the carbonation depth obtained from the phenolphthalein test. Test results indicate the possible range of application for new cements containing calcareous fly ash. PMID:28787821

  5. Enhancing the compressive strength of landfill soil using cement and bagasse ash

    Science.gov (United States)

    Azim, M. A. M.; Azhar, A. T. S.; Tarmizi, A. K. A.; Shahidan, S.; Nabila, A. T. A.

    2017-11-01

    The stabilisation of contaminated soil with cement and agricultural waste is a widely applied method which contributes to the sustainability of the environment. Soil may be stabilised to increase strength and durability or to prevent erosion and other geotechnical failure. This study was carried out to evaluate the compressive strength of ex-landfill soil when cement and bagasse ash (BA) are added to it. Different proportions of cement (5%, 10%, 15% and 20%) was added to sample weights without BA. On the other hand, the cement in a different batch of sample weights was replaced by 2.5%, 5%, 7.5% and 10% of BA. All samples were allowed to harden and were cured at room temperature for 7, 14 and 28 days respectively. The strength of the contaminated soil was assessed using an unconfined compressive strength test (UCS). The laboratory tests also included the index properties of soil, cement and bagasse ash in raw form. The results indicated that the samples with cement achieved the highest compressive strength measuring 4.39 MPa. However, this study revealed that the use of bagasse ash produced low quality products with a reduction in strength. For example, when 5% of cement was replaced with 5% ash, the compressive strength decreased by about 54% from 0.72 MPa to 0.33 MPa. Similarly, the compressive strength of each sample after a curing period of 28 days was higher compared to samples cured for 7 and 14 days respectively. This is proved that a longer curing period is needed to increase the compressive strength of the samples.

  6. Experimental investigation on compressive strength of cement mortar using nano clay and flay ash

    Directory of Open Access Journals (Sweden)

    E. Khalilzadeh Vahidi

    2016-06-01

    Full Text Available In the present paper, compressive strength of cement mortar was investigated through two cases:  case I in which just nano-clay (Nano clay to cement proportion equal to 3% and %5 is included, and case II in which both nano-clay and fly ash were considered (with the same values for Nano-clay as case I, and with fly ash to cement proportion equal to 15%. Gradual interaction of fly Ash with calcium hydroxide and alkalins resulted from cement hydration process, produces more C-S-H, spreading through concrete substructure free spaces. Results indicated that, all samples which contain nano-clay are denser than the reference sample. Adding fly ash and nano-clay have resulted in decreasing short term period (relating to three and seven days age compressive strength of cement mortar. The 28 day age compressive strength of samples of case I, showed a dramatic increase about 27.2% for proportion value equal to 3%, and a considerable increase about 15.1%, for proportion value of equal to 5%. Results, also indicated a considerable increase in the 90 day age compressive strength that was about 28.4% and 22.4% respectively relating to two proportion values, 3% and 5%. The 28 day age compressive strength of samples of case II increased about 1.6% and 4.5% respectively, relating to two values of nano-clay to cement proportion equal to 3% and 5%. The 90 day age compressive strength of samples of case II, showed an increase about 10% and 16% respectively, relating to two values of nano-clay to cement proportion equal to 3% and 5%.

  7. Acid resistance of palm oil fuel ash and metakaolin ternary blend cement mortar

    Directory of Open Access Journals (Sweden)

    Jamilu Usman

    2017-07-01

    Full Text Available This paper examines the effects of blend of Palm Oil fuel ash (POFA and Metakaolin (MK on the resistance of cement mortar to sulphuric acid (H2SO4 attack. Tests were conducted on POFA and MK ternary blended cement mortar immersed in a 3% H2SO4 solution for up 180 d. Binaries of POFA/cement and MK/cement as well as plain ordinary Portland cement (OPC mortar was also tested for comparison. The parameters measured include residual compressive strength and residual mass. Additionally, the microstructures of the specimens were analysed using the X-ray diffraction and Fourier transformed infrared techniques. The residual compressive strengths of the mortar specimens for plain OPC, binary blend of POFA and cement, binary blend of MK and cement, and ternary blend of POFA, MK and cement after 180 d of immersion in the acid solution were 25, 30, 33, and 32%, respectively. Moreover, the corresponding residual masses of the specimens were 39, 52, 58, and 54%. Accordingly, the ternary blended mortar performed better in resisting H2SO4 attack than the plain OPC and binary blend of POFA/cement mortars.

  8. Characterization of cement and bitumen waste forms containing simulated low-level waste incinerator ash

    International Nuclear Information System (INIS)

    Westsik, J.H. Jr.

    1984-08-01

    Incinerator ash from the combustion of general trash and ion exchange resins was immobilized in cement and bitumen. Tests were conducted on the resulting waste forms to provide a data base for the acceptability of actual low-level waste forms. The testing was done in accordance with the US Nuclear Regulatory Commission Technical Position on Waste Form. Bitumen had a measured compressive strength of 130 psi and a leachability index of 13 as measured with the ANS 16.1 leach test procedure. Cement demonstrated a compressive strength of 1400 psi and a leachability index of 7. Both waste forms easily exceed the minimum compressive strength of 50 psi and leachability index of 6 specified in the Technical Position. Irradiation to 10 8 Rad and exposure to 31 thermal cycles ranging from +60 0 ) to -30 0 C did not significantly impact these properties. Neither waste form supported bacterial or fungal growth as measured with ASTM G21 and G22 procedures. However, there is some indication of biodegradation due to co-metabolic processes. Concentration of organic complexants in leachates of the ash, cement and bitumen were too low to significantly affect the release of radionuclides from the waste forms. Neither bitumen nor cement containing incinerator ash caused any corrosion or degradation of potential container materials including steel, polyethylene and fiberglass. However, moist ash did cause corrosion of the steel

  9. The Stabilization of Weathered Dolerite Aggregates with Cement, Lime, and Lime Fly Ash for Pavement Construction

    Directory of Open Access Journals (Sweden)

    Felix N. Okonta

    2014-01-01

    Full Text Available An experimental program was performed on weathered dolerite specimens stabilized by adding varying percentages of cement (4, 8, 12, and 16 % and lime (6 and 12 % and a combination of lime and fly ash (6% lime + 12% Fly ash and 12% lime + 12% Fly ash % by dry weight of soil. The strength was examined under three different curing methods, namely, membrane curing (MBC, alternate moist-air curing (MAC, and water curing (WAC, by conducting unconfined compressive strength (UCS tests. Simple polynomial and linear functions (regression models were used to define the relationships between the variables investigated. Membrane curing (MBC gave results close enough to the water curing (WAC to indicate that it can be confidently used on the field during pavement construction. From the results obtained, for class B (interurban collector and major rural roads pavement construction, addition of 8% cement was recommended for road base construction with stabilized WDA. Also the addition of 12 + 12% Lime and Fly Ash was recommended for road subbase construction with stabilized WDA. Stabilized WDA against the prejudiced myths would perform satisfactorily for base and subbase construction in both heavily trafficked and low volume roads with economic quantities of cement, lime, and fly ash in South Africa.

  10. Study of Experiment on Rock-like Material Consist of fly-ash, Cement and Mortar

    Science.gov (United States)

    Nan, Qin; Hongwei, Wang; Yongyan, Wang

    2018-03-01

    Study the uniaxial compression test of rock-like material consist of coal ash, cement and mortar by changing the sand cement ratio, replace of fine coal, grain diameter, water-binder ratio and height-diameter ratio. We get the law of four factors above to rock-like material’s uniaxial compression characteristics and the quantitative relation. The effect law can be sum up as below: sample’s uniaxial compressive strength and elasticity modulus tend to decrease with the increase of sand cement ratio, replace of fine coal and water-binder ratio, and it satisfies with power function relation. With high ratio increases gradually, the uniaxial compressive strength and elastic modulus is lower, and presents the inverse function curve; Specimen tensile strength decreases gradually with the increase of fly ash. By contrast, uniaxial compression failure phenomenon is consistent with the real rock common failure pattern.

  11. Effect of mixes made of coal bottom ash and fly ash on the mechanical strength and porosity of Portland cement

    Directory of Open Access Journals (Sweden)

    Argiz, C.

    2013-03-01

    Full Text Available New additions to the cement are needed to achieve a more sustainable and durable construction material. Within this context, bottom ashes can be used as a main constituent of Portland cements when it is mixed in an optimized proportion with fly ashes. The mechanical characteristics of standarized mortars made of mixes of pulverized coal combustion bottom and fly ashes are studied. The mortars were made of ordinary Portland cement (CEM I 42.5 N and mixes of bottom ashes with fly ashes in similar proportions to those of CEM II/A-V, CEM II/B-V and CEM IV/A (V. Summing up, it can be said that the utilization of bottom ashes mixed with fly ashes in replacement levels from 0% to 100% do not affect significantively on the mechanical caracteristics of the mortars considered in the present study which had an addition maximum content of 35%.

    La utilización de nuevas adiciones en el cemento es necesaria con el fin de obtener un material más sostenible y durable. En este sentido, las cenizas de fondo o cenicero de las centrales termoeléctricas de carbón se podrían reciclar siendo empleadas como un componente principal de los cementos Portland. Se han estudiado las propiedades mecánicas de unos morteros normalizados elaborados con mezclas de cenizas volantes con cenizas de fondo fabricados con unos porcentajes similares a los correspondientes de los CEM II/A-V, CEM II/B-V y CEM IV/A (V. En conclusión, la utilización de mezclas de cenizas de fondo o cenicero con cenizas volantes sustituyendo a éstas últimas entre el 0% y el 100%, no influye significativamente en el comportamiento mecánico de los morteros estudiados en los que el contenido máximo de adición ha sido del 35%, si bien afecta a determinados aspectos microestructurales, como la cantidad y distribución de poros capilares.

  12. Study of Compressive Strength of Concrete with Coal Power Plant Fly Ash as Partial Replacement of Cement and Fine Aggregate

    Directory of Open Access Journals (Sweden)

    FAREED AHMED MEMON

    2010-10-01

    Full Text Available This research study comprises of concrete cubes made with Ordinary Portland Cement and with different configurations of fly ash by replacing cement and fine aggregate. To achieve the aim of this study, total 81 concrete cubes were cast. Among 81 cubes, 9 cubes were made with normal concrete, 36 cubes were made by replacing 25%, 50%, 75% and 100% of fine aggregate with fly ash and 36 cubes were made by replacing 10%, 25%, 50%, and 75% of cement with fly ash. The cubes were 6\\" x 6\\" in cross-section, and the mix design was aimed for 5000 psi. After proper curing of all 81 cubes, they were tested at 3, 7 and 28 days curing age. The cubes were tested in Forney Universal Testing Machine. By analyzing the test results of all the concrete cubes, the following main findings have been drawn. The compressive strength of concrete cubes made by replacing 100 % fine aggregate by fly ash was higher than the concrete cubes made with Ordinary Portland Cement at all 3, 7 and 28 days curing ages. On the other hand, the compressive strength of concrete cubes made by replacing 10 % and 25 % cement by fly ash was slightly lower than the concrete cubes made with Ordinary Portland Cement at all curing ages, whereas, the compressive strength of concrete cubes made by replacing 50 % and 75 % of cement by fly ash were quite lower than the concrete cubes made with Ordinary Portland Cement at all curing ages.

  13. INFLUENCES OF SUPERPLASTICIZER, MIXING TIME, MIXING TEMPERATURE AND CEMENT CONTENT ON HIGH-VOLUME FLY ASH CONCRETE

    OpenAIRE

    Nobuhiro, KAWAGUCHI; Kiyoshi, KOHNO; Masakazu, MITA; Department of Civil Engineering, Faculty of Engineering, The University of Tokushima; Department of Civil Engineering, Faculty of Engineering, The University of Tokushima; Department of Civil Engineering, Faculty of Engineering, The University of Tokushima

    1996-01-01

    The influences of superplasticizers, mixing time, mixing temperature and cement content on high-volume fly ash concrete were investigated in order to use the industrial by-product, fly ash from coal thermal power plant, more actively for concrete. The slump, air content, compressive strength and tensile strength of high-volume fly ash concrete were investigated using different mixtures. The results of these investigations indicate that the properties of fly ash concrete are influenced by the ...

  14. Preliminary Examination of the System Fly Ash-Bottom Ash-Flue Gas Desulphurization Gypsum-Portland Cement-Water for Road Construction

    Directory of Open Access Journals (Sweden)

    R. Tokalic

    2013-01-01

    Full Text Available This paper describes an investigation into the use of three power plant wastes: fly ash, flue gas desulphurization gypsum, and bottom ash for subbase layers in road construction. Two kinds of mixtures of these wastes with Portland cement and water were made: first with fly ash consisting of coarser particles (<1.651 mm and second with fly ash consisting of smaller particles (<0.42 mm. The mass ratio of fly ash-Portland cement-flue gas desulphurization gypsum-bottom ash was the same (3 : 1 : 1 : 5 in both mixtures. For both mixtures, the compressive strength, the mineralogical composition, and the leaching characteristics were determined at different times, 7 and 28 days, after preparation. The obtained results showed that both mixtures could find a potential use for subbase layers in road construction.

  15. Evaluation Some Properties of NanoMetakaolin or Rice Husk Ash Cement Mortar and its Resistance to Elevated Temperature

    Directory of Open Access Journals (Sweden)

    Jassim Atiya Alwan

    2016-12-01

    Full Text Available The objective of this research is to find the optimum value of some properties like compressive, flexural strength of blended cement mortar by nanometakaolin ( NMK or rice husk ash (RHA and to evaluate the effect of high temperature on these properties. The ordinary Portland cement(OPC of mortar was partially substituted by NMK or RHA of 5,10,15 and 20% by weight of cement. (108 control and blended specimens were casted and tested at ambient temperature (33 ºC for compressive and flexural strength for 28 and 90 days. Another (270 of the control and blended specimens were casted and cured for 90 days and exposed to elevated temperature of a gradual increase in temperature up to 200 ºC,300 ºC, 400 ºC,600 ºC and 800 ºC for two hours in an electrical furnace and they were under the same previous tests. The test results at ambient temperature indicate that the optimum compressive and flexural strength was with ratio of 15% NMK cement replacement in mortar for 28 and 90 days but for RHA was ratio of 10% for 28 days and 15% of cement weight in mortar for 90 days compared to control specimens. The results of exposing control and blended specimens of (90 days to elevated temperature showed that the optimum strength for control and the best MK replacement ratio were found at 200 ºC, and the best RHA replacement ratio specimens was found at 300 ºC. It is also found that exposing the mortar to more than these temperatures destroyed its strength and it was detrimental to its properties.

  16. EFFECT ON COMPRESSIVE STRENGTH OF CONCRETE WITH PARTIAL REPLACEMENT OF CEMENT BY MUNICIPAL SOLID WASTE INCINERATION ASH

    OpenAIRE

    V. Alivelu Mangamma

    2016-01-01

    The municipal solid waste incineration ash reduces are worldwide studied topic over the last decades, so that utilize the municipal solid waste is the one of the possibilities is to use MSWI in concrete production as it is done the bottom ash features the most convenient composition in concrete and it is a available in highest amounts among the MSWI ashes the bottom ash was used as partial replacement of cement of cement in concrete strength has to find ,if the prepared concrete will get suff...

  17. Probability based design of concrete mixes with cow-bone ash admixed cement

    Directory of Open Access Journals (Sweden)

    Mahmud ABUBAKAR

    2016-06-01

    Full Text Available A probability-based procedure for design of concrete mixes with cow-cone ash admixed cement has been developed considering the strength as a random variable. However, the compressive strength of concrete in turn, depends on the properties of its constituent materials: cement, fine aggregate, coarse aggregate and cow-bone ash. The compressive strength data generated experimentally has been analysed using normal-probability distribution functions based on 95% confidence interval. The proposed probability based design was compared to the method of trial mixture. It was observed that for reliability index (β of 1.3, the proposed probability methodology uses 10.2% less cement content than the method of trial mixture; thus, indicating that the method is conservative. It was also observed that, for concrete grade 25, the proposed methodology gives higher compressive strength at both 7 and 28 days. Hence, the probability-based design procedure was found appropriate and is therefore recommended for the design of concrete mixes with cow-bone ash admixed cement.

  18. PREPARATION AND PROPERTIES OF ALKALI-ACTIVATED CEMENT CONTAINING PHOSPHOROUS SLAG AND FLY ASH

    Directory of Open Access Journals (Sweden)

    Duo You

    2016-03-01

    Full Text Available Phosphorous slag is an industrial waste which potentially pollutes environments. The aim of the present work is to use phosphorous slag as a raw material to produce alkali-activated cement. The influence of mix proportion of phosphorous slag and fly ash, alkali content and modulus of water glass on the properties of alkali-activated phosphorous slag and fly ash cement (AA-PS-FA-C was studied. The results show that AA-PS-FA-C with normal setting performance and desirable mechanical properties can be prepared using water glass as the activator. Changing the fly ash content in the range of 0-40 wt% has only a small influence on the setting time of AA-PS-FA-C. The strengths significantly decrease when the fly ash content exceeds 30 wt%. The carbonation resistance of AA-PS-FA-C is similar to that of ordinary Portland cement (OPC, while the frost resistance is much better. The hardened paste of AA-PS-FA-C is much more compact than OPC paste.

  19. Effect of fly ash on the hydration process in cemented paste backfill at early stages

    Energy Technology Data Exchange (ETDEWEB)

    Simon, D.; Grabinsky, M.W. [Toronto Univ., ON (Canada). Dept. of Civil Engineering

    2009-07-01

    Cemented paste backfill (CPB) is a sustainable backfilling technique used in underground mining operations that ensures ground stabilization. The technique uses mine waste for filling the voids created by underground mining. Compared to conventional backfilling technologies, CPB has the advantage of rapid transport to the stopes; shorter turn-around cycle time; elimination of the drainage barricades in the CPB-filled stopes; and diversion of mine waste from surface disposal sites to underground stopes. Partial replacement of Portland cement with fly ash or ground blast furnace slag, can significantly reduce production costs and improve the performance of typical CPBs. This paper studied the effect of fly ash on the hydration process in CPB during the early stages of hydration using non-destructive, electromagnetic (EM) wave-based techniques. The study showed that the use of fly ash in Portland cement delayed the hydration process, and that the delay was proportional to the replacement level. At later onset times, the fly ash particles enhanced the hydration process by providing additional ions that contributed to the formation of hydration products and ultimately increased the mechanical strength of CPB. The EM test results on CPB obtained in the controlled laboratory environment were compared with in situ test results obtained in an actual backfilled test stope. The EM-wave based techniques were found to be sensitive to paste composition, including binder content, binder type and water content of the paste. 16 refs., 3 tabs., 6 figs.

  20. Investigation on the Rheological Behavior of Fly Ash Cement Composites at Paste and Concrete Level

    Science.gov (United States)

    Thiyagarajan, Hemalatha; Mapa, Maitri; Kushwaha, Rakhi

    2018-02-01

    Towards developing sustainable concrete, nowadays, high volume replacement of cement with fly ash (FA) is more common. Though the replacement of fly ash at 20-30% is widely accepted due to its advantages at both fresh and hardened states, applicability and acceptability of high volume fly ash (HVFA) is not so popular due to some adverse effects on concrete properties. Nowadays to suit various applications, flowing concretes such as self compacting concrete is often used. In such cases, implications of usage of HVFA on fresh properties are required to be investigated. Further, when FA replacement is beyond 40% in cement, it results in the reduction of strength and in order to overcome this drawback, additions such as nano calcium carbonate (CC), lime sludge (LS), carbon nano tubes (CNT) etc. are often incorporated to HVFA concrete. Hence, in this study, firstly, the influence of replacement level of 20-80% FA on rheological property is studied for both cement and concrete. Secondly, the influence of additions such as LS, CC and CNT on rheological parameters are discussed. It is found that the increased FA content improved the flowability in paste as well as in concrete. In paste, the physical properties such as size and shape of fly ash is the reason for increased flowability whereas in concrete, the paste volume contributes dominantly for the flowability rather than the effect due to individual FA particle. Reduced density of FA increases the paste volume in FA concrete thus reducing the interparticle friction by completely coating the coarse aggregate.

  1. TECHNOLOGY AND EFFICIENCY IN USAGE OF BROWN COAL ASH FOR CEMENT AND CONCRETE MIXTURES AT THE LELCHITSKY DEPOSIT

    Directory of Open Access Journals (Sweden)

    G. D. Lyahevich

    2017-01-01

    Full Text Available Modern visions on the role of high-dispersity additives in concrete mixtures reflect a positive effect of optimal amount of ash left after combustion of solid fuel on structure and physico-mechanical characteristics of cement compositions: hardening of contact zone between cement stone and aggregates with formation of “binder – aggregate” clusters due to high surface energy of aggregate particles; reduction of total cement stone porosity in concrete while increasing volumetric concentration and aggregate dispersion; binding of calcium hydroxide by amorphized silicon of pozzolanic aggregates; increase in pozzolanic aggregate activity with its fine grinding, etc. Experimental investigations have ascertained that usage of portland cement clinker ash samples left after brown coal burning at the Lelchitsky deposit contributed to an increase of cement working life and activity. Concrete samples have been obtained that have improved physico-mechanical properties owing to introduction the following components in their composition: 2–14 % (of cement mass of ash left after brown coal burning and 1.6–2.1 % of sodium salt that is a condensation product of sulfur oxidate in aromatic hydrocarbons with formaldehyde. Efficiency of the executed work has been proved by solution of the problems pertaining to an increase of neat cement working life, cement activity, concrete strength. The paper also considers no less important problem concerning protection of the environment from contamination with ash left after burning of high-ash brown coal. 

  2. Elaboration and characterization of an iodate-substituted hydroxyapatite cement

    International Nuclear Information System (INIS)

    Coulon, A.; Campayo, L.; Laurencin, D.; Grandjean, A.; Cau Dit Coumes, C.; Rossignol, S.

    2015-01-01

    In the last decades, robust host matrices have been developed to guarantee a durable confinement of some of the most mobile radionuclides. In this work, we describe a novel method for iodine incorporation into an iodate-substituted hydroxyapatite by means of a cementation route. Such a material is obtained from a stoichiometric mixture of tetra-calcium-phosphate (TTCP)/tricalcium-phosphate (αTCP)/sodium iodate with a molar ratio 1/2/0.5. This material corresponds to an iodine incorporation content ∼6.5 wt.%. The evolution of this system during the early age (followed by calorimetric and conductimetric measurements) was compared to the same cementitious system without iodate. Results show that sodium iodate acts as a retarder that can be appropriate to control setting for an industrial application. The delay is due to the precipitation of non-cohesive intermediate phases like calcium iodate that are then totally consumed when the crystallization of hydroxyapatite occurs. At later age, a porous bulk material consisting of traces of TTCP and αTCP particles covered by needles is obtained. The composition of these needles is in agreement with that of the desired iodate-containing apatite. (authors)

  3. Reuse of sewage sludge ashes (SSA) in cement mixtures: the effect of SSA on the workability of cement mortars.

    Science.gov (United States)

    Monzó, J; Payá, J; Borrachero, M V; Girbés, I

    2003-01-01

    The influence of sewage sludge ash (SSA) on workability of cement mortars has been studied. The irregular morphology of SSA particles produced a decrease of mortar workability. A nonlinear reduction of workability in mortars containing SSA was observed, but when SSA content in mortars was increased the workability reduction was less significant. A superplasticizer is used in order to compensate the decrease of workability produced by SSA. When SSA sized fractions were used, only significant differences in workability for mortars prepared with high water volumes or with the presence of superplasticizer were observed.

  4. Radon exhalation of cementitious materials made with coal fly ash: Part 1 - scientific background and testing of the cement and fly ash emanation

    International Nuclear Information System (INIS)

    Kovler, K.; Perevalov, A.; Steiner, V.; Metzger, L.A.

    2005-01-01

    Increased interest in measuring radionuclides and radon concentrations in fly ash, cement and other components of building products is due to the concern of health hazards of naturally occurring radioactive materials (NORM). The current work focuses on studying the influence of fly ash (FA) on radon-exhalation rate (radon flux) from cementitious materials. The tests were carried out on cement paste specimens with different FA contents. The first part of the paper presents the scientific background and describes the experiments, which we designed for testing the radon emanation of the raw materials used in the preparation of the cement-FA pastes. It is found that despite the higher 226 Ra content in FA (more than 3 times, compared with Portland cement) the radon emanation is significantly lower in FA (7.65% for cement vs. 0.52% only for FA)

  5. Detrimental effects of cement mortar and fly ash mortar on asthma progression.

    Science.gov (United States)

    Cho, Ara; Jang, Hong-Seok; Roh, Yoon Seok; Park, Hee Jin; Talha, A F S M; So, Seung-Young; Lim, Chae Woong; Kim, Bumseok

    2013-11-01

    Currently, concrete additive materials are used worldwide to improve properties of concrete production and to reduce the total cost of the materials used in the concrete. However, the effects of exposure to various gases emitted from mortar mixed with additive materials are poorly understood. To evaluate the pattern of gas emission from cement mortar and additives, the emission levels of gas including ammonia (NH3) and volatile organic compounds (VOCs) were measured from two different mortar types, Ordinary Portland Cement (OPC), and OPC with fly ash on various time points after manufacture. On days 1, 3, 10 and 30 after manufacture, moderate concentrations of NH3 (4, 9, 12 and 5 ppm) were measured in OPC mortar (24h, 150 mm × 150 mm × 50 mm), whereas higher concentrations of NH3 (73, 55, 20 and 5 ppm) were measured in OPC mortar with fly ash (24h, 150 mm × 150 mm × 50 mm). Furthermore, the concentration of VOCs was more than 10 ppm on 1, 3, and 10 days of age in OPC and OPC with fly ash mortars. To examine the mortars' allergic effects on the respiratory system, mice were sensitized with ovalbumin (OVA) and divided into four groups: normal, asthma control, OPC mortar and OPC mortar with fly ash. The mice were housed in corresponding group cage for 10 days with OVA challenges to induce asthma. Histopathologically, increased infiltration of lymphocytes was observed in the lung perivascular area of mice housed in OPC mortar and OPC mortar with fly ash cages compared to lungs of asthma control mice. Moreover, severe bronchial lumen obstruction and increased hypertrophy of bronchial epithelial cells (pAdditionally, the OPC mortar with fly ash group showed higher expression of IL-5, 13 and monocyte chemoattractant protein-1 (MCP-1) compared to the asthma control group. These results indicate that OPC mortar and OPC mortar with fly ash might exacerbate asthma. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Data for the physical and mechanical properties of high volume fly ash cement paste composites.

    Science.gov (United States)

    Aydin, Ertug; Arel, Hasan Şahan

    2018-02-01

    The data presented herein are compiled of the research summary of "Characterization of High-Volume Fly-Ash Cement Paste for Sustainable Construction Application" (Aydin and Arel, 2017) [1]. This data article provides general information about the ASTM Class C and Class F fly ash cement paste composites composed of silica fume, lime, water reducing admixtures in three different level of workability (0 mm, 100 mm and 200 mm). The dataset here also helps the readers to understand the links with the basic properties of the ingredients, for example, how can porosity be predicted based on the mixture design? how can the strength of the material be linked with the basic strengths of the constituent ingredients?.

  7. Performance evaluation of cement-stabilized pond ash-rice husk ash-clay mixture as a highway construction material

    Directory of Open Access Journals (Sweden)

    Deepak Gupta

    2017-02-01

    Full Text Available This paper reports the results of an investigation carried out on clay soil stabilized with pond ash (PA, rice husk ash (RHA and cement. Modified Proctor compaction tests were performed in order to investigate the compaction behavior of clay, and California bearing ratio (CBR tests were performed to determine the strength characteristics of clay. For evaluation purpose, the specimens containing different amounts of admixtures were prepared. Clay was replaced with PA and RHA at a dosage of 30%–45% and 5%–20%, respectively. The influence of stabilizer types and dosages on mechanical properties of clay was evaluated. In order to study the surface morphology and crystallization characteristics of the soil samples, scanning electron microscopy (SEM and X-ray diffraction (XRD analyses were carried out, respectively. The results obtained indicated a decrease in the maximum dry density (MDD and a simultaneous increase in the optimum moisture content (OMC with the addition of PA and RHA. Multiple linear regression analysis (MLRA showed that the predicted values of CBR tests are in good agreement with the experimental values. Developed stabilized soil mixtures showed satisfactory strength and can be used for construction of embankments and stabilization of sub-grade soil. The use of locally available soils, PA, RHA, and cement in the production of stabilized soils for such applications can provide sustainability for the local construction industry.

  8. Cohesive Soil Stabilized Using Sewage Sludge Ash/Cement and Nano Aluminum Oxide

    Directory of Open Access Journals (Sweden)

    Huan-Lin Luo

    2012-03-01

    Full Text Available In order to improve soft soil strength, a mixture of incinerated sewage sludge ash (SSA and cement was applied as a soil stabilizer. The intended mix ratio for SSA and cement was 3:1. A-6 clay was selected as the untreated soil. In this study, 15% of clay soil was replaced by SSA/cement to produce the treated soil specimens. Then, four different volumes, namely 0, 1, 2, and 3%, of nano-Al2O3 were mixed with the treated soil as an additive. Tests such as compaction, pH values, Atterberg limits, unconfined compressive strength (UCS, swell potential, California bearing ratio (CBR, and permeability were performed. The results indicate that both UCSs and CBR values of untreated soil were greatly improved by the use of 15% SSA/cement. Moreover, a 1% addition of nano-Al2O3 enhanced the treated soil in terms of both UCS and CBR values. Furthermore, the swell potential was effectively reduced by the use of 15% SSA/cement as compared with untreated soil and the 1% nano-Al2O3 additive fraction offered the best performance. From this study, we conclude that 15% of SSA/cement replacement could effectively stabilize A-6 clay soil, and 1% of nano-Al2O3 additive may be the optimum amount to add to the soil.

  9. THE EFFECT OF NATURAL POZZOLAN AND FLY ASH HAVING DIFFERENT FINENESS ON THE STRENGTH OF CEMENT

    Directory of Open Access Journals (Sweden)

    Özlem ÇELİK

    2004-03-01

    Full Text Available In this study, three groups of mixtures containing 40 % constant fly-ash and natural pozolan ratios were prepared. In the first group mixtures 45 µ sieve values, in the second Blaine values were equalized, and in the third fly-ash and natural pozzolan were grinded in the labaratory for 15 minutes. The compression strength values of the prepared cement mortars having these group mixtures were obtained at the end of 2, 7, 28, 60, 90 and 360-day curing. In these trength tests , the highest strength values were found in the mortars produced with fly-ash admixture having the highest Blaine value, which is in the third group of mixtures.

  10. Utilization of sugarcane bagasse ash in concrete as partial replacement of cement

    Science.gov (United States)

    Mangi, Sajjad Ali; Jamaluddin, N.; Ibrahim, M. H. Wan; Halid Abdullah, Abd; Awal, A. S. M. Abdul; Sohu, Samiullah; Ali, Nizakat

    2017-11-01

    This research addresses the suitability of sugarcane bagasse ash (SCBA) in concrete used as partial cement replacement. Two grades of concrete M15 and M20 were used for the experimental analysis. The cement was partially replaced by SCBA at 0%, 5%, and 10%, by weight in normal strength concrete (NSC). The innovative part of this study is to consider two grades of concrete mixes to evaluate the performance of concrete while cement is replaced by sugarcane bagasse ash. The cylindrical specimens having size 150 mm × 300 mm were used and tested after curing period of 7, 14 and 28 days. It was observed through the experimental work that the compressive strength increases with incorporating SCBA in concrete. Results indicated that the use of SCBA in concrete (M20) at 5% increased the average amount of compressive strength by 12% as compared to the normal strength concrete. The outcome of this work indicates that maximum strength of concrete could be attained at 5% replacement of cement with SCBA. Furthermore, the SCBA also gives compatible slump values which increase the workability of concrete.

  11. The Use of Fly Ash and Lime Sludge as Partial Replacement of Cement in Mortar

    Directory of Open Access Journals (Sweden)

    Vaishali Sahu

    2014-01-01

    Full Text Available The increased demand of drinking water and power has led huge generation of water treatment plant residue i.e. sludge and the thermal power plant by-product such as fly ash. Large quantities of sludge and fly ash are produced in India and disposed off by landfilling or dumping in and around sites. In this study fly ash and water softening sludge (lime sludge has been utilized in mortar. Two types of mortar (type I and II with four binder combinations have been tried. Binder I consists of 70% fly ash (FA and 30% lime sludge (LS , 0 % gypsum (G, binder II is 70% FA, 30% LS and 1% G, binder III is 50% FA, 30% LS and 20% cement and the binder IV is 40% FA, 40% LS with 20% cement. The effect of various combinations on strength has been discussed here. This paper outlines the composition of the composite material, method of preparation of mortar specimen, testing procedure and salient results thereof.

  12. Study on concrete with partial replacement of cement by rice husk ash

    Science.gov (United States)

    Kaarthik Krishna, N.; Sandeep, S.; Mini, K. M.

    2016-09-01

    Increase in the demand of conventional construction materials and the need for providing a sustainable growth in the construction field has prompted the designers and developers to opt for ‘alternative materials’ feasible for use in construction. For this objective, the use of industrial waste products and agricultural byproducts are very constructive. These industrial wastes and agricultural by products such as Fly Ash, Rice Husk Ash, Silica Fume, and Slag can be replaced instead of cement because of their pozzolanic behavior, which otherwise requires large tract of lands for dumping. In the present investigation, Rice Husk Ash has been used as an admixture to cement in concrete and its properties has been studied. An attempt was also done to examine the strength and workability parameters of concrete. For normal concrete, mix design is done based on Indian Standard (IS) method and taking this as reference, mix design has been made for replacement of Rice Husk Ash. Four different replacement levels namely 5%, 10%, 15% and 20% are selected and studied with respect to the replacement method.

  13. Cement replacement by sugar cane bagasse ash: CO2 emissions reduction and potential for carbon credits.

    Science.gov (United States)

    Fairbairn, Eduardo M R; Americano, Branca B; Cordeiro, Guilherme C; Paula, Thiago P; Toledo Filho, Romildo D; Silvoso, Marcos M

    2010-09-01

    This paper presents a study of cement replacement by sugar cane bagasse ash (SCBA) in industrial scale aiming to reduce the CO(2) emissions into the atmosphere. SCBA is a by-product of the sugar/ethanol agro-industry abundantly available in some regions of the world and has cementitious properties indicating that it can be used together with cement. Recent comprehensive research developed at the Federal University of Rio de Janeiro/Brazil has demonstrated that SCBA maintains, or even improves, the mechanical and durability properties of cement-based materials such as mortars and concretes. Brazil is the world's largest sugar cane producer and being a developing country can claim carbon credits. A simulation was carried out to estimate the potential of CO(2) emission reductions and the viability to issue certified emission reduction (CER) credits. The simulation was developed within the framework of the methodology established by the United Nations Framework Convention on Climate Change (UNFCCC) for the Clean Development Mechanism (CDM). The State of São Paulo (Brazil) was chosen for this case study because it concentrates about 60% of the national sugar cane and ash production together with an important concentration of cement factories. Since one of the key variables to estimate the CO(2) emissions is the average distance between sugar cane/ethanol factories and the cement plants, a genetic algorithm was developed to solve this optimization problem. The results indicated that SCBA blended cement reduces CO(2) emissions, which qualifies this product for CDM projects. 2010 Elsevier Ltd. All rights reserved.

  14. Field and lab evaluation of the use of lime fly ash to replace soil cement as a base course : final report.

    Science.gov (United States)

    1997-09-01

    This study evaluates the performance of lime/fly ash stabilized base as an alternative to soil cement stabilized base for flexible pavement systems on reconstructed highways in Louisiana. Louisiana has historically used soil cement for most flexible ...

  15. The maximum percentage of fly ash to replace part of original Portland cement (OPC) in producing high strength concrete

    Science.gov (United States)

    Mallisa, Harun; Turuallo, Gidion

    2017-11-01

    This research investigates the maximum percent of fly ash to replace part of Orginal Portland Cement (OPC) in producing high strength concrete. Many researchers have found that the incorporation of industrial by-products such as fly ash as in producing concrete can improve properties in both fresh and hardened state of concrete. The water-binder ratio was used 0.30. The used sand was medium sand with the maximum size of coarse aggregate was 20 mm. The cement was Type I, which was Bosowa Cement produced by PT Bosowa. The percentages of fly ash to the total of a binder, which were used in this research, were 0, 10, 15, 20, 25 and 30%; while the super platicizer used was typed Naptha 511P. The results showed that the replacement cement up to 25 % of the total weight of binder resulted compressive strength higher than the minimum strength at one day of high-strength concrete.

  16. COMPARATIVE ASSESSMENT OF RICE HUSK ASH, POWDERED GLASS AND CEMENT AS LATERITIC SOIL STABILIZERS

    Directory of Open Access Journals (Sweden)

    Adebisi Ridwan

    2016-10-01

    Full Text Available This paper compares the stabilizing effects of three different materials, namely: rice husk ash, powdered glass, and cement on the properties of lateritic soil. The basic properties of the lateritic soil were first obtained through colour, moisture content determination, specific gravity, particle size distribution and Atterberg limits tests. Each of the stabilizing materials was then mixed with the lateritic soil in varying percentages of 2.5%, 5%, 7.5%, 10%, 12.5% and 15% by weight of the soil. Thereafter, compaction and California bearing ratio (CBR tests were carried out on the sample mixes to determine the effects of the materials on the lateritic soil. Chemical tests were also carried out on the samples to determine their percentage oxides composition. The compaction test showed that the highest maximum dry densities (MDD obtained for the mixed samples were 2.32 g/cm3 (at 2.5% cement addition, 2.28g/cm3 (at 5% powdered glass (PG addition and 2.18 g/cm3 (at 5% rice husk ash (RHA addition with corresponding optimum moisture contents (OMC of 10.06%, 14.3% and 12.31% respectively. The CBR tests showed that the CBR values increased in all cases as the materials were added with those of the cement and powdered glass giving the highest values and showing close semblance under unsoaked conditions. The chemical test showed that the significant oxides present in the cement, powdered glass and rice husk ash were CaO (53.60%, SiO2 (68.45% and SiO2 (89.84% respectively.

  17. Stabilization treatment of soft subgrade soil by sewage sludge ash and cement.

    Science.gov (United States)

    Chen, Li; Lin, Deng-Fong

    2009-02-15

    In this study, incinerated sewage sludge ash (ISSA) is mixed with cement in a fixed ratio of 4:1 for use as a stabilizer to improve the strength of soft, cohesive, subgrade soil. Five different ratios (in wt%: 0%, 2%, 4%, 8%, and 16%) of ISSA/cement admixture are mixed with cohesive soil to make soil samples. In order to understand the influences of admixtures on the soil properties, tests of the pH value, Atterberg limits, compaction, California bearing ratio (CBR), unconfined compressive strength, and triaxial compression were performed on those samples. The study shows that the unconfined compressive strength of specimens with the ISSA/cement addition was improved to approximately 3-7 times better than that of the untreated soil; furthermore, the swelling behavior was also effectively reduced as much as 10-60% for those samples. In some samples, the ISSA/cement additive improved the CBR values by up to 30 times that of untreated soil. This suggests that ISSA/cement has many potential applications in the field of geotechnical engineering.

  18. Substitution of strontium for calcium in glass ionomer cements (Part ...

    African Journals Online (AJOL)

    ) (PAA) and aqueous tartaric acid to form glass ionomer cements, whose properties were investigated at different time points: the compressive and bi-axial flexure strengths were tested; and, the ion release profile was studied by fluoride Ion ...

  19. Substitution of strontium for calcium in glass ionomer cements (Part ...

    African Journals Online (AJOL)

    ) (PAA) and aqueous tartaric acid to form glass ionomer cements, whose properties were investigated at different time points: working and setting times were determined by rheometry; and, the setting reaction was studied by Fourier transform ...

  20. Mechanical performance and ultrasonic properties of cemented gangue backfill with admixture of fly ash.

    Science.gov (United States)

    Wu, Di; Zhang, Yongliang; Liu, Yucheng

    2016-01-01

    Cemented gangue backfill (CGB) is prepared by mixing cement, coal gangue and water. Fly ash from the combustion of coal is commonly utilized as admixture to improve the mechanical performance and fluidity of CGB, as well as to reduce cost of preparing CGB. Uniaxial compressive strength (UCS) is one of the most commonly used indicators for evaluating the mechanical performance of CGB. Ultrasonic testing, which is a non-destructive measurement, can also be applied to determine the mechanical properties of cementitious materials such as CGB. So this paper investigates the UCS and ultrasonic pulse velocity (UPV) of CGB prepared at different fly ash dosage (19, 20 and 21 wt.%) and solid content (76.5, 77.5 and 78.5 wt.%), versus curing periods of 3-28 days. The UCS and UPV values of CGB increase with increasing fly ash dosage and solid content. In order to find out the correlation between the UCS and UPV values of CGB, different types (linear, logarithmic, exponential and power) of curve fitting are conducted on the CGB samples made at different solid content. An exponential relationship with the correlation coefficient of 0.959 appears to exist between the UCS and UPV for CGB samples. This obtained exponential relationship is validated to be available by performing the t- and F- tests. The results acquired by this paper are capable of providing guidance for utilizing UPV test to estimate the strength of underground CGB structures. Copyright © 2015 Elsevier B.V. All rights reserved.

  1. Sulfate resistance evaluation of the cement with fly ash (using the Koch & Steinegger method

    Directory of Open Access Journals (Sweden)

    Irassar, Edgardo F.

    1988-12-01

    Full Text Available The increase of active mineral admixtures consumption in contemporaneous cementiceous materials has stablished revision of some test methods. In the evaluation of blended cement durability, many accelerated tests of large application in portland cements become unvalid, because they don't allow to value the improvements produced by pozzolan materials. Koch-Steinegger Method appears as the most appropiate to evaluate sulfate resistance of cement with active mineral admixtures. In this paper are presented the results obtained with this test in the evaluation of an ordinary portland cement (CPN and one resisting sulfates (CPARS, with low calcium fly ash addition. Fly ash is incorporated with three fineness (280, 420 and 480 m2/Kg Blaine. The results show that this addition improves sulfate resistance of CPN and in minor way of ARS cement. Fly ash influences evolution of mechanical strength in water and chemical resistance at first ages.

    El aumento del consumo de las adiciones minerales activas en los materiales cementíceos contemporáneos ha determinado la revisión de algunos métodos de ensayo utilizados para determinar sus propiedades. En la evaluación de la durabilidad de los cementos compuestos, muchos ensayos de corta duración (de gran aplicación en cementos portland dejan de tener validez, pues no permiten evaluar las mejoras que producen los materiales puzolánicos. El método propuesto por KOCH & STEINEGGER (1960 aparece como uno de los más apropiados para determinar el comportamiento de cementos con adiciones minerales activas frente al ataque de sulfatos. En este trabajo se presentan los resultados alcanzados con ente ensayo en la determinación del comportamiento de un cemento portland normal (CRN y uno resistente a los sulfatos (CPARS, adicionados con ceniza volante de bajo contenido en óxido de calcio. La ceniza se incorpora con tres finuras (280, 420 y 480 m2/kg —Blaine—. Estos

  2. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Directory of Open Access Journals (Sweden)

    Yann-Hwang Wu

    2015-02-01

    Full Text Available This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS. The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%, SiO2 (21.1%, Al2O3 (13.8%, SO3 (10.06%, Fe2O3 (2.25% and others (4.29%. SA fly ash consists of Al2O3 (19.7%, SiO2 (36.3%, Fe2O3 (28.4% and others (15.6%. SB fly ash consists of Al2O3 (15%, SiO2 (25.4%, Zn (20.6%, SO3 (10.9%, Fe2O3 (8.78% and others (19.32%. The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste. The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  3. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements.

    Science.gov (United States)

    Wu, Yann-Hwang; Huang, Ran; Tsai, Chia-Jung; Lin, Wei-Ting

    2015-02-16

    This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO₃ (48.5%), SiO₂ (21.1%), Al₂O₃ (13.8%), SO₃ (10.06%), Fe₂O₃ (2.25%) and others (4.29%). SA fly ash consists of Al₂O₃ (19.7%), SiO₂ (36.3%), Fe2O3 (28.4%) and others (15.6%). SB fly ash consists of Al₂O₃ (15%), SiO₂ (25.4%), Zn (20.6%), SO₃ (10.9%), Fe₂O₃ (8.78%) and others (19.32%). The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7-14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste). The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements.

  4. Recycling of Sustainable Co-Firing Fly Ashes as an Alkali Activator for GGBS in Blended Cements

    Science.gov (United States)

    Wu, Yann-Hwang; Huang, Ran; Tsai, Chia-Jung; Lin, Wei-Ting

    2015-01-01

    This study investigates the feasibility of co-firing fly ashes from different boilers, circulating fluidized beds (CFB) or stokers as a sustainable material in alkali activators for ground granulated blast-furnace slag (GGBS). The mixture ratio of GGBS and co-firing fly ashes is 1:1 by weight. The results indicate that only CF fly ash of CFB boilers can effectively stimulate the potential characteristics of GGBS and provide strength as an alkali activator. CF fly ash consists of CaO3 (48.5%), SiO2 (21.1%), Al2O3 (13.8%), SO3 (10.06%), Fe2O3 (2.25%) and others (4.29%). SA fly ash consists of Al2O3 (19.7%), SiO2 (36.3%), Fe2O3 (28.4%) and others (15.6%). SB fly ash consists of Al2O3 (15%), SiO2 (25.4%), Zn (20.6%), SO3 (10.9%), Fe2O3 (8.78%) and others (19.32%). The mixtures of SA fly ash and SB fly ash with GGBS, respectively, were damaged in the compressive strength test during seven days of curing. However, the built up strength of the CF fly ash and GGBS mixture can only be maintained for 7–14 days, and the compressive strength achieves 70% of that of a controlled group (cement in hardening cement paste). The strength of blended CF fly ash and GGBS started to decrease after 28 days, and the phenomenon of ettrigite was investigated due to the high levels of sulfur content. The CaO content in sustainable co-firing fly ashes must be higher than a certain percentage in reacting GGBS to ensure the strength of blended cements. PMID:28787970

  5. APC fly ashes stabilized with Portland cement for further development of road sub-base aggregates

    Science.gov (United States)

    Formosa, J.; Giro-Paloma, J.; Maldonado-Alameda, A.; Huete-Hernández, S.; Chimenos, J. M.

    2017-10-01

    Although waste-to-energy plants allow reducing the mass and volume of municipal solid waste (MSW) incinerated, an average around 30 % of the total content remains as bottom ash (BA) and air pollution control (APC) ashes at the end of combustion process. While weathered bottom ash (WBA) is considered a non-hazardous residue that can be revalorized as a secondary aggregate, APC fly ashes generated during the flue gas treatment are classified as hazardous waste and are handled in landfill disposal after stabilization, usually with Portland cement (OPC). However, taking into account the amount of APC residues produced and the disposing cost in landfill, their revalorization is an important issue that could be effectively addressed. As MSW can be incinerated producing bottom ashes (BA) or air pollutant control (APC) residues, the development of a mortar formulated with APC fly ash as secondary building material is a significant risk to the environment for their content of heavy metals. In this way, Design of Experiment (DoE) was used for the improvement of granular material (GM) formulation composed by APC and OPC for further uses as road sub-base aggregate. DoE analysis was successful in the modelling and optimization the formulation as function of the mechanical properties and APC amount. Consequently, an optimal mortar formulation (OMF) of around 50 wt.% APC and 50 wt.% OPC was considered. The OMF leachates and abrasion resistance have been analyzed. These results have demonstrated the viability of OMF as non-hazardous material feasible to be used as secondary aggregate. Moreover, it would be possible to consider the environmental assessment of a GM composed by ≈20 wt.% of OMF and ≈80 wt.% of WBA in order to improve mechanical properties and heavy metals stabilization.

  6. Polymer--calcium phosphate cement composites for bone substitutes.

    Science.gov (United States)

    Mickiewicz, Rafal A; Mayes, Anne M; Knaack, David

    2002-09-15

    The use of self-setting calcium phosphate cements (CPCs) as bioresorbable bone-replacement implant materials presently is limited to non-load-bearing applications because of their low compressive strength relative to natural bone. The present study investigated the possibility of strengthening a commercially available CPC, alpha-BSM, by incorporating various water-soluble polymers into the cement paste during setting. Several polyelectrolytes, poly(ethylene oxide), and the protein bovine serum albumin (BSA) were added in solution to the cement paste to create calcium phosphate-polymer composites. Composites formulated with the polycations poly(ethylenimine) and poly(allylamine hydrochloride) exhibited compressive strengths up to six times greater than that of pure alpha-BSM material, with a maximum value reached at intermediate polymer content and for the highest molecular weight studied. Composites containing BSA developed compressive strengths twice that of the original cement at protein concentrations of 13-25% by weight. In each case, XRD studies correlate the improvement in compressive strength with reduced crystallite dimensions, as evidenced by a broadening of the (0,0,2) reflection. This suggests that polycation or BSA adsorption inhibits crystal growth and possibly leads to a larger crystal aspect ratio. SEM results indicate a denser, more interdigitated microstructure. The increased strength was attributed to the polymer's capacity to bridge between multiple crystallites (thus forming a more cohesive composite) and to absorb energy through plastic flow. Copyright 2002 Wiley Periodicals, Inc.

  7. A brief on high-volume Class F fly ash as cement replacement – A guide for Civil Engineer

    Directory of Open Access Journals (Sweden)

    Alaa M. Rashad

    2015-12-01

    Full Text Available Disposal of fly ash (FA resulting from the combustion of coal-fired electric power stations is one of the major environmental challenges. This challenge continues to increase with increasing the amount of FA and decreasing the capacity of landfill space. Therefore, studies have been carried out to re-use high-volumes of fly ash (HVFA as cement replacement in building materials. This paper presents an overview of the previous studies carried out on the use of high volume Class F FA as a partial replacement of cement in traditional paste/mortar/concrete mixtures based on Portland cement (PC. Fresh properties, mechanical properties, abrasion resistance, thermal properties, drying shrinkage, porosity, water absorption, sorptivity, chemical resistance, carbonation resistance and electrical resistivity of paste/mortar/concrete mixtures containing HVFA (⩾45% as cement replacement have been reviewed. Furthermore, additives used to improve some properties of HVFA system have been reviewed.

  8. Use of hyghly reactive rice husk ash in the production of cement matrix reinforced with Green coconut fiber

    OpenAIRE

    Pereira, C.L.; Savastano, H. Jr; Paya Bernabeu, Jorge Juan; Santos, S. F.; Borrachero Rosado, María Victoria; Monzó Balbuena, José Mª; Soriano Martinez, Lourdes

    2013-01-01

    This study evaluated the influence of partial replacement of Portland cement by rice husk ash (RHA) to enable the use of green coconut husk fiber as reinforcement for cementitious matrix. The use of highly reactive pozzolanic ash contributes for decreasing the alkaline attack on the vegetable fiber, originated from waste materials. The slurry dewatering technique was used for dispersion of the raw materials in aqueous solution, followed by vacuum drainage of water and pressing for the product...

  9. Study on properties of rice husk ash and its use as cement replacement material

    Directory of Open Access Journals (Sweden)

    Ghassan Abood Habeeb

    2010-06-01

    Full Text Available This paper investigates the properties of rice husk ash (RHA produced by using a ferro-cement furnace. The effect of grinding on the particle size and the surface area was first investigated, then the XRD analysis was conducted to verify the presence of amorphous silica in the ash. Furthermore, the effect of RHA average particle size and percentage on concrete workability, fresh density, superplasticizer (SP content and the compressive strength were also investigated. Although grinding RHA would reduce its average particle size (APS, it was not the main factor controlling the surface area and it is thus resulted from RHA's multilayered, angular and microporous surface. Incorporation of RHA in concrete increased water demand. RHA concrete gave excellent improvement in strength for 10% replacement (30.8% increment compared to the control mix, and up to 20% of cement could be valuably replaced with RHA without adversely affecting the strength. Increasing RHA fineness enhanced the strength of blended concrete compared to coarser RHA and control OPC mixtures.

  10. Experimental studies on effect of Date Seed Ash (DSA) on strength properties of cement sand mortar

    Science.gov (United States)

    Gunarani, G. I.; Chakkravarthy, S. P.

    2017-07-01

    The need for alternative material for the cement is arising and being compromised by many engineering researchers. However, the growing demand and surging prices of raw materials challenges the constructional field. India, being one of the largest agricultural economy, produces a quantitative volume of agro-waste that is being dumped. In the conventional concrete production, coarse aggregate (CA) plays an important filler material. The initial study on date seed as a replacement for CA was not successful. This study primarily focuses on Date seed ash as a replacement material for ordinary Portland cement. OPC was replaced by Date Palm Seed Ash (DPSA) in the ratio up to 10% in terms of 2% interval. The main objective of this paper was to study the variation of strength properties of mortar by DPSA in specified ratio along with curing period of 3,7,14 and 28 days. The stress strain behavior has indicated a significant improvement. The overall results indicated the increase in replacing ratio, decreases the strength properties. However the physical, chemical and mechanical properties increased gradually in strength in minimal ratio.

  11. Efficiency of fly ash belite cement and zeolite matrices for immobilizing cesium

    International Nuclear Information System (INIS)

    Goni, S.; Guerrero, A.; Lorenzo, M.P.

    2006-01-01

    The efficiency of innovative matrices for immobilizing cesium is presented in this work. The matrix formulation included the use of fly ash belite cement (FABC-2-W) and gismondine-type Na-P1 zeolite, both of which are synthesized from fly ash of coal combustion. The efficiency for immobilizing cesium is evaluated from the leaching test ANSI/ANS 16.1-1986 at the temperature of 40 deg. C, from which the apparent diffusion coefficient of cesium is obtained. Matrices with 100% of FABC-2-W are used as a reference. The integrity of matrices is evaluated by porosity and pore-size distribution from mercury intrusion porosimetry, X-ray diffraction and nitrogen adsorption analyses. Both matrices can be classified as good solidify systems for cesium, specially the FABC-2-W/zeolite matrix in which the replacement of 50% of belite cement by the gismondine-type Na-P1 zeolite caused a decrease of two orders of magnitude of cesium mean Effective Diffusion Coefficient (D e ) (2.8e-09 cm 2 /s versus 2.2e-07 cm 2 /s, for FABC-2-W/zeolite and FABC-2-W matrices, respectively)

  12. The Effect of Sodium Hydroxide Molarity on Strength Development of Non-Cement Class C Fly Ash Geopolymer Mortar

    Science.gov (United States)

    Wardhono, A.

    2018-01-01

    The use of fly ash as cement replacement material can overcome the environmental issues, especially the global warming problem caused by the greenhouse effect. This is attributed to the CO2 gas produced during the cement manufacturing process, which 1 ton of cement is equivalent to 1 ton CO2. However, the major problem of fly ash is the requirement of activators to activate the polymer reactions. The most common activator used in non-cement or geopolymer material is the combination of sodium hydroxide (NaOH) and sodium silicate. This study aims to identify the effect of NaOH molarity as activator on strength development of non-cement class C fly ash geopolymer mortar. The molarity variations of NaOH were 6 Molar (M), 8M, 10M, 12M, 14M and 15M. The compressive strength test was performed at the age of 3, 7 and 28 days in accordance with ASTM standard, and the specimens were cured at room temperature. The results show that the highest compressive strength was achieved by geopolymer mortar with a molarity of 12M. It exhibits a higher strength to that normal mortar at 28 days. However, the use of NaOH molarity more than 12M tends to decrease the strength of non-cement geopolymer mortar specimens.

  13. Recycling ash into the first stage of cyclone pre-heater of cement kiln.

    Science.gov (United States)

    Zhan, Ming-Xiu; Fu, Jian-Ying; Havukainen, Jouni; Chen, Tong; Li, Xiao-Dong; Yan, Jian-Hua; Buekens, Alfons

    2016-10-01

    Fly ash collected from the bag filter could be recycled into the first stage of the cyclone pre-heater of the cement kiln, resulting in the possible enrichment of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). In this study, soxhlet fly ash (SFA) and raw meal (RM) were selected as the basis for the PCDD/F formation experiments. The levels of 2,3,7,8-PCDD/Fs formed on the SFA and RM were observed to be 2550pg/g (157pg I-TEQ/g) and 1142pg/g (55pg I-TEQ/g), respectively. While less 2,3,7,8-PCDD/Fs was detected when SFA was mixed with RM, suggesting that recycling cement kiln ash would not largely increase the concentration of PCDD/Fs in flue gas. Furthermore, the possible influencing factors on the PCDD/F formation were also investigated. The formation of 2,3,7,8-PCDD/Fs was up to 10,871pg/g (380pg I-TEQ/g) with the adding of CuCl2, which was much higher than the results of CuO and activated carbon. Most importantly, the homologue, congener and gas/particle distribution of PCDD/Fs indicated that de novo synthesis was the dominant PCDD/F formation pathway for SFA. Lastly, principal component analysis (PCA) was also conducted to identify the relationship between the compositions of reactant and the properties of PCDD/Fs produced. Copyright © 2016 Elsevier Ltd. All rights reserved.

  14. Characterization of sugar cane bagasse ash as supplementary material for Portland cement

    Directory of Open Access Journals (Sweden)

    Janneth Torres Agredo

    2014-01-01

    Full Text Available Sugar Cane Bagasse is a by-product of the sugar agroindustry; it is partly used as fuel. However, bagasse ash (SCBA is considered waste, which creates a disposal problem. Furthermore, if sugar cane bagasse is burned under controlled conditions, the SCBA can be potentially reused. This paper considers the technical viability of using SCBA as a partial replacement for cement. Two samples of SCBA from a Colombian sugar industry were characterized. The chemical composition of the samples shows high percentages of silica, 76.3% and 63.2%. The mineralogical and morphological characteristics of the waste were determined by X-ray diffraction patterns (XRD, thermal analysis (TG/DTA and scanning electron microscopy (SEM. The pozzolanic activity of SCBA was evaluated using the Frattini test and the strength activity index test (SAI. The ASTM C618 defines an SAI of at least 75% as a requirement for classifying material as a pozzolan. This condition was achieved in the experiments performed. The results indicate that SCBA produced in the manufacture of commercial cements can be recycled for use as pozzolanic material. This supplementary material can partially replace cement and therefore reduce CO2 emissions.

  15. Compressive strength, flexural strength and thermal conductivity of autoclaved concrete block made using bottom ash as cement replacement materials

    International Nuclear Information System (INIS)

    Wongkeo, Watcharapong; Thongsanitgarn, Pailyn; Pimraksa, Kedsarin; Chaipanich, Arnon

    2012-01-01

    Highlights: ► Autoclaved aerated concrete were produced using coal bottom ash as a cement replacement material. ► Coal bottom ash was found to enhance concrete strengths. ► Thermal conductivity of concrete was not significantly affected. ► X-ray diffraction and thermal analysis show tobermorite formation. -- Abstract: The bottom ash (BA) from Mae Moh power plant, Lampang, Thailand was used as Portland cement replacement to produce lightweight concrete (LWC) by autoclave aerated concrete method. Portland cement type 1, river sand, bottom ash, aluminium powder and calcium hydroxide (Ca(OH) 2 ) were used in this study. BA was used to replace Portland cement at 0%, 10%, 20% and 30% by weight and aluminium powder was added at 0.2% by weight in order to produce the aerated concrete. Compressive strength, flexural and thermal conductivity tests were then carried out after the concrete were autoclaved for 6 h and left in air for 7 days. The results show that the compressive strength, flexural strength and thermal conductivity increased with increased BA content due to tobermorite formation. However, approximately, 20% increase in both compressive (up to 11.61 MPa) and flexural strengths (up to 3.16 MPa) was found for mixes with 30% BA content in comparison to just around 6% increase in the thermal conductivity. Thermogravimetry analysis shows C–S–H formation and X-ray diffraction confirm tobermorite formation in bottom ash lightweight concrete. The use of BA as a cement replacement, therefore, can be seen to have the benefit in enhancing strength of the aerated concrete while achieving comparatively low thermal conductivity when compared to the results of the control Portland cement concrete.

  16. Optimization of fly ash and bottom ash substitution against paving block manufacture according to SNI 03-0691-1996

    Science.gov (United States)

    Karolina, R.; Syahrizal; Bahri, N.

    2018-02-01

    The waste of coal burning has a very negative impact on the environment if the waste is not managed as well as possible. The remaining waste of coal combustion consists of fly ash and bottom ash. FA and BA can be developed into substitution materials in the process of making paving blocks. The purpose of this study was to determine the quality of paving block in accordance with SK SNI 03-0691-1996 with optimization in the use of FA and BA. This study uses a 351 paving block sample size of 20x10x6 cm. Paving blocks are divided by 4 categories, namely normal paving block, paving block with FA substitution, BA substitution and combination of FA-BA with each variation 0%, 25%, 50%, 75% and 100%. Each variation amounted to 27 samples. Paving block quality measurement is done through 4 tests: absorption, compressive strength, sodium sulphate resistance and Los Angeles tests. The result of the test shows the absorption of normal paving block is 3,229%, paving block with 25% FA is 3,889%, paving block with 50% BA is 5,560% and paving block with 25% FA-BA combination is 5,794%. Compressive strength in normal paving block is 25,50 MPa, paving block with 25% FA is 25,28 MPa, paving block with 25% BA is equal to 27,61 MPa and paving block with 25% FA-BA is 26, 00 MPa. In testing of sodium sulfate resistance, almost all test specimens are eligible except for paving block with 50% FA and 75% FA. In the test of wear resistance, no specimen is eligible according to SK SNI 03-0691-1996. The comparison of the strength of the test specimen can be seen in substitution with 25% BA which reaches maximum strength.

  17. Leachability of Arsenic (As) Contaminated Landfill Soil Stabilised by Cement and Bagasse Ash

    Science.gov (United States)

    Azhar, A. T. S.; Azim, M. A. M.; Aziman, M.; Nabila, A. T. A.

    2016-11-01

    Contaminated soil with heavy metals, especially Arsenic (As) has become a major issue worldwide. As is reported to be a metal that affects human health and is related to have caused serious diseases that interrupts the nervous system, blood vessels and kidneys. However, proper treatment techniques such as Stabilization/Solidification (S/S) method can be employed and is capable of controlling these heavy metals from contaminating the soil strata and groundwater resources. This study is to investigate the leachability of Arsenic (As) in S/S method when bagasse ash (BA) is added to remedy contaminated Landfill soil. Cement is added at a proportion of 5%, 10%, 15% and 20% in sample weights without BA while in another sample; the cement replaces BA at a proportion of 2.5%, 5%, 7.5%. and 10%. All samples were allowed to harden and cured at room temperature for 7, 14 and 28 days. The effectiveness of the treatment was assessed by conducting Synthetic Precipitation Leaching Procedure (SPLP). Results indicate that pH and leachability are found to have major influence on metal release. The final pH after leaching tests showed improvements especially samples containing BA. In addition, the concentration of As in the SPLP test after the curing period of 28 days were detected to be below the leachability limit as regulated by WHO's Guidelines for Drinking-water Quality. As a whole, the results obtained from testing showed that sample containing 10% cement with 10% BA is the most effective and is the optimum mix since this proportion succeeded in minimising the leachability of As at total reduction by 100%, In conclusion, partial replacement of cement with BA in the binder system has been successful in reducing the leachability.

  18. Evaluation of sulfate resistance of cement mortars containing black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2009-03-01

    In this paper, black rice husk ashes (BRHAs), which are agrowastes from an electricity generating power plant and a rice mill, were ground and used as a partial cement replacement. The durability of mortars under sulfate attack including expansion and compressive strength loss were investigated. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 30%, and 50% by weight of binder. The water-to-binder ratios were 0.55 and 0.65. For the durability of mortar exposed to sulfate attack, 5% sodium sulfate (Na2SO4) and magnesium sulfate (MgSO4) solutions were used. As a result, when increasing the percentage replacement of BRHA, the expansion and compressive strength loss of mortar decreased. At the replacement levels of 30% and 50% of BRHA, the expansion of the mortars was less than those mixed with sulfate-resistant cement. However, the expansion of the mortars exposed to Na2SO4 was more than those exposed to MgSO4. Increasing the replacement level of BRHA tends to reduce the compressive strength loss of mortars exposed to Na2SO4 attack. In contrary, under MgSO4 attack, when increasing the replacement level of BRHA, the compressive strength loss increases from 0% to 50% in comparison to Portland cement mortar. Results show that ground BRHA can be applied as a pozzolanic material to concrete and also improve resistance to sodium sulfate attack, but it can impair resistance to magnesium sulfate attack.

  19. Influence of portland cement replacement in high calcium fly ash geopolymer paste

    Directory of Open Access Journals (Sweden)

    Tanakorn Phoo-ngernkham

    2014-03-01

    Full Text Available This article presents the influence of ordinary Portland cement (OPC replacement in high calcium fly ash (FA geopolymer paste. FA was used to replace OPC at the rate of 5, 10 and 15% by mass of binder. Sodium silicate (Na2SiO3 and 10 molar sodium hydroxide (NaOH solutions were used as the alkaline solution in the reaction. The Na2SiO3/NaOH ratio of 2.0 and the liquid/binder (L/B ratio of 0.60 were used in all mixtures. The results of increase OPC replacement, the setting time and compressive strain capacity decreased while the compressive strength and modulus of elasticity increased. The compressive strength and modulus of elasticity at 28 days of geopolymer pastes with 15% OPC replacement were 36.7 MPa and 13,300 MPa, respectively.

  20. Hydraulic activity of belite cement from class C coal fly ash. Effect of curing and admixtures

    Directory of Open Access Journals (Sweden)

    Guerrero, A.

    2006-09-01

    Full Text Available The effect of curing method and a water-reducing additive on the hydraulic activity of high lime content (ASTM type C fly ash belite cement (FABC-2-W is reported. A class C fly ash was subjected to hydrothermal treatment and subsequent calcination to synthesize FABC. Hydraulic activity was evaluated in the cement paste over 180 days from the physically bound water content as determined by thermogravimetric analysis and the degree of hydration, in turn found with X-ray diffraction (XRD analysis. Mechanical strength, porosity and pore size distribution were also studied in equivalent mortar samples.En este trabajo se discute la influencia del tipo de curado y de un aditivo reductor de la demanda de agua en la actividad hidráulica de un cemento belítico de cenizas volantes de alto contenido en cal denominado (CBCV-2-A. Este cemento ha sido sintetizado por una ruta húmeda hidrotermal con posterior calcinación, empleando ceniza volante de alto contenido en cal (ASTM tipo C como materia prima. La actividad hidráulica se ha estudiado en la pasta de cemento, durante un periodo de 180 días, por medio del contenido de agua combinada, determinada por análisis termogravimétrico, y el grado de hidratación por difracción de rayos X (DRX. La resistencia mecánica y la porosidad total y distribución de tamaño de poro se han estudiado en probetas equivalentes de mortero

  1. Solidification of Simulated Radioactive Incineration Ash by Alkali-activated Slag Composite Cement

    International Nuclear Information System (INIS)

    Li changcheng; Cui Qi; Zhao Yanhong; Pan Sheqi

    2010-01-01

    Simulated radioactive incineration ash (SRIA) was solidified by alkali-activated slag composite cement (AASCC) modified by metakaolin, zeolite, and polymer emulsion powder. The results show that the performance of solidified waste form containing 40% SRIA meets the requirements of GB 14569.1-93. The lowest leaching rate of Cs + on 42nd days reaches 1.32 x 10 -4 cm/d (GB 7023-86,25 degree C), cumulative leach percentage is only 0.041 cm. Also, the lowest 28 days compressive strength of solidified waste form is 45.6 MPa, and later strength growth is still high. The fast setting characteristic of AASCC overcomes effectively the disadvantageous influence caused by some components in SRIA on hydration of cement. The compressive strength of solidified waste is enhanced remarkably, and the ability of immobilizing radionuclide ions is also improved. This is mainly due to synergistic effect between metakaolin and zeolite. Polymer modification also improves the performance of solidified waste form significantly. The three-dimensional polymer network structure formed by emulsion powder in solidified waste form enhances its toughness and impact resistance, and the durability is improved by reducing interconnected pores and optimizing pore structure. However,it also results in reduction in compressive strength. Thus, it is concluded that the suitable dosage percentage is 5%. (authors)

  2. Rice husk ash (RHA) as a partial cement replacement in modifying peat soil properties

    Science.gov (United States)

    Daud, Nik Norsyahariati Nik; Daud, Mohd Nazrin Mohd; Muhammed, Abubakar Sadiq

    2018-02-01

    This paper describes the effect of rice husk ash (RHA) and ordinary Portland cement (OPC) as a potential binder for modifying the properties of peat soil. The amounts RHA and OPC added to the peat soil sample, as percentage of the dry soil mass were in the range of 10-15% and 15%, respectively. Observations were made for the changes in the properties of the soil such as maximum dry density (MDD), optimum moisture content (OMC) and shear strength. Scanning Electron Micrograph-Energy Dispersive X-Ray (SEM-EDX) test were also conducted to observe the microstructure of treated and untreated peat soil. The results show that the modified soil of MDD and OMC values are increased due to the increment amount of binder material. Shear strength values of modified peat showing a good result by assuming that it is relative to the formation of major reaction products such as calcium silicate hydrate (C-S-H). The presence of C-S-H formation is indicated by the results produced from microstructural analysis of peat before and after modification process. This depicts the potential usage of RHA as a partial cement replacement in peat soil which is also improving its engineering properties.

  3. Palm Oil Fuel Ash (POFA) and Eggshell Powder (ESP) as Partial Replacement for Cement in Concrete

    Science.gov (United States)

    Ezdiani Mohamad, Mazizah; Mahmood, Ali A.; Min, Alicia Yik Yee; Nur Nadhira A., R.

    2018-03-01

    This study is an attempt to partially replace Ordinary Portland cement (OPC) in concrete with palm oil fuel ash (POFA) and eggshell powder (ESP). The mix proportions of POFA and ESP were varied at 10% of cement replacement and compared with OPC concrete as control specimen. The fineness of POFA is characterized by passing through 300 μm sieve and ESP by passing through 75 μm sieve. Compressive strength testing was conducted on concrete specimens to determine the optimum mix proportion of POFA and ESP. Generally the compressive strength of OPC concrete is higher compared to POFA-ESP concrete. Based on the results of POFA-ESP concrete overall, it shows that the optimum mix proportion of concrete is 6%POFA:4% ESP achieved compressive strength of 38.60 N/mm2 at 28 days. The compressive strength of OPC concrete for the same period was 42.37 N/mm2. Higher water demand in concrete is needed due to low fineness of POFA that contributing to low compressive strength of POFA-ESP concrete. However, the compressive strength and workability of the POFA-ESP concrete were within the ranges typically encountered in regular concrete mixtures indicating the viability of this replacement procedure for structural and non-structural applications.

  4. Resistance of class C fly ash belite cement to simulated sodium sulphate radioactive liquid waste attack

    International Nuclear Information System (INIS)

    Guerrero, A.; Goni, S.; Allegro, V.R.

    2009-01-01

    The resistance of class C fly ash belite cement (FABC-2-W) to concentrated sodium sulphate salts associated with low level wastes (LLW) and medium level wastes (MLW) is discussed. This study was carried out according to the Koch and Steinegger methodology by testing the flexural strength of mortars immersed in simulated radioactive liquid waste rich in sulphate (48 000 ppm) and demineralised water (used as a reference), at 20 deg. C and 40 deg. C over a period of 180 days. The reaction mechanisms of sulphate ion with the mortar was carried out through a microstructure study, which included the use of Scanning electron microscopy (SEM), porosity and pore-size distribution and X-ray diffraction (XRD). The results showed that the FABC mortar was stable against simulated sulphate radioactive liquid waste (SSRLW) attack at the two chosen temperatures. The enhancement of mechanical properties was a result of the formation of non-expansive ettringite inside the pores and an alkaline activation of the hydraulic activity of cement promoted by the ingress of sulphate. Accordingly, the microstructure was strongly refined

  5. Properties of high calcium fly ash geopolymer pastes with Portland cement as an additive

    Science.gov (United States)

    Phoo-ngernkham, Tanakorn; Chindaprasirt, Prinya; Sata, Vanchai; Pangdaeng, Saengsuree; Sinsiri, Theerawat

    2013-02-01

    The effect of Portland cement (OPC) addition on the properties of high calcium fly ash geopolymer pastes was investigated in the paper. OPC partially replaced fly ash (FA) at the dosages of 0, 5%, 10%, and 15% by mass of binder. Sodium silicate (Na2SiO3) and sodium hydroxide (NaOH) solutions were used as the liquid portion in the mixture: NaOH 10 mol/L, Na2SiO3/NaOH with a mass ratio of 2.0, and alkaline liquid/binder (L/B) with a mass ratio of 0.6. The curing at 60°C for 24 h was used to accelerate the geopolymerization. The setting time of all fresh pastes, porosity, and compressive strength of the pastes at the stages of 1, 7, 28, and 90 d were tested. The elastic modulus and strain capacity of the pastes at the stage of 7 d were determined. It is revealed that the use of OPC as an additive to replace part of FA results in the decreases in the setting time, porosity, and strain capacity of the paste specimens, while the compressive strength and elastic modulus seem to increase.

  6. Mechanical Behavior of Concrete Modified by Replacement of Cement by Rice Husk Ash

    Directory of Open Access Journals (Sweden)

    M.M. Saravanan

    Full Text Available ABSTRACT Construction industry is in need of lump sum quantities of materials which has increased both their demand and price. The use of large quantities of cement leads to increasing CO2 emission and as a consequence, the greenhouse effect. Consumption of wastes and byproducts from various sources in the manufacture of concrete has gained a great deal of importance in present days. Various researches are currently being conducted concerning the use of such products in concrete. RHA is a carbon neutral green product. Lots of ways are being thought of for disposing them by making commercial use of this. Rice husk ash is a good super-pozzolan which can be used to make special concrete mixes. The rice husk ash has been taken for this present study due to its easy availability and effective pozzolonic properties that are expected to improve the mechanical strength properties of concrete. Concrete specimens were made for evaluation of Compressive, Split Tensile, Flexural strength and Stress-Strain Behavior of concrete. The tests were conducted at the age of 7 and 28 days. Generally all mixes containing RHA achieved better properties than the conventional mix without RHA. By the experimental investigation the recommendation is given for using optimum percentage of RHA in concrete.

  7. Engineering properties of cement mortar with pond ash in South Korea as construction materials: from waste to concrete

    Science.gov (United States)

    Jung, Sang Hwa; Kwon, Seung-Jun

    2013-09-01

    Among the wastes from coal combustion product, only fly ash is widely used for mineral mixture in concrete for its various advantages. However the other wastes including bottom ash, so called PA (pond ash) are limitedly reused for reclamation. In this paper, the engineering properties of domestic pond ash which has been used for reclamation are experimentally studied. For this, two reclamation sites (DH and TA) in South Korea are selected, and two domestic PAs are obtained. Cement mortar with two different w/c (water to cement) ratios and 3 different replacement ratios (0%, 30%, and 60%) of sand are prepared for the tests. For workability and physical properties of PA cement mortar, several tests like flow, setting time, and compressive strength are evaluated. Several durability tests including porosity measuring, freezing and thawing, chloride migration, and accelerated carbonation are also performed. Through the tests, PA (especially from DH area) in surface saturated condition is evaluated to have internal curing action which leads to reasonable strength development and durability performances. The results show a potential applicability of PA to concrete aggregate, which can reduce consuming natural resources and lead to active reutilization of coal product waste.

  8. Utilization of municipal solid waste incineration (MSWI) fly ash in blended cement Part 1: Processing and characterization of MSWI fly ash.

    Science.gov (United States)

    Aubert, J E; Husson, B; Sarramone, N

    2006-08-25

    This paper is the first of a series of two articles dealing with the processes applied to MSWI fly ash with a view to reusing it safely in cement-based materials. Part 1 presents two stabilization processes and Part 2 deals with the use of the two treated fly ashes (TFA) in mortars. Two types of binder were used: an Ordinary Portland Cement (OPC) containing more than 95% clinker (CEM I 52.5R) and a binary blend cement composed of 70% ground granulated blast furnace slag and 30% clinker (CEM III-B 42.5N). In this first part, two stabilization processes are presented: the conventional process, called "A", based on the washing, phosphation and calcination of the ash, and a modified process, called "B", intended to eliminate metallic aluminum and sulfate contained in the ash. The physical, chemical and mineralogical characteristics of the two TFA were comparable. The main differences observed were those expected, i.e. TFA-B was free of metallic aluminum and sulfate. The mineralogical characterization of the two TFAs highlighted the presence of large amounts of a calcium aluminosilicate phase taking two forms, a crystalline form (gehlenite) and an amorphous form. Hydration studies on pastes containing mixed TFA and calcium hydroxide showed that this phase reacted with calcium hydroxide to form calcium aluminate hydrates. This formation of hydrates was accompanied by a hardening of the pastes. These results are very encouraging for the reuse of such TFA in cement-based materials because they can be considered as pozzolanic additions and could advantageously replace a part of the cement in cement-based materials. Finally, leaching tests were carried out to evaluate the environmental impact of the two TFAs. The elements which were less efficiently stabilized by process A were zinc, cadmium and antimony but, when the results of the leaching tests were compared with the thresholds of the European landfill directive, TFA-A could nevertheless be accepted at landfills for non

  9. Strength development in concrete with wood ash blended cement and use of soft computing models to predict strength parameters

    Directory of Open Access Journals (Sweden)

    S. Chowdhury

    2015-11-01

    Full Text Available In this study, Wood Ash (WA prepared from the uncontrolled burning of the saw dust is evaluated for its suitability as partial cement replacement in conventional concrete. The saw dust has been acquired from a wood polishing unit. The physical, chemical and mineralogical characteristics of WA is presented and analyzed. The strength parameters (compressive strength, split tensile strength and flexural strength of concrete with blended WA cement are evaluated and studied. Two different water-to-binder ratio (0.4 and 0.45 and five different replacement percentages of WA (5%, 10%, 15%, 18% and 20% including control specimens for both water-to-cement ratio is considered. Results of compressive strength, split tensile strength and flexural strength showed that the strength properties of concrete mixture decreased marginally with increase in wood ash contents, but strength increased with later age. The XRD test results and chemical analysis of WA showed that it contains amorphous silica and thus can be used as cement replacing material. Through the analysis of results obtained in this study, it was concluded that WA could be blended with cement without adversely affecting the strength properties of concrete. Also using a new statistical theory of the Support Vector Machine (SVM, strength parameters were predicted by developing a suitable model and as a result, the application of soft computing in structural engineering has been successfully presented in this research paper.

  10. Preparation of fluoride substituted apatite cements as the building blocks for tooth enamel restoration

    Science.gov (United States)

    Wei, Jie; Wang, Jiecheng; Liu, Xiaochen; Ma, Jian; Liu, Changsheng; Fang, Jing; Wei, Shicheng

    2011-06-01

    Fluoride substituted apatite cement (fs-AC) was synthesized by using the cement powders of tetracalcium phosphate (TTCP) and sodium fluoride (NaF), and the cement powders were mixed with diluted phosphoric acid (H 3PO 4) as cement liquid to form fs-AC paste. The fs-AC paste could be directly filled into the carious cavities to repair damaged dental enamel. The results indicated that the fs-AC paste was changed into fluorapatite crystals with the atom molar ratio for calcium to phosphorus of 1.66 and the F ion amount of 3 wt% after self-hardening for 2 days. The solubility of fs-AC in Tris-HCl solution (pH 6) was slightly lower than hydroxyapatite cement (HAC) that was similar to the apatite in enamel, indicating the fs-AC was much insensitive to the weakly acidic solution than the apatite in enamel. The fs-AC was tightly combined with the enamel surface because of the chemical reaction between the fs-AC and the apatite in enamel after the caries cavities was filled with fs-AC. The extracts of fs-AC caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. The fs-AC had potential prospect for the reconstitution of carious lesion of dental enamel.

  11. Preparation of fluoride substituted apatite cements as the building blocks for tooth enamel restoration

    International Nuclear Information System (INIS)

    Wei Jie; Wang Jiecheng; Liu Xiaochen; Ma Jian; Liu Changsheng; Fang Jing; Wei Shicheng

    2011-01-01

    Fluoride substituted apatite cement (fs-AC) was synthesized by using the cement powders of tetracalcium phosphate (TTCP) and sodium fluoride (NaF), and the cement powders were mixed with diluted phosphoric acid (H 3 PO 4 ) as cement liquid to form fs-AC paste. The fs-AC paste could be directly filled into the carious cavities to repair damaged dental enamel. The results indicated that the fs-AC paste was changed into fluorapatite crystals with the atom molar ratio for calcium to phosphorus of 1.66 and the F ion amount of 3 wt% after self-hardening for 2 days. The solubility of fs-AC in Tris-HCl solution (pH 6) was slightly lower than hydroxyapatite cement (HAC) that was similar to the apatite in enamel, indicating the fs-AC was much insensitive to the weakly acidic solution than the apatite in enamel. The fs-AC was tightly combined with the enamel surface because of the chemical reaction between the fs-AC and the apatite in enamel after the caries cavities was filled with fs-AC. The extracts of fs-AC caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. The fs-AC had potential prospect for the reconstitution of carious lesion of dental enamel.

  12. Preparation of fluoride substituted apatite cements as the building blocks for tooth enamel restoration

    Energy Technology Data Exchange (ETDEWEB)

    Wei Jie [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Wang Jiecheng; Liu Xiaochen [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Ma Jian [Hospital of Stomatology, Tongji University, Shanghai 200072 (China); Liu Changsheng [Key Laboratory for Ultrafine Materials of Ministry of Education, East China University of Science and Technology, Shanghai 200237 (China); Fang Jing, E-mail: biomater2006@yahoo.com.cn [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China); Wei Shicheng, E-mail: nic7505@263.net [Center for Biomedical Materials and Tissue Engineering, Academy for Advanced Inter-disciplinary Studies, Peking University, Beijing 100871 (China) and School and Hospital of Stomatology, Peking University, Beijing 100081 (China)

    2011-06-15

    Fluoride substituted apatite cement (fs-AC) was synthesized by using the cement powders of tetracalcium phosphate (TTCP) and sodium fluoride (NaF), and the cement powders were mixed with diluted phosphoric acid (H{sub 3}PO{sub 4}) as cement liquid to form fs-AC paste. The fs-AC paste could be directly filled into the carious cavities to repair damaged dental enamel. The results indicated that the fs-AC paste was changed into fluorapatite crystals with the atom molar ratio for calcium to phosphorus of 1.66 and the F ion amount of 3 wt% after self-hardening for 2 days. The solubility of fs-AC in Tris-HCl solution (pH 6) was slightly lower than hydroxyapatite cement (HAC) that was similar to the apatite in enamel, indicating the fs-AC was much insensitive to the weakly acidic solution than the apatite in enamel. The fs-AC was tightly combined with the enamel surface because of the chemical reaction between the fs-AC and the apatite in enamel after the caries cavities was filled with fs-AC. The extracts of fs-AC caused no cytotoxicity on L929 cells, which satisfied the relevant criterion on dental biomaterials, revealing good cytocompatibility. The fs-AC had potential prospect for the reconstitution of carious lesion of dental enamel.

  13. Properties of Cement Mortar by Use of Hot-Melt Polyamides as Substitute for Fine Aggregate

    Directory of Open Access Journals (Sweden)

    Xiongzhou Yuan

    2015-06-01

    Full Text Available This paper presents an experimental study on use of hot-melt polyamide (HMP to prepare mortar specimens with improved crack healing and engineering properties. The role of HMP in the crack repairing of cement mortar subjected to several rounds of heat treatment was investigated. Compatibility between HMP and hydraulic cement was investigated through X-ray diffraction (XRD and Fourier transform infrared spectra (FTIR technology. Mortar specimens were prepared using standard cement mortar mixes with HMP at 1%, 3% and 5% (by volume for fine aggregate substitute. After curing for 28 days, HMP specimens were subjected to heating at temperature of 160 °C for one, two, and three days and then natural cooling down to ambient temperature. Mechanical and durability properties of the heated HMP mortars were evaluated and compared with those of the corresponding mortars without heating. The microscopic observation of the interfacial transition zone (ITZ of HMP mortar was conducted through environmental scanning electron microscopy (ESEM. Results reveal that incorporation of HMP improves the workability of the HMP/cement binder while leading to decrease in compressive strength and durability. The heated HMP mortars after exposure to heating for one, two, and three days exhibit no obvious change in compressive strength while presenting notable increase in flexural strength and durability compared with the corresponding mortars without heating. The XRD, FTIR and ESEM analyses indicate that no obvious chemical reaction occurs between HMP and hydraulic cement, and thus the self-repairing for interfacial micro-crack in HMP/cement composite system is ascribed to the physical adhesion of HMP to cement matrix rather than the chemical bonding between them.

  14. Combined effect of sodium sulphate and superplasticizer on the hydration of fly ash blended Portland® cement

    Directory of Open Access Journals (Sweden)

    Mukesh Kumar

    2010-06-01

    Full Text Available Combined effect of polycarboxylate type superplasticizer and sodium sulphate on the hydration of fly ash blended Portland® cement has been studied by using different techniques. Water consistency, setting times, non-evaporable water contents, water percolation, air contents, compressive strengths and expansion in corrosive atmosphere were determined. Hydration products were examined with the help of DTA and X-ray diffraction techniques. It is found that the superplasticizer reduces the pore size and its adsorption on cement surfaces is decreased in the presence of sodium sulphate. Mechanism of hydration is discussed.

  15. Electromagnetic interference shielding with Portland cement paste containing carbon materials and processed fly ash

    Directory of Open Access Journals (Sweden)

    Zornoza, E.

    2010-12-01

    Full Text Available The study described in this article explored the effect of adding different types of carbon materials (graphite powder and three types of carbon fibre, fly ash (with 5.6%, 15.9% and 24.3% Fe2O3, and a mix of both on electromagnetic interference (EMI shielding in Portland cement pastes. The parameters studied included the type and aspect ratio of the carbonic material, composite material thickness, the frequency of the incident electromagnetic radiation and the percentage of the magnetic fraction in the fly ash. The findings showed that the polyacrylonitrile-based carbon fibres, which had the highest aspect ratio, provided more effective shielding than any of the other carbon materials studied. Shielding was more effective in thicker specimens and at higher radiation frequencies. Raising the magnetic fraction of the fly ash, in turn, also enhanced paste shielding performance. Finally, adding both carbon fibre and fly ash to the paste resulted in the most effective EMI shielding as a result of the synergies generated.

    En el presente trabajo se investiga la influencia de la adición de diferentes tipos de materiales carbonosos (polvo de grafito y 3 tipos de fibra de carbono, de una ceniza volante con diferentes contenidos de fase magnética (5,6%, 15,9% y 24,3% de Fe2O3 y de una mezcla de ambos, sobre la capacidad de apantallar interferencias electromagnéticas de pastas de cemento Pórtland. Entre los parámetros estudiados se encuentra: el tipo de material carbonoso, la relación de aspecto del material carbonoso, el espesor del material compuesto, la frecuencia de la radiación electromagnética incidente y el porcentaje de fracción magnética en la ceniza volante. Los resultados obtenidos indican que entre los materiales carbonosos estudiados son las fibras de carbono basadas en poliacrilonitrilo con una mayor relación de aspecto las que dan mejores resultados de apantallamiento. Al aumentar

  16. Effect of incorporation of fly ash and granulated blast furnace in the electrochemical behavior of concretes of commercial cement

    International Nuclear Information System (INIS)

    Gutierrez-Junco, O. J.; Pineda-Triana, Y.; Vera-Lopez, E.

    2015-01-01

    This paper presents the findings of the research properties evaluation pastes of commercial cement (CPC), mixed with fly ash (FA) and granulated blast furnace slag (GBFS). Initially, the sample of 30 combinations were evaluated in terms of compressive strength to establish the optimal proportions from raw material. After that, four optimized blends were characterized during the setting and hardening process. Electrochemical tests were performed on concrete cylinders samples prepared with cementitious materials and a structural steel rod placed in the center of the specimen. With the objective to evaluate the performance before corrosion, thermodynamic and kinetic aspects were taken into consideration. The findings showed that commercial cements blended with fly ash and blast furnace slag as the ones used in this research presents a decreased behavior in mechanical and corrosion strength regarding to CPC. (Author)

  17. Ternary Blends of High Aluminate Cement, Fly ash and Blast-furnace slag for Sewerage Lining Mortar

    Science.gov (United States)

    Chao, L. C.; Kuo, C. P.

    2018-01-01

    High aluminate cement (HAC), fly ash (FA) and blast-furnace slag (BFS) have been treated sustainable materials for the use of cement products for wastewater infrastructure due to their capabilities of corrosion resistance. The purpose of this study is to optimize a ternary blend of above mentioned materials for a special type of mortar for sewerage lining. By the using of Taguchi method, four control parameters including water/cementitious material ratio, mix water content, fly ash content and blast-furnace slag content were considered in nine trial mix designs in this study. By evaluating target properties including (1) maximization of compressive strength, (2) maximization of electricity resistance and (3) minimization of water absorption rate, the best possible levels for each control parameter were determined and the optimal mix proportions were verified. Through the implementation of the study, a practical and completed idea for designing corrosion resistive mortar comprising HAC, FA and BSF is provided.

  18. Improved cement mortars by addition of carbonated fly ash from solid waste incinerators

    Directory of Open Access Journals (Sweden)

    López-Zaldívar, O.

    2015-09-01

    Full Text Available This article presents the results of a research developing high performance cement mortars with the addition of municipal solid waste incineration fly ash (MSWIFA stabilized as insoluble carbonates. The encapsulation of hazardous wastes in mortar matrixes has also been achieved. The ashes present high concentrations of chlorides, Zn and Pb. A stabilization process with NaHCO3 has been developed reducing 99% the content of chlorides. Developed mortars replace 10% per weight of the aggregates by treated MSWIFA. Physical/mechanical properties of these mortars have been studied. Presence of Zn, Pb, Cu and Cd has been also analyzed confirming that leaching of these heavy metal ions is mitigated. Conclusions prove better behavior of CAC and CSA mortars than those of CEM-I and CEM-II cement. Results are remarkable for the CAC mortars, improving reference strengths in more than 25%, which make them a fast-curing product suitable for the repair of structures or industrial pavements.Este artículo presenta los resultados del desarrollo de morteros mejorados con la incorporación de cenizas volantes de residuos sólidos urbanos inertizadas en forma de carbonatos. Además se consigue la encapsulación de un residuo peligroso. Las cenizas presentan una alta concentración de cloruros, Zn y Pb. Se ha desarrollado un proceso de estabilización con NaHCO3 reduciendo en un 99% el contenido de cloruros. Los morteros reemplazan un 10% en peso del árido por cenizas tratadas. Se han analizado sus propiedades físico/mecánicas y la presencia de Zn, Pb, Cu y Cd. Se demuestra un mejor comportamiento de los morteros de CAC y CSA que los de CEM-I y CEM-II y se mitiga el lixiviado de metales pesados. Los resultados son significativos en los morteros CAC al mejorar las resistencias de los de referencia en un 25%. Los morteros desarrollados son de curado rápido adecuados para la reparación de estructuras o soleras industriales.

  19. The incorporation of wood waste ash as a partial cement replacement material for making structural grade concrete: An overview

    Directory of Open Access Journals (Sweden)

    Swaptik Chowdhury

    2015-06-01

    Full Text Available With increasing industrialization, the industrial byproducts (wastes are being accumulated to a large extent, leading to environmental and economic concerns related to their disposal (land filling. Wood ash is the residue produced from the incineration of wood and its products (chips, saw dust, bark for power generation or other uses. Cement is an energy extensive industrial commodity and leads to the emission of a vast amount of greenhouse gases, forcing researchers to look for an alternative, such as a sustainable building practice. This paper presents an overview of the work and studies done on the incorporation of wood ash as partial replacement of cement in concrete from the year 1991 to 2012. The aspects of wood ash such as its physical, chemical, mineralogical and elemental characteristics as well as the influence of wood ash on properties such as workability, water absorption, compressive strength, flexural rigidity test, split tensile test, bulk density, chloride permeability, freeze thaw and acid resistance of concrete have been discussed in detail.

  20. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements

    DEFF Research Database (Denmark)

    Cai, Zuansi; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

    2003-01-01

    Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filter in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration...... weeks. Cylinders (diameter 100 mm, length 150 mm) were drilled from these cubes for tank leaching experiments. Duplicate specimens were subject to compression strength testing and to tank leaching experiments. The compressive strength of the CTB fulfilled the Danish requirements for CTB, i.e. strength...... more than 5 MPa after 7 days. The tank leaching tests revealed that leaching of heavy metals was not significantly affected by the use of chemically stabilised flue gas ashes from waste incineration. Assuming that diffusion controls the leaching process it was calculated that less than 1% of the metals...

  1. Re-use of stabilised flue gas ashes from solid waste incineration in cement-treated base layers for pavements

    DEFF Research Database (Denmark)

    Cai, Zuansi; Jensen, Dorthe Lærke; Christensen, Thomas Højlund

    2003-01-01

    Fly ash from coal-burning power plants has been used extensively as a pozzolan and fine filter in concrete for many years. Laboratory experiments were performed investigating the effect of substituting the coal-based fly ash with chemically stabilised flue gas ashes (FGA) from waste incineration...... would teach during a 100-year period from a 0.5 m thick concrete stab exposed to water on one side. Leaching of the common ions Ca, Cl, Na and SO4 was increased 3-20 times from the specimens with chemically stabilised flue gas ashes from waste incineration. However, the quantities leached were still...... modest. These experiments suggest that FGA from waste incineration after Ferrox-treatment could be re-used in CTB without compromising the strength and teaching from the base layer....

  2. Inorganic contaminants attenuation in acid mine drainage by fly ash and fly ash-ordinary Portland cement (OPC) blends : column experiments

    International Nuclear Information System (INIS)

    Gitari, W.M.; Petrik, L.F.; Etchebers, O.; Key, D.L.; Okujeni, C.

    2010-01-01

    The infiltration of acid mine drainage (AMD) material into mine voids is one of the environmental impacts of underground coal mining. In this study, the mitigation of AMD in a mine void was simulated in laboratory conditions. Various mixtures of fly ash, solid residues, and Portland cement were added to packed columns over a 6-month period. The fly ash additions generated near-neutral to alkaline pH levels, which in turn induced precipitation, co-precipitation, and adsorption contaminant attenuation mechanisms. A modelling study demonstrated that the precipitation of ferrihydrite, Al-hydroxides, Al-oxyhydroxysulphates, gypsum, ettringite, manganite, and rhodochrosite lowered contaminant levels. Results of the study indicated that the pH regime and acidity level of the AMD strongly influenced both the leaching of the toxic trace elements as well as the attenuation of the AMD. 3 refs., 2 figs.

  3. Mechanism of alkalinity lowering and chemical equilibrium model of high fly ash silica fume cement

    International Nuclear Information System (INIS)

    Hoshino, Seiichi; Honda, Akira; Negishi, Kumi

    2014-01-01

    The mechanism of alkalinity lowering of a High Fly ash Silica fume Cement (HFSC) under liquid/solid ratio conditions where the pH is largely controlled by the soluble alkali components (Region I) has been studied. This mechanism was incorporated in the chemical equilibrium model of HFSC. As a result, it is suggested that the dissolution and precipitation behavior of SO 4 2- partially contributes to alkalinity lowering of HFSC in Region I. A chemical equilibrium model of HFSC incorporating alkali (Na, K) adsorption, which was presumed as another contributing factor of the alkalinity lowering effect, was also developed, and an HFSC immersion experiment was analyzed using the model. The results of the developed model showed good agreement with the experiment results. From the above results, it was concluded that the alkalinity lowering of HFSC in Region I was attributed to both the dissolution and precipitation behavior of SO 4 2- and alkali adsorption, in addition to the absence of Ca(OH) 2 . A chemical equilibrium model of HFSC incorporating alkali and SO 4 2- adsorption was also proposed. (author)

  4. Characterisation of magnesium potassium phosphate cements blended with fly ash and ground granulated blast furnace slag

    International Nuclear Information System (INIS)

    Gardner, Laura J.; Bernal, Susan A.; Walling, Samuel A.; Corkhill, Claire L.; Provis, John L.; Hyatt, Neil C.

    2015-01-01

    Magnesium potassium phosphate cements (MKPCs), blended with 50 wt.% fly ash (FA) or ground granulated blast furnace slag (GBFS) to reduce heat evolution, water demand and cost, were assessed using compressive strength, X-ray diffraction (XRD), scanning electron microscopy (SEM) and nuclear magnetic resonance (NMR) spectroscopy on 25 Mg, 27 Al, 29 Si, 31 P and 39 K nuclei. We present the first definitive evidence that dissolution of the glassy aluminosilicate phases of both FA and GBFS occurred under the pH conditions of MKPC. In addition to the main binder phase, struvite-K, an amorphous orthophosphate phase was detected in FA/MKPC and GBFS/MKPC systems. It was postulated that an aluminium phosphate phase was formed, however, no significant Al–O–P interactions were identified. High-field NMR analysis of the GBFS/MKPC system indicated the potential formation of a potassium-aluminosilicate phase. This study demonstrates the need for further research on these binders, as both FA and GBFS are generally regarded as inert fillers within MKPC

  5. THE IMPACT OF DISSOLVED SALTS ON PASTES CONTAINING FLY ASH, CEMENT AND SLAG

    Energy Technology Data Exchange (ETDEWEB)

    Harbour, J.; Edwards, T.; Williams, V.

    2009-09-21

    The degree of hydration of a mixture of cementitious materials (Class F fly ash, blast furnace slag and portland cement) in highly concentrated alkaline salt solutions is enhanced by the addition of aluminate to the salt solution. This increase in the degree of hydration, as monitored with isothermal calorimetry, leads to higher values of dynamic Young's modulus and compressive strength and lower values of total porosity. This enhancement in performance properties of these cementitious waste forms by increased hydration is beneficial to the retention of the radionuclides that are also present in the salt solution. The aluminate ions in the solution act first to retard the set time of the mix but then enhance the hydration reactions following the induction period. In fact, the aluminate ions increase the degree of hydration by {approx}35% over the degree of hydration for the same mix with a lower aluminate concentration. An increase in the blast furnace slag concentration and a decrease in the water to cementitious materials ratio produced mixes with higher values of Young's modulus and lower values of total porosity. Therefore, these operational factors can be fine tuned to enhance performance properties of cementitious waste form. Empirical models for Young modulus, heat of hydration and total porosity were developed to predict the values of these properties. These linear models used only statistically significant compositional and operational factors and provided insight into those factors that control these properties.

  6. Ultrasonic characterization of GRC with high percentage of fly ash substitution.

    Science.gov (United States)

    Genovés, V; Gosálbez, J; Miralles, R; Bonilla, M; Payá, J

    2015-07-01

    New applications of non-destructive techniques (NDT) with ultrasonic tests (attenuation and velocity by means of ultrasonic frequency sweeps) have been developed for the characterization of fibre-reinforced cementitious composites. According to new lines of research on glass-fibre reinforced cement (GRC) matrix modification, two similar GRC composites with high percentages of fly ash and different water/binder ratios will be studied. Conventional techniques have been used to confirm their low Ca(OH)(2) content (thermogravimetry), fibre integrity (Scanning Electron Microscopy), low porosity (Mercury Intrusion Porosimetry) and good mechanical properties (compression and four points bending test). Ultrasound frequency sweeps allowed the estimation of the attenuation and pulse velocity as functions of frequency. This ultrasonic characterization was correlated successfully with conventional techniques. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. Application of the electrical characterization to the study of the hydrated phases of the cement with coal bottom ash; Aplicacion de la caracterizacion electrica al estudio de las fases hidratadas de cemento con adicion de escorias de centrales termicas

    Energy Technology Data Exchange (ETDEWEB)

    Menendez, E.; Frutos, J. de; Alvaro, A. M.

    2014-02-01

    The present paper investigates the influence of using Bottom and Fly Ash as partial replacement of cement in the hydration process. Through measurements of electrical impedance spectroscopy (EIS) and X -ray diffraction (XRD), we analyze from the early stages to the hydration process to the end. Values of EIS, XRD and its relation, are used to determine transformation of hydrated phases, and for each of the substitutions, is indicated as modified the hydrated phase as a function of time and compared it with the reference material. It also proves the relevance of using EIS measures in real time, and as non destructive testing to characterize the hydration process of these materials. (Author)

  8. Brushite-Forming Mg-, Zn- and Sr-Substituted Bone Cements for Clinical Applications

    Directory of Open Access Journals (Sweden)

    José M.F. Ferreira

    2010-01-01

    Full Text Available Calcium phosphate cements have been in clinical use for the last 10 years. Their most salient features include good biocompatibility, excellent bioactivity, self-setting characteristics, low setting temperature, adequate stiffness, and easy shaping to accomodate any complicated geometry. They are commonly used in filling bone defects and trauma surgeries as mouldable paste-like bone substitute materials. Substitution of trace elements, such as Mg, Sr and Zn ions, into the structure of calcium phosphates is the subject of widespread investigation nowadays, because of their impending role in the biological process. Subtle differences in composition and structure of these materials may have a profound effect on their in vivo behaviour. Therefore, the main goal of this paper is to provide a simple, but comprehensive overview of the present achievements relating to brushite-forming cements doped with Mg, Zn and Sr, and to identify new developments and trends. In particular, the influence of ionic substitution on the chemical, physical and biological properties of these materials is discussed.

  9. UTILIZATION OF TORAY FLY ASH AS FILLER SUBSTITUTION IN THE HOT ROLLED SHEET-WEARING COURSE (HRS-WC MIXTURE

    Directory of Open Access Journals (Sweden)

    F. Candra

    2012-02-01

    Full Text Available In road construction materials, the utilization of fly ash as additive materials is limited and also small in quantity, while the disposal of fly ash is quite high. An abundance of fly ash can be found at PT Toray Company in Jakarta and Surabaya. Toray fly ash is disposed coal ash resulting from coal-fired electricity generating power plants. Toray fly ash in this research is used as substitute mineral filler in asphalt paving mixtures. Research on utilization of Toray fly ash as filler is conducted in the Hot Rolled Sheet – Wearing Course Mixture.  Filler content in the HRS –WC mixture is 9%. Variations of Toray fly ash in the mixture tested are 0%, 25%, 50%, 75%, 100% and the variations of asphalt content are 6%, 6.5%, 7%, 7.5%, 8%. Marshall test is  performed to determine the Optimum Asphalt Content  and Marshall Stability, Indirect Tensile Strength (ITS test and Tensile Strength Ratio (TSR to select the optimum Toray fly ash utilization in the mixture based on the moisture susceptibility of specimens. The research results show that in variations of 0%, 25%, 50%, 75% and 100% Toray fly ash in the HRS-WC Mixture, the Optimum Asphalt Contents are at 6.8%, 7.0%, 7.0%, 7.1% and 7.6%  and Marshall Stability values of the variations are 1649 kg, 1541 kg, 1568 kg, 1678 kg, 1718 kg respectively. TSR values in variations of Toray fly ash are 98.32%, 90.28%, 89.38%, 87.62%, 64.71% respectively, with Minimum TSR value required is 80%. Based on the overall parameters, the optimum Toray fly ash utilization in the HRS-WC Mixture recommended is 75% of Toray fly ash at 7.1% Optimum Asphalt Content.

  10. Properties of fresh and hardened sustainable concrete due to the use of palm oil fuel ash as cement replacement

    Science.gov (United States)

    Hamada, Hussein M.; Jokhio, Gul Ahmed; Mat Yahaya, Fadzil; Humada, Ali M.

    2018-04-01

    Palm oil fuel ash (POFA) is a by-product resulting from the combustion of palm oil waste such as palm oil shell and empty fruit bunches to generate electricity in the palm oil mills. Considerable quantities of POFA thus generated, accumulate in the open fields and landfills, which causes atmospheric pollution in the form of generating toxic gases. Firstly, to protect the environment; and secondly, having excellent properties for this purpose; POFA can be and has been used as partial cement replacement in concrete preparation. Therefore, this paper compiles the results obtained from previous studies that address the properties of concrete containing POFA as cement replacement in fresh and hardened states. The results indicate that there is a great potential to using POFA as cement replacement because of its ability to improve compressive strength, reduce hydration heat of cement mortar and positively affect other fresh and hardened concrete properties. The paper recommends that conducting further studies to exploit high volume of POFA along with other additives as cement replacement while maintaining high quality of concrete can help minimize CO2 emissions due to concrete.

  11. Using Cementitious Materials Such as Fly Ash to Replace a Part of Cement in Producing High Strength Concrete in Hot Weather

    Science.gov (United States)

    Turuallo, Gidion; Mallisa, Harun

    2018-03-01

    The use of waste materials in concrete gave many advantages to prove the properties of concrete such as its workability, strength and durability; as well to support sustaianable development programs. Fly ash was a waste material produced from coal combustion. This research was conducted to find out the effect of fly ash as a part replacement of cement to produce high strength concrete. The fly ash, which was used in this research, was taken from PLTU Mpanau Palu, Central Sulawesi. The water-binder ratio used in this research was 0.3 selected from trial mixes done before. The results of this research showed that the strength of fly ash concretes were higher than concrete with PCC only. The replacement of cement with fly ash concrete could be up to 20% to produce high strength concrete.

  12. Potential use of sewage sludge ash (SSA as a cement replacement in precast concrete blocks

    Directory of Open Access Journals (Sweden)

    Pérez-Carrión, M.

    2014-03-01

    Full Text Available The present study explored the technological feasibility of re-using sewage sludge ash (SSA as a Portland cement replacement in commercially manufactured pre cast concrete blocks. The blocks analysed were made to the guidelines laid down in Spain’s National Plan for Waste Water Treatment Plant Sludge, 2001–2006, and European Union specifications (CE marking for such products. Performance was compared in three families of blocks, with 0, 10 and 20% SSA. The findings proved that SSA is apt for pre cast concrete block manufacture and that, in addition to the economic and environmental benefits afforded, its use would improve certain of the properties of conventional block.El objetivo de esta investigación es estudiar el uso potencial de las cenizas de lodos de depuradora (CLD, como sustitución del cemento Portland en bloques de hormigón prefabricados, de forma que se pueda lograr una revalorización de este material de desecho mediante este procedimiento. La metodología utilizada en este trabajo se rige por las directrices del Plan Nacional Español de Lodos de Aguas Residuales de 2001–2006, y por las exigencias del Consejo Europeo (marcado CE, que es obligatorio para este tipo de productos. Se han utilizado dos niveles de sustitución de cemento (10% y 20%, y todos los resultados han sido referidos a las muestras control. Los resultados obtenidos muestran que es posible utilizar una sustitución parcial del cemento por CLD, en la fabricación de bloques de hormigón prefabricados, y por lo tanto, se pueden conseguir beneficios económicos y ambientales, así como la mejora de una serie de propiedades.

  13. Review: Potential Strength of Fly Ash-Based Geopolymer Paste with Substitution of Local Waste Materials with High-Temperature Effect

    Science.gov (United States)

    Subekti, S.; Bayuaji, R.; Darmawan, M. S.; Husin, N. A.; Wibowo, B.; Anugraha, B.; Irawan, S.; Dibiantara, D.

    2017-11-01

    This research provided an overview of the potential fly ash based geopolymer paste for application in building construction. Geopolymer paste with various variations of fly ash substitution with local waste material and high-temperature influence exploited with the fresh and hardened condition. The local waste material which utilized for this study were sandblasting waste, carbide waste, shell powder, bagasse ash, rice husk and bottom ash. The findings of this study indicated that fly-based geopolymer paste with local waste material substitution which had high-temperature influence ash showed a similar nature of OPC binders potentially used in civil engineering applications.

  14. High-efficiency cogeneration boiler bagasse-ash geochemistry and mineralogical change effects on the potential reuse in synthetic zeolites, geopolymers, cements, mortars, and concretes.

    Science.gov (United States)

    Clark, Malcolm W; Despland, Laure M; Lake, Neal J; Yee, Lachlan H; Anstoetz, Manuela; Arif, Elisabeth; Parr, Jeffery F; Doumit, Philip

    2017-04-01

    Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia) where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α -quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product.

  15. High-efficiency cogeneration boiler bagasse-ash geochemistry and mineralogical change effects on the potential reuse in synthetic zeolites, geopolymers, cements, mortars, and concretes

    Directory of Open Access Journals (Sweden)

    Malcolm W. Clark

    2017-04-01

    Full Text Available Sugarcane bagasse ash re-utilisation has been advocated as a silica-rich feed for zeolites, pozzolans in cements and concretes, and geopolymers. However, many papers report variable success with the incorporation of such materials in these products as the ash can be inconsistent in nature. Therefore, understanding what variables affect the ash quality in real mills and understanding the processes to characterise ashes is critical in predicting successful ash waste utilisation. This paper investigated sugarcane bagasse ash from three sugar mills (Northern NSW, Australia where two are used for the co-generation of electricity. Data shows that the burn temperatures of the bagasse in the high-efficiency co-generation boilers are much higher than those reported at the temperature measuring points. Silica polymorph transitions indicate the high burn temperatures of ≈1550 °C, produces ash dominated α −quartz rather than expected α-cristobilite and amorphous silica; although α-cristobilite, and amorphous silica are present. Furthermore, burn temperatures must be ≤1700 °C, because of the absence of lechatelierite where silica fusing and globulisation dominates. Consequently, silica-mineralogy changes deactivate the bagasse ash by reducing silica solubility, thus making bagasse ash utilisation in synthetic zeolites, geopolymers, or a pozzolanic material in mortars and concretes more difficult. For the ashes investigated, use as a filler material in cements and concrete has the greatest potential. Reported mill boiler temperatures discrepancies and the physical characteristics of the ash, highlight the importance of accurate temperature monitoring at the combustion seat if bagasse ash quality is to be prioritised to ensure a usable final ash product. Keywords: Materials Science, Civil Engineering

  16. Gel/Space Ratio Evolution in Ternary Composite System Consisting of Portland Cement, Silica Fume, and Fly Ash.

    Science.gov (United States)

    Wu, Mengxue; Li, Chen; Yao, Wu

    2017-01-11

    In cement-based pastes, the relationship between the complex phase assemblage and mechanical properties is usually described by the "gel/space ratio" descriptor. The gel/space ratio is defined as the volume ratio of the gel to the available space in the composite system, and it has been widely studied in the cement unary system. This work determines the gel/space ratio in the cement-silica fume-fly ash ternary system (C-SF-FA system) by measuring the reaction degrees of the cement, SF, and FA. The effects that the supplementary cementitious material (SCM) replacements exert on the evolution of the gel/space ratio are discussed both theoretically and practically. The relationship between the gel/space ratio and compressive strength is then explored, and the relationship disparities for different mix proportions are analyzed in detail. The results demonstrate that the SCM replacements promote the gel/space ratio evolution only when the SCM reaction degree is higher than a certain value, which is calculated and defined as the critical reaction degree (CRD). The effects of the SCM replacements can be predicted based on the CRD, and the theological predictions agree with the test results quite well. At low gel/space ratios, disparities in the relationship between the gel/space ratio and the compressive strength are caused by porosity, which has also been studied in cement unary systems. The ratio of cement-produced gel to SCM-produced gel ( G C to G S C M ratio) is introduced for use in analyzing high gel/space ratios, in which it plays a major role in creating relationship disparities.

  17. Properties of palm oil fuel ash cement sand brick containing pulverized cockle shell as partial sand replacement

    Science.gov (United States)

    Mat Aris, S.; Muthusamy, K.; Uzer, A.; Ahmad, S. Wan

    2018-04-01

    Environmental pollution caused by the disposal of solid wastes generated from both palm oil industry and cockle shell trade has motivated researches to explore the potential of these wastes. Integrating these wastes in production of construction material is one of the ways to reduce amount of waste thrown at dumping area. Thus, the present investigation investigates the performance of palm oil fuel ash (POFA) cement sand brick containing pulverized cockle shell as partial fine aggregate replacement. All mixes used contain 20% of POFA as partial cement replacement. Total of six mixes were prepared by adding a range of pulverized cockle shell that is 0%, 10%, 20%, 30%, 40% and 50% as partial sand replacement. The mixes were prepared in form of brick. All the water cured samples were tested for compressive strength and flexural strength until 28 days. Findings show that brick produced using 20% pulverized cockle shell exhibit the highest compressive strength and flexural strength also the lowest water absorption value.

  18. Biological responses of brushite-forming Zn- and ZnSr- substituted beta-tricalcium phosphate bone cements

    Directory of Open Access Journals (Sweden)

    S Pina

    2010-09-01

    Full Text Available The core aim of this study was to investigate zinc (Zn- and zinc and strontium (ZnSr-containing brushite-forming beta-tricalcium phosphate (TCP cements for their effects on proliferation and differentiation of osteoblastic-like cells (MC3T3-E1 cell line as well as for their in vivo behaviour in trabecular bone cylindrical defects in a pilot study. In vitro proliferation and maturation responses of MC3T3-E1 osteoblastic-like cells to bone cements were studied at the cellular and molecular levels. The Zn- and Sr-containing brushite cements were found to stimulate pre-osteoblastic proliferation and osteoblastic maturation. Indeed, MC3T3-E1 cells exposed to the powdered cements had increased proliferative rates and higher adhesiveness capacity, in comparison to control cells. Furthermore, they exhibited higher alkaline phosphatase (ALP activity and increased Type-I collagen secretion and fibre deposition into the extracellular matrix. Proliferative and collagen deposition properties were more evident for cells grown in cements doped with Sr. The in vivo osteoconductive propertiesof the ZnCPC and ZnSrCPC cements were also pursued. Histological and histomorphometric analyses were performed at 1 and 2 months after implantation, using carbonated apatite cement (Norian SRS® as control. There was no evidence of cement-induced adverse foreign body reactions, and furthermore ZnCPC and ZnSrCPC cements revealed better in vivo performance in comparison to the control apatite cement. Additionally, the presence of both zinc and strontium resulted in the highest rate of new bone formation. These novel results indicate that the investigated ZnCPC and ZnSrCPC cements are both biocompatible and osteoconductive, being good candidate materials to use as bone substitutes.

  19. CO2 REDUCTION OPTIONS IN CEMENT INDUSTRY - THE NOVI POPOVAC CASE

    Directory of Open Access Journals (Sweden)

    Gordana M Stefanović

    2010-01-01

    Full Text Available The cement industry contributes about 5% to global anthropogenic CO2 emissions, and is thus an important sector in CO2-emission mitigation strategies. Carbon dioxide is emitted from the calcination process of limestone, from combustion of fuels in the kiln, and from the coal combustion during power generation. Strategies to reduce these CO2 emissions include energy efficiency improvement, new processes, shift to low carbon fuels or waste fuels in cement production, increased use of additives in cement production, alternative cements, and CO2 removal from flue gases in clinker kilns. Increased use of fly ash as an additive to cement and concrete has a number of advantages, the primary being reduction of costs of fly ash disposal, resource conservation, and cost reduction of the product. Since the production of cement requires a large amount of energy (about 2.9-3.2 GJt-1, the substitution of cement by fly ash saves not only energy but also reduces the associated greenhouse gas emissions. The paper evaluates the reduction of CO2 emissions that can be achieved by these mitigation strategies, as well as by partial substitution of cement by fly ash. The latter is important because the quality of the produced concrete depends on the physical-chemical properties of the fly ash and thus partial substitution as well as the type of fly ash (e.g., the content of CaO has an effect not only on energy consumption and emissions, but also on the produced concrete quality.

  20. Bulk physicochemical, interconnectivity, and mechanical properties of calcium phosphate cements-fibrin glue composites for bone substitute applications

    NARCIS (Netherlands)

    Lopez-Heredia, M.A.; Pattipeilohy, J.; Hsu, S.; Grykien, M.; Weijden, B. van der; Leeuwenburgh, S.C.G.; Salmon, P.; Wolke, J.G.C.; Jansen, J.A.

    2013-01-01

    Calcium phosphate cements (CPCs) and fibrin glue (FG) are used for surgical applications. Their combination is promising to create bone substitutes able to promote cell attachment and bone remodeling. This study proposes a novel approach to create CPC-FG composites by simultaneous CPC setting and FG

  1. The Effect of Using Sewage Sludge Ash with and without Nano Silica Particles on Properties of Self-compacting Cement Based Materials

    Directory of Open Access Journals (Sweden)

    Amin Khoshravesh

    2014-10-01

    Full Text Available Nowadays using pozzolanic materials is crucial as a replacement of needed cement, improving properties of cement based materials and saving costs. On the other hand sewage sludge is harmful to the environment and human health. So in this research the sewage sludge ash has been used as an artificial pozzolan to produce self compacting cement based materials which could be evaluated as a revolution in the concrete industry. The objective of this research was to accelerate the performance of sewage sludge ash by utilizing nano silica particles. This research includes 10 mix designs for self compacting mortar and concrete made up of binary and ternary cementitious blends of sewage sludge ash (0%,5%,10%,15%,20% and nano silica (0%,1%. The results showed that by adding the sewage sludge ash, rheological and mechanical properties of the samples were reduced and for small percentages of sewage sludge ash, the durability characteristics were improved. The results also showed that adding nano silica improved the mechanical and durability properties of self compacting mortar and concrete. Finally in presence of nano silica, the reactivity of the sewage sludge ash was increased and its performance was improved.

  2. Swine deep bedding ashes as a mineral additive for cement based mortar Cinzas de cama sobreposta de suínos como adição mineral em argamassas de cimento

    Directory of Open Access Journals (Sweden)

    Melissa Selaysim Di Campos

    2008-04-01

    Full Text Available The sustainability of intensive swine production demands alternative destinations for the generated residues. Ashes from swine rice husk-based deep bedding were tested as a mineral addition for cement mortars. The ashes were obtained at 400 to 600ºC, ground and sieved through a 325 mesh sieve (# 0.045 mm. The characterization of the ashes included the determination of the index of pozzolanic activity with lime. The ashes were also tested as partial substitutes of Portland cement. The mortars were prepared using a cement:sand proportion of 1:1.5, and with water/cement ratio of 0.4. Three percentages of mass substitution of the cement were tested: 10, 20 and 30%. Mortar performances were assessed at 7 and 28 days determining their compressive strength. The chosen condition for calcinations at the laboratory scale was related to the maximum temperature of 600ºC since the resulting ashes contained vitreous materials and presented satisfactory values for the pozzolanic index under analysis. The pozzolanic activity indicated promising results for ashes produced at 600ºC as a replacement of up to 30% in cement masses.A sustentabilidade das regiões de produção intensiva de suínos requer destinos alternativos para os resíduos gerados. Cinzas de cama sobreposta de suínos à base casca de arroz, foram testadas como adição mineral em substituição ao cimento. As cinzas foram obtidas nas temperaturas de 400 a 600ºC, moídas e passadas por peneira ABNT 325 (# 0,045 mm. A caracterização de cinzas incluiu a determinação do índice de atividade pozolânica com a cal. As cinzas também foram testadas como substitutos parciais de cimento Portland. As argamassas foram preparadas na proporção cimento:areia de 1:1,5 e com fator água-cimento de 0,4. Três porcentagens de substituição do cimento comercial foram usadas: 10, 20 e 30% em massa. O desempenho das argamassas foi avaliado aos 7 e aos 28 dias com a determinação da resistência

  3. The application of waste fly ash and construction-waste in cement filling material in goaf

    Science.gov (United States)

    Chen, W. X.; Xiao, F. K.; Guan, X. H.; Cheng, Y.; Shi, X. P.; Liu, S. M.; Wang, W. W.

    2018-01-01

    As the process of urbanization accelerated, resulting in a large number of abandoned fly ash and construction waste, which have occupied the farmland and polluted the environment. In this paper, a large number of construction waste and abandoned fly ash are mixed into the filling material in goaf, the best formula of the filling material which containing a large amount of abandoned fly ash and construction waste is obtained, and the performance of the filling material is analyzed. The experimental results show that the cost of filling material is very low while the performance is very good, which have a good prospect in goaf.

  4. Field and lab evaluation of the use of lime fly ash to replace soil cement as a base course : technical summary.

    Science.gov (United States)

    1997-09-01

    The purpose of this project was to design and construct lime/fly ash stabilized base course test sections which would be economical compared to a soil cement stabilized base, utilize a recyclable material, and possibly reduce shrinkage cracking on ba...

  5. Evaluation of cement and fly ash treated recycled asphalt pavement and aggregates for base construction.

    Science.gov (United States)

    2011-12-01

    Many entities currently use recycled asphalt pavement (RAP) and other aggregates as base material, temporary haul roads, : and, in the case of RAP, hot mix asphalt construction. Several states currently allow the use of RAP combined with cement : for...

  6. Evaluation of fly ash concrete durability containing class II durability aggregates.

    Science.gov (United States)

    1986-07-01

    Fly ash was used in this evaluation study to replace 15% of the cement in : Class C-3 concrete paving mixes. One Class "c" ash from Iowa approved : sources was examined in each mix. Substitution rate was based on 1 to 1 : basis, for each pound of cem...

  7. The calcination process in a system for washing, calcinating, and converting treated municipal solid waste incinerator fly ash into raw material for the cement industry.

    Science.gov (United States)

    Zhu, Fenfen; Takaoka, Masaki; Oshita, Kazuyuki; Morisawa, Shinsuke

    2011-07-01

    Calcination is the second step in a washing-calcination-conversion system in which treated municipal solid waste incinerator fly ash and bottom ash can be reused as raw material in the cement industry and can decompose or stabilize hazardous compounds, reduce residue amounts, and alter residue characteristics. In this research, only fly ash is discussed. Chloride reduction is important if treated fly ash is to be reused in cement; however, the relationship between washed fly ash properties and chloride reduction by calcination is not well understood. This study used washed residues of three types of fly ash-raw fly ash (RFA) from the boiler or economizer of an incineration system, fly ash collected in a bag filter injected with calcium hydroxide (Ca(OH)2) for acid removal (CaFA), and fly ash collected in a bag filter injected with sodium bicarbonate (NaHCO3) for acid removal (NaFA)-in calcination experiments with varying temperature (400-1100 degrees C) and atmosphere (100% nitrogen [N2] at 25 mL/min or 10% oxygen [O2] [90% N2] at fluxes of 25, 50, and 75 mL/min). From the perspective of chloride reduction, heating to 1000 degrees C with 1-hr heating time, 1-hr holding time, and an atmosphere of 10% O2/90% N2 was most suitable for calcination. Under these conditions, chloride levels were reduced by 91, 52, and 96% in washed residues of RFA, CaFA, and NaFA, respectively. Among the washed residues, the weight of the washed residue of NaFA decreased the most.

  8. Volcanic ash-based geopolymer cements/concretes: the current state of the art and perspectives.

    Science.gov (United States)

    Djobo, Jean Noël Yankwa; Elimbi, Antoine; Tchakouté, Hervé Kouamo; Kumar, Sanjay

    2017-02-01

    The progress achieved with the use of volcanic ash for geopolymer synthesis has been critically reviewed in this paper. This consists of an overview of mineralogy and chemistry of volcanic ash. The role of chemical composition and mineral contents of volcanic ash on their reactivity during geopolymerization reaction and, consequently, mechanical properties have been accessed. An attempt has been made to establish a relationship between synthesis factors and final properties. A critical assessment of some synthesis conditions has been addressed and some practical recommendations given along with suggestions of future works that have to be done. All this has shown that there are still many works such as durability tests (carbonation, freeze-thaw, resistance, etc.), life cycle analysis, etc. that need to be done in order to satisfy both suitability and sustainability criteria for a large-scale or industrial application.

  9. Leaching of saltstones containing fly ash

    International Nuclear Information System (INIS)

    Barnes, M.W.; Roy, D.M.; Langton, C.A.

    1985-01-01

    Two types of fly ash were incorporated in saltstones designed for potential encapsulation of Savannah River Plant low level defense waste. These fly ashes have some cementitious properties while at the same time their presence in substitution for cement slows early hydration. Class C fly ash has a high calcium content and is considered cementitious; Class F fly ash has a low calcium content and is not classified as cementitious. Leach tests were performed and physical properties were measured for saltstones containing each class, to see the differences in the effect of the fly ashes. The four waste ions nitrate, nitrite, sodium and sulfate were shown to leach by diffusion. Effective diffusivities were determined for these ions. Data for nitrate, the most important species from the environmental point of view, are shown in Table A. Saltstones made with Class C fly ash have substantially lower leach rates than those made with Class F fly ash. The leach rates, and therefore the square roots of the effective diffusivities, have been found to be proportional to the pore surface area per unit volume (or the ratio of pore volume to pore radius), to the fraction of waste containing solution, and to the inverse of the fraction of calcium in the saltstone. Rates and diffusivities are not proportional to the water to cement ratio, because this number depends on whether the fly ash is counted as cementitious, as in Class C cement, or not cementitious, as in Class F cement. In fact the relatively small amount of calcium in Class F cement contributes to the cementitious properties overall, though not so much as Class C cement. 4 refs., 2 figs., 6 tabs

  10. Experimental Analysis of Fly Ash & Coir Fiber Mix Cement Concrete for Rigid Pavement

    OpenAIRE

    Er. Amit Kumar Ahirwar; Prof. Rajesh Joshi

    2015-01-01

    In India Thermal power plants which use pounded coal as a fuel, generates million tones of fly ash every year as a waste. Conservative clearance of this material which gets easily air-borne and constitutes a serious health hazards to the community, is an expensive operation. A part from this compacted fly ash can be used in embankments, road sub-bases and also for structural fills. The major drawbacks of such materials are their limited load carrying capacity and poor settlement c...

  11. Effect of Copolymer Latexes on Physicomechanical Properties of Mortar Containing High Volume Fly Ash as a Replacement Material of Cement

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

    Full Text Available This paper investigates the physicomechanical properties of mortar containing high volume of fly ash (FA as partial replacement of cement in presence of copolymer latexes. Portland cement (PC was partially replaced with 0, 10, 20, 30 50, and 60% FA. Copolymer latexes were used based on 2-hydroxyethyl acrylate (2-HEA and 2-hydroxymethylacrylate (2-HEMA. Testing included workability, setting time, absorption, chemically combined water content, compressive strength, and scanning electron microscopy (SEM. The addition of FA to mortar as replacement of PC affected the physicomechanical properties of mortar. As the content of FA in the concrete increased, the setting times (initial and final were elongated. The results obtained at 28 days of curing indicate that the maximum properties of mortar occur at around 30% FA. Beyond 30% FA the properties of mortar reduce and at 60% FA the properties of mortar are lower than those of the reference mortar without FA. However, the addition of polymer latexes into mortar containing FA improved most of the physicomechanical properties of mortar at all curing times. Compressive strength, combined water, and workability of mortar containing FA premixed with latexes are higher than those of mortar containing FA without latexes.

  12. Evaluation of nitric and acetic acid resistance of cement mortars containing high-volume black rice husk ash.

    Science.gov (United States)

    Chatveera, B; Lertwattanaruk, P

    2014-01-15

    This paper presents the performance of cement mortar containing black rice husk ash (BRHA) under nitric and acetic acid attacks. The BRHA, collected from an electrical generating power plant that uses rice husk as fuel, was ground using a grinding machine. The compressive strength loss, weight loss, and expansion of mortars under nitric and acetic acid attack were investigated. The test results of BRHA properties in accordance with the ASTM C 618 standard found that the optimal grinding time was 4 h as this achieved a Blaine fineness of 5370 cm(2)/g. For parametric study, BRHA were used as a Portland cement Type 1 replacement at the levels of 0%, 10%, 20%, 30%, 40%, and 50% by weight of binder. The water-to-binder ratios were 0.55, 0.60, and 0.65. From test results, when the percentage replacements of BRHA in cement increased, it was observed that the strength loss and weight loss of mortars containing BRHA under acetic acid attack were higher than those of the mortars against nitric acid attack. It was found that, of the various BHRA mortars, the strength loss and weight loss due to nitric and acetic acid attacks were the lowest in the mortar with 10% BRHA replacement. For 10%, 20% and 30% BRHA replacements, the rate of expansion of the BRHA mortar decreased when compared with the control mortar. For the mortars with other percentage replacements of BRHA, the rate of expansion increased. Furthermore, the effective water-to-binder ratios of control and BRHA mortars were the primary factor for determining the durability of mortar mixed with BRHA. Copyright © 2013 Elsevier Ltd. All rights reserved.

  13. Influence of various amount of diatomaceous earth used as cement substitute on mechanical properties of cement paste

    Science.gov (United States)

    Pokorný, Jaroslav; Pavlíková, Milena; Medved, Igor; Pavlík, Zbyšek; Zahálková, Jana; Rovnaníková, Pavla; Černý, Robert

    2016-06-01

    Active silica containing materials in the sub-micrometer size range are commonly used for modification of strength parameters and durability of cement based composites. In addition, these materials also assist to accelerate cement hydration. In this paper, two types of diatomaceous earths are used as partial cement replacement in composition of cement paste mixtures. For raw binders, basic physical and chemical properties are studied. The chemical composition of tested materials is determined using classical chemical analysis combined with XRD method that allowed assessment of SiO2 amorphous phase content. For all tested mixtures, initial and final setting times are measured. Basic physical and mechanical properties are measured on hardened paste samples cured 28 days in water. Here, bulk density, matrix density, total open porosity, compressive and flexural strength, are measured. Relationship between compressive strength and total open porosity is studied using several empirical models. The obtained results give evidence of high pozzolanic activity of tested diatomite earths. Their application leads to the increase of both initial and final setting times, decrease of compressive strength, and increase of flexural strength.

  14. Partial Replacement of Cement with Bagasse Ash in Hot Mix Asphalt ...

    African Journals Online (AJOL)

    It is in this light that a laboratory based investigation for the replacement of cement with BA in Hot Mix Asphalt (HMA) was conducted. Tests on the suitability of materials used and their performance in terms of known engineering properties was carried out. Bitumen content of 4.5%, 5.5%, 6.5% and 7.5% was adopted.

  15. Studies on the Effect of Rice Husk Ash as Cement Admixture * M.U ...

    African Journals Online (AJOL)

    acer

    weights of the block samples were always taken before the compressive strength test was conducted. Three sample blocks were crushed each at 1, 3, 7, 14, and 28 days after casting at different replacement levels using the compressive testing machine according to CCNN. (1984). Chemical Analysis of RHA and Cement.

  16. ground nut husk ash (gha) as a partial replacement of cement in ...

    African Journals Online (AJOL)

    NIJOTECH

    The sand was obtained from Bayara. River near Bauchi town. The cement was. Ashaka Brand produced in Gombe State,. Nigeria. Groundnut husk was obtained from local groundnut oil mills in Bauchi metropolis. Samples collected were burnt up to 600 o. C using a kerosene vaporization burner kiln at the Industrial Design.

  17. 23 Effects of Groundnut Husk Ash-blended Cement on Chemical ...

    African Journals Online (AJOL)

    Arc. Usman A. Jalam

    areas or site for usage (Neville, 2000). Since. OPC is typically the most expensive constituent of concrete, the replacement of proportion of it with Groundnut Husk Ash. (GHA) may improve concrete affordability particularly for low-cost housing in developing countries like Nigeria. The use of GHA may contribute not only to the.

  18. Synthesis of alpha'L-C2S cement from fly-ash using the hydrothermal method at low temperature and atmospheric pressure.

    Science.gov (United States)

    Kacimi, Larbi; Cyr, Martin; Clastres, Pierre

    2010-09-15

    The objective of this study was the synthesis of alpha'(L)-C(2)S (Ca(2)SiO(4)) belite cement, starting from fly-ash of system CaO-SiO(2)-Al(2)O(3)-SO(3), and using the hydrothermal method in alkaline solution. The lime deficit in these ashes was compensated by the addition of slaked lime from lime bagging workshops. The hydrothermal treatment of the mixture was carried out in demineralized water, NaOH or KOH solution, continually stirred at a temperature below 100 degrees C and atmospheric pressure. The dehydration and calcination of the mixtures at temperatures between 800 and 1100 degrees C allowed alpha'(L)-C(2)S-rich cement to be obtained. The optimization of the synthesis parameters (temperature and time of stirring, pH of solution, temperature and duration of mixture burning) was also studied. The phase formation during various synthesis stages was studied by X-ray diffraction (XRD). Other techniques, such as SEM and EDX, were used to characterize the cement minerals. The results obtained showed that these ashes could form belite cement composed of only one dicalcium silicate phase (alpha'(L)-C(2)S). Copyright 2010 Elsevier B.V. All rights reserved.

  19. THE INFLUENCE OF CaO AND P2O5 OF BONE ASH UPON THE REACTIVITY AND THE BURNABILITY OF CEMENT RAW MIXTURES

    Directory of Open Access Journals (Sweden)

    TOMÁŠ IFKA

    2012-03-01

    Full Text Available The influence of CaO and P2O5 upon the reactivity of cement raw meal was investigated in this paper. Ash of bone meal containing Ca3(PO42 - 3CaO·P2O5 was used as the source of P2O5. Two series of samples with different content of the ash of bone meal were prepared. In the first series, the ash of bone was added into cement raw meal. The second series of samples were prepared by considering ash as one of CaO sources. Therefore, the total content of CaO in cement raw meal was kept constant, while the amount of P2O5 increased. These different series of samples were investigated by analyzing free lime content in the clinkers. The XRD analysis and Electron Micro Probe Analyzer analysis of the clinkers were also carried out. Two parameters were used to characterize the reactivity of cement raw meal: content of free lime and Burnability Index (BI calculated from free lime content in both series of samples burnt at 1350 ºC, 1400 ºC, 1450 ºC and 1500 ºC. According to the first parameter, P2O5 content that drastically makes worse the reactivity of cement raw meal was found at 1.11 wt.% in the first series, while this limit has reached 1.52 wt.% in the second one. According to the BI, the limit of P2O5 was found at 1.42 wt. % in the first series and 1, 61 wt.% in the second one. Furthermore, EPMA has demonstrated the presence of P2O5 in both calcium silicate phases forming thus solid solutions.

  20. Effect of Tartaric Acid on Hydration of a Sodium-Metasilicate-Activated Blend of Calcium Aluminate Cement and Fly Ash F

    Directory of Open Access Journals (Sweden)

    Tatiana Pyatina

    2016-05-01

    Full Text Available An alkali-activated blend of aluminum cement and class F fly ash is an attractive solution for geothermal wells where cement is exposed to significant thermal shocks and aggressive environments. Set-control additives enable the safe cement placement in a well but may compromise its mechanical properties. This work evaluates the effect of a tartaric-acid set retarder on phase composition, microstructure, and strength development of a sodium-metasilicate-activated calcium aluminate/fly ash class F blend after curing at 85 °C, 200 °C or 300 °C. The hardened materials were characterized with X-ray diffraction, thermogravimetric analysis, X-ray computed tomography, and combined scanning electron microscopy/energy-dispersive X-ray spectroscopy and tested for mechanical strength. With increasing temperature, a higher number of phase transitions in non-retarded specimens was found as a result of fast cement hydration. The differences in the phase compositions were also attributed to tartaric acid interactions with metal ions released by the blend in retarded samples. The retarded samples showed higher total porosity but reduced percentage of large pores (above 500 µm and greater compressive strength after 300 °C curing. Mechanical properties of the set cements were not compromised by the retarder.

  1. Diffusion of He in OPC paste and low-heat Portland cement paste containing fly-ash in contact with aqueous phase

    International Nuclear Information System (INIS)

    Sato, Fuminori; Miwata, Chikanori; Noda, Natsuko; Sato, Seichi; Kozaki, Tamotsu; Higashihara, Tomohiro; Hironaga, Michihiko; Kawanishi, Motoi

    2008-01-01

    As a part of gas migration studies in concrete package for nuclear waste surrounded by water-saturated rock, the helium diffusion in ordinary Portland cement paste (OPC) was studied using disk form specimen at various water-to-cement (w/c) ratios. The helium diffusion in low-heat Portland cement paste containing fly-ash (LPF) was also studied. Apparent diffusion coefficients of helium in OPC paste were ∼1 x 10 -10 m 2 s -1 at 0.4 w/c ratio, independent of increase of w/c ratio. It is likely that the materials formation such as C-S-H and CH in capillary pores in OPC plays an important role on the helium diffusion rather than porosity increase. Apparent diffusion coefficient of helium in LPF was two orders of magnitude smaller than that in OPC. It is quite possible that the addition of fly-ash contributes to the formation of hydration products which markedly enhance discontinuity of capillary pore. The results of the present study on the two kinds of cement pastes give us valuable information about alternatives to release gas from cement package. (author)

  2. Cement technology for borehole plugging: interim report on the effects of fly ash and salt on the physical properties of cementitious solids

    International Nuclear Information System (INIS)

    Moore, J.G.; Morgan, M.T.; McDaniel, E.W.; Greene, H.B.; West, W.A.

    1980-03-01

    Results of initial studies of a systematic investigation to determine the effects of fly ash and salt on the physical properties of pozzolanic concretes and saltcretes are reported. Addition of fly ash to mortars decreased the set time and bleed characteristics and increased the compressive strength and permeability, but it had very little effect on the density or the thermal conductivity of the solid. The magnitude of these effects was only slightly related to the lime content of the fly ash. In the case of saltcretes, low-lime fly ash slightly decreased the set time and the bleed characteristics of the wet mix. However, a high-lime fly ash doubled the set time and decreased the bleed characteristics to essentially zero. The compressive strength of saltcretes was increased by the addition of fly ash and was independent of the lime content. Such additions had little effect on the thermal conductivity or density. The thermal conductivities of cement pastes containing fly ash showed a near-linear relationship with the density of the resulting solids. In the case of mortars, the thermal conductivity decreased with increasing temperature and showed some hysteresis in the initial heating cycle. After the first cycle, the thermal conductivity decreased from about 1.32 W/m.K at 350 0 K to 1.27 W/m.K at 475 0 K

  3. Environmental and technical assessments of the potential utilization of sewage sludge ashes (SSAs) as secondary raw materials in construction.

    Science.gov (United States)

    Chen, Maozhe; Blanc, Denise; Gautier, Mathieu; Mehu, Jacques; Gourdon, Rémy

    2013-05-01

    Ashes produced by thermal treatments of sewage sludge exhibit common properties with cement. For example, major elements present in SSA are the same of major elements of cement. Hydraulic properties of SSA are quite the same of cement ones. They may therefore be used to substitute part of cement in concrete or other cementitious materials, provided that technical prescriptions are satisfied and that environmental risks are not significantly increased. The objective of the present study was to determine the appropriate substitution ratios to satisfy both technical and environmental criteria. In a first step, the elemental composition and particle size distribution of the ashes were measured. Then the ashes were used along with Portland cement and sand at different ratios of substitution to produce mortar and concrete which were cured for up to 90 days into parallelepipedic or cylindrical monoliths. The mechanical properties of the monoliths were measured using standard procedures for flexural and compressive strengths, and compared to blanks containing no ashes. The environmental criteria were assessed using leaching tests conducted according to standard protocols both on the ashes and the monoliths, and compared to the blanks. Results showed that the characteristics of the ashes ranged between those of cement and sand because of their larger particle size and higher content in SiO2 as compared to cement. The monoliths made with the highest substitution ratios exhibited a significant decrease in flexural and compressive strengths. However, when the ashes were used in partial substitution of cement at appropriate ratios, the concrete monoliths exhibited similar compressive strengths as the blank samples. The most appropriate ratios were found to be 10% substitution of cement and 2% substitution of sand. The leaching tests conducted on the ashes in their powdery form revealed that amongst the potential contaminants analyzed only Mo and Se were leached at

  4. Studies on the Effect of Rice Husk Ash as Cement Admixture | Dabai ...

    African Journals Online (AJOL)

    ... 28.50 and 36.30 N/mm2 respectively and increased with age of curing but decreased with increase in RHA content for all mixes. The chemical analysis of the rice husk ash revealed high amount of silica (68.12%), alumina (1.01%) and oxides such as calcium oxide (1.01%) and iron oxide (0.78%) responsible for strength,

  5. Study on the effects of white rice husk ash and fibrous materials additions on some properties of fiber-cement composites.

    Science.gov (United States)

    Hamzeh, Yahya; Ziabari, Kamran Pourhooshyar; Torkaman, Javad; Ashori, Alireza; Jafari, Mohammad

    2013-03-15

    This work assesses the effects of white rice husk ash (WRHA) as pozzolanic material, virgin kraft pulp (VKP), old corrugated container (OCC) and fibers derived from fiberboard (FFB) as reinforcing agents on some properties of blended cement composites. In the sample preparation, composites were manufactured using fiber-to-cement ratio of 25:75 by weight and 5% CaCl(2) as accelerator. Type II Portland cement was replaced by WRHA at 0%, 25% and 50% by weight of binder. A water-to-binder ratio of 0.55 was used for all blended cement paste mixes. For parametric study, compressive strength, water absorption and density of the composite samples were evaluated. Results showed that WRHA can be applied as a pozzolanic material to cement and also improved resistance to water absorption. However, increasing the replacement level of WRHA tends to reduce the compressive strength due to the low binding ability. The optimum replacement level of WRHA in mortar was 25% by weight of binder; this replacement percentage resulted in better compressive strengths and water absorption. OCC fiber is shown to be superior to VKF and FFB fibers in increasing the compressive strength, due to its superior strength properties. As expected, the increase of the WRHA content induced the reduction of bulk density of the cement composites. Statistical analysis showed that the interaction of above-mentioned variable parameters was significant on the mechanical and physical properties at 1% confidence level. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

  6. Diffusion behavior of anion in hardened low-heat portland cement paste containing fly ash. Dependence of effective diffusion coefficient on pore structure

    International Nuclear Information System (INIS)

    Chida, Taiji; Yoshida, Takahiro

    2012-01-01

    In the sub-surface disposal system, the closely packed concrete layer is expected the low diffusivity to retard the migration of radionuclides. Low-heat portland cement containing 30 wt% fly ash (FAC) is a candidate cement material for the construction of sub-surface repository because of its high dense structure and its resistance to cracking. Previously, we reported that FAC has lower diffusivity than Ordinary Portland Cement (OPC) for acetic acid and iodine. However, the mechanism for low diffusivity of FAC was not clear. In this study, the diffusion of multiple trace ions (chlorine, bromine and iodine) in hardened cement pastes was examined by through-diffusion experiments. The effective diffusion coefficients, D e , of the trace ions for hardened OPC cement pastes were on the order of 10 -12 m 2 s -1 for trace ions, and D e for hardened FAC cement pastes were on the order of 10 -13 m 2 s -1 for chlorine, 10 -14 m 2 s -1 for bromine and 10 -15 m 2 s -1 for iodine. Additionally, the pore size distribution and porosity of FAC changed to more closely packed structure for 13 months by the pozzolanic reaction, and the pore size distribution of FAC (mainly 3-10 nm) were an order of magnitude smaller than that of OPC. These results suggest that the low diffusivity of FAC is based on the continuous change in the pore structure and the nano-scale pore size retarding the migration of trace ions. (author)

  7. A new quantification method based on SEM-EDS to assess fly ash composition and study the reaction of its individual components in hydrating cement paste

    Energy Technology Data Exchange (ETDEWEB)

    Durdziński, Paweł T., E-mail: pawel.durdzinski@gmail.com [Laboratory of Construction Materials, École Polytechnique Fédérale de Lausanne (EPFL), Station 12, CH-1015 Lausanne (Switzerland); Dunant, Cyrille F. [Laboratory of Construction Materials, École Polytechnique Fédérale de Lausanne (EPFL), Station 12, CH-1015 Lausanne (Switzerland); Haha, Mohsen Ben [HeidelbergCement Technology Center GmbH (HeidelbergCement AG), Rohrbacher Str. 95, 69181 Leimen (Germany); Scrivener, Karen L. [Laboratory of Construction Materials, École Polytechnique Fédérale de Lausanne (EPFL), Station 12, CH-1015 Lausanne (Switzerland)

    2015-07-15

    Calcareous fly ashes are high-potential reactive residues for blended cements, but their qualification and use in concrete are hindered by heterogeneity and variability. Current characterization often fails to identify the dominant, most reactive, amorphous fraction of the ashes. We developed an approach to characterize ashes using electron microscopy. EDS element composition of millions of points is plotted in a ternary frequency plot. A visual analysis reveals number and ranges of chemical composition of populations: silicate, calcium-silicate, aluminosilicate, and calcium-rich aluminosilicate. We quantified these populations in four ashes and followed their hydration in two Portland-ash systems. One ash reacted at a moderate rate: it was composed of 70 vol.% of aluminosilicates and calcium-silicates and reached 60% reaction at 90 days. The other reacted faster, reaching 60% at 28 days due to 55 vol.% of calcium-rich aluminosilicates, but further reaction was slower and 15 vol.% of phases, the silica-rich ones, did not react.

  8. A new quantification method based on SEM-EDS to assess fly ash composition and study the reaction of its individual components in hydrating cement paste

    International Nuclear Information System (INIS)

    Durdziński, Paweł T.; Dunant, Cyrille F.; Haha, Mohsen Ben; Scrivener, Karen L.

    2015-01-01

    Calcareous fly ashes are high-potential reactive residues for blended cements, but their qualification and use in concrete are hindered by heterogeneity and variability. Current characterization often fails to identify the dominant, most reactive, amorphous fraction of the ashes. We developed an approach to characterize ashes using electron microscopy. EDS element composition of millions of points is plotted in a ternary frequency plot. A visual analysis reveals number and ranges of chemical composition of populations: silicate, calcium-silicate, aluminosilicate, and calcium-rich aluminosilicate. We quantified these populations in four ashes and followed their hydration in two Portland-ash systems. One ash reacted at a moderate rate: it was composed of 70 vol.% of aluminosilicates and calcium-silicates and reached 60% reaction at 90 days. The other reacted faster, reaching 60% at 28 days due to 55 vol.% of calcium-rich aluminosilicates, but further reaction was slower and 15 vol.% of phases, the silica-rich ones, did not react

  9. Electrodialytic upgrading of municipal waste incineration fly ash for reuse

    DEFF Research Database (Denmark)

    Jensen, Pernille Erland; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.

    2012-01-01

    content of water soluble, mobile salts and heavy metals. It was shown that the mobility of salts and toxic elements can be significantly reduced by extraction with electrodialysis in stack [1, 2]; and that treated MSWI fly ash may potentially be utilized as a substitute for cement in concrete [3...

  10. Durability of class C fly ash belite cement in simulated sodium chloride radioactive liquid waste: Influence of temperature

    International Nuclear Information System (INIS)

    Guerrero, A.; Goni, S.; Allegro, V.R.

    2009-01-01

    This work is a continuation of a previous durability study of class C fly ash belite cement (FABC-2-W) in simulated radioactive liquid waste (SRLW) that is very rich in sulphate salts. The same experimental methodology was applied in the present case, but with a SRLW rich in sodium chloride. The study was carried out by testing the flexural strength of mortars immersed in simulated radioactive liquid waste that was rich in chloride (0.5 M), and demineralised water as a reference, at 20 and 40 deg. C over a period of 180 days. The reaction mechanism of chloride ions with the mortar was evaluated by scanning electron microscopy (SEM), porosity and pore-size distribution, and X-ray diffraction (XRD). The results showed that the FABC mortar was stable against simulated chloride radioactive liquid waste (SCRLW) attack at the two chosen temperatures. The enhancement of mechanical properties was a result of the formation of non-expansive Friedel's salt inside the pores; accordingly, the microstructure was refined

  11. Use of cement-fly ash-based stabilization techniques for the treatment of waste containing aromatic contaminants

    Science.gov (United States)

    Banaszkiewicz, Kamil; Marcinkowski, Tadeusz

    2017-11-01

    Research on evaluation of evaporation rate of volatile organic compounds from soil beds during processing is presented. For the experiment, soil samples were prepared with the same amounts of benzene and stabilized using a mixture of CEMI 42.5R cement and fly ash from pit-coal combustion. Solidification of soils contaminated with BTEX hydrocarbons using hydraulic binders involves a risk of releasing vapours of these compounds during homogenization of waste with stabilizing mixture introduced and its dilution with water. The primary purposes of the research were: analysis of benzene volume emitted from soil during stabilization/solidification process and characterization of factors that may negatively affect the quality of measurements/the course of stabilization process. Analysis of benzene emission intensity during the process was based on concentration (C6H6) values, recorded with flame-ionization detector above the surface of reacting mixture. At the same time, gaseous contaminants emitted during waste stabilization were passed through pipes filled with activated carbon (SCK, Anasorb CSC). Benzene vapours adsorbed on activated carbon were subjected to analysis using gas chromatograph Varian 450-GC. Evaporation characteristics of benzene during processing contaminated soils revealed the stages creating the highest danger to workers' health, as well as a need for actions connected with modification of technological line.

  12. Oil-Sludge Extended Asphalt Mastic Filled with Heavy Oil Fly Ash and Cement Waste for Waterproofing

    Directory of Open Access Journals (Sweden)

    H.I. Al-Abdul Wahhab

    2014-12-01

    Full Text Available Recycling as an economic disposal process for many hazardous waste materials has become a popular means of conserving our planet’s scarce and diminishing natural resources. This paper is a study of the influence of oil sludge (OS on the physical behavior and performance of asphalt filled with heavy oil fly ash (HOFA, cement kiln dust (CKD and limestone dust (LMD. Conventional asphalt consistency tests in addition to a new bond strength (BS test were conducted on the modified asphalt mastics. The results were statistically analyzed and assessed in accordance with American Society for Testing and Materials (ASTM D 332 and ASTM D 449 specifications. Too much OS resulted in strength deterioration of the asphalt mastic, which can be compensated for by filling the mastic with HOFA. OS interacts constructively with the fillers to improve their effectiveness in raising the softening point (SP and viscosity of the asphalt, and also in reducing its penetration and ductility. Even though sludge mastics hold promise as suitable composites for damp proofing and waterproofing, the resulting low flash point (FP and SP of some of these mastics make their suitability for roofing applications questionable.

  13. Effect of addition of sugar cane biomass ash in properties of fresh state in cement slurries for oil wells; Efeito da adicao de cinza de biomassa de cana-de-acucar nas propriedades no estado fresco de pastas de cimento para pocos de petroleo

    Energy Technology Data Exchange (ETDEWEB)

    Galvao, Lornna L.A.; Santos, Herculana T.; Souza, Pablo Diego Pinheiro; Freitas, Julio Cezar Oliveira [Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil); Nascimento, Julio Cesar S. [Universidade Federal da Bahia (UFBA), BA (Brazil); Amorim, Natalia M.M. [Universidade Potiguar (UNP), RN (Brazil); Martinell, Antonio E. [Mcgill University (MCGILL) (Canada); Universidade Federal do Rio Grande do Norte (UFRN), RN (Brazil)

    2012-07-01

    Recent studies have shown that ashes from biomass, in particular those generated by the alcohol industry have pozzolanic activity and can replace cement in many applications, reducing the consumption of cement and, consequently, the environmental impact caused by the production of this material. The present work evaluated the behavior of ash sugarcane biomass partially replacing Portland cement in concentrations of 10, 20 and 40% BWOC in oil well slurries. The results of rheology, thickening time and stability showed that the addition of 40% of biomass ash in oil well slurries significantly improves their properties, enabling the replacement of cement by ash. (author)

  14. The mechanical and physical properties of concrete containing polystyrene beads as aggregate and palm oil fuel ash as cement replacement material

    Science.gov (United States)

    Adnan, Suraya Hani; Abadalla, Musab Alfatih Salim; Jamellodin, Zalipah

    2017-10-01

    One of the disadvantages of normal concrete is the high self-weight of the concrete. Density of the normal concrete is in the range of 2200 kg/m3 to 2600 kg/ m3. This heavy self-weight make it as an uneconomical structural material. Advantages of expended polystyrene beads in lightweight concrete is its low in density which can reduce the dead load (self-weight) Improper disposal of the large quantity of palm oil fuel ash which has been produced may contribute to environmental problem in future. In this study, an alternative of using palm oil fuel ash as a cement replacement material is to improve the properties of lightweight concrete. The tests conducted in this study were slump test, compression strength, splitting tensile and water absorption test. These samples were cured under water curing condition for 7, 28 and 56 days before testing. Eight types of mixtures were cast based on percentage (25%, 50%) of polystyrene beads replacement for control samples and (25%, 50%) of polystyrene beads by different ratio 10%, 15%, and 20% replacement of palm oil fuel ash, respectively. Samples with 25% polystyrene beads and 10% palm oil fuel ash obtained the highest compressive strength which is 16.8 MPa, and the splitting tensile strength is 1.57 MPa. The water absorption for samples 25%, 50% polystyrene and 20% palm oil fuel ash is 3.89% and 4.67%, respectively which is lower compared to control samples.

  15. Study on the valorization routes of ashes from thermoelectric power plants working under mono-and co-combustion regimes

    Science.gov (United States)

    Barbosa, Rui Pedro Fernandes

    The main objective of this thesis was to study new valorization routes of ashes produced in combustion and co-combustion processes. Three main valorization pathways were analyzed: (i)production of cement mortars, (ii) production of concretes, and (iii) use as chemical agents to remove contaminants from wastewaters. Firstly, the ashes produced during the mono-combustion of coal, co-combustion of coal and meat and bone meal (MBM), and mono-combustion of MBM were characterized. The aim of this study was to understand the ashes properties in extreme levels of substitution of coal by a residue with a high contamination of specific metals. The substitution of coal by MBM produced ashes with higher content of heavy metals. Secondly, the ashes coming from an industrial power plant working under mono-combustion(coal) and co-combustion conditions (coal+sewage sludge+MBM) were studied. The use of cofuels did not promote significant changes in the chemical and ecotoxicological properties of ashes. Fly ashes were successfully stabilized/solidified in cement mortar, and bottom and circulating ashes were successfully used as raw materials in concrete. The third step involved the characterization and valorization of biomass ashes resulting from the combustion of forestry residues. The highest concentrations of metals/metalloids were found in the lowest particle size fractions of ashes. Biomass ashes successfully substituted cement and natural aggregates in concretes, without compromising their mechanical, chemical, and ecotoxicological properties. Finally, the biomass ashes were tested as chemical agents to remove contaminants from wastewaters. The removal of P, mainly phosphates, and Pb from wastewaters was assayed. Biomass ashes presented a high capacity to remove phosphates. As fly ashes were more efficient in removing phosphates, they were further used to remove Pb from wastewaters. Again, they presented a high efficiency in Pb removal. New potential valorization routes for

  16. Conditioning of incinerator ash at the CEN, Cadarache

    International Nuclear Information System (INIS)

    Kertesz, C.; Courtois, C.

    1989-01-01

    The Cadarache Nuclear Research Centre (CEN) has several stocks of incinerator ash resulting from the treatment of low and medium level wastes. The ash is at present in temporary storage awaiting conditioning which would allow it to be stored as a surface site. Laboratory studies have been carried out to test various embedding matrices, such as hydraulic binders, bitumen, thermosetting plastic (epoxy) and, finally, a composite matrix of cement and epoxy resin. The cement-resin composite matrix has several advantages, including compatibility with the various types of ash tested, unlike cement alone, whose composition must be adapted to the nature of the ash (problems with phosphated ash resulting from incineration of tributyl phosphate), or epoxy resin, which may require pretreatment of the wastes. A characterization programme has been produced for the embedded ash in the cement-resin composite in order to obtain Andra approval for surface storage of the packages produced. The guiding principles of the programme are the characterization criteria defined in the Basic Safety Regulations and the Andra minimum characterization programme; it includes laboratory scale tests and a series of tests to be carried out on real packages (100 L drums). A pilot plant for embedding on a scale appropriate to the quantities of stored ash requiring conditioning is being set up. It is being commissioned for two purposes: (1) as an industrial tool, it will facilitate the resorption of existing and future stocks of ash; (2) as an R and D tool, it is designed to facilitate a change in embedding matrix by substitution of the cement-resin compound for epoxy resin or cement alone. This makes it possible to manufacture industrial embedded materials in three different matrices at a single installation. (author). 4 refs, 4 figs, 7 tabs

  17. Greatly increased use of fly ash in hydraulic cement concrete (HCC) for pavement layers and transportation structures - volume I.

    Science.gov (United States)

    2012-03-01

    The purpose of this phase is to evaluate the past, current and future trends of use of fly ash in concrete and restrictions to its use. The American Coal Ash Association (ACAA) conducts an annual survey of fly ash production and use. Typically on an ...

  18. Reuse of ash coal in the formulation of mortars

    International Nuclear Information System (INIS)

    Siqueira, J.S.; Souza, C.A.G.; Souza, J.A.S.

    2012-01-01

    This paper aims to study the ash incorporation from the combustion of coal in fluidized bed boilers, in production of mortar, replacing part of cement. Specimens were prepared using Portland cement to the specifications CPII-E-32 of normal characteristics and classification of sand below 100 mesh. Blends in the 4:1 ratio, that is, 4 parts of aggregate to 1 part of cement, with insertion of ashes in the proportions 0, 10, 20, 30, 40 and 50%. The mortar was developed in mixing and casting was made in a mold of 5 cm x 10 cm. The behavior of compressive strength was evaluated after 28 days; the strength decreases with increasing percentage of ash. Additional analysis was carried out by X-ray diffraction, and it was found that the substitution of this waste can be successfully used in mortars with blends of up to 30%. (author)

  19. Pore structure in blended cement pastes

    DEFF Research Database (Denmark)

    Canut, Mariana Moreira Cavalcanti

    Supplementary cementitious materials (SCMs), such as slag and fly ash, are increasingly used as a substitute for Portland cement in the interests of improvement of engineering properties and sustainability of concrete. According to studies improvement of engineering properties can be explained...... supplement each other. Cement pastes (w/b=0.4) with and without slag and fly ash cured at two moisture (sealed and saturated) and temperature (20 and 55ºC) conditions were used to investigate the combined impact of SCMs addition and curing on the pore structure of pastes cured up to two years. Also...... volume and threshold pore size were found when comparing with plain cement paste at the same curing conditions. The porosity methods MIP, LTC and SEM have been shown to be suitable to characterise pore parameters of the pastes. MIP is a simple and fast method which covers a large range of pore sizes...

  20. Chemical and Physical Characterization of Fly Ash as Geopolymer Material

    Directory of Open Access Journals (Sweden)

    Risdanareni Puput

    2017-01-01

    Full Text Available Research on finding suitable cement substitute material becomes massive due to environmental effect. Geopolymer as inorganic material is potential to be the smart solution to overcome global warming issue. Fly ash is a waste material rich in silica and alumina becomes popular raw material to produce geopolymer. The best properties ofgeopolymer paste come from the high quality of fly ash. Therefore, it is important to investigate various types of fly ash and geopolymer properties. Their chemical and physical properties characterized by XRF, pH value, XRD and SEM. The results showed that type of fly ash depended on amount of Si-based of Ca-based compound which consisted of spherical morphology. Geopolymer paste produced from the ash with different compound has bulky and irregular shape morphology. The pH value of each ash has also a correlation with the setting time of fresh paste.

  1. Bauxite residue (Red mud) as a pulverised fuel ash substitute in the manufacture of lightweight aggregate

    OpenAIRE

    Molineux, Chloe J.; Newport, Darryl J.; Ayati, Bamdad; Wang, Chuang; Connop, Stuart; Green, Jon E.

    2015-01-01

    This study looked at the potential of bauxite residue or red mud to be used in the manufacture of lightweight aggregate in replacement of pulverised fuel ash (PFA), commonly used as a way of recycling problematic wastes. The percentage replacements of red mud with PFA were as follows: 25, 31, 38, 44 and 50%. These were blended in a mix with waste excavated clay and sewage sludge – all from the Chongqing municipality in China. Lightweight pellets were produced using a Trefoil rotary kiln and w...

  2. Effect of Fly Ash and Silica Fume on the Mechanical Properties of Cement Paste at Different Stages of Hydration

    Science.gov (United States)

    2015-08-10

    hardening, temperature rise, and shrinkage which can lead to cracking . Similarly, the degradation resistance of cement is a property that is less...buildings, bridges, pavements , precast structures, etc. Type 2: Moderate sulfate resistance cement with low C3A content below 8%. Usually used for...cement cracking when subjected to sulfate attack. The belite hydrates to form calcium silicate hydrates and heat. The calcium silicate hydrates

  3. Investigation on Leaching Behaviour of Fly Ash and Bottom Ash Replacement in Self-Compacting Concrete

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    Fly ash and bottom ash are some of the waste generated by coal-fired power plants, which contains large quantities of toxic and heavy metals. In recent years, many researchers have been interested in studying on the properties of self-compacting concrete incorporated with fly ash and bottom ash but there was very limited research from the combination of fly ash and bottom ash towards the environmental needs. Therefore, this research was focused on investigating the leachability of heavy metals of SCC incorporated with fly ash and bottom ash by using Toxicity Characteristic Leaching Procedure, Synthetic Precipitation Leaching Procedure and Static Leaching Test. The samples obtained from the coal-fired power plant located at Peninsula, Malaysia. In this study, the potential heavy metals leached out from SCC that is produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a substitute for sand with the ratios from 10% to 30% respectively were designated and cast. There are eight heavy metals of concern such as As, Cr, Pb, Zn, Cu, Ni, Mn and Fe. The results indicated that most of the heavy metals leached below the permissible limits from the United States Environmental Protection Agency and World Health Organization limit for drinking water. As a conclusion, the minimum leaching of the heavy metals from the incorporation of fly ash and bottom ash in self-compacting concrete was found in 20% of fly ash and 20% of bottom ash replacement. The results also indicate that this incorporation could minimize the potential of environmental problems.

  4. Use of wood ash for road stabilisation

    International Nuclear Information System (INIS)

    Lagerkvist, A.; Lind, B.

    2009-01-01

    Due to warmer winters in Sweden, the bearing capacity of forestry roads has become increasingly problematic in recent years. Road stabilization is needed in order to get timber out from the forests. This usually involves the addition of cement to the road body. However, wood ash is a possible substitute for cement because it has similar properties. Using wood ash has the added advantage of saving landfill space. This paper presented an ongoing laboratory study on leaching and mechanical stability, as well as frost-sensitivity using a 30 per cent ash addition to natural soils for reinforcing a forestry road near Timra in central Sweden. The road was being monitored with regard to environmental impact and mechanical properties. The paper discussed the potential of biofuel ashes and the increasing need to reinforce infrastructure due to climate change. The environmental impact from ash use in road constructions was then addressed. It was concluded that the application of ash in road construction would help to strengthen forest roads, make them more resistant to climatic change and render them accessible year-round. 32 refs., 3 tabs., 2 figs.

  5. Microstructure and Engineering Properties of Alkali Activated Fly Ash -as an environment friendly alternative to Portland cement

    NARCIS (Netherlands)

    Ma, Y.

    2013-01-01

    Alkali activated fly ash (AAFA), also named “geopolymer”, has emerged as a novel engineering material in the construction industry. This material is normally formed by the reaction between fly ash and aqueous hydroxide or alkali silicate solution. With proper mix design, AAFA can present comparable

  6. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    KAUST Repository

    Lima, A.T.

    2010-12-17

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. © 2010 Elsevier Ltd.

  7. Assessing fly ash treatment: remediation and stabilization of heavy metals.

    Science.gov (United States)

    Lima, A T; Ottosen, Lisbeth M; Ribeiro, Alexandra B

    2012-03-01

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted by cement fraction or aggregate fraction. Surprisingly, better compressive strengths were obtained by replacing the aggregate fraction. CW ashes presented promising results for the substitution of aggregate in mortar and possibly in concrete. Copyright © 2010 Elsevier Ltd. All rights reserved.

  8. Hydration and microstructure of Portland cement partially substituted with ultrafine silica

    Directory of Open Access Journals (Sweden)

    Escalante, J. I.

    2009-12-01

    Full Text Available Geothermal waste, a by-product of steam power plants that use geothermal underground resources, was studied as a possible replacement for Portland cement. This waste consists primarily in amorphous nanometric silica with traces of sodium and potassium chlorides. The replacement ratios studied were 0, 10 and 20% in cements cured at 20 and 60 ºC. X-ray diffraction analysis showed that clinker phase hydration took place earlier in the presence of the geothermal waste. Scanning electron microscopy, in turn, revealed a reduction in porosity and intense calcium hydroxide consumption as a result of the pozzolanic reaction. The pastes containing 20% waste, however, an intense cracking was observed due to the formation of alkali silica reaction gel and ettringite. Cracking was more prominent at 60 ºC but was not observed in either the neat cement or the blend with 10 % waste. The presence of these detrimental phases was attributed to the formation of Friedel’s salt in the initial hydration stages, induced by the chlorides in the geothermal material.Se investigaron pastas de cemento Portland sustituido con un desecho geotérmico, subproducto de la generación de electricidad en plantas que emplean recursos geotérmicos. El desecho está compuesto principalmente de sílice amorfa de tamaño nanométrico, con cloruros de sodio y potasio. Se investigaron cementos con niveles de substitución de 0, 10 y 20%, curados a 20 y 60 °C. En presencia del desecho geotérmico, se observó por Difracción de rayos X cuantitativa que la hidratación de las fases del clínker se aceleró; además mediante microscopía electrónica de barrido se encontró una disminución en la porosidad y un intenso consumo de hidróxido de calcio por la reacción puzolánica. Sin embargo, para pastas con 20% de desecho geotérmico, se observó agrietamiento con la presencia de gel de reacción álcali sílice y ettringita; fue más acentuado a 60 °C y no se observó para pastas de

  9. Electrodialytically treated MSWI APC residue as substitute for cement in mortar

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Geiker, Mette Rica; Jensen, Pernille Erland

    2014-01-01

    Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are considered hazardous waste and need pretreatment prior to possible reuse. Here, two MSWI APC residues, from which the most mobile fraction of heavy metals and salts has been removed by carbonation and/or elect......Air pollution control (APC) residues from municipal solid waste incineration (MSWI) are considered hazardous waste and need pretreatment prior to possible reuse. Here, two MSWI APC residues, from which the most mobile fraction of heavy metals and salts has been removed by carbonation and...... and comparable to both the reference mortar and mortar with coal fly ash. These results indicate that electrodialytic remediation could be used a pre-treatment method for MSWI APC residues prior to reuse in mortar....

  10. Design, quality, and quality assurance of solid recovered fuels for the substitution of fossil feedstock in the cement industry.

    Science.gov (United States)

    Sarc, R; Lorber, K E; Pomberger, R; Rogetzer, M; Sipple, E M

    2014-07-01

    This paper describes the requirements for the production, quality, and quality assurance of solid recovered fuels (SRF) that are increasingly used in the cement industry. Different aspects have to be considered before using SRF as an alternative fuel. Here, a study on the quality of SRF used in the cement industry is presented. This overview is completed by an investigation of type and properties of input materials used at waste splitting and SRF production plants in Austria. As a simplified classification, SRF can be divided into two classes: a fine, high-calorific SRF for the main burner, or coarser SRF material with low calorific value for secondary firing systems, such as precombustion chambers or similar systems. In the present study, SRFs coming from various sources that fall under these two different waste fuel classes are discussed. Both SRFs are actually fired in the grey clinker kiln of the Holcim (Slovensko) plant in Rohožnik (Slovakia). The fine premium-quality material is used in the main burner and the coarse regular-quality material is fed to a FLS Hotdisc combustion device. In general, the alternative fuels are used instead of their substituted fossil fuels. For this, chemical compositions and other properties of SRF were compared to hard coal as one of the most common conventional fuels in Europe. This approach allows to compare the heavy metal input from traditional and alternative fuels and to comment on the legal requirements on SRF that, at the moment, are under development in Europe. © The Author(s) 2014.

  11. THE USE OF NATURAL TRASS FROM SAYUTAN MAGETAN AND LIME FROM NGAMPEL BLORA AS THE MATERIAL OF CEMENT SUBSTITUTION FOR MORTAR MIXTURE

    Directory of Open Access Journals (Sweden)

    Muhammad Nurzain

    2015-05-01

    Full Text Available Construction works in the Regency of Magetan, as well as in the mountain area far from capital cities and remote from transportation facilities, require large amount of material. In order to cope with the need of sand, people uses natural trass which are plenty to be found in the area. Test and research on its characteristic and strength with its potentials to be used as cement substitution have never been carried out. Lime was taken from Ngampel village, Blora as it is commonly sold in the area. The planned mixture of lime-trass paste was in the effort to obtain the best composition. The weight ratios used were 100%:0%, 80%:20%, 60%:40%, 40%:60%, 20%:80 and 0%:100%. The mortar mixture with cement substitution was 100%, 80%, 60%, 40%, 20% and 0%.The compressive strength of the lime-trash mixture was between 0.000 MPa and 2.545 MPa. The mortar compressive strength achieved was 0.373 MPa - 26.585 MPa. The test results of mortar compressive strength showed that the more cement substitution amount used, the less the compressive strength would be. The mortar compressive strength increased in line to the age of the mortar. The mortar tensile strength obtained was 0.000 MPa - 2.169 MPa. The block compressive strength obtained was 3.336 MPa - 3.403 MPa. Water absorbency of the block was 15.831% -16.056%.

  12. Effect of Crashed Stone on Properties of Fly Ash Based-Geopolymer Concrete with Local Alkaline Activator in Egypt

    OpenAIRE

    O. M. Omar; G. D. Abd Elhameed; A. M. Heniegal H. A. Mohamadien

    2015-01-01

    Green concrete are generally composed of recycling materials as hundred or partial percent substitutes for aggregate, cement, and admixture in concrete. To reduce greenhouse gas emissions, efforts are needed to develop environmentally friendly construction materials. Using of fly ash based geopolymer as an alternative binder can help reduce CO2 emission of concrete. The binder of geopolymer concrete is different from the ordinary Portland cement concrete. Geopolymer Concr...

  13. Synthesis of geopolymer from biomass-coal ash blends

    Science.gov (United States)

    Samadhi, Tjokorde Walmiki; Wulandari, Winny; Prasetyo, Muhammad Iqbal; Fernando, Muhammad Rizki; Purbasari, Aprilina

    2017-09-01

    Geopolymer is an environmentally attractive Portland cement substitute, owing to its lower carbon footprint and its ability to consume various aluminosilicate waste materials as its precursors. This work describes the development of geopolymer formulation based on biomass-coal ash blends, which is predicted to be the prevalent type of waste when biomass-based thermal energy production becomes mainstream in Indonesia. The ash blends contain an ASTM Class F coal fly ash (FA), rice husk ash (RHA), and coconut shell ash (CSA). A mixture of Na2SiO3 and concentrated KOH is used as the activator solution. A preliminary experiment identified the appropriate activator/ash mass ratio to be 2.0, while the activator Na2SiO3/KOH ratio varies from 0.8 to 2.0 with increasing ash blend Si/Al ratio. Both non-blended FA and CSA are able to produce geopolymer mortars with 7-day compressive strength exceeding the Indonesian national SNI 15-2049-2004 standard minimum value of 2.0 MPa stipulated for Portland cement mortars. Ash blends have to be formulated with a maximum RHA content of approximately 50 %-mass to yield satisfactory 7-day strength. No optimum ash blend composition is identified within the simplex ternary ash blend compositional region. The strength decreases with Si/Al ratio of the ash blends due to increasing amount of unreacted silicate raw materials at the end of the geopolymer hardening period. Overall, it is confirmed that CSA and blended RHA are feasible raw materials for geopolymer production..

  14. The ovens of the industry of the cement and their contribution to the handling of solid residuals and dangerous

    International Nuclear Information System (INIS)

    Riveros Rojas, Marcelo

    1995-01-01

    The substitution of certain row matters in the process of elaboration of the cement, as flying ashes, polluted soils with petroleum, muds of the industry of the petroleum, oxides of the industry of the steel, foundry sand and tires, they can replace until 40% of the necessities of energy of a cement oven contributing to improve the conservation of the environment. This new technology is using with success in United States and some countries of Europe

  15. Influence of setting liquid composition and liquid-to-powder ratio on properties of a Mg-substituted calcium phosphate cement.

    Science.gov (United States)

    Pina, S; Olhero, S M; Gheduzzi, S; Miles, A W; Ferreira, J M F

    2009-05-01

    The influence of four variables on various properties of a Mg-substituted calcium phosphate cement (CPC) was investigated. The variables were the heat treatment temperature of the precipitated powders, the composition of the setting liquid, the liquid-to-powder ratio (LPR), and the time over which hardened specimens were cured in air. The properties analysed were the phase composition of the starting powder, the initial setting time, the evolution of the storage shear modulus (G') and the loss shear modulus (G'') with the cement paste curing time (t), and the compressive strength. The presence of alpha-TCP in CPC facilitated the setting and hardening properties due to its progressive dissolution and the formation of brushite crystals. As far as the liquid composition is concerned, in cases where citric acid was used, adding a rheology modifier (10 wt.% polyethylene glycol or 0.5 wt.% hydroxyl propylmethylcellulose) to the acid led to an increase in the initial setting time, while an increase in the acid concentration led to a decrease in the initial setting time. The initial setting time showed to be very sensitive towards the LPR. The evolution of G' and G'' with curing time reflected the internal structural changes of cement pastes during the setting process. The compressive strength of the wet-hardened cement specimens with and without Mg increased with curing time increasing, being slightly higher in the case of Mg-substituted CPC. The results suggest that Mg-substituted CPC holds a promise for uses in orthopaedic and trauma surgery such as for filling bone defects.

  16. Hazards from radioactivity of fly ash of Greek coal power plants (CPP)

    International Nuclear Information System (INIS)

    Papastefanou, C.; Charalambous, S.

    1980-01-01

    Fly ash and fine dispersion releases from coal combustion in Greek coal power plants were studied. Concentrations in the fly ash up to 20 pCi/g and 10 pCi/g were measured for 238 U and 226 Ra respectively (not in secular equilibrium). Risk from the fly ash derives from its escape in particulate form or fine dispersion and from its use as a substitute for cement in concrete. The new data indicate that coal power plants discharge relatively larger quantities of radioactive material into the atmosphere than nuclear power plants of comparable size, during normal operation. (H.K.)

  17. CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

    Directory of Open Access Journals (Sweden)

    Nediljka Gaurina-Međimurec

    1994-12-01

    Full Text Available During a well cementing special place belongs to the cement slurry design. To ensure the best quality of cementing, a thorough understanding of well parameters is essential, as well as behaviour of cement slurry (especially at high temperatures and application of proven cementing techniques. Many cement jobs fail because of bad job planning. Well cementing without regarding what should be accomplished, can lead to well problems (channels in the cement, unwanted water, gas or fluid production, pipe corrosion and expensive well repairs. Cementing temperature conditions are important because bot-tomhole circulating temperatures affect slurry thickening time, arheology, set time and compressive strength development. Knowing the actual temperature which cement encounters during placement allows the selection of proper cementing materials for a specific application. Slurry design is affected by well depth, bottom hole circulating temperature and static temperature, type or drilling fluid, slurry density, pumping time, quality of mix water, fluid loss control, flow regime, settling and free water, quality of cement, dry or liquid additives, strength development, and quality of the lab cement testing and equipment. Most Portland cements and Class J cement have shown suitable performances in geot-hermal wells. Cement system designs for geothermal wells differ from those for conventional high temperature oil and gas wells in the exclusive use of silica flour instead of silica sand, and the avoidance of fly ash as an extender. In this paper, Portland cement behaviour at high temperatures is described. Cement slurry and set cement properties are also described. Published in literature, the composition of cement slurries which were tested in geothermal conditions and which obtained required compressive strength and water permeability are listed. As a case of our practice geothermal wells Velika Ciglena-1 and Velika Ciglena-la are described.

  18. Dye-adsorption capacity of bituminous fly ash and its pozzolanic property after used as dye-adsorbent

    Directory of Open Access Journals (Sweden)

    Penpolcharoen, M.

    2004-02-01

    Full Text Available Bituminous fly ash, which is an industrial waste, was used as an adsorbent to remove dyestuff from the textile-dye wastewater. The batch kinetic and isotherm experiments of the synthetic wastewater were firstly conducted to determine the adsorption behavior and optimal conditions for adsorption. The optimal conditions were then applied to the actual textile-dye wastewater. Under the original conditions of fly ash and wastewater, the results indicated that the color could be removed up to 86.65% by 12 g of the fly ash /L of the wastewater within 30 min. Its adsorption was described by the Freundlich isotherm. The dye-adsorbed fly ash was further studied on its pozzolanic property in terms of compressive strength by using it as a partial substitute to Portland cement type I to produce mortar. The result revealed that the highest compressive strength was of the sample containing 10% by weight of the dye-adsorbed fly ash in replacement of cement. It possessed 215 kg/cm2 at 28 days, which is 92.67% of the sample containing 10% by weight of the original fly ash in replacement of cement, or 83.33 of the cement mortar. For the environmental concern, leachabilities of lead (Pb, chromium (Cr, copper (Cu and zinc (Zn from all mortars were also carried out. No leaching of the heavy metals from any samples could be detected. Hence, the dye-adsorbed fly ash can be used as an environmental friendly construction material.

  19. Use of rice straw ash as substitute of feldspar in triaxial porcelain; Cenizas del tamo de arroz como substituto del feldespato en la fabricacion de ceramica blanca

    Energy Technology Data Exchange (ETDEWEB)

    Alvaro Guzman, A.; Silverio Delvasto, A.; Enrique Sanchez, V.; Vicente Amigo, B.

    2013-02-01

    The substitution of raw materials for processing high energy consumption materials by agricultural and agro-industrial wastes causes a positive impacts on the environment preservation. One of these residues is rice straw, which according to FAO estimation, its annual production is about 600 million tons. In this research was studied the use of rice straw ash as substitute of the use of feldspar in the white ware production. Clay-feldspar-quartz porcelains are referred to as triaxial white ware. Specimens of semidry triaxial mixtures, where feldspar was substituted for different percentages of CTA, were prepared by uniaxial pressing, followed by drying and sintering. Physical and mechanical properties of sintered bodies were evaluated. The porosity and the compressive strength of the fired pieces do increase with additions of up to 75% of CTA in substitution of feldspar. Their mineralogical phases were determined by DRX and SEM; grains of quartz, and needles of primary and secondary mullite were identified in a vitreous phase. It was concluded that feldspar can be substituted positively by CTA in white ware pastes. (Author) 22 refs.

  20. Effect of incorporation of fly ash and granulated blast furnace in the electrochemical behavior of concretes of commercial cement; Efecto de la incorporacion de ceniza volante y escoria de horno alto en el comportamiento electroquimico de concretos de cemento comercial

    Energy Technology Data Exchange (ETDEWEB)

    Gutierrez-Junco, O. J.; Pineda-Triana, Y.; Vera-Lopez, E.

    2015-07-01

    This paper presents the findings of the research properties evaluation pastes of commercial cement (CPC), mixed with fly ash (FA) and granulated blast furnace slag (GBFS). Initially, the sample of 30 combinations were evaluated in terms of compressive strength to establish the optimal proportions from raw material. After that, four optimized blends were characterized during the setting and hardening process. Electrochemical tests were performed on concrete cylinders samples prepared with cementitious materials and a structural steel rod placed in the center of the specimen. With the objective to evaluate the performance before corrosion, thermodynamic and kinetic aspects were taken into consideration. The findings showed that commercial cements blended with fly ash and blast furnace slag as the ones used in this research presents a decreased behavior in mechanical and corrosion strength regarding to CPC. (Author)

  1. Characteristics of Portland blast-furnace slag cement containing cement kiln dust and active silica

    Directory of Open Access Journals (Sweden)

    A. Abdel Rahman

    2016-09-01

    Full Text Available This investigation dealt with the effect of active silica, silica fume (SF or rice husk ash (RHA, on the mechanical and physico-chemical characteristics of the hardened blended cement pastes made of Portland blast-furnace slag cement (PSC containing cement kiln dust (CKD cured under normal conditions. Two blends made of PSC and CKD, improved by SF and two blends made of PSC and CKD improved by RHA were investigated. Hardened blended cement pastes were prepared from each cement blend by using water/cement ratio (W/C of 0.30 by weight and hydrated for various curing ages of 1, 3, 7, 28 and 90 days at the normal curing conditions under tap water at room temperature. Each cement paste was tested for its physico-chemical and mechanical characteristics; these characteristics include: compressive strength and kinetics of hydration. The phase composition of the formed hydration products was identified using X-ray diffraction (XRD and differential thermal analysis (DTA. It was found that the partial substitution of PSC by 10% and 15% of CKD is associated with an increase in the rate of hydration and a subsequent improvement of compressive strength of hardened PSC–CKD pastes. In addition, the replacement of PSC, in PSC–CKD blends, by 5% active silica was accompanied by further improvement of the physico-mechanical characteristics of the hardened PSC–CKD pastes.

  2. Microstructural analysis of the potential of sugarcane bagasse ash as a pozzolan material in cement composites; Analise microestrutural do potencial das cinzas de bagaco de cana-de-acucar como material pozolanico em compositos cimenticios

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, A.M.; Assuncao, C.C.; Guimaraes, L. de M.; Malmonge, J.A.; Tashima, M.M; Akasaki, J.L., E-mail: jorge.akasaki@gmail.com [Universidade Estadual Paulista Julio de Mesquita Filho (UNESP), Ilha Solteira, SP (Brazil). Faculdade de Engenharia

    2016-07-01

    For civil construction, the ash obtained by burning sugarcane bagasse (SCBA) in sugar-cane industry is being treated as a pozzolan material because, in addition to containing high amounts of silicon and aluminium oxides, can promote reduction of the environmental impact caused by cement production, since this alternative material may partially replace the Portland cement.The present study evaluated the pozzolanic potential of the SCBA, from different states of Brazil (Sao Paulo (SP), Goias (GO) and Mato Grosso (MT)). The reactivity of the material was analyzed by microstructural characterization, besides the pastes production (lime / SCBA and cement / SCBA) for the analysis of the hydration products formed, which are evaluated by TG and SEM. There was a decrease in the formation of ettringite in the matrixes, inversely proportional to the amount of ash, which favored the reduction of the cracking in cementitious matrices. It has also observed that the pastes produced with the ashes from State of SP showed greater fixation of lime and, consequently, a high reactivity. (author)

  3. Eco-friendly porous concrete using bottom ash aggregate for marine ranch application.

    Science.gov (United States)

    Lee, Byung Jae; Prabhu, G Ganesh; Lee, Bong Chun; Kim, Yun Yong

    2016-03-01

    This article presents the test results of an investigation carried out on the reuse of coal bottom ash aggregate as a substitute material for coarse aggregate in porous concrete production for marine ranch applications. The experimental parameters were the rate of bottom ash aggregate substitution (30%, 50% and 100%) and the target void ratio (15%, 20% and 25%). The cement-coated granular fertiliser was substituted into a bottom ash aggregate concrete mixture to improve marine ranch applications. The results of leaching tests revealed that the bottom ash aggregate has only a negligible amount of the ten deleterious substances specified in the Ministry of Environment - Enforcement Regulation of the Waste Management Act of Republic Korea. The large amount of bubbles/air gaps in the bottom ash aggregate increased the voids of the concrete mixtures in all target void ratios, and decreased the compressive strength of the porous concrete mixture; however, the mixture substituted with 30% and 10% of bottom ash aggregate and granular fertiliser, respectively, showed an equal strength to the control mixture. The sea water resistibility of the bottom ash aggregate substituted mixture was relatively equal to that of the control mixture, and also showed a great deal of improvement in the degree of marine organism adhesion compared with the control mixture. No fatality of fish was observed in the fish toxicity test, which suggested that bottom ash aggregate was a harmless material and that the combination of bottom ash aggregate and granular fertiliser with substitution rates of 30% and 10%, respectively, can be effectively used in porous concrete production for marine ranch application. © The Author(s) 2015.

  4. [Preparation and ectopic osteoinduction study of macroporous bone substitute with calcium phosphate cements and rhBMP-2 loaded gelatin microspheres].

    Science.gov (United States)

    Li, Meng; Liu, Xu-dong; Liu, Xing-yan; Ge, Bao-feng

    2011-05-01

    To prepare macroporous bone substitute composed of calcium phosphate cements and rhBMP-2 loaded gelatin microspheres, and to investigate ectopic osteoinduction of the composite. After being prepared by improved emulsified cold-condensation method and crosslinked by 5% genipin solution,gelatin microspheres (GMs) were observed by scanning electron microscope (SEM) and loaded with rhBMP-2 by adsorption. Macroporous bone substitute was developed by mixing calcium phosphate cement (CPC) with 2.5% GMs, being as the experimental group,and CPC with rhBMP-2 was the control group. After the both composites had been soaked in the sodium chloride for 1 week or 3 weeks, compressive strength of the composites were tested, and the cross-sections were observed by SEM. Concentrations of rhBMP-2 in the solutions at different time by ELISA method and the cumulative drug release amount was calculated. The composites had been implanted in the muscle bags of the mouses for 3 weeks. Then the tissues around the materials were collected, stained by hematoxylin and eosin, and Ca and ALP in the tissues were also measured. Gelatin microspheres were spherical with diameters of (62 +/- 18) microm. Macropores appeared in the experimental materials 1 week and 3 weeks after being soaked,and total porosity, macroporosity, cumulative release amount of rhBMP-2 in the experimental group were higher than that in the control. But compressive strength of the experimental group was lower than that of the control group 3 weeks after being soaked. Results of HE stain showed chondral formation in both groups, but there were more chondral tissues in the experiment group, and so were the concentrations of Ca and ALP. Macroporous calcium phosphate cement can be prepared by using rhBMP-2 loaded gelatin microspheres, and it is an excellent bone substitute due to it's proterty of promoting rhBMP release and powerful ectopic osteoinduction.

  5. Robot based deposition of WC-Co HVOF coatings on HSS cutting tools as a substitution for solid cemented carbide cutting tools

    Science.gov (United States)

    Tillmann, W.; Schaak, C.; Biermann, D.; Aßmuth, R.; Goeke, S.

    2017-03-01

    Cemented carbide (hard metal) cutting tools are the first choice to machine hard materials or to conduct high performance cutting processes. Main advantages of cemented carbide cutting tools are their high wear resistance (hardness) and good high temperature strength. In contrast, cemented carbide cutting tools are characterized by a low toughness and generate higher production costs, especially due to limited resources. Usually, cemented carbide cutting tools are produced by means of powder metallurgical processes. Compared to conventional manufacturing routes, these processes are more expensive and only a limited number of geometries can be realized. Furthermore, post-processing and preparing the cutting edges in order to achieve high performance tools is often required. In the present paper, an alternative method to substitute solid cemented carbide cutting tools is presented. Cutting tools made of conventional high speed steels (HSS) were coated with thick WC-Co (88/12) layers by means of thermal spraying (HVOF). The challenge is to obtain a dense, homogenous, and near-net-shape coating on the flanks and the cutting edge. For this purpose, different coating strategies were realized using an industrial robot. The coating properties were subsequently investigated. After this initial step, the surfaces of the cutting tools were ground and selected cutting edges were prepared by means of wet abrasive jet machining to achieve a smooth and round micro shape. Machining tests were conducted with these coated, ground and prepared cutting tools. The occurring wear phenomena were analyzed and compared to conventional HSS cutting tools. Overall, the results of the experiments proved that the coating withstands mechanical stresses during machining. In the conducted experiments, the coated cutting tools showed less wear than conventional HSS cutting tools. With respect to the initial wear resistance, additional benefits can be obtained by preparing the cutting edge by means

  6. Reuse of ash coal in the formulation of mortars; Reaproveitamento de cinzas de carvao mineral na formulacao de argamassas

    Energy Technology Data Exchange (ETDEWEB)

    Siqueira, J.S.; Souza, C.A.G.; Souza, J.A.S., E-mail: jacilene_s@yahoo.com.br, E-mail: celioag@ufpa.br, E-mail: jass@ufpa.br [Programa de Pos Graduacao em Engenharia Quimica, Universidade Federal do Para, UFPA/PPEQ, Belem, PA (Brazil)

    2012-04-15

    This paper aims to study the ash incorporation from the combustion of coal in fluidized bed boilers, in production of mortar, replacing part of cement. Specimens were prepared using Portland cement to the specifications CPII-E-32 of normal characteristics and classification of sand below 100 mesh. Blends in the 4:1 ratio, that is, 4 parts of aggregate to 1 part of cement, with insertion of ashes in the proportions 0, 10, 20, 30, 40 and 50%. The mortar was developed in mixing and casting was made in a mold of 5 cm x 10 cm. The behavior of compressive strength was evaluated after 28 days; the strength decreases with increasing percentage of ash. Additional analysis was carried out by X-ray diffraction, and it was found that the substitution of this waste can be successfully used in mortars with blends of up to 30%. (author)

  7. Magnesium substitution in brushite cements: Efficacy of a new biomaterial loaded with vancomycin for the treatment of Staphylococcus aureus infections.

    Science.gov (United States)

    Cabrejos-Azama, Jatsue; Alkhraisat, Mohammad Hamdan; Rueda, Carmen; Torres, Jesús; Pintado, Concepción; Blanco, Luis; López-Cabarcos, Enrique

    2016-04-01

    Staphylococcus aureus is the most relevant pathogen associated with bone infection that sometimes appears after implant surgery, thus compromising a successful treatment. The aim of this work was to assess the effectiveness of brushite cements, doped with magnesium, as a new vancomycin carrier system against S.aureus infections. We performed an "in vitro" study to evaluate vancomycin release from the cements by measuring its antimicrobial activity against a strain of S.aureus. We have used two methods to load the cements with vancomycin: i) adsorption from a solution and ii) incorporation of the antibiotic into the solid phase during the cement synthesis. Furthermore, the compression strength of the loaded samples was measured to detect changes in the mechanical properties of the system. The "in vitro" study showed that the sustained release of vancomycin depends on the concentration of magnesium in the cement matrix. In addition, the standardized antibacterial assay revealed that the release of vancomycin from the cements may be helpful to prevent infections in bone regeneration procedures. Copyright © 2015 Elsevier B.V. All rights reserved.

  8. Permeation Properties and Pore Structure of Surface Layer of Fly Ash Concrete.

    Science.gov (United States)

    Liu, Jun; Qiu, Qiwen; Xing, Feng; Pan, Dong

    2014-05-30

    This paper presents an experimental study on the nature of permeation properties and pore structure of concrete surface layers containing fly ash. Concretes containing different dosages of fly ash as a replacement for cement (15% and 30% by weight of total cement materials, respectively) were investigated. Concrete without any fly ash added was also employed as the reference specimen. Laboratory tests were conducted to determine the surface layer properties of concrete including chloride transport, apparent water permeability and pore structure. The results demonstrate that incorporation of fly ash, for the early test period, promotes the chloride ingress at the surface layer of concrete but substituting proportions of fly ash may have little impact on it. With the process of chloride immersion, the chloride concentration at the surface layer of concrete with or without fly ash was found to be nearly the same. In addition, it is suggested that the water permeability at the concrete surface area is closely related to the fly ash contents as well as the chloride exposure time. Pore structure was characterized by means of mercury intrusion porosimetry (MIP) test and the scanning electron microscopy (SEM) images. The modification of pore structure of concrete submersed in distilled water is determined by the pozzolanic reaction of fly ash and the calcium leaching effect. The pozzolanic reaction was more dominant at the immersion time of 180 days while the calcium leaching effect became more evident after 270 days.

  9. MSW fly ash stabilized with coal ash for geotechnical application.

    Science.gov (United States)

    Kamon, M; Katsumi, T; Sano, Y

    2000-09-15

    The solidification and stabilization of municipal solid waste (MSW) fly ash for the purpose of minimizing the geo-environmental impact caused by toxic heavy metals as well as ensuring engineering safety (strength and soaking durability) are experimentally evaluated. The mixtures of MSW fly ash stabilized with cement and fluidized bed combustion coal fly ash (FCA) were used for unconfined compressive strength tests, leachate tests, and soaking tests. The behavior of soluble salts contained in the MSW fly ash significantly affects strength development, soaking durability, and the hardening reaction of the stabilized MSW fly ash mixtures. The cement stabilization of the MSW fly ash does not have enough effect on strength development and soaking durability. The addition of cement only contributes to the containment of heavy metals due to the high level of alkalinity. When using FCA as a stabilizing agent for MSW fly ash, the mixture exhibits high strength and durability. However, the Cd leachate cannot be prevented in the early stages of curing. Using a combination of cement and FCA as a MSW fly ash stabilizer can attain high strength, high soaking durability, and the containment of heavy metals. The stabilized MSW fly ash with cement and FCA can be practically applied to embankments.

  10. Recycling of spent catalyst and waste sludge from industry to substitute raw materials in the preparation of Portland cement clinker

    Directory of Open Access Journals (Sweden)

    Kae-Long Lin

    2017-09-01

    Full Text Available This study investigated the feasibility of using waste limestone sludge, waste stone sludge, iron oxide sludge, and spent catalyst as raw materials in the production of eco-cement. The compressive strength development of the Eco Cement-A (ECO-A paste was similar to that of ordinary Portland cement (OPC pastes. The compressive strength development of the ECO-B paste was higher than that of OPC pastes. In addition, the C2S (Ca2SiO4, C2S and C3S (Ca3SiO5 minerals in the eco-cement paste were continuously utilized to hydrate the Ca(OH2 and calcium silicate hydrates gel (Ca6Si3O12·H2O, C–S–H throughout the curing time. When ECO-C clinker contained 8% spent catalyst, the C3S mineral content decreased and C3A (3 CaO·Al2O3 content increased, thereby causing the structure to weaken and compressive strength to decrease. The results showed that the developed eco-cement with 4% spent catalyst possessed compressive strength properties similar to those of OPC pastes.

  11. Potencial da cinza do bagaço da cana-de-açúcar como material de substituição parcial de cimento Portland Potential of sugarcane bagasse ash as a partial replacement material for Portland cement

    Directory of Open Access Journals (Sweden)

    Marcos O. de Paula

    2009-06-01

    Full Text Available Este trabalho, voltado para a avaliação do potencial da cinza do bagaço da cana-de-açúcar (CBC como material de substituição parcial do cimento Portland em argamassa, objetivou apresentar opção viável para a destinação deste resíduo, cuja quantidade gerada aumentará significativamente nos próximos anos, em decorrência da ampliação do setor de produção de álcool combustível; além disso, o emprego da CBC como adição mineral, substituindo parte do cimento em argamassas e concretos, contribui para a redução do impacto ambiental desses materiais, em boa parte decorrente da produção do cimento. O procedimento experimental abordou não só caracterização da CBC mas também a avaliação, através de ensaios físicos e mecânicos, em que os resultados mostraram que o bagaço apresenta rendimento de CBC de 10%, com a cinza sendo composta de 84% de SiO2 e 5% de Carbono. A sílica na CBC apresenta-se na fase amorfa e nas fases cristalinas de cristobalita e quartzo. Os índices de atividade pozolânica comprovam a reatividade da CBC. Do ponto de vista da resistência à compressão, argamassas com teores de CBC entre 0 e 30% indicaram a possibilidade de substituição de até 20% do cimento pela CBC.This study is focused on the evaluation of the effects of the partial replacement of Portland cement by sugarcane bagasse ash (CBC in mortars. The main objective was to find a suitable destination for an agricultural residue generated in an increasing amount in Brazil, as a result of the boom of the use of ethanol as an alternative fuel to gasoline. Also, the use of CBC as a mineral admixture in mortars and concretes contributes to a decrease in the environmental impact of these materials related to cement production. Experimental techniques were applied both for the CBC characterization and for the evaluation of its use as a mineral admixture in mortars, based on mechanical and physical tests. The yield of CBC from sugarcane

  12. Interaction of acid mine drainage with Ordinary Portland Cement blended solid residues generated from active treatment of acid mine drainage with coal fly ash.

    Science.gov (United States)

    Gitari, Wilson M; Petrik, Leslie F; Key, David L; Okujeni, Charles

    2011-01-01

    Fly ash (FA) has been investigated as a possible treatment agent for Acid mine drainage (AMD) and established to be an alternative, cheap and economically viable agent compared to the conventional alkaline agents. However, this treatment option also leads to generation of solid residues (SR) that require disposal and one of the proposed disposal method is a backfill in coal mine voids. In this study, the interaction of the SR with AMD that is likely to be present in such backfill scenario was simulated by draining columns packed with SR and SR + 6% Ordinary Portland Cement (OPC) unsaturated with simulated AMD over a 6 month period. The evolving geochemistry of the liquid/solid (L/S) system was evaluated in-terms of the mineral phases likely or controlling contaminants attenuation at the different pH regimes generated. Stepwise acidification of the percolates was observed as the drainage progressed. Two pH buffer zones were observed (7.5-9 and 3-4) for SR and (11.2-11.3 and 3.5-4) for SR + 6% OPC. The solid residue cores (SR) appeared to have a significant buffering capacity, maintaining a neutral to slightly alkaline pH in the leachates for an extended period of time (97 days: L/S 4.3) while SR + 6% OPC reduced this neutralization capacity to 22 days (L/S 1.9). Interaction of AMD with SR or SR + 6% OPC generated alkaline conditions that favored precipitation of Fe, Al, Mn-(oxy) hydroxides, Fe and Ca-Al hydroxysulphates that greatly contributed to the contaminants removal. However, precipitation of these phases was restricted to the pH of the leachates remaining at neutral to circum-neutral levels. Backfill of mine voids with SR promises to be a feasible technology for the disposal of the SR but its success will greatly depend on the disposal scenario, AMD generated and the alkalinity generating potential of the SR. A disadvantage would be the possible re-dissolution of the precipitated phases at pH water column. However extrapolation of this concept to a field

  13. Polyether-substituted mannich-bases as fuel and ash-free dispersion compounds. Polyetersubstituerte mannichbaser som brennstoff og askefrie dispergeringsmidler

    Energy Technology Data Exchange (ETDEWEB)

    Blain, D.A.; Cardis, A.B.

    1994-07-04

    The invention relates to reaction products formed from polyether-modified phenol-containing mannich-bases. They have appeared to be efficient ash-free dispersion means and detergents for hydrocarbon fuels and lubricants. According to the invention, the reaction products are formed by (1) transforming phenol or a c[sub 1] to about a c[sub 4]0 phenol with a suitable primary or secondary amine and a c[sub 1] to about a c[sub 3]0 aldehyde, thereafter (2) transforming the resulting medium product, according to (1), with an alkali metal or an alkali metal salt thereof, and afterwards (3), transforming the product, according to (2), with a c[sub 2] to about c[sub 8] alkylene epoxide or a mixture thereof for producing a polyether-substituted mannich-base. 1 tab.

  14. Mineralogy of fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Moon Young; Park, Suk Whan [Korea Inst. of Geology Mining and Materials, Taejon (Korea, Republic of); Lee, Moo Seung [Chonbuk National University, Chonju (Korea, Republic of)

    1995-12-01

    This study is focused on mineralogical and chemical characteristics of coal fly ash collected from Boreong, Honam, Samcheonpo, Gunsan, Seocheon power plants. Mineralogical and chemical characters of fly ashes are clarified by experimental studies, using x-ray diffractometer, scanning electron microscope, differential thermal analyzer, grain size analyzer and chemical analysis. The results of this study can be summarized as follows; The coal fly ashes from the all power plants are mainly consisted with mullite and quartz, and minor quantity of hematite. In particular, fly ash from the Honam power plant is converted into the anorthite under the 1200 degree. According to the result grain size analysis, most of the fly ashes are under the 200 mesh except 66% of fly ashes from the Boreong and Honam, 54% from Seocheon, 83% from Gunsan and 31% from Samcheonpo power plants. The unburned carbon contents are decreased in the small grain size of fly ashes. Under the 200 mesh grain size of Honam fly ashes shows particularly less than 1% content of unburned carbon. Chemical components of fly ashes are found to be 49-80% of SiO{sub 2} and Al{sub 2}O{sub 3} contents in the bituminous and anthracite coal ash are 49-69% and 75-80%, respectively. The Fe{sub 2}O{sub 3} and CaO concentrations in the bituminous coal ash are higher than anthracite coal ash. The trace elements such as Pb and Zn are higher anthracite coal ash than bituminous coal ash, which is mainly due to the grain size characteristic. The fly ash from Honam power plant with high CaO content can be used potassium silicate fertilizer and raw materials for cements after separation of 200 mesh. Anorthite are formed after 1200 degree heating of bituminous coal ash, which can be utilized as aggregate and bricks. (author). 21 refs., 32 figs., 7 tabs.

  15. Use of the “red gypsum” industrial waste as substitute of natural gypsum for commercial cements manufacturing

    Directory of Open Access Journals (Sweden)

    Gázquez, M. J.

    2012-06-01

    Full Text Available The main objective of this research has been the valorisation of a waste from the TiO2 production process (sulphate method, called red gypsum, in the production of cements. This waste is mainly formed by di-hydrate calcium sulphate and iron hydroxides. To cover this objective it has been necessary to perform the physico-chemical characterisation of the red gypsum as well as the main components in the production of cements and of the new cements generated. Moreover, for the red gypsum, has been analyzed its radioactive content because it is generated in a NORM (Naturally Occurring Radioactive Materials industry. Finally, the most important properties of the obtained cements with different proportions of red gypsum in their composition have been studied by comparing them with the standard ones obtained in a Portland cement. Lastly, we have demonstrated that the new cements fulfil all the quality tests imposed by the European legislation.

    El objetivo de esta investigación ha sido analizar la valorización de un residuo generado en el proceso de producción de dióxido de titanio (vía sulfato, denominado yeso rojo, en la producción de cementos. Dicho residuo está compuesto fundamentalmente por sulfato de calcio di-hidratado e hidróxidos de hierro. Para ello, ha sido necesaria la caracterización físico-química del yeso rojo, así como la de los otros componentes fundamentales en la fabricación de cementos y de los cementos generados con el mencionado residuo. Además, en el caso del yeso rojo, se ha analizado su contenido radiactivo al generarse éste en una industria NORM (Natural Occurring Radioactive Materials. Posteriormente, se han estudiado las propiedades más importantes de los cementos producidos con diferentes porcentajes de yeso rojo añadido, comparando estas mezclas con las propiedades de un cemento Portland comercial, comprobándose que se cumplen todas las normas Europeas de calidad exigibles.

  16. Low pH Cements

    Energy Technology Data Exchange (ETDEWEB)

    Savage, David; Benbow, Steven [Quintessa Ltd., Henley-on-Thames (United Kingdom)

    2007-05-15

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit {<=} 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio {<=} 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  17. Low pH Cements

    International Nuclear Information System (INIS)

    Savage, David; Benbow, Steven

    2007-05-01

    The development of low-pH cements for use in geological repositories for radioactive waste stems from concerns over the potential for deleterious effects upon the host rock and other EBS materials (notably bentonite) under the hyperalkaline conditions (pH > 12) of cement pore fluids. Low pH cement (also known as low heat cement) was developed by the cement industry for use where large masses of cement (e.g. dams) could cause problems regarding heat generated during curing. In low pH cements, the amount of cement is reduced by substitution of materials such as fly ash, blast furnace slag, silica fume, and/or non-pozzolanic silica flour. SKB and Posiva have ruled out the use of blast furnace slag and fly-ash and are focusing on silica fume as a blending agent. Currently, no preferred composition has been identified by these agencies. SKB and Posiva have defined a pH limit ≤ 11 for cement grout leachates. To attain this pH, blending agents must comprise at least 50 wt % of dry materials. Because low pH cement has little, or no free portlandite, the cement consists predominantly of calcium silicate hydrate (CSH) gel with a Ca/Si ratio ≤ 0.8. Although there are potential implications for the performance of the spent fuel and cladding due to the presence of hyperalkaline fluids from cement, the principal focus for safety assessment lies with the behaviour of bentonite. There are a number of potential constraints on the interaction of hyperalkaline cement pore fluids with bentonite, including mass balance, thermodynamic issues, mass transport, and kinetics, but none of these is likely to be limiting if conventional OPC cements are employed in repository construction. Nevertheless: Low-pH cements may supply approximately 50 % less hydroxyl ions than conventional OPC for a given volume of cement, but mass balance constraints are complicated by the uncertainty concerning the type of secondary minerals produced during cement-bentonite interaction. The change of aqueous

  18. Conditioning processes for incinerator ashes

    International Nuclear Information System (INIS)

    Jouan, A.; Ouvrier, N.; Teulon, F.

    1990-01-01

    Three conditioning processes for alpha-bearing solid waste incineration ashes were investigated and compared according to technical and economic criteria: isostatic pressing, cold-crucible direct-induction melting and cement-resin matrix embedding

  19. Optimization of fly ash content in concrete. Part I: Non-air-entrained concrete made without superplasticizer

    Energy Technology Data Exchange (ETDEWEB)

    N. Bouzoubaa; B. Fournier [International Centre for Sustainable Development of Cement and Concrete (ICON), Ottawa, ON (Canada)

    2003-07-01

    This paper outlines the preliminary results of a research project aimed at optimizing the fly ash content in concrete. Such fly ash concrete would develop an adequate 1-day compressive strength and would be less expensive than the normal Portland cement concrete with similar 28-day compressive strength. The results show that, in a normal Portland cement concrete having a 28-day compressive strength of 40 MPa, it is possible to replace 50% of cement by a fine fly ash (about 3000 cm{sup 2}/g) with a CaO content of about 13%, yielding a concrete of similar 28-day compressive strength. This concrete can be designed to yield an early-age strength of 10 MPa and results in a cost reduction of about 20% in comparison to the control concrete. In a case of a coarser fly ash (about 2000 cm{sup 2}/g) with a CaO content of about 4%, substitution levels of cement by this ash could be from 30% to 40%. This concrete yields a 1-day compressive strength of 10 MPa and a 28-day compressive strength similar to that of the control concrete. The total cost of this concrete is about 10% lower than that of the control concrete.

  20. Effects of Incorporating High-Volume Fly Ash into Tricalcium Silicate on the Degree of Silicate Polymerization and Aluminum Substitution for Silicon in Calcium Silicate Hydrate

    Directory of Open Access Journals (Sweden)

    Sungchul Bae

    2017-02-01

    Full Text Available This study assesses the quantitative effects of incorporating high-volume fly ash (HVFA into tricalcium silicate (C3S paste on the hydration, degree of silicate polymerization, and Al substitution for Si in calcium silicate hydrate (C–S–H. Thermogravimetric analysis and isothermal conduction calorimetry showed that, although the induction period of C3S hydration was significantly extended, the degree of hydration of C3S after the deceleration period increased due to HVFA incorporation. Synchrotron-sourced soft X-ray spectromicroscopy further showed that most of the C3S in the C3S-HVFA paste was fully hydrated after 28 days of hydration, while that in the pure C3S paste was not. The chemical shifts of the Si K edge peaks in the near-edge X-ray fine structure of C–S–H in the C3S-HVFA paste directly indicate that Al substitutes for Si in C–S–H and that the additional silicate provided by the HVFA induces an enhanced degree of silicate polymerization. This new spectromicroscopic approach, supplemented with 27Al and 29Si magic-angle spinning nuclear magnetic resonance spectroscopy and transmission electron microscopy, turned out to be a powerful characterization tool for studying a local atomic binding structure of C–S–H in C3S-HVFA system and presented results consistent with previous literature.

  1. Compressive strength and initial water absorption rate for cement brick containing high-density polyethylene (HDPE) as a substitutional material for sand

    Science.gov (United States)

    Ali, Noorwirdawati; Din, Norhasmiza; Sheikh Khalid, Faisal; Shahidan, Shahiron; Radziah Abdullah, Siti; Samad, Abdul Aziz Abdul; Mohamad, Noridah

    2017-11-01

    The rapid growth of today’s construction sector requires high amount of building materials. Bricks, known to have solid properties and easy to handle, which leads to the variety of materials added or replaced in its mixture. In this study, high density polyethylene (HDPE) was selected as the substitute materials in the making of bricks. The reason behind the use of HDPE is because of its recyclable properties and the recycling process that do not emit hazardous gases to the atmosphere. Other than that, the use of HDPE will help reducing the source of pollution by avoiding the millions of accumulated plastic waste in the disposal sites. Furthermore, the material has high endurance level and is weatherproof. This study was carried out on experimenting the substitute materials in the mixture of cement bricks, a component of building materials which is normally manufactured using the mixture of cement, sand and water, following a certain ratios, and left dried to produce blocks of bricks. A series of three different percentages of HDPE were used, which were 2.5%, 3.0% and 3.5%. Tests were done on the bricks, to study its compressive strength and the initial water absorption rate. Both tests were conducted on the seventh and 28th day. Based on the results acquired, for compressive strength tests on the 28th day, the use of 2.5% of HDPE shown values of 12.6 N/mm2 while the use of 3.0% of HDPE shown values of 12.5 N/mm2. Onto the next percentage, 3.5% of HDPE shown values of 12.5 N/mm2.

  2. Thermal Shock-resistant Cement

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Pyatina, T.; Gill, S.

    2012-02-01

    We studied the effectiveness of sodium silicate-activated Class F fly ash in improving the thermal shock resistance and in extending the onset of hydration of Secar #80 refractory cement. When the dry mix cement, consisting of Secar #80, Class F fly ash, and sodium silicate, came in contact with water, NaOH derived from the dissolution of sodium silicate preferentially reacted with Class F fly ash, rather than the #80, to dissociate silicate anions from Class F fly ash. Then, these dissociated silicate ions delayed significantly the hydration of #80 possessing a rapid setting behavior. We undertook a multiple heating -water cooling quenching-cycle test to evaluate the cement’s resistance to thermal shock. In one cycle, we heated the 200 and #61616;C-autoclaved cement at 500 and #61616;C for 24 hours, and then the heated cement was rapidly immersed in water at 25 and #61616;C. This cycle was repeated five times. The phase composition of the autoclaved #80/Class F fly ash blend cements comprised four crystalline hydration products, boehmite, katoite, hydrogrossular, and hydroxysodalite, responsible for strengthening cement. After a test of 5-cycle heat-water quenching, we observed three crystalline phase-transformations in this autoclaved cement: boehmite and #61614; and #61543;-Al2O3, katoite and #61614; calcite, and hydroxysodalite and #61614; carbonated sodalite. Among those, the hydroxysodalite and #61614; carbonated sodalite transformation not only played a pivotal role in densifying the cementitious structure and in sustaining the original compressive strength developed after autoclaving, but also offered an improved resistance of the #80 cement to thermal shock. In contrast, autoclaved Class G well cement with and without Class F fly ash and quartz flour failed this cycle test, generating multiple cracks in the cement. The major reason for such impairment was the hydration of lime derived from the dehydroxylation of portlandite formed in the autoclaved

  3. Greenlandic Waste Incineration Fly And Bottom Ash As Secondary Resource In Mortar

    DEFF Research Database (Denmark)

    Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2016-01-01

    Today, 900 tons incineration fly ash is shipped abroad annually from Greenland for deposits, whereas the 6,000 tons incineration bottom ash is deposited locally. These incineration ashes could be valuable in concrete production, where the cement has to be shipped to Greenland. For this purpose...... and cement with fly ash. Based on the compressive strength tests, it is found that using Greenlandic incineration ashes in mortar as 5% cement replacement could consume all ash instead of disposals, and could thus turn the ashes into a local resource and simultaneously reduce the import of cement....

  4. Fly ash, a multi-purpose resource for the production of cost effective building materials

    Energy Technology Data Exchange (ETDEWEB)

    Mahadew, D. [Hoogovens Technical Services Energy and Environment BV, IJmuiden (Netherlands)

    1994-12-31

    Fly ash is successfully being used as a feedstock for the production of artificial gravel which can be used as a substitute for natural gravel. Herewith an environmental problem is solved and the winning of primary raw materials can be limited. When using the cold bounded Aardelite technology for producing fly ash light-weight gravel an internal recycling stream is generated which due to its physical and chemical properties can also be used as an excellent substitute for sand and as a partial substitute for cement in the production of concrete and concrete products. This paper deals with an integrated technology for the production of building products (blocks, bricks, etc.) with up to 94% fly ash. The amount of cement required is very low and the building products meet the physical requirements. This technology opens possibilities for a large scale production of low cost housing building materials based on an effective utilization of useful properties of fly ash. 5 refs., 23 figs., 4 tabs.

  5. Geotechnical properties of clayey soil stabilized with cement ...

    African Journals Online (AJOL)

    The study was conducted to investigate the different effects of cement-sawdust ash and cement on a clayey soil sampled from Mandate Lodge, Landmark University, Omu-Aran, Nigeria. The binder mix of cementsawdust ash (CSDA) was mixed in a ratio of 1:1. The CSDA and cement were added to the soil samples at ...

  6. Evaluation of fly ash quality control tools.

    Science.gov (United States)

    2010-06-30

    Many entities currently use fly ash in portland cement concrete (PCC) pavements and structures. Although the body of knowledge is : great concerning the use of fly ash, several projects per year are subject to poor performance where fly ash is named ...

  7. A Review of Partial Replacement of Cement with Some Agro Wastes ...

    African Journals Online (AJOL)

    The use of Acha husk ash (AHA), Bambara groundnut husk ash (BGHA), Bone powder ash (BPA), Groundnut husk ash (GHA), Rice husk ash (RHA), and Wood ash (WA) to partially replace cement as a binder was reviewed. Analysis of results, using oxide composition, compound composition obtained using Bogue's model, ...

  8. Properties of Fly Ash Blocks Made from Adobe Mould

    Science.gov (United States)

    Chokhani, Alankrit; Divakar, B. S.; Jawalgi, Archana S.; Renukadevi, M. V.; Jagadish, K. S.

    2018-02-01

    Fly ash being one of the industrial waste products poses a serious disposal problem. This paper presents an experimental study of utilization of fly ash to produce blocks with varying proportions and mix combinations. Composition of fly ash blocks mainly consist of fly ash and sand, with cementitious product as either cement, lime or both, such as fly ash-sand-cement, fly ash-sand-lime and fly ash-sand-cement-lime are used. Four different proportions for each of the mix combinations are experimented. Compressive strength, water absorption, Initial rate of absorption, and dry density of fly ash blocks are studied. The influence of partial and complete replacement of cement by lime is examined.

  9. Histological Analysis of the Effect of Accelerated Portland Cement as a Bone Graft Substitute on Experimentally-Created Three-Walled Intrabony Defects in Dogs

    Directory of Open Access Journals (Sweden)

    Mohamad Javad Ashraf

    2007-12-01

    Full Text Available

    Background and aims. Recent literature shows that accelerated Portland cement (APC is a non-toxic material that may have potential to promote bone healing. The objective of this study was to histologically evaluate periodontal healing focusing on new bone regeneration following implantation of APC into intra-bony defects in dogs.

    Materials and methods. Three-wall intra-bony periodontal defects were surgically created at the mesial aspect of the first molar in both sides of mandible in six dogs. One side was randomly filled with the material and other received a flap operation only. The animals were euthanized eight weeks post-surgery when block sections of the defect sites were collected and prepared for qualitative histological analysis.

    Results. Compared to control group, stimulation of growth of new bone tissue in the cavity containing APC was significantly prominent in three of six cases, showing osteoid formation with osteoblastic rimming and new bone trabeculla. New bone formation was observed just close to cavity containing APC. Connective tissue proliferation and downgrowth of epithelium were significantly less than those of control group.

    Conclusion. Our results are encouraging for the use of APC as a bone substitute, but more comprehensive study are necessary before warranting clinical use.

  10. Reuse of municipal solid wastes incineration fly ashes in concrete mixtures.

    Science.gov (United States)

    Collivignarelli, Carlo; Sorlini, Sabrina

    2002-01-01

    This study is aimed at assessing the feasibility of concrete production using stabilized m.s.w. (municipal solid waste) incineration fly ashes in addition to natural aggregates. The tested fly ashes were washed and milled, then stabilized by a cement-lime process and finally were reused as a "recycled aggregate" for cement mixture production, in substitution of a natural aggregate (with dosage of 200-400 kg m(-3)). These mixtures, after curing, were characterized with conventional physical-mechanical tests (compression, traction, flexure, modulus of elasticity, shrinkage). In samples containing 200 kg(waste) m(-3)(concrete), a good compressive strength was achieved after 28 days of curing. Furthermore, concrete leaching behavior was evaluated by means of different leaching tests, both on milled and on monolithic samples. Experimental results showed a remarkable reduction of metal leaching in comparison with raw waste. In some cases, similar behavior was observed in "natural" concrete (produced with natural aggregates) and in "waste containing" concrete.

  11. Utilization of coal ash contributing to environment and power reduction. Sekitanbai no kankyo koken riyo to doryoku setsugen riyo no bun prime ya

    Energy Technology Data Exchange (ETDEWEB)

    Yasuda, M.. (Electric Power Development Co. Ltd., Tokyo (Japan))

    1991-09-30

    Some techniques relating to the contribution to surrounding environment and power reduction of utilizing techniques of coal ash which is produced at the rate of 500,000,000 tons/year in this world are explained. Almost all coal ash produced in Japan originates from pulverized coal firing and the utilizing areas are as follows: (1) resource preserving area including the application to the asphalt filler; (2) product substituting area including the cement substitution; (3) industrial waste processing area including the deodorant; (4) mixing area with industrial waste including the recycling one after mixing with industrial waste and mixing with mud; (5) land planting area including soil improver and culture medium pelletized with industrial waste; and (6) seabed planting area including the surface lining on sludge area in seabed. Further, the effective cases of representative applications are as follows: When coal ash is used as the filler for asphalt concrete, the effect is raised by pulverizing coal ash followed by repressing to the filler form. When coal ash is used as the cement substitute, the concrete deterioration is prevented by suppressing the alkaline aggregate reaction. 5 refs.. 5 figs., 1 tab.

  12. Investigation of Expanding Cements. Report 1. Summary of Information Available as of 1 July 1963

    Science.gov (United States)

    1965-09-01

    research) be tamed and utiliz -a. Today, expectations of such kind may with some right be stamped as banalities, and one might prefer the more limited...the following tabulation: Cementing Material,% by weight Grout Portland Expansive Aluminium Mi_z Type of Grout Cement Fly Ash Component Powder A 8o 20...tures, as a function of the behaviour of cements. Cold cements-- workable cements--ductile cements--non-shrinking cements and cements with controlled

  13. Contribution of Fineness Level of Fly Ash to the Compressive Strength of Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Firdaus

    2017-01-01

    Full Text Available The development of geopolymers has allowed the flash as the substitution of cement in the application of concrete. Therefore, this will be very useful considering the quite abundant by-product materials from power plants burning coal in South Sumatera. However, the untreated fly ash from the source caused its fineness level unpredictable, whereas the fineness of binder in cementitious material significantly affects the mechanical properties of the harden. Therefore, this study aims to determine the contribution of the fineness level of fly ash to the compressive strength of geopolymer mortar, as well as its excellent composition. Type F fly ash from Tanjung Enim Power Plant was treated by filtering to obtain different fineness levels based on the fall zones of the ash. Activators used in geopolymer mixing were sodium hydroxide (NaOH and sodium silicate (Na2SiO3 with three activator/fly ash ratios which was 0.25, 0.35 and 0.45. The results showed that the fineness level based on fall zone as well as the activator to fly ash ratio significantly influenced the compressive strength of the geopolymer mortar. The compressive strength of the F4-P4 specimen of geopolymer mortar with zone-4 fly ash and an activator ratio of 0.45 achieved 28.2 MPa at 28 days.

  14. Strength Properties of Processed Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Sivakumar Anandan

    2015-07-01

    Full Text Available The present paper reports on the mechanical treatment of fly ash for improving the delayed reactivity of fly ash with the hydration product of cement. Grinding of fly ash was carried out in a ball mill for different time durations and processing time was optimized for maximum fineness. Concrete mixes were prepared using various proportions of processed and unprocessed fly ash replacement in cement (25% and 50%. The influence of steel fiber addition on the mechanical properties of the concrete was studied for different curing periods. The test results on pozzolanic activity and lime reactivity indicate that the processed fly ash exhibited a higher strength gain than the unprocessed fly ash, with a maximum increase in compressive strength of up to 12%. Improved pozzolanic properties were noticed due to the increase in fineness of the fly ash particles.

  15. Pengaruh Kombinasi Fly Ash dan Bottom Ash sebagai Bahan Substitusi pada Campuran Beton terhadap Sifat Mekanis

    OpenAIRE

    Yahya, Tengku Tantoni; Kurniawandy, Alex; Djauhari, Zulfikar

    2017-01-01

    Fly ash and bottom ash were waste that generated from the power plant burning coal process. Fly ash and bottom ash has the potential to be developed as a basic ingredient in concrete composites. This research aimed to obtain the properties of fresh concrete and hard concrete of the combined effect of fly ash and bottom ash as a substitute ingredient in composite concrete. This research has examined the influence of a combination of waste fly ash and bottom ash to the compressive strength of a...

  16. Feasibility Of Making Concrete Using Lignite Coal Bottom Ash As Fine Aggregate

    Directory of Open Access Journals (Sweden)

    Thandavamoorthy T. S.

    2015-09-01

    Full Text Available Concrete is generally produced using materials such as crushed stone and river sand to the extent of about 80-90% combined with cement and water. These materials are quarried from natural sources. Their depletion will cause strain on the environment. To prevent this, bottom ash produced at thermal power plants by burning of coal has been utilized in this investigation into making concrete. The experimental investigation presents the development of concrete containing lignite coal bottom ash as fine aggregate in various percentages of 25, 50, and 100. Compressive, split tensile, and flexural strength as part of mechanical properties; acid, sulphate attack, and sustainability under elevated temperature as part of durability properties, were determined. These properties were compared with that of normal concrete. It was concluded from this investigation that bottom ash to an extent of 25% can be substituted in place of river sand in the production of concrete.

  17. Cementation of Nuclear Graphite Using Geopolymers

    International Nuclear Information System (INIS)

    Girke, N.A.; Steinmetz, H-J.; Bukaemsky, A.; Bosbach, D.; Hermann, E.; Griebel, I.

    2016-01-01

    Geopolymers are solid aluminosilicate materials usually formed by alkali hydroxide or alkali silicate activation of solid precursors such as coal fly ash, calcined clay and/or metallurgical slag. Today the primary application of geopolymer technology is in the development of alternatives to Portland-based cements. Variations in the ratio of aluminium to silicon, and alkali to silicon or addition of structure support, produce geopolymers with different physical and mechanical properties. These materials have an amorphous three-dimensional structure that gives geopolymers certain properties, such as fire and acid resistance, low leach rate, which make them an ideal substitute for ordinary Portland cement (OPC) in a wide range of applications especially in conditioning and storage of radioactive waste. Therefore investigations have been initiated on how and to which amount graphite as a hydrophobic material can be mixed with cement or concrete to form stable waste products and which concretes fulfil the necessary specifications best. As a result, geopolymers have been identified as a promising matrix for graphite containing nuclear wastes. With geopolymers, both favourable properties in the cementation process and a high long time structural stability of the products can be achieved. Investigations include: • direct mixing of graphite with geopolymers with or without sand as a mechanically stabilizing medium; • production of cement-graphite granulates as intermediate products and embedding of these granulates in geopolymer; • coating of formed graphite pieces with geopolymer.The report shows that carbon in the form of graphite can both be integrated with different grain size spectra as well as shaped in the hydraulic binder geopolymer and meets the requirements for a stable long-term immobilisation. (author)

  18. The effect of fly ashes in the corrosion and durability in concretes; Efecto de las Cenizas Volantes en la Durabilidad y en la Corrosion en Armaduras del Hormigon

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-12-31

    From the beginning of this century, fly ashes have been the object of a variety of studies and research-looking for different ways of application. The construction industry reuses the highest volume of the fly ash actually produced. Researches carried out on the behaviour of hydraulic blended materials mixed with fly ash have supported the progressive use of these by-products, and simultaneously have opened new ways of application. Spanish fly ash producers together with research centers, as IETcc, have been involved in investigations since 70`s. The last important research carried out has been the one dealing with the durability of concrete made with fly ash and its interaction with the corrosion of reinforcements. In this work five fly ashes of silicon-aluminous type were mixed with portland cement containing low alkali and aluminates in order to enhance the effect of those components from the fly ash. The main goal was to study the degradation mechanisms of concretes made with fly ashes, substituting partially the cement (15 and 35%) in several aggressive media: containing sulfates, chlorides or sea water. The effect to these aggressive media on the durability has also been considered regarding reinforcements. Different type of tests were carried out in laboratory and under natural exposure. In the case of laboratory studies the objectives were: 1) to stablish the mechanisms of hardening. The effect of fly ashes in pozolanic reaction and in the microstructure of the material. 2) Resistance of the addition of fly ashes against chloride and sulfates. Definition of the deterioration mechanisms. 3) Effect of fly ashes on the corrosion of reinforcements. Influence on the passivation process. Resistance against carbonation and chloride attack. (Author)

  19. Experimental studies on effect of cow dung ash (pozzolanic binder) and coconut fiber on strengthproperties of concrete

    Science.gov (United States)

    Venkatasubramanian, C.; Muthu, D.; Aswini, G.; Nandhini, G.; Muhilini, K.

    2017-07-01

    The studies on durability of concrete have attracted attention in the recent years and its long term strength depends on quality of ingredients used in production of concrete. Now a days, the availability of ingredients is limited and in order to overcome this problem, research studies focuses on some alternate materials in the concrete production process. Also, Incorporation of waste materials consumes less energy leading to reduction of emission of green house gases. The application of fly ash and cow dung ash as a pozzolanic binder instead of cement and coir fibers finds extensive application in the manufacturing process of building materials. In this project an attempt has been made to utilize cow dung ash and coconut fiber as a replacement material of cement in the production of concrete. The cement is partially replaced with cow dung ash by about 2.5, 3 & 3.5 % by weight and with 1% of coconut fiber. The Compressive and Tensile strengths of concrete were found at different curing periods (7,14 & 28 days). From this study, it is inferred that these replacements will have a reasonable improvement in the strength properties of concrete by about 55-70%. The substitution of CDA, CF is economical in terms of cost and this usage eliminates the problem of landfills, reducing the environmental risk, maintaining the ecological balance, which is very much required for our nation.

  20. Effect of blended materials on U(VI) retention characteristics for portland cement solidification product

    International Nuclear Information System (INIS)

    Tan Hongbin; Ma Xiaoling; Li Yuxiang

    2006-01-01

    Using the simulated groundwater as leaching liquid, the retention capability of U(VI) in solidification products with Portland cement, the Portland cement containing silica fume, the Portland cement containing metakaolin and the Portland cement containing fly ash was researched by leaching experiments at 25 degree C for 42 d. The results indicate silica fume and metakaolin as blended materials can improve the U(VI) retention capability of Portland cement solidification product, but fly ash can not. (authors)

  1. Effect NaOH Concentration on Bagasse Ash Based Geopolymerization

    Directory of Open Access Journals (Sweden)

    Saloma

    2016-01-01

    Full Text Available Geopolymer is a natural adhesive material which can be developed as a substitute for cement. The natural ingredients which want to use should contain silica and alumina. This paper uses bagasse ash as a basic material of mortar geopolymer. As an adhesive, the bagasse ash should be mixed with water and another activator alkali such as sodium hydroxide (NaOH and sodium silicate (Na2SiO3. The NaOHs molarity variation are 8, 10, 12, 14 and 16 M with Na2SiO3/NaOH = 1,0 sand/bagasse ash = 2,75 and activator/bagasse ash = 0,42. This research use 50 × 50 × 50 mm cube sized specimen and conduct a compressive strength test with 3, 7, 14, 21 and 28 days. The fresh mortar test result showed that the use of NaOHs molarity variation influences the slump value and time setting. The bigger NaOH molarity variation that been used, the smaller slump value. But, the time setting is increased. While the result for density and compressive strength shown that the bigger NaOH molarity variation, the bigger density and the compressive strength. Maximum compressive strength resulted from the mixture of mortar geopolymer with 16 M concentration.

  2. Biofuel Combustion Fly Ash Influence on the Properties of Concrete

    Directory of Open Access Journals (Sweden)

    Aurelijus Daugėla

    2016-02-01

    Full Text Available Cement as the binding agent in the production of concrete can be replaced with active mineral admixtures. Biofuel combustion fly ash is one of such admixtures. Materials used for the study: Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer, water. Six compositions of concrete were designed by replacing 0%, 5%, 10%, 15% 20%, and 25% of cement with biofuel fly ash. The article analyses the effect of biofuel fly ash content on the properties of concrete. The tests revealed that the increase of biofuel fly ash content up to 20% increases concrete density and compressive strength after 7 and 28 days of curing and decreases water absorption, with corrected water content by using plasticizing admixture. It was found that concrete where 20% of cement is replaced by biofuel ash has higher frost resistance.

  3. Comparative Cost and Strength Analysis of Cement and Aggregate ...

    African Journals Online (AJOL)

    This research presents a comparative cost and strength analysis of cement and aggregate replacement materials which is aimed at reducing the cost of concrete production. Tests were performed to compare the strength and cost of seven various cement replacement materials(rice husk ash, groundnut husk ash, palm oil ...

  4. Synthesis of Portland cement and calcium sulfoaluminate-belite cement for sustainable development and performance

    Science.gov (United States)

    Chen, Irvin Allen

    Portland cement concrete, the most widely used manufactured material in the world, is made primarily from water, mineral aggregates, and portland cement. The production of portland cement is energy intensive, accounting for 2% of primary energy consumption and 5% of industrial energy consumption globally. Moreover, portland cement manufacturing contributes significantly to greenhouse gases and accounts for 5% of the global CO2 emissions resulting from human activity. The primary objective of this research was to explore methods of reducing the environmental impact of cement production while maintaining or improving current performance standards. Two approaches were taken, (1) incorporation of waste materials in portland cement synthesis, and (2) optimization of an alternative environmental friendly binder, calcium sulfoaluminate-belite cement. These approaches can lead to less energy consumption, less emission of CO2, and more reuse of industrial waste materials for cement manufacturing. In the portland cement part of the research, portland cement clinkers conforming to the compositional specifications in ASTM C 150 for Type I cement were successfully synthesized from reagent-grade chemicals with 0% to 40% fly ash and 0% to 60% slag incorporation (with 10% intervals), 72.5% limestone with 27.5% fly ash, and 65% limestone with 35% slag. The synthesized portland cements had similar early-age hydration behavior to commercial portland cement. However, waste materials significantly affected cement phase formation. The C3S--C2S ratio decreased with increasing amounts of waste materials incorporated. These differences could have implications on proportioning of raw materials for cement production when using waste materials. In the calcium sulfoaluminate-belite cement part of the research, three calcium sulfoaluminate-belite cement clinkers with a range of phase compositions were successfully synthesized from reagent-grade chemicals. The synthesized calcium sulfoaluminate

  5. Evaluation of fly ash in water reduced paving mixtures.

    Science.gov (United States)

    1985-06-01

    Fly ash was used to replace 15% of the cement in C3WR and C6WR concrete : paving mixes containing ASTM C494 Type A water reducin9 admixtures. Two Class : C ashes and one Class F ash from Iowa approved sources were examined in each : mix. When Class C...

  6. Evaluation of fly ash quality control tools : tech summary.

    Science.gov (United States)

    2010-06-01

    Many entities currently use fl y ash in portland cement concrete (PCC) pavements and structures. Although : the body of knowledge is great concerning the use of fl y ash, several projects per year are subject to poor : performance where fl y ash is n...

  7. Evaluation of Fly Ash Quality Control Tools : Technical Summary

    Science.gov (United States)

    2010-06-01

    Many entities currently use fl y ash in portland cement concrete (PCC) pavements and structures. Although : the body of knowledge is great concerning the use of fl y ash, several projects per year are subject to poor : performance where fl y ash is n...

  8. Formulating a low-alkalinity cement for radioactive waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X

    2004-07-01

    A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

  9. Mix design and properties of fly ash waste lightweight aggregates in structural lightweight concrete

    Directory of Open Access Journals (Sweden)

    Manu S. Nadesan

    2017-12-01

    Full Text Available Concrete is one of the most widely used construction materials and has the ability to consume industrial wastes in high volume. As the demand for concrete is increasing, one of the effective ways to reduce the undesirable environmental impact of the concrete is by the use of waste and by-product materials as cement and aggregate substitutes in concrete. One such waste material is fly ash, which is produced in large quantities from thermal power plants as a by-product. A substantial amount of fly ash is left unused posing environmental and storage problems. The production of sintered lightweight aggregate with fly ash is an effective method to dispose of fly ash in large quantities. Due to lack of a proper mix design procedure, the production and application of lightweight aggregate in structural concrete are not much entertained. The absorption characteristic of lightweight aggregate is a major concern, while developing the mix proportioning of lightweight concretes. The present study is an attempt to establish a new mix design procedure for the development of sintered fly ash lightweight aggregate concretes, which is simple and more reliable than the existing procedures. Also, the proposed methodology has been validated by developing a spectrum of concretes having water cement ratios varying from 0.25 to 0.75. From the study, it is obvious that the development of 70 MPa concrete is possible by using cement alone without any additives. Also, it is ensured that all the concretes have densities less than 2000 kg/m3.

  10. Utilization of hospital waste ash in concrete

    International Nuclear Information System (INIS)

    Memon, S.; Sheikh, M.

    2013-01-01

    Hospital waste management is a huge problem in Pakistan. The annual production of medical waste produced from health care facilities, in Pakistan, is around 250,000 tons. This research paper is intended to evaluate the feasibility of using of hospital waste ash obtained from Pakistan Institute of Medical Sciences, Rawalpindi, Pakistan, as partial replacement of cement. The main variable in this research is the amount of hospital waste ash (2, 4, 6 and 8% by weight of cement) while the amount of cementitious material, water to cementitious material ratio, fine and coarse aggregate content were kept constant. Test results substantiate that hospital waste ash can be used in concrete. XRD (X-Ray Diffraction) of hospital waste ash showed that it is rich in calcite while scanning electron micrographs indicated that the particles of hospital waste ash have highly irregular shape. The slump value, density of fresh concrete and water absorption decreased with the increase in the quantity of hospital waste ash in the mix. At 3 days of testing, the compressive strength of mixes with hospital waste ash was higher than the control mix while at 7 and 28 days the CM (Control Mix) showed higher strength than the hospital waste ash mixes except the mix containing 2% hospital waste ash by weight of cement. (author)

  11. Pemanfaatan limbah abu terbang (fly ash) , abu dasar (bottom ash) batubara dan limbah padat (sludge) industri karet sebagai bahan campuran pada pembuatan batako

    OpenAIRE

    Faisal, Hendri

    2012-01-01

    Brick-making research has been conducted from a mixture of fly ash as a cement mixed with aggregate materials based bottom ash and sludge, and sand, where fly ash and cement used as an adhesive matrix. The percentage addition of fly ash is 10%, 20%, 30%, 40% and 50% of initial weight of cement. The percentage addition of bottom ash and sludge as an aggregate is 5%, 10%, 15%, 20% and 25% of initial weight of sand with the time of hardening for 28 days. Parameter tests performed include: metals...

  12. Identifying glass compositions in fly ash

    Directory of Open Access Journals (Sweden)

    Katherine eAughenbaugh

    2016-01-01

    Full Text Available In this study, four Class F fly ashes were studied with a scanning electron microscope; the glassy phases were identified and their compositions quantified using point compositional analysis with k-means clustering and multispectral image analysis. The results showed that while the bulk oxide contents of the fly ashes were different, the four fly ashes had somewhat similar glassy phase compositions. Aluminosilicate glasses (AS, calcium aluminosilicate glasses (CAS, a mixed glass, and, in one case, a high iron glass were identified in the fly ashes. Quartz and iron crystalline phases were identified in each fly ash as well. The compositions of the three main glasses identified, AS, CAS, and mixed glass, were relatively similar in each ash. The amounts of each glass were varied by fly ash, with the highest calcium fly ash containing the most of calcium-containing glass. Some of the glasses were identified as intermixed in individual particles, particularly the calcium-containing glasses. Finally, the smallest particles in the fly ashes, with the most surface area available to react in alkaline solution, such as when mixed with portland cement or in alkali-activated fly ash, were not different in composition than the large particles, with each of the glasses represented. The method used in the study may be applied to a fly ash of interest for use as a cementing material in order to understand its potential for reactivity.

  13. Durability of Cement Composites Reinforced with Sisal Fiber

    Science.gov (United States)

    Wei, Jianqiang

    understanding of degradation mechanisms, two approaches are proposed to mitigate the degradation of sisal fiber in the cement matrix. In order to relieve the aggressive environment of hydrated cement, cement substitution by a combination of metakaolin and nanoclay, and a combination of rice husk ash and limestone are studied. Both metakaolin and nanoclay significantly optimize the cement hydration, while the combination of these two supplementary cementitious materials validates their complementary and synergistic effect at different stages of aging. The presented approaches effectively reduce the calcium hydroxide content and the alkalinity of the pore solution, thereby mitigating the fiber degradation and improving both the initial mechanical properties and durability of the fiber-cement composites. The role of rice husk ash in cement modification is mainly as the active cementitious supplementary material. In order to improve the degradation resistance of sisal fiber itself, two novel, simple, and economical pretreatments of the fibers (thermal and sodium carbonate treatment) are investigated. Both thermal treatment and Na 2CO3 treatment effectively improve the durability of sisal fiber-reinforced concrete. The thermal treatment achieves improvement of cellulose's crystallization, which ensures the initial strength and improved durability of sisal fiber. A layer consisting of calcium carbonate sediments, which protects the internals of a fiber from the strong alkali pore solution, is formed and filled in pits and cavities on the Na2CO3 treated sisal fiber's surface.

  14. Características físicas e mecânicas de misturas de solo, cimento e cinzas de bagaço de cana-de-açúcar Physical and mechanical characteristics of soil-cement-bagasse ash mixtures

    Directory of Open Access Journals (Sweden)

    Martha Del C. Mesa Valenciano

    2004-12-01

    Full Text Available Este trabalho teve por finalidade analisar algumas características de misturas de solo, cimento e cinzas de bagaço de cana-de-açúcar para sua possível utilização na fabricação de materiais alternativos de construção. Para tal, amostras de cinzas de bagaço de cana-de-açúcar foram submetidas a um tratamento prévio que consistia de peneiramento e moagem, antes de serem incorporadas às misturas de solo e cimento. Diferentes combinações de cimento-cinzas foram estudadas, determinando-se, para cada uma delas, a consistência normal e a resistência à compressão simples, aos 7 e 28 dias. Posteriormente, corpos-de-prova moldados com tais misturas de solo-cimento-cinzas foram submetidos a ensaios de compactação, compressão simples e absorção de água. Os resultados indicaram a possibilidade de substituir até 20% do cimento Portland, na mistura, por cinzas de bagaço de cana-de-açúcar, sem prejuízo da resistência à compressão simples.This work was done with the objective of studying some physical and mechanical characteristics of the sugarcane bagasse ash added to a soil-cement mixture, in order to obtain an alternative construction material. The sugarcane bagasse ash pre-treatment included both sieving and grinding, before mixing with soil and cement. Different proportions of cement-ash were tested by determining its standard consistence and its compressive resistance at 7 and 28 days age. The various treatments were subsequently applied to the specimens molded with different soil-cement-ash mixtures which in turns were submitted to compaction, unconfined compression and water absorption laboratory tests. The results showed that it is possible to replace up to 20% of Portland cement by sugarcane bagasse ash without any damage to the mixture's compressive strength.

  15. The behavior of self-compacting concrete (SCC) with bagasse ash

    Science.gov (United States)

    Hanafiah, Saloma, Whardani, Putri Nurul Kusuma

    2017-11-01

    Self-Compacting Concrete (SCC) has the ability to flow and self-compacting. One of the benefit of SCC can reduced the construction time and labor cost. The materials to be used for see slightly different with the conventional concrete. Less coarse aggregate to be used up to 50%. The maximum size of coarse aggregate was also limited e.g. 10 mm. Other material was quartz sand with grain size of 50-650 µm. For reducing the around of cement, bagasse ash was used as partial replacement of cement. In this research, the variations of w/c to be used, e.g. 0.275, 0.300, 0.325 and the percentage of bagasse ash substitution were 10%, 15%, and 20%. EFNARC standard was conducted for slump flow test following the V-funnel test and L-box shape test. The maximum value of slump flow test was 75.75 cm, V-funnel test was 4.95 second, and L-box test was 1.000 yielded by mixture with w/c = 0.325 and 0% of bagasse ash. The minimum value of slump flow test was 61.50 cm, V-funnel test is 21.05 second, and L-box test was 0.743 yielded by mixture with w/c = 0.275 and 20% of bagasse ash. The maximum value of compressive strength was 67.239 MPa yielded by mixture with w/c = 0.275 and 15% of bagasse ash. And the minimum value of compressive strength was 41.813 MPa yielded by mixture with w/c = 0.325 and 20% bagasse ash.

  16. Performance of Cement Containing Laterite as Supplementary Cementing Material

    Directory of Open Access Journals (Sweden)

    Abbas Bukhari, Z. S.

    2013-03-01

    Full Text Available The utilization of different industrial waste, by-products or other materials such as ground granulated blast furnace slag, silica fume, fly ash, limestone, and kiln dust, etc. as supplemen- tary cementing materials has received considerable attention in recent years. A study has been conducted to look into the performance of laterite as Supplementary Cementing Materials (SCM. The study focuses on compressive strength performance of blended cement containing different percentage of laterite. The cement is replaced accordingly with percentage of 2 %, 5 %, 7 % and 10 % by weight. In addition, the effect of use of three chemically different laterites have been studied on physical performance of cement as in setting time, Le-Chatlier expansion, loss on ignition, insoluble residue, free lime and specifically compressive strength of cement cubes tested at the age of 3, 7, and 28 days. The results show that the strength of cement blended with laterite as SCM is enhanced. Key words: Portland cement, supplementary cementing materials (SCM, laterite, compressive strength KUI – 6/2013 Received January 4, 2012 Accepted February 11, 2013

  17. Possibilities of utilizing power plant fly ashes

    Directory of Open Access Journals (Sweden)

    Mezencevová Andrea

    2003-09-01

    Full Text Available The burning of fossil fuels in industrial power stations plays a significant role in the production of thermal and electrical energy. Modern thermal power plants are producing large amounts of solid waste, mainly fly ashes. The disposal of power plant waste is a large environmental problem at the present time. In this paper, possibilities of utilization of power plant fly ashes in industry, especially in civil engineering, are presented. The fly ash is a heterogeneous material with various physical, chemical and mineralogical properties, depending on the mineralogical composition of burned coal and on the used combustion technology. The utilization of fly ashes is determined of their properties. The fineness, specific surface area, particle shape, density, hardness, freeze-thaw resistance, etc. are decisive. The building trade is a branch of industry, which employs fly ash in large quantities for several decades.The best utilization of fluid fly ashes is mainly in the production of cement and concrete, due to the excellent pozzolanic and cementitious properties of this waste. In the concrete processing, the fly ash is utilized as a replacement of the fine aggregate (fine filler or a partial replacement for cement (active admixture. In addition to economic and ecological benefits, the use of fly ash in concrete improves its workability and durability, increases compressive and flexural strength, reduces segregation, bleeding, shrinkage, heat evolution and permeability and enhances sulfate resistance of concrete.The aim of current research is to search for new technologies for the fly ash utilization. The very interesting are biotechnological methods to recovery useful components of fly ashes and unconventional methods of modification of fly ash properties such as hydrothermal zeolitization and mechanochemical modification of its properties. Mechanochemistry deals with physico - chemical transformations and chemical reactions of solids induced by

  18. The future resources for eco-building materials: II. Fly ash and coal waste

    Energy Technology Data Exchange (ETDEWEB)

    Hui Li; Delong Xu [Xi' an University of Architecture & Technology, Xi' an (China). China State key Laboratory of Western Architecture & Technology

    2009-08-15

    To use fly ash and coal waste effectively, the current technologies for reprocessing and recycling these wastes into eco-building materials were reviewed, such as utilizing fly ash as the component of fly ash cement and low heat cement after the processes of separation, removal of carbon remains and fine comminution, calcining coal waste into kaolin and meta-kaolin with suspension technology, and preparing clinkerless alkali-activated geopolymer materials with fly ash and meta-kaolin.

  19. Innovative use of recovered municipal solid waste incineration bottom ash as a component in growing media.

    Science.gov (United States)

    Sormunen, Annika; Teo, Kanniainen; Tapio, Salo; Riina, Rantsi

    2016-07-01

    The utilisation of municipal solid waste incineration bottom ash has been extensively studied, for example, in the unbound layers of roads and the products of cement and concrete industry. On the other hand, less attention has been given to other innovative utilisation possibilities, such as using the municipal solid waste incineration bottom ash as a component in growing media of plants. The municipal solid waste incineration bottom ash contains useful substances, such as calcium, that can influence plant growth in a positive manner. Therefore, the utilisation of this waste-derived material in the growing media may substitute the use of commercial fertilisers. Since the municipal solid waste incineration bottom ash also contains hazardous substances that can be toxic to plants, the main aim of this study was to add different amounts of recovered municipal solid waste incineration bottom ash in the growing media and to evaluate the effect of this material on plant growth. Based on the obtained results, the concentration of, for example copper and zinc, increased in test plants; ryegrass and barley, when recovered municipal solid waste incineration bottom ash was added in their growing media. On the other hand, this did not have a significant effect on plant growth, if compared with the growth of plants in commercially produced growing medium. Furthermore, the replacement of natural sand with municipal solid waste incineration bottom ash had a positive liming effect in the growing media. Overall, these findings suggest that the utilisation of recovered municipal solid waste incineration bottom ash as a component in growing media is possible and, thus, may allow more widespread and innovative use of this waste-derived material. © The Author(s) 2016.

  20. Alkali silica reaction (ASR) in cement free alkali activated sustainable concrete.

    Science.gov (United States)

    2016-12-19

    This report summarizes the findings of an experimental evaluation into alkali silica : reaction (ASR) in cement free alkali-activated slag and fly ash binder concrete. The : susceptibility of alkali-activated fly ash and slag concrete binders to dele...

  1. A review of binders used in cemented paste tailings for underground and surface disposal practices.

    Science.gov (United States)

    Tariq, Amjad; Yanful, Ernest K

    2013-12-15

    Increased public awareness of environmental issues coupled with increasingly stringent environmental regulations pertaining to the disposal of sulphidic mine waste necessitates the mining industry to adopt more competent and efficient approaches to manage acid rock drainage. Cemented paste tailings (CPT) is an innovative form of amalgamated material currently available to the mining industry in developed countries. It is made usually from mill tailings mingled with a small amount of binder (customarily Portland cement) and water. The high cost associated with production and haulage of ordinary Portland cement and its alleged average performance as a sole binder in the long term (due to vulnerability to internal sulphate attack) have prompted users to appraise less expensive and technically efficient substitutes for mine tailings paste formulations. Generally, these binders include but are not limited to sulphate resistant cements, and/or as a partial replacement for Portland cement by artificial pozzolans, natural pozzolans, calcium sulphate substances and sodium silicates. The approach to designing environmentally efficient CPT is to ensure long-term stability and effective control over environmental contaminants through the use of composite binder systems with enhanced engineering properties to cater for inherit deficiencies in the individual constituents. The alkaline pore solution created by high free calcium rich cement kiln dust (CKD) (byproduct of cement manufacturing) is capable of disintegrating the solid glassy network of artificial pozzolans to produce reactive silicate and aluminate species when attacked by (OH(-)) ions. The augmented pozzolanic reactivity of CKD-slag and CKD-fly ash systems may produce resilient CPT. Since cemented paste comprising mine tailings and binders is a relatively new technology, a review of the binding materials used in such formulations and their performance evaluation in mechanical fill behaviour was considered pertinent in

  2. Fly ash quality and utilization

    Energy Technology Data Exchange (ETDEWEB)

    Barta, L.E.; Lachner, L.; Wenzel, G.B. [Inst. for Energy, Budapest (Hungary); Beer, M.J. [Massachusetts Inst. of Technology, Cambridge, MA (United States)

    1995-12-01

    The quality of fly ash is of considerable importance to fly ash utilizers. The fly ash puzzolanic activity is one of the most important properties that determines the role of fly ash as a binding agent in the cementing process. The puzzolanic activity, however is a function of fly ash particle size and chemical composition. These parameters are closely related to the process of fly ash formation in pulverized coal fired furnaces. In turn, it is essential to understand the transformation of mineral matter during coal combustion. Due to the particle-to-particle variation of coal properties and the random coalescence of mineral particles, the properties of fly ash particles e.g. size, SiO{sub 2} content, viscosity can change considerably from particle to particle. These variations can be described by the use of the probability theory. Since the mean values of these randomly changing parameters are not sufficient to describe the behavior of individual fly ash particles during the formation of concrete, therefore it is necessary to investigate the distribution of these variables. Examples of these variations were examined by the Computer Controlled Scanning Electron Microscopy (CCSEM) for particle size and chemical composition for Texas lignite and Eagel Butte mineral matter and fly ash. The effect of combustion on the variations of these properties for both the fly ash and mineral matter were studied by using a laminar flow reactor. It is shown in our paper, that there are significant variations (about 40-50% around the mean values) of the above-listed properties for both coal samples. By comparing the particle size and chemical composition distributions of the mineral matter and fly ash, it was possible to conclude that for the Texas lignite mineral matter, the combustion did not effect significantly the distribution of these properties, however, for the Eagel Butte coal the combustion had a major impact on these mineral matter parameters.

  3. Wet-Treated MSWI Fly Ash Used as Supplementary Cementitious Material

    Directory of Open Access Journals (Sweden)

    Martin Keppert

    2015-01-01

    Full Text Available Municipal solid waste incineration (MSWI is a common technique in treatment of domestic waste. This technique annually produces approximately 25 Mt solid residues (i.e., bottom and fly ash worldwide which is also a major issue in current research. In this research we are concerned with reusing the fly ash (FA as supplementary cementitious material (SCM in concrete. Such application solves the problem with heavy metal immobilization as well. To remove the high content of undesired soluble salts, number of washing treatments has been applied. Chemical composition of FA has been examined before and after treatments. The impact of cement substitution by FA in concrete was evaluated by measurement of its compressive strength and durability.

  4. NEW TECHNOLOGY OF ASH AND SLAG CONCRETES

    Directory of Open Access Journals (Sweden)

    PAVLENKO T. M.

    2017-03-01

    Full Text Available Summary. Purpose. Development of scientific-technical bases of manufacture and application of concrete on the basis of ash and slag mixes of thermal power plants. Methods. It is proposed a new technology of preparation of ash and slag concrete mixes. First the ash and slag mix is dispersed through the sieve with meshes 5 mm in a fine-grained fraction and slag. Then, in accordance with the composition of the concrete, obtained fine-grained fraction, slag, cement and tempering water are separately dosed into the mixer. Results. It is proven the high efficiency of the proposed technology of manufacture of ash and slag concretes. It is established that this technological solution allows to increase the strength of concrete by 20...30%, and in the preparation of full-strength concrete to reduce the cement consumption by 15...20%. Scientific novelty. It is developed the new technology of ash and slag mixes application. The concrete mix on the basis of ash and slag mix has an optimal particle size distribution, which ensures the best compaction and, accordingly, the greatest strength of ash and slag concrete with the given cement consumption. Practical significance. The research results promote the mass application of ash and slag mixes of thermal power plants in construction, obtaining of products from the proposed concretes of low cost with high physical-mechanical properties. Conclusion. It is proven the high efficiency of the proposed technology of production of ash and slag concretes. It is established that this technological solution allows increasing concrete strength, and obtaining full-strength concrete to reduce cement consumption. The extensive application of such concrete in construction makes it possible to solve the problem of aggregates for concrete, promotes recycling of TPP waste and consequently the protection of the environment.

  5. Mechanical properties and microstructure analysis of fly ash geopolymeric recycled concrete

    Energy Technology Data Exchange (ETDEWEB)

    Shi, X.S. [College of Architecture and Environment, Sichuan University, Chengdu (China); Collins, F.G.; Zhao, X.L. [Department of Civil Engineering, Monash University, Clayton (Australia); Wang, Q.Y., E-mail: wangqy@scu.edu.cn [College of Architecture and Environment, Sichuan University, Chengdu (China)

    2012-10-30

    Highlights: Black-Right-Pointing-Pointer Sodium silicate solution and sodium hydroxide solution were used to activate fly ash, which substitute cement totally in the concrete. Black-Right-Pointing-Pointer Utilizing two kinds of waste materials (fly ash and recycled aggregates) at the same time. Black-Right-Pointing-Pointer The mechanical properties and microstructures were studied and compared with different recycled aggregates replacement ratios. Black-Right-Pointing-Pointer Such concrete has greater compressive strength and better microstructure than ordinary concrete and also geopolymer concrete. - Abstract: Six mixtures with different recycled aggregate (RA) replacement ratios of 0%, 50% and 100% were designed to manufacture recycled aggregate concrete (RAC) and alkali-activated fly ash geopolymeric recycled concrete (GRC). The physical and mechanical properties were investigated indicating different performances from each other. Optical microscopy under transmitted light and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) were carried out in this study in order to identify the mechanism underlying the effects of the geopolymer and RA on concrete properties. The features of aggregates, paste and interfacial transition zone (ITZ) were compared and discussed. Experimental results indicate that using alkali-activated fly ash geopolymer as replacement of ordinary Portland cement (OPC) effectively improved the compressive strength. With increasing of RA contents in both RAC and GRC, the compressive strength decreased gradually. The microstructure analysis shows that, on one hand, the presence of RA weakens the strength of the aggregates and the structure of ITZs; on the other hand, due to the alkali-activated fly ash in geopolymer concrete, the contents of Portlandite (Ca(OH){sub 2}) and voids were reduced, as well as improved the matrix homogeneity. The microstructure of GRC was changed by different reaction products, such

  6. Mechanical properties and microstructure analysis of fly ash geopolymeric recycled concrete

    International Nuclear Information System (INIS)

    Shi, X.S.; Collins, F.G.; Zhao, X.L.; Wang, Q.Y.

    2012-01-01

    Highlights: ► Sodium silicate solution and sodium hydroxide solution were used to activate fly ash, which substitute cement totally in the concrete. ► Utilizing two kinds of waste materials (fly ash and recycled aggregates) at the same time. ► The mechanical properties and microstructures were studied and compared with different recycled aggregates replacement ratios. ► Such concrete has greater compressive strength and better microstructure than ordinary concrete and also geopolymer concrete. - Abstract: Six mixtures with different recycled aggregate (RA) replacement ratios of 0%, 50% and 100% were designed to manufacture recycled aggregate concrete (RAC) and alkali-activated fly ash geopolymeric recycled concrete (GRC). The physical and mechanical properties were investigated indicating different performances from each other. Optical microscopy under transmitted light and scanning electron microscopy (SEM) coupled with energy dispersive X-ray spectroscopy (EDX) were carried out in this study in order to identify the mechanism underlying the effects of the geopolymer and RA on concrete properties. The features of aggregates, paste and interfacial transition zone (ITZ) were compared and discussed. Experimental results indicate that using alkali-activated fly ash geopolymer as replacement of ordinary Portland cement (OPC) effectively improved the compressive strength. With increasing of RA contents in both RAC and GRC, the compressive strength decreased gradually. The microstructure analysis shows that, on one hand, the presence of RA weakens the strength of the aggregates and the structure of ITZs; on the other hand, due to the alkali-activated fly ash in geopolymer concrete, the contents of Portlandite (Ca(OH) 2 ) and voids were reduced, as well as improved the matrix homogeneity. The microstructure of GRC was changed by different reaction products, such as aluminosilicate gel.

  7. Composites Based on Fly Ash and Clay

    International Nuclear Information System (INIS)

    Fidancevska, E.; Jovanov, V.; Angusheva, B.; Srebrenkoska, V.

    2014-01-01

    Fly ash is a waste generated from the coal combustion during the production of electricity in the thermal power plants. It presents industrial by-product containing Technologically Enhanced Natural Occurring Radioactive Materials (TENORM) with the great potential for valorisation. Fly ash is successfully utilized in cement and concrete industry, also in ceramics industry as component for manufacturing bricks and tiles, and recently there are many investigations for production of glass-ceramics from fly ash. Although the utilization of fly ash in construction and civil engineering is dominant, the development of new alternative application for its further exploitation into new products is needed. This work presents the possibility for fly ash utilization for fabricating dense composites based on clay and fly ash with the potential to be used in construction industry

  8. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    OpenAIRE

    Solikin Mochamad; Setiawan Budi

    2017-01-01

    High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC) and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly ...

  9. Solidification/stabilization of fly and bottom ash from medical waste incineration facility.

    Science.gov (United States)

    Anastasiadou, Kalliopi; Christopoulos, Konstantinos; Mousios, Epameinontas; Gidarakos, Evangelos

    2012-03-15

    In the present work, the stabilization/solidification of fly and bottom ash generated from incinerated hospital waste was studied. The objectives of the solidification/stabilization treatment were therefore to reduce the leachability of the heavy metals present in these materials so as to permit their disposal in a sanitary landfill requiring only a lower degree of environmental protection. Another objective of the applied treatment was to increase the mechanical characteristics of the bottom ash using different amounts of Ordinary Portland Cement (OPC) as a binder. The solidified matrix showed that the cement is able to immobilize the heavy metals found in fly and bottom ash. The TCLP leachates of the untreated fly ash contain high concentrations of Zn (13.2 mg/l) and Pb (5.21 mg/l), and lesser amounts of Cr, Fe, Ni, Cu, Cd and Ba. Cement-based solidification exhibited a compressive strength of 0.55-16.12 MPa. The strength decreased as the percentage of cement loading was reduced; the compressive strength was 2.52-12.7 MPa for 60% cement mixed with 40% fly ash and 6.62-16.12 MPa for a mixture of 60% cement and 40% bottom ash. The compressive strength reduced to 0.55-1.30 MPa when 30% cement was mixed with 70% fly ash, and to 0.90-7.95 MPa when 30% cement was mixed with 70% bottom ash, respectively. Copyright © 2011 Elsevier B.V. All rights reserved.

  10. effect of carbide waste on the properties of rice husk ash concrete.

    African Journals Online (AJOL)

    DJFLEX

    KEY WORDS: Carbide Waste, Rice Husk Ash, Cement, Concrete and Rigid Pavement. ... the use of the remaining agro waste materials. Rice Husk Ash, RHA is .... served as the control mix. Summary of the mix design is as presented in Table 1. Table 1. Summary of Mix Design. Material. Quantities (Kg) per m3. Cement. 450.

  11. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    OpenAIRE

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-01-01

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone pow...

  12. Cement Formation

    DEFF Research Database (Denmark)

    Telschow, Samira; Jappe Frandsen, Flemming; Theisen, Kirsten

    2012-01-01

    Cement production has been subject to several technological changes, each of which requires detailed knowledge about the high multiplicity of processes, especially the high temperature process involved in the rotary kiln. This article gives an introduction to the topic of cement, including...... an overview of cement production, selected cement properties, and clinker phase relations. An extended summary of laboratory-scale investigations on clinkerization reactions, the most important reactions in cement production, is provided. Clinker formations by solid state reactions, solid−liquid and liquid...

  13. Ruedersdorf cement works substitutes raw material and fuel by means of a circulating fluidised bed; Roh- und Brennstoffsubstitution mit einer Zirkulierenden Wirbelschicht im Zementwerk Ruedersdorf

    Energy Technology Data Exchange (ETDEWEB)

    Scur, P. [Ruedersdorfer Zement GmbH, Ruedersdorf (Germany)

    1998-09-01

    The purpose of the present paper is to point out the great potential the cement industry holds for the utilisation of waste materials. There are meanwhile sufficient studies and measuring results to demonstrate the environmental acceptability of the processes and products involved. The solution found for Ruedersdorf cement kiln of using a circulating a fluidised bed for waste utilisation is a good example of the potential still available for conserving natural resources and landfill area. Efficient industrial applications of this kind should become a future mainstay of the waste industry. [Deutsch] In dem vorliegenden Beitrag sollte gezeigt werden, dass die Zementindustrie ueber ein hohes Potential zur thermischen und stofflichen Verwertung von Abfallstoffen verfuegt. Es liegen ausreichende Untersuchungen und konkrete Messergebnisse vor, mit denen die Umweltvertraeglichkeit von Prozess und Produkt nachgewiesen werden kann. Die Loesung zur Abfallverwertung an der Ruedersdorfer Zementofenanlage mit Hilfe einer Zirkulierenden Wirbelschicht ist ein Beispiel fuer die Reserven zur Schonung natuerlicher Ressourcen und zur Einsparung von Deponieraeumen. Derartige sinnvolle industrielle Einsatzmoeglichkeiten sollten ein wichtiges Standbein fuer die zukuenftige Abfallwirtschaft sein. (orig.)

  14. Mechanical Properties of High Volume Fly Ash Concrete Reinforced with Hybrid Fibers

    Directory of Open Access Journals (Sweden)

    Rooban Chakravarthy

    2016-01-01

    Full Text Available Fly ash substitution to cement is a well-recognized approach to reduce CO2 emissions. Although fly ash concrete is prone to brittle behavior, researchers have shown that addition of fibers could reduce brittle behavior. Previous research efforts seem to have utlised a single type of fiber or two types of fibers. In this research, three types of fibers, steel, polypropylene, and basalt as 0%, 0.50%, 0.75%, and 1% by volume of concrete, were mixed in varying proportions with concrete specimens substituted with 50% fly ash (class F. All specimens were tested for compressive strength, indirect tensile strength, and flexural strength over a period of 3 to 56 days of curing. Test results showed that significant improvement in mechanical properties could be obtained by a particular hybrid fiber reinforcement combination (1% steel fiber, 0.75% polypropylene fiber, and 0.75% basalt fiber. The strength values were observed to exceed previous research results. Workability of concrete was affected when the fiber combination exceeded 3%. Thus a limiting value for adding fibers and the combination to achieve maximum strengths have been identified in this research.

  15. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-01-01

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability. PMID:28793518

  16. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash

    Directory of Open Access Journals (Sweden)

    Isamu Yoshitake

    2015-08-01

    Full Text Available Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  17. Recyclability of Concrete Pavement Incorporating High Volume of Fly Ash.

    Science.gov (United States)

    Yoshitake, Isamu; Ishida, Takeo; Fukumoto, Sunao

    2015-08-21

    Recyclable concrete pavement was made from fly ash and crushed limestone sand and gravel as aggregates so that the concrete pavement could be recycled to raw materials for cement production. With the aim to use as much fly ash as possible for the sustainable development of society, while achieving adequate strength development, pavement concrete having a cement-replacement ratio of 40% by mass was experimentally investigated, focusing on the strength development at an early age. Limestone powder was added to improve the early strength; flexural strength at two days reached 3.5 MPa, the minimum strength for traffic service in Japan. The matured fly ash concrete made with a cement content of 200 kg/m3 achieved a flexural strength almost equal to that of the control concrete without fly ash. Additionally, Portland cement made from the tested fly ash concrete was tested to confirm recyclability, with the cement quality meeting the Japanese classification of ordinary Portland cement. Limestone-based recyclable fly ash concrete pavement is, thus, a preferred material in terms of sustainability.

  18. Geometric models for lateritic soil stabilized with cement and ...

    African Journals Online (AJOL)

    . Thus this study attempted to investigate into the effects of bagasse ash on compaction and strength characteristics of cement-stabilized lateritic soil and also to develop geometric models. The compaction, California bearing ratio, unconfined ...

  19. Rheological Properties of Cemented Tailing Backfill and the Construction of a Prediction Model

    OpenAIRE

    Lang, Liu; Song, KI-IL; Lao, Dezheng; Kwon, Tae-Hyuk

    2015-01-01

    Workability is a key performance criterion for mining cemented tailing backfill, which should be defined in terms of rheological parameters such as yield stress and plastic viscosity. Cemented tailing backfill is basically composed of mill tailings, Portland cement, or blended cement with supplementary cement material (fly ash and blast furnace slag) and water, among others, and it is important to characterize relationships between paste components and rheological properties to optimize the w...

  20. Corrosion Behavior of Steel Reinforcement in Concrete with Recycled Aggregates, Fly Ash and Spent Cracking Catalyst

    Science.gov (United States)

    Gurdián, Hebé; García-Alcocel, Eva; Baeza-Brotons, Francisco; Garcés, Pedro; Zornoza, Emilio

    2014-01-01

    The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the environment by replacing a 50% of cement by industrial by-products (15% of spent fluid catalytic cracking catalyst and 35% of fly ash) and a 100% of natural coarse aggregate by recycled aggregate. The concretes prepared according to these considerations have been tested in terms of mechanical strengths and the protection offered against steel reinforcement corrosion under carbonation attack and chloride-contaminated environments. The proposed concrete combinations reduced the mechanical performance of concretes in terms of elastic modulus, compressive strength, and flexural strength. In addition, an increase in open porosity due to the presence of recycled aggregate was observed, which is coherent with the changes observed in mechanical tests. Regarding corrosion tests, no significant differences were observed in the case of the resistance of these types of concretes under a natural chloride attack. In the case of carbonation attack, although all concretes did not stand the highly aggressive conditions, those concretes with cement replacement behaved worse than Portland cement concretes. PMID:28788613

  1. Corrosion Behavior of Steel Reinforcement in Concrete with Recycled Aggregates, Fly Ash and Spent Cracking Catalyst

    Directory of Open Access Journals (Sweden)

    Hebé Gurdián

    2014-04-01

    Full Text Available The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the environment by replacing a 50% of cement by industrial by-products (15% of spent fluid catalytic cracking catalyst and 35% of fly ash and a 100% of natural coarse aggregate by recycled aggregate. The concretes prepared according to these considerations have been tested in terms of mechanical strengths and the protection offered against steel reinforcement corrosion under carbonation attack and chloride-contaminated environments. The proposed concrete combinations reduced the mechanical performance of concretes in terms of elastic modulus, compressive strength, and flexural strength. In addition, an increase in open porosity due to the presence of recycled aggregate was observed, which is coherent with the changes observed in mechanical tests. Regarding corrosion tests, no significant differences were observed in the case of the resistance of these types of concretes under a natural chloride attack. In the case of carbonation attack, although all concretes did not stand the highly aggressive conditions, those concretes with cement replacement behaved worse than Portland cement concretes.

  2. Corrosion Behavior of Steel Reinforcement in Concrete with Recycled Aggregates, Fly Ash and Spent Cracking Catalyst.

    Science.gov (United States)

    Gurdián, Hebé; García-Alcocel, Eva; Baeza-Brotons, Francisco; Garcés, Pedro; Zornoza, Emilio

    2014-04-21

    The main strategy to reduce the environmental impact of the concrete industry is to reuse the waste materials. This research has considered the combination of cement replacement by industrial by-products, and natural coarse aggregate substitution by recycled aggregate. The aim is to evaluate the behavior of concretes with a reduced impact on the environment by replacing a 50% of cement by industrial by-products (15% of spent fluid catalytic cracking catalyst and 35% of fly ash) and a 100% of natural coarse aggregate by recycled aggregate. The concretes prepared according to these considerations have been tested in terms of mechanical strengths and the protection offered against steel reinforcement corrosion under carbonation attack and chloride-contaminated environments. The proposed concrete combinations reduced the mechanical performance of concretes in terms of elastic modulus, compressive strength, and flexural strength. In addition, an increase in open porosity due to the presence of recycled aggregate was observed, which is coherent with the changes observed in mechanical tests. Regarding corrosion tests, no significant differences were observed in the case of the resistance of these types of concretes under a natural chloride attack. In the case of carbonation attack, although all concretes did not stand the highly aggressive conditions, those concretes with cement replacement behaved worse than Portland cement concretes.

  3. Water permeabilities of pulverized fuel ash; Bifuntan sekitanbai no tosui tokusei

    Energy Technology Data Exchange (ETDEWEB)

    Ichikawa, T. [Center for Coal Utilization, Japan, Tokyo (Japan); Nagataki, S. [Niigata University, Niigata (Japan); Hosoda, N. [Kumagai Gumi Co. Ltd., Tokyo (Japan); Utsuki, T. [The Coal Mining Research Center, Japan, Tokyo (Japan); Kubo, H. [Obayashi Corp., Tokyo (Japan)

    1996-09-01

    It is intended to establish a technology to utilize coal ash in bulk to deal with its increasing production. In order to expand its use into earth engineering materials, two kinds of combustion ashes produced from dust coal burning power plants were used for studies using different kinds of tests. The tests were carried out on strength properties, water permeability, and characteristics of dissolving trace amounts of chemical constituents, with regard to addition effects of cement into compacted and slurry-state dust coal burned ashes. The derived findings may be summarized as follows: as the strength properties, the strength for both of the compacted and slurry-state ashes increases as the cement addition ratio is increased; growth of the strength due to the cement addition ratio and material age varies depending on the kinds of dust coal burned ash; comparison of strengths of the compacted and the slurry-state ashes indicates the strength of the latter ash is about one-third to quarter of that of the former ash; water permeability of the ashes decreases both in the compacted and slurry- state ashes as the cement addition ratio is increased; and the cement addition ratio gives greater impact to the water permeability than the density of the ashes. 28 figs., 5 tabs.

  4. Laboratory Investigations on Mechanical Properties of High Volume Fly Ash Concrete and Composite Sections

    OpenAIRE

    Aravindkumar B. Harwalkar; S. S. Awanti

    2013-01-01

    Use of fly ash as a supplementary cementing material in large volumes can bring both technological and economic benefits for concrete industry. In this investigation mix proportions for high volume fly ash concrete were determined at cement replacement levels of 50%, 55%, 60% and 65% with low calcium fly ash. Flexural and compressive strengths of different mixes were measured at ages of 7, 28 and 90 days. Flexural strength of composite section prepared from pavement quali...

  5. Solidification of radioactive incinerator ash

    International Nuclear Information System (INIS)

    Schuler, T.F.; Charlesworth, D.L.

    1986-01-01

    The Ashcrete process will solidify ash generated by the Beta Gamma Incinerator (BGI) at the Savannah River Plant (SRP). The system remotely handles, adds material to, and tumbles drums of ash to produce ashcrete, a stabilized wasteform. Full-scale testing of the Ashcrete unit began at Savannah River Laboratory (SRL) in January 1984, using nonradioactive ash. Tests determined product homogeneity, temperature distribution, compressive strength, and final product formulation. Product formulations that yielded good mix homogeneity and final product compressive strength were developed. Drum pressurization and temperature rise (resulting from the cement's heat of hydration) were also studied to verify safe storage and handling characteristics. In addition to these tests, an expert system was developed to assist process troubleshooting

  6. Geopolymer obtained from coal ash

    International Nuclear Information System (INIS)

    Conte, V.; Bissari, E.S.; Uggioni, E.; Bernardin, A.M.

    2011-01-01

    Geopolymers are three-dimensional alumino silicates that can be rapidly formed at low temperature from naturally occurring aluminosilicates with a structure similar to zeolites. In this work coal ash (Tractebel Energy) was used as source of aluminosilicate according a full factorial design in eight formulations with three factors (hydroxide type and concentration and temperature) and two-levels. The ash was dried and hydroxide was added according type and concentration. The geopolymer was poured into cylindrical molds, cured (14 days) and subjected to compression test. The coal ash from power plants belongs to the Si-Al system and thus can easily form geopolymers. The compression tests showed that it is possible to obtain samples with strength comparable to conventional Portland cement. As a result, temperature and molarity are the main factors affecting the compressive strength of the obtained geopolymer. (author)

  7. Topics in cement and concrete research

    OpenAIRE

    Brouwers, Jos; Russel, M.I.; Basheer, P.A.M.

    2007-01-01

    The present paper addresses several topics in regard to the sustainable design and use of concrete. First, major features concerning the sustainable aspects of the material concrete are summarised. Then the major constituent, from an environmental point of view, cement is discussed in detail, particularly the hydration and application of slag cement. The intelligent combining of mineral oxides, which are found in clinker, slag, fly ashes etc., is designated as mineral oxide engineering. It re...

  8. Estudo das características químicas e físicas da cinza da casca da castanha de caju para uso em materiais cimentícios = A study of the chemical and physical properties of cashew nut shell ash for use in cement materials

    Directory of Open Access Journals (Sweden)

    Sofia Araujo Lima

    2010-10-01

    Full Text Available As cinzas ocupam lugar de destaque dentre os resíduos agroindustriais por resultarem de processos de geração de energia. Sabe-se que muitas dessas cinzas possuem reatividade pozolânica, podendo ser utilizadas como adição mineral em matrizes de cimento Portland. O presente estudo tem como objetivo investigar as características físicas equímicas da cinza da casca da castanha de caju (CCCC, por meio dos seguintes ensaios: análise química, massa unitária, massa específica, extratos lixiviado e solubilizado, difratometria de raios X (DrX, superfície específica (BET e análise da pozolanicidade com o cimento Portland e com a cal. O conjunto de análises deste trabalho indica a restrição ao uso da CCCC em matrizes cimentícias em função da baixa reatividade com o hidróxido de cálcio (CH e dos altos teores de álcalis, dos metais pesados e do fenol detectados nessa cinza.Ash occupies a prominent place among agro-industrial wastes, as it is derived from energy generation processes. Several types of ash havepozzolanic reactivity, and might be used as replacement material for cement, resulting in less energy waste and lower cost. This work aimed to investigate the physical and chemical properties of the cashew nut shell ash (CNSA, by performing the following measurementtests: chemical analysis, bulk density, specific mass, leaching and solubilization process, Xray diffraction (XrD, specific surface area (BET and pozzolanicity analysis with cement and lime. The results indicate a low reactivity of CNSA and the presence of heavy metals,alkalis and phenol.

  9. Comparison of compressive strength of paving block with a mixture of Sinabung ash and paving block with a mixture of lime

    Science.gov (United States)

    Hastuty, I. P.; Sembiringand Nursyamsi, I. S.

    2018-02-01

    Paving block is one of the material used as the top layer of road structure besides asphalt and concrete paving block is usually made of mixed material such as Portland cement or other adhesive material, water, and aggregate. People nowadays prefer paving block compared to other pavement such as concrete or asphalt. Their interest toward the use of paving block increase because paving block is an eco-friendly construction which is very useful in helping soil water conservation, can be done faster, has easier installation and maintenance, has a variety of shades that increase the aesthetic value, also costs cheaper than the other. Preparation of the specimens with a mixture of Sinabung ash and a mixture of Sinabung ash and lime are implemented with a mixture ratio of cement : sand : stone ash is 1: 2 : 3. The mixture is used as a substitute material by reducing the percentage amount of the weight of the cement with the composition ratio variation based on the comparative volume category of the paving block aggregate, i.e. 0%, 5%, 10%, 15%, 20%, and 25%. The result of this research shows that the maximum compressive strength value is 42.27 Mpa, it was obtained from a mixture of 10% lime with curing time 28 days. The maximum compressive strength value which is obtained from the mixture of sinabung ash is 41.60 Mpa, it was obtained from a mixture of 15% sinabung ash. From the use of these two materials, paving blocks produced are classified as paving blocks quality A and B (350 - 400 Mpa) in accordance to specification from SNI 03-0691-1996.

  10. Early-age Performance of Cement Combination Concrete

    Directory of Open Access Journals (Sweden)

    Samuel Olufemi Folagbade

    2017-03-01

    Full Text Available Heat of hydration up to 72 hours and compressive strength up to 7 days of Portland cement and 17 binary and ternary cements containing fly ash, silica fume, and metakaolin, at a water/cement ratio of 0.50 and addition contents of 20%, 35%, and 55%, were used to examine the early-age performance of concrete. Results revealed that early-age performance depends on the fineness, heat of hydration, and dilution effect of cement combinations. Fly ash, due to dilution effect, reduces the heat of hydration and compressive strength. Using silica fume and metakaolin with increasing content of up to 10% as binary and ternary cement components, due to their fineness and increased heat of hydration, supports the strength development. Most of the cement combinations met the standard of strength requirements for ordinary early-age performance of concrete, while only half of it satisfied the standard for high early-age performance.

  11. Geotechnical Properties of Clayey Soil Stabilized with Cement ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... lime and cement are the two major additives for the stabilization of soils. The cost of the materials has however ... improving additives like cement, and lime, has made the cost of road construction on stabilized soils huge. Thus .... with sugarcane straw ash. American J. Sci. Ind.Res. (2):323-331. Asiagwu, AK ...

  12. Cement matrix composite construction features for production of waterproofing coatings

    OpenAIRE

    Суханевич, Марина Володимирівна

    2014-01-01

    It is investigated the properties of the matrix based on Portland cement, slag-contain and fly-ash- slag-contain cements modified with the addition of natural zeolite and complex additives consisting of carbon nanotubes in C-3 solution plasticizer as the main component of composite waterproofing material that is applied to wet concrete in the form of thin-layer coatings.

  13. Geotechnical Properties of Clayey Soil Stabilized with Cement ...

    African Journals Online (AJOL)

    ADOWIE PERE

    2017-12-31

    Dec 31, 2017 ... increase in energy cost since 1970s (Neville, 2000). Much dependence on the use of manufactured soil improving additives like cement, and lime, has made the cost of road construction on stabilized soils huge. Thus, the use of waste materials such as rice husk ash, sawdust ash etc., which are pozzolanic ...

  14. Development of Ecoefficient Engineered Cementitious Composites Using Supplementary Cementitious Materials as a Binder and Bottom Ash Aggregate as Fine Aggregate

    Directory of Open Access Journals (Sweden)

    Jin Wook Bang

    2015-01-01

    Full Text Available The purpose of this study is to develop ecoefficient engineered cementitious composites (ECC using supplementary cementitious materials (SCMs, including fly ash (FA and blast furnace slag (SL as a binder material. The cement content of the ECC mixtures was replaced by FA and SL with a replacement rate of 25%. In addition, the fine aggregate of the ECC was replaced by bottom ash aggregate (BA with a substitution rate of 10%, 20%, and 30%. The influences of ecofriendly aggregates on fresh concrete properties and on mechanical properties were experimentally investigated. The test results revealed that the substitution of SCMs has an advantageous effect on fresh concrete’s properties; however, the increased water absorption and the irregular shape of the BA can potentially affect the fresh concrete’s properties. The substitution of FA and SL in ECC led to an increase in frictional bond at the interface between PVA fibers and matrix, improved the fiber dispersion, and showed a tensile strain capacity ranging from 3.3% to 3.5%. It is suggested that the combination of SCMs (12.5% FA and 12.5% SL and the BA aggregate with the substitution rate of 10% can be effectively used in ECC preparation.

  15. Influence of Fly Ash, Bottom Ash, and Light Expanded Clay Aggregate on Concrete

    Directory of Open Access Journals (Sweden)

    S. Sivakumar

    2015-01-01

    Full Text Available Invention of new methods in strengthening concrete is under work for decades. Developing countries like India use the extensive reinforced construction works materials such as fly ash and bottom ash and other ingredients in RCC construction. In the construction industry, major attention has been devoted to the use of fly ash and bottom ash as cement and fine aggregate replacements. In addition, light expanded clay aggregate has been introduced instead of coarse aggregate to make concrete have light weight. This paper presents the results of a real-time work carried out to form light weight concrete made with fly ash, bottom ash, and light expanded clay aggregate as mineral admixtures. Experimental investigation on concrete mix M20 is done by replacement of cement with fly ash, fine aggregate with bottom ash, and coarse aggregate with light expanded clay aggregate at the rates of 5%, 10%, 15%, 20%, 25%, 30%, and 35% in each mix and their compressive strength and split tensile strength of concrete were discussed for 7, 28, and 56 days and flexural strength has been discussed for 7, 28, and 56 days depending on the optimum dosage of replacement in compressive strength and split tensile strength of concrete.

  16. The utilization of stone ash on cellular lightweight concrete

    Science.gov (United States)

    Karolina, R.; Sianipar, Y. G. C.

    2018-02-01

    Lightweight concrete brick is a brick which made of cement, sand, water, and foam as the basic composition. This brick are divided into 2, based on the foam used such as AAC (Autoclave Aerated Concrete) that use aluminium paste and CLC(Cellular Lightweight Concrete) that use foaming agent from BASF as its foaming material. In this trial, the lightweight brick that are ging to be use are the CLC with foaming agent as its foaming material with the mixture of stone ash that are produced by the Stone Crusher with spesific gravity 2666 kg/m3 as their partly sand substitution . In this research, the stone ash variant that are used are 10%, 15%, and 20% from the amount of sand that planned before. After casting, the result of the 10% will receive a reduction of compressive strength while an increasing in absorption as 25.07% and 39.005% and the 15% variant will recieve a reduction of compressive strength as much as 65.8% and a reduction of absorption as much as 17.441% and the 20% variant will recieve a reduction of compressive strength as much as 67.4% while an increasing of absorption as much as 17.956%.

  17. Alternative Fuels in Cement Production

    DEFF Research Database (Denmark)

    Larsen, Morten Boberg

    The substitution of alternative for fossil fuels in cement production has increased significantly in the last decade. Of these new alternative fuels, solid state fuels presently account for the largest part, and in particular, meat and bone meal, plastics and tyre derived fuels (TDF) accounted...... for the most significant alternative fuel energy contributors in the German cement industry. Solid alternative fuels are typically high in volatile content and they may differ significantly in physical and chemical properties compared to traditional solid fossil fuels. From the process point of view......, considering a modern kiln system for cement production, the use of alternative fuels mainly influences 1) kiln process stability (may accelerate build up of blockages preventing gas and/or solids flow), 2) cement clinker quality, 3) emissions, and 4) decreased production capacity. Kiln process stability...

  18. Effect of olive waste (Husk on behavior of cement paste

    Directory of Open Access Journals (Sweden)

    Sharaf Alkheder

    2016-12-01

    Full Text Available Jordan is a famous country in terms of olive trees agriculture that resulted in a mass production of olive oil products. The huge amounts of olive waste (husk that resulted from olives processing to produce olive oil represent an environmental challenge in the country. The idea in this paper comes to use olive waste as a partial replacement for Portland cement in cement paste to conserve the environment, reduce cement consumption and increase cost efficiency. The wastes were burned properly in an oven and maintained for 6 h until it was fully transformed into ashes. Then, the oven was turned off and ashes were allowed to cool. After cooling, the material passed sieve #200 were used. The sieved ashes were used in the cement mix as a partial cement replacement for making the mortar and cement paste. Normal consistency and setting time were determined as well as soundness, compressive strength. Results indicated that normal consistency of the cement pastes containing different percentage of olive waste is somehow lower than that of the ordinary cement paste and slightly decreases with increasing the percentage. The results also indicated that the compressive strength of hardened blended cement paste containing different percentages of olive waste slightly decrease with olive waste content at 3, 7, and 28 days.

  19. Properties and Leachability of Self-Compacting Concrete Incorporated with Fly Ash and Bottom Ash

    Science.gov (United States)

    Kadir, Aeslina Abdul; Ikhmal Haqeem Hassan, Mohd; Jamaluddin, Norwati; Bakri Abdullah, Mohd Mustafa Al

    2016-06-01

    The process of combustion in coal-fired power plant generates ashes, namely fly ash and bottom ash. Besides, coal ash produced from coal combustion contains heavy metals within their compositions. These metals are toxic to the environment as well as to human health. Fortunately, treatment methods are available for these ashes, and the use of fly ash and bottom ash in the concrete mix is one of the few. Therefore, an experimental program was carried out to study the properties and determine the leachability of selfcompacting concrete incorporated with fly ash and bottom ash. For experimental study, self-compacting concrete was produced with fly ash as a replacement for Ordinary Portland Cement and bottom ash as a replacement for sand with the ratios of 10%, 20%, and 30% respectively. The fresh properties tests conducted were slump flow, t500, sieve segregation and J-ring. Meanwhile for the hardened properties, density, compressive strength and water absorption test were performed. The samples were then crushed to be extracted using Toxicity Characteristic Leaching Procedure and heavy metals content within the samples were identified accordingly using Atomic Absorption Spectrometry. The results demonstrated that both fresh and hardened properties were qualified to categorize as self-compacting concrete. Improvements in compressive strength were observed, and densities for all the samples were identified as a normal weight concrete with ranges between 2000 kg/m3 to 2600 kg/m3. Other than that, it was found that incorporation up to 30% of the ashes was safe as the leached heavy metals concentration did not exceed the regulatory levels, except for arsenic. In conclusion, this study will serve as a reference which suggests that fly ash and bottom ash are widely applicable in concrete technology, and its incorporation in self-compacting concrete constitutes a potential means of adding value to appropriate mix and design.

  20. Caracterização física e mecânica de argamassas à base de cimento Portland e cinza de casca de arroz residual Physical and mechanical characterization on Portland cement mortar with rice husk ash addition

    Directory of Open Access Journals (Sweden)

    Michelle S Rodrigues

    2010-04-01

    Full Text Available A casca de arroz, utilizada como fonte de energia em indústrias de beneficiamento de arroz, converte-se, depois da queima, em uma cinza residual. Esse resíduo, ainda sem um destino adequado, é muitas vezes depositado em grandes áreas abertas e provoca elevado impacto ambiental. Este trabalho teve como objetivo avaliar a viabilidade de utilização da cinza de casca de arroz (CCA residual na produção de argamassas, como substituta parcial do cimento. A caracterização da CCA foi realizada por meio da análise de fluorescência de raios-X (composição química, análise do teor de carbono e difração de raios-X; também foi realizada análise granulométrica a laser. Os corpos de prova foram submetidos a dois tipos de exposição: ambientes externo e interno, com duração máxima de cinco meses. Foram realizados os ensaios de resistência à compressão simples e não destrutivo (velocidade do pulso ultrassônico - VPU. Embora as argamassas tenham apresentado bom desempenho mecânico, os ensaios de pozolanicidade indicaram que a cinza de casca de arroz residual utilizada não é uma pozolana, mas pode ser utilizada em matrizes cimentícias como material inerte (filler.Rice husk, employed as an energy source at milling industries in Brazil generates, after burning, a dark ash. This residue is not yet conveniently disposed, being currently dumped on large areas, causing environmental problems. This research intended to evaluate the applications of residual rice husk ashes (RHA as a partial replacement of cement for mortar production. Rice husk ash was chemically characterized through X-ray fluorescence, determination of carbon content, X-ray diffraction, and laser granulometric analysis. Mortar specimens were submitted to two different exposure conditions: internal and external environments at a maximum period of five months. Physical-mechanical testing were compressive strength and ultrasonic pulse velocity (UPV. Although presenting good

  1. Possibilities of municipal solid waste incinerator fly ash utilisation.

    Science.gov (United States)

    Hartmann, Silvie; Koval, Lukáš; Škrobánková, Hana; Matýsek, Dalibor; Winter, Franz; Purgar, Amon

    2015-08-01

    Properties of the waste treatment residual fly ash generated from municipal solid waste incinerator fly ash were investigated in this study. Six different mortar blends with the addition of the municipal solid waste incinerator fly ash were evaluated. The Portland cement replacement levels of the municipal solid waste incinerator fly ash used were 25%, 30% and 50%. Both, raw and washed municipal solid waste incinerator fly ash samples were examined. According to the mineralogical composition measurements, a 22.6% increase in the pozzolanic/hydraulic properties was observed for the washed municipal solid waste incinerator fly ash sample. The maximum replacement level of 25% for the washed municipal solid waste incinerator fly ash in mortar blends was established in order to preserve the compressive strength properties. Moreover, the leaching characteristics of the crushed mortar blend was analysed in order to examine the immobilisation of its hazardous contents. © The Author(s) 2015.

  2. Radioactivity aspects of Indian fly ash for agricultural use

    International Nuclear Information System (INIS)

    Vijayan, V.; Behera, S.N.

    1999-01-01

    Fly ash is a major component of solid waste material produced by the coal-fired thermal power plants. In India the total amount of fly ash produced per annum is around 60 million tons. However fly ash has a great potential for utilization in making industrial products such as cement, concrete mix, bricks as well as building materials, besides being used as a soil conditioner and a provider of macro and micro nutrients in agriculture. It can also be used as a material for mine fills. However, given the large amount of fly ash fly that accumulate at thermal power plants, their possible reuse and dispersion and mobilization into the environment of the various elements depend on climate, soils, indigenous vegetation and agriculture practices, hence there is a need to characterize the radioactivity of ash. This paper presents the results of a study of the radioactivity aspects of fly ashes and pond ashes from thermal power plants of India. (author)

  3. THE COMPRESSIVE AND FLEXURAL STRENGTHS OF SELF-COMPACTING CONCRETE USING RAW RICE HUSK ASH

    Directory of Open Access Journals (Sweden)

    MD NOR ATAN

    2011-12-01

    Full Text Available This study investigates the compressive and flexural strengths of self-compacting concrete incorporating raw rice husk ash, individually and in combination with other types of mineral additives, as partial cement replacement. The additives paired with raw rice husk ash were fine limestone powder, pulverized fuel ash and silica fumes. The mix design was based on the rational method where solid constituents were fixed while water and superplasticizer contents were adjusted to produce optimum viscosity and flowability. All mixes were designed to achieve SF1 class slump-flow with conformity criteria ≥ 520 mm and ≤ 700 mm. Test results show that 15% replacement of cement using raw rice husk ash produced grade 40 concrete. It was also revealed that 30% and 45% cement replacements using raw rice husk ash combined with limestone powder and raw rice husk ash combined with limestone powder and silica fume respectively, produced comparable compressive strength to normal concrete and improved flexural strengths.

  4. The effect of w/c ratio on microstructure of self-compacting concrete (SCC) with sugarcane bagasse ash (SCBA)

    Science.gov (United States)

    Hanafiah, Saloma, Victor, Amalina, Khoirunnisa Nur

    2017-11-01

    Self-Compacting Concrete (SCC) is a concrete that can flow and compact by itself without vibrator. The ability of SCC to flow by itself makes this concrete very suitable for construction that has very small reinforcement gaps. In this study, SCC was designed to get a compressive strength above 60 MPa at the age of 28 days. Sugarcane bagasse ash was used as substitution material for cement replacement. Percentages of sugarcane bagasse ash used were 10%, 15%, and 20%. There were three w/c values that vary from 0.275, 0.300, and 0.325. Testing standards referred to ASTM, EFNARC and ACI. The fresh concrete test was slump flow, L-box and V-funnel. The maximum compressive strength was in the mixture with the sugarcane bagasse ash composition of 15% and w/c=0.275 which was 67.24 MPa. The result of SEM test analysis found that the mixture composition with 15% sugarcane bagasse ash has solid CSH structure, small amount of pores, and smaller pore diameter than other mixtures.

  5. Creep Behaviour of Fly Ash-Based Geopolymer Concrete

    OpenAIRE

    Wallah S.E.

    2010-01-01

    Fly ash-based geopolymer concrete is manufactured using fly ash as its source material and does not use Portland cement at all. Beside fly ash, alkaline solution is also utilized to make geopolymer paste which binds the aggregates to form geopolymer concrete. This paper presents the study of creep behaviour of fly ash-based geopolymer concrete. Four series of specimens with various compressive strengths were prepared to study its creep behaviour for the duration of test up to one year. The te...

  6. BRICKS WITH TOTAL REPLACEMENT OF CLAY BY FLY ASH MIXED WITH DIFFERENT MATERIALS

    OpenAIRE

    J.N Akhtar; J.Alam; M.N Akhtar

    2011-01-01

    Fly ash is a powdery substance obtained from the dust collectors in the Thermal power plants that use coal as fuel. From the cement point of view the mineralogy of Fly ash is important as it contains 80% - 90% of glass. The impurities in coal-mostly clays, shale’s, limestone & dolomite; they cannot be burned so they turn up as ash. The Fly ash of class C category was used as a raw material to total replacement of clay for making Fly ash bricks. In present study the effect of Fly ash with high...

  7. The Effects of Bottom Ash from MSWI Used as Mineral Additions in Concrete

    Directory of Open Access Journals (Sweden)

    Che Amat Roshazita

    2017-01-01

    Full Text Available Municipal solid waste incinerators (MSWI produce by products which can be classified as bottom and fly ashes. The bottom ash accounts for 85–90 % of the solid product resulting from MSW combustion. The aimed of the present work is to study the effect of replacing partial of bottom ash were manufactured. Fresh and hardened properties of the concrete were compared in order to study the suitable cement-bottom ash replacement. Bottom ash was found to have some reactivity, but without greatly affecting the hydration process of OPC at 10 % replacement. However at more than 10 % replacement, the addition of bottom ash greatly affected strength.

  8. Inclusion of geopolymers derivate from fly ash and pumice in reinforced concrete

    Science.gov (United States)

    Montaño, A. M.; González, C. P.; Castro, D.; Gualdron, G.; Atencio, R.

    2017-12-01

    This paper presents results of a research project related to the development of alkali-activated geopolymers, synthesized from alumina-silicate minerals (fly ash and pumice) which are added to concrete. Alkali sources used in geopolymer synthesis were sodium hydroxide and sodium silicate solution. New materials were structurally characterized by Infra-Red spectroscopy (IR) and X-Ray Diffraction (XRD). Concretes obtained after geopolymers addition as Portland cement substitutes at 10%, 20% and 30%, were mechanically analysed by compression resistance at 7, 14, 28 and 90 drying days. Results were referred to standard (concrete of Portland cement) allows to know cementitious characteristics of geopolymers are lower than those for standard, but it keeps growing at longer drying time than Portland cement. By Electrochemical Impedance Spectroscopy (EIS) it is found that this new material shows high electrical resistance and have been proved as a protection agent against corrosion in reinforced concrete exhibiting anticorrosive properties higher than those showed by the conventional concrete mixture.

  9. Evaluation of Pollutant Leaching Potential of Coal Ashes for Recycling

    Science.gov (United States)

    Park, D.; Woo, N. C.; Kim, H.; Yoon, H.; Chung, D.

    2011-12-01

    By 2009, coal ashes produced from coal-based power plants in Korea have been reused as cement supplement materials; however, the rest is mostly disposed in landfills inside the plant properties. Continuous production of coal ashes and limited landfill sites require more recycles of coal ashes as base materials, specifically in constructions of roads and of huge industrial complex. Previous researches showed that coal ashes could contain various metals such as arsenic(As), chromium(Cr), lead(Pb), nickel(Ni), selenium(Se), etc. In this study, we collected four types of bottom ashes and two of fly ashes from four coal-based power plants. These ash samples were tested with distilled water through the column leaching process in oxidized conditions. The column test results were compared with those of total digestion, sequential extraction processes and TCLP. Concentrations of metals in outflows from columns are generally greater in fly ashes than in bottom ashes, specifically for As, Se, B, Sr and SO4. Only one fly ash (J2-F) shows high concentrations of arsenic and selenium in leachate. Sequential extraction results indicate that these metals are in readily soluble forms, such as adsorbed, carbonated, and reducible forms. Results of TCLP analysis indicate no potential contaminants leached from the ashes. In conclusion, recycling of coal combustion ashes could be encouraged with proper tests such as sequential and leaching experiments.

  10. Influence Of Mould Pressure And Substitution Of Quartz By Palm Oil

    African Journals Online (AJOL)

    where oil palm residues are burned to generate electricity. Malaysia is one of the largest producer of palm oil with ... To solve this potential environmental problem, many researchers have studied the use of POFA in .... Portland Cement Mortar Containing Palm Oil Fuel. Ash, Rice Husk Ash and Fly Ash" Construction and.

  11. Influence of Utilization of High-Volumes of Class F Fly Ash on the Abrasion Resistance of Concrete

    Directory of Open Access Journals (Sweden)

    William PRINCE

    2007-01-01

    Full Text Available Utilization of large volumes of fly ash in various concrete applications is a becoming a more general practice in an efforts towards using large quantities of fly ash. Around the world, Class C or Class F or both as available have been used in high volumes in cement-based materials. In India, majority of fly generated is of Class F type as per ASTM C 618. Yearly fly ash generation in India is approximately 95 million tonnes. Out of which around 15-20% is utilized in cement production and cement/concrete related activities. In order to increase its percentage utilization, an investigation was carried out to use it in concrete.In this paper, abrasion resistance of high volume fly ash (HVFA concretes made with 35, 45, 55, and 65% of cement replacement was evaluated in terms of its relation with compressive strength. Comparison was made between ordinary Portland cement and fly ash concrete. Test results indicated that abrasion resistance of concrete having cement replacement up to 35 percent was comparable to the normal concrete mix with out fly ash. Beyond 35% cement replacement, fly ash concretes exhibited slightly lower resistance to abrasion relative to non-fly ash concretes. Test results further indicated that abrasion resistance of concrete is closely related with compressive strength, and had a very good correlation between abrasion resistance and compressive strength (R2 value between 0.9018 and 0.9859 depending upon age.

  12. Utilization of recycled glass derived from cathode ray tube glass as fine aggregate in cement mortar

    International Nuclear Information System (INIS)

    Ling, Tung-Chai; Poon, Chi-Sun

    2011-01-01

    Graphical abstract: Display Omitted Highlights: → A recycling/treatment process to remove lead on funnel glass surface is described. → Utilizing recycled funnel glass in mortar can reduce hazardous CRT glass wastes. → Effects of CRT glass content on the properties of cement mortar are studied. → Fly ash can effectively mitigate ASR expansion of mortar even at 100% glass content. → Alkaline medium in cement matrix successfully prevented the leaching of lead. - Abstract: Rapid advances in the electronic industry led to an excessive amount of early disposal of older electronic devices such as computer monitors and old televisions (TV) before the end of their useful life. The management of cathode ray tubes (CRT), which have been a key component in computer monitors and TV sets, has become a major environmental problem worldwide. Therefore, there is a pressing need to develop sustainable alternative methods to manage hazardous CRT glass waste. This study assesses the feasibility of utilizing CRT glass as a substitute for natural aggregates in cement mortar. The CRT glass investigated was an acid-washed funnel glass of dismantled CRT from computer monitors and old TV sets. The mechanical properties of mortar mixes containing 0%, 25%, 50%, 75% and 100% of CRT glass were investigated. The potential of the alkali-silica reaction (ASR) and leachability of lead were also evaluated. The results confirmed that the properties of the mortar mixes prepared with CRT glass was similar to that of the control mortar using sand as fine aggregate, and displayed innocuous behaviour in the ASR expansion test. Incorporating CRT glass in cement mortar successfully prevented the leaching of lead. We conclude that it is feasible to utilize CRT glass in cement mortar production.

  13. Centralized cement solidification technique for low-level radioactive wastes

    International Nuclear Information System (INIS)

    Matsuda, Masami; Nishi, Takashi; Izumida, Tatsuo; Tsuchiya, Hiroyuki.

    1996-01-01

    A centralized cement solidification system has been developed to enable a single facility to solidify such low-level radioactive wastes as liquid waste, spent ion exchange resin, incineration ash, and miscellaneous solid wastes. Since the system uses newly developed high-performance cement, waste loading is raised and deterioration of waste forms after land burial prevented. This paper describes the centralized cement solidification system and the features of the high-performance cement. Results of full-scale pilot plant tests are also shown from the viewpoint of industrial applicability. (author)

  14. Geopolymer Mortar with Fly Ash

    Directory of Open Access Journals (Sweden)

    Saloma

    2016-01-01

    Full Text Available The cement industry accounts for about 7% of all CO2 emissions caused by humans. Therefore, it is necessary to find another material in order to support sustainable material. An alternative way is replacing cement material with alternative material as fly ash. Fly ash as binder need to be added alkaline activator in the form of sodium silicate (Na2SiO3 or potassium silicate (K2SiO3 and sodium hydroxide (NaOH or potassium hydroxide (KOH. The purpose of this research is to analyze the effect of activator liquid concentration on geopolymer mortar properties and to know the value of compressive strength. Molarity variation of NaOH are 8, 12, 14, and 16 M with ratio of Na2SiO3/NaOH = 1.0. Ratio of sand/fly ash = 2.75 and ratio of activator/fly ash = 0.8. The cube-shaped specimen 50 × 50 × 50 mm is cured by steam curing with a temperature of 60°C for 48 hours. The experimental result of fresh mortar reported that the molarity of NaOH affect the slump flow and setting time, higher of NaOH produces the smaller value of slump and the faster time of setting. The experimental of density results reported that the increase of specific gravity when the molarity of NaOH increased. The experimental results of the compressive strength are showed that the maximum compressive strength of geopolymer mortar 14 M is 10.06 MPa and the lowest compressive strength produced by geopolymer mortar 8 M is 3.95 MPa. Testing the compressive strength of geopolymer mortar 16 M produces compressive strength lower than 14 M geopolymer mortar is 9.16 MPa.

  15. Corrosion rate of rebars from linear polarization resistance and destructive analysis in blended cement concrete after chloride loading

    NARCIS (Netherlands)

    Polder, R.B.; Peelen, W.H.A.; Bertolini, L.; Guerriere, M.

    2002-01-01

    Concrete specimens with various binders including Portland cement, fly ash, blast furnace slag and composite cement and three water-to-cement ratios were subjected to cyclic wetting with salt solution and drying. Specimens contained six mild steel bars at two cover depths and two activated titanium

  16. Processed bottom ash for replacing fine aggregate in making high-volume fly ash concrete

    Directory of Open Access Journals (Sweden)

    Antoni

    2017-01-01

    Full Text Available Bottom ash is a coal plant by-product that is abundant and underutilized. There is the potential use of bottom ash as a fine aggregate replacement in concrete mixtures; however, the problems of water absorption and uniformity of quality of the material need to be overcome first. In this study, bottom ash was treated by sieve separation and pounding to smaller particle size for use as a sand substitute. The physical and chemical characteristics of bottom ash were tested after treatment including water absorption, sieve analysis, and fineness modulus. Highvolume fly ash (HVFA mortar specimens were made and the compressive strength and flowability test using bottom ash after treatment are compared with that of the sand specimen. Low water to cementitious ratio was used to ensure higher strength from the cementitious paste and superplasticizer demand was determined for each treatment. The result showed that bottom ash can be used as fine aggregate replacement material. Sieve separation of the bottom ash could produce 75% of the compressive strength compared with the control sand specimen, whereas pounded bottom ash could have up to 96% of the compressive strength of the control specimen. A 28-day compressive strength of 45 MPa was achievable with 100% replacement of fine aggregate with bottom ash.

  17. High performance concrete with blended cement

    International Nuclear Information System (INIS)

    Biswas, P.P.; Saraswati, S.; Basu, P.C.

    2012-01-01

    Principal objectives of the proposed project are two folds. Firstly, to develop the HPC mix suitable to NPP structures with blended cement, and secondly to study its durability necessary for desired long-term performance. Three grades of concrete to b considered in the proposed projects are M35, M50 and M60 with two types of blended cements, i.e. Portland slag cement (PSC) and Portland pozzolana cement (PPC). Three types of mineral admixtures - silica fume, fly ash and ground granulated blast furnace slag will be used. Concrete mixes with OPc and without any mineral admixture will be considered as reference case. Durability study of these mixes will be carried out

  18. Electrochemical removal of Cd from bioashes in pilot scale and evaluation of possibilities for utilizing treated ashes in concrete; Elektrokemisk fjernelse af Cd fra bioasker i pilotskala og vurdering af mulighederne for nyttiggoerelse af behandlet aske i beton

    Energy Technology Data Exchange (ETDEWEB)

    Juul Pedersen, A.; Ottosen, L.M. [BYG-DTU, Copenhagen (Denmark); Simonsen, P. [Energi E2 A/S, Copenhagen (Denmark); Aune, J. [MT Hoejgaard A/S, Soeborg (Denmark)

    2006-07-01

    value generally was lowered in the treated ashes, but it was also expected that the removed fertilizing elements such as potassium can be recovered and recycled. With respect to reuse in concrete it was found that the electrochemical treatment generally reduced the concentration of potentially deleterious elements such as chloride, sulphate, phosphate and heavy metals in the ashes, and on the basis of these findings it was expected that electrochemically treated bio ash is more suitable for reuse in concrete compared to the untreated ash. Mortar samples containing different concentrations of treated and untreated ash were made, and after curing, the compressive strength of the samples was tested in order to evaluate whether the ashes can be used as a substitute for cement in concrete, as coal fly ashes are already used today. The results from the tests revealed that the bio ashes are not directly applicable, since the compressive strength (which is an indication of pozzulan-reactivity) of the samples containing bio ash was significantly lower than was the case with reference samples without addition of ash, no matter if the ash had been electrochemically treated or not. The co-combustion fly ash, though, was performing a little better compared to the straw fly ash and may be applicable in low concentrations. It is suggested to examine whether the ashes may be applicable as a substitute for e.g. the sand fraction in concrete instead, since no pozzulan-reactivity is then needed. On the basis of the demonstration experiments and the related ash examinations, the electrodialytic remediation method is estimated to be technically and economically beneficial for full scale treatment of bio ashes, at least when it comes to straw ashes, which can subsequently be recycled. With respect to co-combustion ashes, the economical potential of the method depends on the reusing potential for the treated ash e.g. as a substitute for sand in concrete. (au)

  19. Identification of potential concerns associated with FDOT use of ammoniated coal fly ash.

    Science.gov (United States)

    2012-12-01

    The objectives of this project include a careful examination of the issues surrounding high ammonia content in cement due to the use of ammoniated fly ash. The researchers will gather information from published material and consider policies and prac...

  20. Characterization of bottom ashes from coal pulverized power plants to determine their potential use feasibility

    International Nuclear Information System (INIS)

    Menendez, E.; Alvaro, A. M.; Argiz, C.; Parra, J. L.; Moragues, A.

    2013-01-01

    The disposal of coal by products represents environmental and economical problems around the world. Therefore, the reuse and valorisation of this waste has become an important issue in the last decades. While high-value construction products containing fly ash were developed and its use is actually totally accepted as an addition to cement, the use of the bottom ash as supplementary cementitious material has not been allow. This paper examines the chemical and physical properties of fly ashes and bottom ashes from two different coal power plants in order to compare them and analyse the potential feasibility of bottom ash as cement replacement. The mechanical properties of cement mortars made with different percentages of both ashes were also study. The results obtained showed similar chemical composition of both kinds of ashes. The compressive strength values of mortars with 10 % and 25 % of cement replacement (at 28 days) were above the limits established in European standards and there were not significant differences between fly ash and bottom ash from both origins. (Author)

  1. High fire resistance in blocks containing coal combustion fly ashes and bottom ash.

    Science.gov (United States)

    García Arenas, Celia; Marrero, Madelyn; Leiva, Carlos; Solís-Guzmán, Jaime; Vilches Arenas, Luis F

    2011-08-01

    Fire resistance recycled blocks, containing fly ash and bottom ash from coal combustion power plants with a high fire resistance, are studied in this paper by testing different compositions using Portland cement type II, sand, coarse aggregate and fly ash (up to 50% of total weight) and bottom ash (up to 30% of total weight). The fire resistance, physical-chemical (density, pH, humidity, and water absorption capacity), mechanical (compressive and flexural strength), and leaching properties are measured on blocks made with different proportions of fly ash and bottom ash. The standard fire resistance test is reproduced on 28cm-high, 18cm-wide and 3cm-thick units, and is measured as the time needed to reach a temperature of 180°C on the non-exposed surface of the blocks for the different compositions. The results show that the replacement of fine aggregate with fly ash and of coarse aggregate with bottom ash have a remarkable influence on fire resistance and cause no detriment to the mechanical properties of the product. Additionally, according to the leaching tests, no environmental problems have been detected in the product. These results lead to an analysis of the recycling possibilities of these by-products in useful construction applications for the passive protection against fire. Copyright © 2011 Elsevier Ltd. All rights reserved.

  2. The Netherlands, guide to ash-utilization: Novem's contribution

    International Nuclear Information System (INIS)

    Stork, J.

    1991-01-01

    The production of fly ash in coal-fired utility plants in Sweden has more than doubled since 1983 although in future gasification slag and sulphur will be the most prolific waste products as clean coal technologies are introduced. About 50% of fly ash produced is shipped to Belgium and France for use in the cement industry; bottom ash is used for road construction in France and as a concrete filler in Belgium; a large percentage of gypsum is used in Belgium, France and Germany for making wall boards. Novem's programme to investigate the various applications of coal residues in the building industry is described. The three-phase programme involves investigation of the market for products, research into application of fly ash in the cement sector and for artificial gravel and sand-lime bricks. The Kaldin demonstration project on the uses of waste limestone is mentioned

  3. The effect of bagasse ash on the compressive strength of concrete ...

    African Journals Online (AJOL)

    In this research work, the effect of bagasse ash in the production of concrete was investigated. A mix proportion of 1:1.8:3.7with water-cement ratio of 0.47 was used. The percentage replacement of Ordinary Portland Cement (OPC) with bagasse ash is 0, 5, 10, 20, 30 and 40%. Concrete cubes of 150 x 15 x 150 mm of ...

  4. The starting up of a pilot plant for radioactive incinerator ash conditioning - results of two embedding campaigns

    International Nuclear Information System (INIS)

    Kertesz, C.J.; Chenavas, P.R.; Naud, G.M.

    1990-01-01

    A new pilot plant called 'PICC' designed for radioactive incinerator ash conditioning, by embedding in several matrices, was launched at the Nuclear Research Centre in Cadarache - France - in the middle of 1988. This polyvalent facility can work with the three following embedding products = cement, thermosetting epoxide resin and an epoxide-cement compound. The capacity per day of the plant is two 100 or 200 I drums of solidified ash form. Two embedding campaigns have been carried out on inactive ashes: the first is a cementation campaign, done on phosphated ash coming from incineration of spent tributylphosphate. The second is a polymer cement campaign done on simulated alpha ash coming from technological wastes. Description of the PICC and data on these two campaigns are given

  5. 0-6717 : investigation of alternative supplementary cementing materials (SCMs) : [project summary].

    Science.gov (United States)

    2014-08-01

    In Texas, Class F fly ash is extensively used as a : supplementary cementing material (SCM) : because of its ability to control thermal cracking : in mass concrete and to mitigate deleterious : expansions in concrete from alkali-silica reaction : (AS...

  6. Portland-pfa cement: a comparison between intergrinding and blending

    Energy Technology Data Exchange (ETDEWEB)

    Monk, M.

    1983-09-01

    Portland-pfa cements containing 20-40% (by weight) pfa have been prepared in the laboratory both by intergrinding the ashes with clinker and by blending with cement. Cement properties have been assessed according to BS 4550 and scanning electron microscopy was used to examine the effects of grinding upon the pfa particles. The work has shown that intergrinding leads to an improvement in the water-reducing properties of coarse pfas and also in their pozzolanic activity as indicated by compressive strength development at later ages. Setting times have been found to be essentially the same for blended and interground cements, both being considerably longer than for typical ordinary Portland cements. Thus the results of this investigation indicate that, provided pfa's are chemically acceptable, they can be used for Portland-pfa cement manufacture by intergrinding irrespective of their coarseness.

  7. Comparison of modified sulfur cement and hydraulic cement for encapsulation of radioactive and mixed wastes

    International Nuclear Information System (INIS)

    Kalb, P.D.; Heiser, J.H. III; Colombo, P.

    1990-01-01

    The majority of solidification/stabilization systems for low-level radioactive waste (LLW) and mixed waste, both in the commercial sector and at Department of Energy (DOE) facilities, utilize hydraulic cement (such as portland cement) to encapsulate waste materials and yield a monolithic solid waste form for disposal. Because hydraulic cement requires a chemical hydration reaction for setting and hardening, it is subject to potential interactions between elements in the waste and binder that can retard or prevent solidification. A new and innovative process utilizing modified sulfur cement developed by the US Bureau of Mines has been applied at Brookhaven National Laboratory (BNL) for the encapsulation of many of these problem wastes. Modified sulfur cement is a thermoplastic material, and as such, it can be heated above its melting point, combined with dry waste products to form a homogeneous mixture, and cooled to form a monolithic solid product. Under sponsorship of the DOE, research and development efforts at BNL have successfully applied the modified sulfur cement process for treatment of a range of LLWs including sodium sulfate salts, boric acid salts, and incinerator bottom ash and for mixed waste contaminated incinerator fly ash. Process development studies were conducted to determine optimal waste loadings for each waste type. Property evaluation studies were conducted to test waste form behavior under disposal conditions by applying relevant performance testing criteria established by the Nuclear Regulatory Commission (for LLW) and the Environmental Protection Agency (for hazardous wastes). Based on both processing and performance considerations, significantly greater waste loadings were achieved using modified sulfur cement when compared with hydraulic cement. Technology demonstration of the modified sulfur cement encapsulation system using production-scale equipment is scheduled for FY 1991

  8. Concretes and mortars with waste paper industry: Biomass ash and dregs.

    Science.gov (United States)

    Martínez-Lage, Isabel; Velay-Lizancos, Miriam; Vázquez-Burgo, Pablo; Rivas-Fernández, Marcos; Vázquez-Herrero, Cristina; Ramírez-Rodríguez, Antonio; Martín-Cano, Miguel

    2016-10-01

    This article describes a study on the viability of using waste from the paper industry: biomass boiler ash and green liquor dregs to fabricate mortars and concretes. Both types of ash were characterized by obtaining their chemical and mineralogical composition, their organic matter content, granulometry, adsorption and other common tests for construction materials. Seven different mortars were fabricated, one for reference made up of cement, sand, and water, three in which 10, 20, or 30% of the cement was replaced by biomass ash, and three others in which 10, 20, or 30% of the cement was replaced with dregs. Test specimens were fabricated with these mortars to conduct flexural and compression tests. Flexural strength is reduced for all the mortars studied. Compressive strength increases for the mortars fabricated with biomass ash and decreases for the mortar with dregs. Finally, 5 concretes were made, one of them as a reference (neither biomass ash nor dregs added), two of them with replacements of 10 and 20% of biomass ash instead of cement and another two with replacements of 10 and 20% of dregs instead of cement. The compressive and tensile splitting strength increase when a 10% of ash is replaced and decrease in all the other cases. The modulus of elasticity always decreases. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. [Study on mercury re-emissions during fly ash utilization].

    Science.gov (United States)

    Meng, Yang; Wang, Shu-Xiao

    2012-09-01

    The amount of fly ash produced during coal combustion is around 400 million tons per year in China. About 65%-68% of fly ash is used in building material production, road construction, architecture and agriculture. Some of these utilization processes include high temperature procedures, which may lead to mercury re-emissions. In this study, experiments were designed to simulate the key process in cement production and steam-cured brick production. A temperature programmed desorption (TPD) method was used to study the mercury transformation in the major utilization processes. Mercury re-emission during the fly ash utilization in China was estimated based on the experimental results. It was found that mercury existed as HgCl2 (Hg2 Cl2), HgS and HgO in the fly ash. During the cement production process, more than 98% of the mercury in fly ash was re-emitted. In the steam-curing brick manufacturing process, the average mercury re-emission percentage was about 28%, which was dominated by the percentage of HgCl2 (Hg2 Cl2). It is estimated that the mercury re-emission during the fly ash utilization have increased from 4.07 t in 2002 to 9.18 t in 2008, of which cement industry contributes about 96.6%.

  10. Wear Resistance of High-Volume Fly Ash Concrete

    Directory of Open Access Journals (Sweden)

    Rafat SIDDIQUE

    2010-12-01

    Full Text Available Wear resistance of high-volume fly ash concrete (HVFA intended for pavement applications is presented in this paper. In India, yearly production of fly ash is more than 100 million tons. Majority of fly ash is of Class F type. Out of which 20-25% is being utilized in cement-based materials. In order to increase its percentage utilization, an investigation was carried out for its large scale utilization. Concrete mixtures were prepared by replacing cement with 40, 50, and 60% of fly ash. Experiments were conducted for fresh concrete properties, compressive strength and wear resistance. Test results indicated that wear resistance of concrete having cement replacement up to 40% was comparable to the normal concrete. Beyond 40% fly ash content, concretes exhibited slightly lower resistance to wear in relation non-fly ash concretes. There is very good correlation between wear resistance and compressive strength (R2 value between 0.8482 and 0.9787 depending upon age.

  11. Utilization of mine tailings as partial cement replacement

    DEFF Research Database (Denmark)

    Sigvardsen, Nina Marie; Nielsen, M.R.; Ottosen, Lisbeth M.

    2017-01-01

    Depositing mine tailings entail major economic costs and negative environmental impacts. Thus finding an alternative to depositing is of interest. This study focused on the use of mine tailings as partial cement replacement, thereby preventing depositing the mine tailings. At the same time......, such use would reduce the CO2 emission related to the production of cement. Mine tailings from two different mines Zinkgruvan (Sweden) and Nalunaq (Greenland) were both tested as 5 and 10 % cement replacement. All mortar specimens with mine tailings had lower compressive strength compared to a reference...... compared to a specimen containing a 10 % replacement of cement with coal fly ash, commonly used in Denmark. The compressive strength of specimens containing mine tailings exceeded the compressive strength of the specimen containing coal fly ash, indicating further the amorphous content of volcanic decent...

  12. Development of an Improved Cement for Geothermal Wells

    Energy Technology Data Exchange (ETDEWEB)

    Trabits, George [Trabits Group, LLC, Wasilla, AK (United States)

    2015-04-20

    After an oil, gas, or geothermal production well has been drilled, the well must be stabilized with a casing (sections of steel pipe that are joined together) in order to prevent the walls of the well from collapsing. The gap between the casing and the walls of the well is filled with cement, which locks the casing into place. The casing and cementing of geothermal wells is complicated by the harsh conditions of high temperature, high pressure, and a chemical environment (brines with high concentrations of carbon dioxide and sulfuric acid) that degrades conventional Portland cement. During the 1990s and early 2000s, the U.S. Department of Energy’s Geothermal Technologies Office (GTO) provided support for the development of fly-ash-modified calcium aluminate phosphate (CaP) cement, which offers improved resistance to degradation compared with conventional cement. However, the use of CaP cements involves some operational constraints that can increase the cost and complexity of well cementing. In some cases, CaP cements are incompatible with chemical additives that are commonly used to adjust cement setting time. Care must also be taken to ensure that CaP cements do not become contaminated with leftover conventional cement in pumping equipment used in conventional well cementing. With assistance from GTO, Trabits Group, LLC has developed a zeolite-containing cement that performs well in harsh geothermal conditions (thermal stability at temperatures of up to 300°C and resistance to carbonation) and is easy to use (can be easily adjusted with additives and eliminates the need to “sterilize” pumping equipment as with CaP cements). This combination of properties reduces the complexity/cost of well cementing, which will help enable the widespread development of geothermal energy in the United States.

  13. The Effects of Bottom Ash from MSWI Used as Mineral Additions in Concrete

    OpenAIRE

    Che Amat Roshazita; Ismail Khairul Nizar; Mohamed Noor Norazian; Mohamad Ibrahim Norlia

    2017-01-01

    Municipal solid waste incinerators (MSWI) produce by products which can be classified as bottom and fly ashes. The bottom ash accounts for 85–90 % of the solid product resulting from MSW combustion. The aimed of the present work is to study the effect of replacing partial of bottom ash were manufactured. Fresh and hardened properties of the concrete were compared in order to study the suitable cement-bottom ash replacement. Bottom ash was found to have some reactivity, but without greatly aff...

  14. The use of limestone powder as an alternative cement replacement ...

    African Journals Online (AJOL)

    This research paper examines the effects of partial substitution of Portland cement clinker with limestone addition on the physical and chemical properties of cement paste and hardened mortar in two ranges of blain fineness values. Laboratory tests were conducted on limestone and clinker samples before used for the ...

  15. Effects of fly ash fineness on the mechanical properties of concrete

    Indian Academy of Sciences (India)

    ing the pulverized coal in the thermal power plants. In the construction sector, the fly ash is used in the production of cement as an additive-material, in production of concrete instead of some of the cement or instead of some of the fine aggregate, as a base and sub-base material in high- way construction, as a filling material ...

  16. Rice husk ash with high carbon content proves favourable for soil stabilization

    NARCIS (Netherlands)

    Pham, P.V.; van der Star, WRL; van Paassen, L.A.; Ye, G.

    2015-01-01

    Rice husk ash is a promising pozzolanic material produced from rice husk burning and has significant potential a sustainable replacement for cement in construction and ground improvement applications. In this study the effect of burning conditions on the ash reactivity and its potential for soil

  17. Influence of bottom ash of palm oil on compressive strength of concrete

    Science.gov (United States)

    Saputra, Andika Ade Indra; Basyaruddin, Laksono, Muhamad Hasby; Muntaha, Mohamad

    2017-11-01

    The technological development of concrete demands innovation regarding the alternative material as a part of the effort in improving quality and minimizing reliance on currently used raw materials such as bottom ash of palm oil. Bottom ash known as domestic waste stemming from palm oil cultivation in East Kalimantan contains silica. Like cement in texture and size, bottom ash can be mixed with concrete in which the silica in concrete could help increase the compressive strength of concrete. This research was conducted by comparing between normal concrete and concrete containing bottom ash as which the materials were apart of cement replacement. The bottom ash used in this research had to pass sieve size (#200). The composition tested in this research involved ratio between cement and bottom ash with the following percentages: 100%: 0%, 90%: 10%, 85%: 15% and 80%: 20%. Planned to be within the same amount of compressive strength (fc 25 MPa), the compressive strength of concrete was tested at the age of 7, 14, and 28 days. Research result shows that the addition of bottom ash to concrete influenced workability in concrete, but it did not significantly influence the compressive strength of concrete. Based on the result of compressive strength test, the optimal compressive strength was obtained from the mixture of 100% cement and 0% bottom ash.

  18. Nanoparticulate fillers improve the mechanical strength of bone cement.

    Science.gov (United States)

    Gomoll, Andreas H; Fitz, Wolfgang; Scott, Richard D; Thornhill, Thomas S; Bellare, Anuj

    2008-06-01

    Polymethylmethacrylate (PMMA-) based bone cement contains micrometer-size barium sulfate or zirconium oxide particles to radiopacify the cement for radiographic monitoring during follow-up. Considerable effort has been expended to improve the mechanical qualities of cements, largely through substitution of PMMA with new chemical structures. The introduction of these materials into clinical practice has been complicated by concerns over the unknown long-term risk profile of these new structures in vivo. We investigated a new composite with the well characterized chemical composition of current cements, but with nanoparticles instead of the conventional, micrometer-size barium sulfate radiopacifier. In this study, we replaced the barium sulfate microparticles that are usually present in commercial PMMA cements with barium sulfate nanoparticles. The resultant "microcomposite" and "nanocomposite" cements were then characterized through morphological investigations such as ultra-small angle X-ray scattering (USAXS) and scanning electron microscopy (SEM). Mechanical characterization included compression, tensile, compact tension, and fatigue testing. SEM and USAXS showed excellent dispersion of nanoparticles. Substitution of nanoparticles for microparticles resulted in a 41% increase in tensile strain-to-failure (p = 0.002) and a 70% increase in tensile work-of-fracture (p = 0.005). The nanocomposite cement also showed a two-fold increase in fatigue life compared to the conventional, microcomposite cement. In summary, nanoparticulate substitution of radiopacifiers substantially improved the in vitro mechanical properties of PMMA bone cement without changing the known chemical composition.

  19. The effectiveness of stone ash and volcanic ash of mount Sinabung as a filler on the initial strength of self-compacting concrete

    Science.gov (United States)

    Karolina, R.; Muhammad, W.; Saragih, M. D. S. M.; Mustaqa, T.

    2018-02-01

    Self Compacting Concrete is a concrete variant that has a high degree of workability and also has great initial strength, but low water cement factor. It is also self-flowable that can be molded on formwork with a very little or no compacted use of compactors. This concrete, using a variety of aggregate sizes, aggregate portions and superplasticizer admixture to achieve a special viscosity that allows it to flow on its own without the aid of a compactor. Lightweight concrete brick is a type of brick made from cement, sand, water, and developers. Lightweight concrete bricks are divided into 2 based on the developed materials used are AAC (Autoclave Aerated Concrete) using aluminum paste and CLC (Cellular Lightweight Concrete) that use Foaming Agent from BASF as a developer material. In this experiment, the lightweight bricks that will be made are CLC type which uses Foaming Agent as the developer material by mixing the Ash Stone produced by Stone Crusher machine which has the density of 2666 kg / m3 as Partial Pair Substitution. In this study the variation of Ash Stone used is 10%, 15%, and 20% of the planned amount of sand. After doing the tasting the result is obtained for 10% variation. Compressive Strength and Absorption Increase will decrease by 25.07% and 39.005% and Variation of 15% compressive strength will decrease by 65,8% and decrease of absorbtion equal to 17,441% and variation of 20% compressive strength will decreased by 67,4 and absorption increase equal to 17,956%.

  20. Environmental impact assessment of combustible wastes utilization in rotary cement kilns

    OpenAIRE

    Khrunyk, Sofiya

    2013-01-01

    This study focuses on the environmental impact assessment of the coal combustion and its substitution by alternative fuels from combustible wastes during Portland cement clinker sinterization in rotary cement kiln. Environmental impact assessment was carried out based on the fuels chemical composition and operating parameters of a rotary cement kiln in accordance with EURITS and IMPACT 2002+ methods.

  1. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

    Science.gov (United States)

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-07-01

    Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores.

  2. Increasing Class C fly ash reduces alkali silica reactivity

    Energy Technology Data Exchange (ETDEWEB)

    Hicks, J.K. [Mineral Resources Technologies, Inc. (United States)

    2007-07-01

    Contrary to earlier studies, it has been found that incremental additions of Class C fly ash do reduce alkali silica reactivity (ASR), in highly reactive, high alkali concrete mixes. AST can be further reduced by substituting 5% metakaolin or silica fume for the aggregate in concrete mixes with high (more than 30%) Class C fly ash substitution. The paper reports results of studies using Class C fly ash from the Labadie Station plant in Missouri which typically has between 1.3 and 1.45% available alkalis by ASTM C311. 7 figs.

  3. Rice Husk Ash (RHA): radon remediations and other applications

    International Nuclear Information System (INIS)

    Sethi, Beena; Sharma, Jyoti; Kant, Krishan

    2013-01-01

    Rice Husk Ash has been used to obstruct the diffusion of radon through building materials and it has been reported that the substitution of 20-30% rice husk ash with cement leads to lower radon diffusion and exhalation rates with higher compressive strength as compared to control concrete. It can also be used to treat dyes. The waste water containing dyes is very difficult to treat, since the dyes are recalcitrant organic molecules, resistant to aerobic digestion, and are stable to light, heat and oxidising agents. Light is one of the components which aquatic organisms require for their development and any deficit caused by coloured effluent leads to an imbalance of the ecosystem. Because of increasingly stringent restrictions on the organic content of industrial effluents, it is necessary and important to eliminate dyes from wastewater before it is discharged. In the present work, thermodynamic study of adsorption of Amaranth dye on to steam activated pigmented carbon prepared from rice husk (Oryza sativa) was investigated. The adsorbent was investigated under variable system parameters, such as initial concentration of dye, adsorbent dose and temperature. The adsorption equilibrium studied both by Langmuir and Freundlich isotherms. Linearity of the Langmuir isotherm plots indicate the chemical nature of the interactions while the linear Freundlich isotherms point to non specific and energetically non - uniform nature of the adsorption sites. The values of Langmuir monolayer capacity (q m ) are between 0.9 and 1.0 mg/g. The results obtained indicate a potential use of SAPRHC for removing dyes like Amaranth dye from water. (author)

  4. Densified ultra-light cement-based materials

    DEFF Research Database (Denmark)

    Esteves, Luis Pedro

    2015-01-01

    Densified cement systems were developed in the early 1980s, about three decades past. The research led to historical developments in cement and concrete research, forming the baseline for the design of modern cement systems, the socalled high-performance and ultra-high performance concrete. Cement...... production comprehends one of the relevant carbon emission footprints in the world. The substitution of cement by supplementary cementitious additions encompasses several other health hazards, risks and also technical difficulties such as limited or incoherent pozzolanic activity. Superabsorbent polymers can...... be used as a “clean technology” in the production of cement-based materials for structural applications with a low carbon footprint. This paper describes the principles of this concept coupled with experimental results on the basic properties of this enhanced type of cement-based materials with combined...

  5. Influence of Temperature on Workability and Compressive Strength of Ordinary Concrete with High Calcium Fly Ash

    Directory of Open Access Journals (Sweden)

    Gołaszewski Jacek

    2017-06-01

    Full Text Available The rheological properties of fresh ordinary concrete are closely affected by temperature and time. The paper presents the study of consistency of fresh concrete mixtures made with Portland cement and cement with calcareous fly ash. Two types of admixtures were used. It was proven that the temperature has a clear effect on workability and compressive strength concrete. Influence on workability can be reduced by selecting the appropriate superplasticizer and cement.

  6. Creep Behaviour of Fly Ash-Based Geopolymer Concrete

    Directory of Open Access Journals (Sweden)

    Wallah S.E.

    2010-01-01

    Full Text Available Fly ash-based geopolymer concrete is manufactured using fly ash as its source material and does not use Portland cement at all. Beside fly ash, alkaline solution is also utilized to make geopolymer paste which binds the aggregates to form geopolymer concrete. This paper presents the study of creep behaviour of fly ash-based geopolymer concrete. Four series of specimens with various compressive strengths were prepared to study its creep behaviour for the duration of test up to one year. The test method followed the procedures applied for Ordinary Portland Cement (OPC concrete. Test results show that fly ash-based geopolymer concrete undergoes low creep which is generally less than that of OPC concrete. After one year of loading, the results for specific creep of fly ash-based geopolymer concrete in this study ranges from 15 to 29 microstrain for concrete compressive strength 67–40 MPa respectively. From the test results, it is also found out that the creep coefficient of fly ash-based geopolymer concrete is about half of that predicted using Gilbert’s Method for OPC concrete.

  7. Comparison of modified sulfur cement and hydraulic cement for encapsulation of radioactive and mixed wastes

    International Nuclear Information System (INIS)

    Kalb, P.D.; Heiser, J.H. III; Colombo, P.

    1990-01-01

    The majority of solidification/stabilization systems for low-level radioactive waste (LLW) and mixed waste, both in the commercial sector and at Department of Energy (DOE) facilities, utilize hydraulic cement (such as portland cement) to encapsulate waste materials and yield a monolithic solid waste form for disposal. A new and innovative process utilizing modified sulfur cement developed by the US Bureau of Mines has been applied at Brookhaven National Laboratory (BNL) for the encapsulation of many of these ''problem'' wastes. Modified sulfur cement is a thermoplastic material, and as such, it can be heated above it's melting point (120 degree C), combined with dry waste products to form a homogeneous mixture, and cooled to form a monolithic solid product. Under sponsorship of the DOE, research and development efforts at BNL have successfully applied the modified sulfur cement process for treatment of a range of LLWs including sodium sulfate salts, boric acid salts, and incinerator bottom ash and for mixed waste contaminated incinerator fly ash. Process development studies were conducted to determine optimal waste loadings for each waste type. Property evaluation studies were conducted to test waste form behavior under disposal conditions by applying relevant performance testing criteria established by the Nuclear Regulatory Commission (for LLW) and the Environmental Protection Agency (for hazardous wastes). Based on both processing and performance considerations, significantly greater waste loadings were achieved using modified sulfur cement when compared with hydraulic cement. Technology demonstration of the modified sulfur cement encapsulation system using production-scale equipment is scheduled for FY 1991. 12 refs., 8 figs., 3 tabs

  8. Modified water-cement ratio law for compressive strength of rice ...

    African Journals Online (AJOL)

    This work examines the modification of age long water – cement ratio law of Ordinary Portland Cement (OPC) concrete to cater for concrete with Rice Husk Ash (RHA). Chemical analysis of RHA produced under controlled temperature of 600°C was carried out. A total of one hundred and fifty (150) RHA concrete cubes at ...

  9. Packing issue in cement blending for sustainability developments - Approach by discrete element method

    NARCIS (Netherlands)

    Le, L.B.N.; Stroeven, P.

    2014-01-01

    Common cement blending materials for concrete like fly ashes, blast furnace slag, silica fume, metakaolin and rice husk ash have been investigated experimentally as to their impact on concrete’s mechanical, physical and sustainability capabilities. Such efforts offer but case-related information on

  10. Conditioning of alpha incinerator ash by means of embedding in different matrices

    International Nuclear Information System (INIS)

    Kertesz, C.J.; Chenavas, P.R.; Auffret, L.; Biagini, A.

    1990-01-01

    The programme of conditioning alpha incinerator ash coming from a MOX fuel fabrication plant - MELOX project - has several steps. The first one is the fabrication of embedding formulation representative ash. The following step is an embedding formulation study at laboratory scale, with a comparison between three embedding matrices i.e. cement, thermosetting epoxide resin, and an epoxide cement compound. To establish the confinment behavior, a study was done including leaching test and radiolysis of 238 Pu doped samples. At the industrial scale a polyvalent pilot plant called 'PICC' was put in service. The qualification of the polymer cement process is shown

  11. Cementitious Spray Dryer Ash-Tire Fiber Material for Maximizing Waste Diversion

    OpenAIRE

    Riley, Charles E.; Atadero, Rebecca A.; van de Lindt, John W.; Heyliger, Paul R.

    2011-01-01

    Spray dryer absorber (SDA) material, also known as spray dryer ash, is a byproduct of coal combustion and flue gas scrubbing processes that has self-cementing properties similar to those of class C fly ash. SDA material does not usually meet the existing standards for use as a pozzolan in Portland cement concrete due to its characteristically high sulfur content, and thus unlike fly ash, it is rarely put to beneficial use. This paper presents the results of a study with the objective of devel...

  12. Petroleum Sludge as gypsum replacement in cement plants: Its Impact on Cement Strength

    Science.gov (United States)

    Benlamoudi, Ali; Kadir, Aeslina Abdul; Khodja, Mohamed

    2017-08-01

    Due to high cost of cement manufacturing and the huge amount of resources exhaustion, companies are trying to incorporate alternative raw materials or by-products into cement production so as to produce alternative sustainable cement. Petroleum sludge is a dangerous waste that poses serious imparts on soil and groundwater. Given that this sludge contains a high percentage of anhydrite (CaSO4), which is the main component of gypsum (CaSO4.2H2O), it may play the same gypsum role in strength development. In this research, a total replacement of gypsum (100%) has been substituted by petroleum sludge in cement production and has led to an increase of 28.8% in UCS values after 28 curing days. Nevertheless, the burning of this waste has emitted a considerable amount of carbon monoxide (CO) gas that needs to be carefully considered prior to use petroleum sludge within cement plants.

  13. Study of mechanical and physicochemical properties of cementated spent ion-exchange-resins

    International Nuclear Information System (INIS)

    Patek, P.

    1981-09-01

    As first part of a study on the possibilities, to immobilize spent ion exchange resins, for final disposal, the dependence of compressive strength from the composition of cement - resin mixtures was detected. Powdered resins, bead resins and ashes from the incinerator plant and several cement brands were examinated. As result an area was defined in the three-phase diagram of cement, resins and water, in which the following leach tests will be performed. (author)

  14. Pozzolanic characteristics of municipal solid waste ash | Sanewu ...

    African Journals Online (AJOL)

    Where conventional stabilizing agents like cement and lime have been used, they have considerably increased the cost of construction. It is with this backdrop that this paper describes the pozzolanic characteristics of municipal solid waste ash (MSWA) and its use as a stabilizing agent. The total elemental concentration in ...

  15. influence of addition of rice husk ash on porcelain composition

    African Journals Online (AJOL)

    ABSTRACT. Rice husk ash (RHA) has long been known to possess high silica content. The abundance of rice husk as agricultural waste makes it the most promising to be used as a supplementary cementations and ceramic material. In this study RHA was used as an additive material on porcelain body. The rice husk was ...

  16. Effect of Neem Seed Husk Ash on Concrete Strength Properties ...

    African Journals Online (AJOL)

    Neem Seed Husk is a by-product obtained during industrial processing of Neem Seed to extract oil and produce fertilizer. Laboratory tests on Neem seed husk ash (NSHA) mixed with cement were conducted to find its effect on concrete strength and workability. Tests including slump test, compressive strength test, concrete ...

  17. Mechanical Properties of Millet Husk Ash Bitumen Stabilized Soil ...

    African Journals Online (AJOL)

    Akorede

    lateritic soil blocks using Millet Husk Ash (MHA) and Bitumen as additives so as to reduce its high cost and find alternative disposal method for agricultural waste. The lateritic soil samples ... MHA as partial replacement of cement will provide an economic use of by-product and consequently produce a cheaper soil block ...

  18. Self hardening property of Botswana fly ash | Sahu | Botswana ...

    African Journals Online (AJOL)

    In Botswana, it is being produced at the rate of more than 300 t per day at Morupule Power Station. Almost 70% of this production is disposed off as a waste and only 30% is being used in making cement. Few limited studies suggest that a fly ash containing low unburnt carbon (LOI) may exhibit self hardening property even ...

  19. Characterization of a Treated Palm Oil Fuel Ash | Hassan | Science ...

    African Journals Online (AJOL)

    Palm oil fuel ash (POFA) has been known to possess a pozzolanic property. The abundance of POFA as an agricultural waste makes it a promising candidate to be used as a supplementary cementations material in palm oil producing countries. This paper presents structural analysis and surface morphology of a treated ...

  20. Production of portland cement using Moroccan oil shale and comparative study between conventional cement plant and cement plant using oil shale

    International Nuclear Information System (INIS)

    Doumbouya, M.; Kacemi, K.E.; Kitane, S.

    2012-01-01

    Like the use of coal ash from power plants as an addition to cement, oil shale are used for cement production on an industrial scale in Estonia, China, USA and Germany. Oil shale can be utilized in manufacturing the cement. In addition to the utilization of these by-products after combustion, it can also reduce the required temperature for the clinkering reactions during the production of Portland clinker. We performed a study on the Moroccan oil shale to maximize the use of oil shale ash in the manufacturing of Portland cement. We found that Moroccan oil shale ash can be used up to 30% with 70% Portland clinker without altering its principle properties. The corresponding temperature required to generate the required liquid for the clinkering reactions as well as the essential ingredients for clinker was found to be around 850 to 1000 deg. C. The operating temperatures for this optimized blend ratio were found to 1000 deg. C. The resulting Portland clinker from this ratio will need further testing in accordance with international standards for Portland cement to examine properties like strength and setting time. (author)

  1. Binary Effect of Fly Ash and Palm Oil Fuel Ash on Heat of Hydration Aerated Concrete

    Science.gov (United States)

    Mehmannavaz, Taha; Ismail, Mohammad; Radin Sumadi, Salihuddin; Rafique Bhutta, Muhammad Aamer; Samadi, Mostafa

    2014-01-01

    The binary effect of pulverized fuel ash (PFA) and palm oil fuel ash (POFA) on heat of hydration of aerated concrete was studied. Three aerated concrete mixes were prepared, namely, concrete containing 100% ordinary Portland cement (control sample or Type I), binary concrete made from 50% POFA (Type II), and ternary concrete containing 30% POFA and 20% PFA (Type III). It is found that the temperature increases due to heat of hydration through all the concrete specimens especially in the control sample. However, the total temperature rises caused by the heat of hydration through both of the new binary and ternary concrete were significantly lower than the control sample. The obtained results reveal that the replacement of Portland cement with binary and ternary materials is beneficial, particularly for mass concrete where thermal cracking due to extreme heat rise is of great concern. PMID:24696646

  2. Leaching behavior of heavy metals from municipal solid wastes incineration (MSWI) fly ash used in concrete

    International Nuclear Information System (INIS)

    Shi Huisheng; Kan Lili

    2009-01-01

    The characteristics of municipal solid waste incineration (MSWI) fly ash, surface leaching toxicity and successive leaching concentration of heavy metals from MSWI fly ash-cement hardened pastes were studied. And, the relationships between leaching concentrations of heavy metals and leaching time were also discussed. Experimental results showed that immobilization effect of cement on MSWI fly ash is good. Even if MSWI fly ash-cement hardened pastes were damaged, the leaching toxicity is still in a safety range. In early leaching stage, the surface leaching rate is relatively a little high, up to 10 -5 -10 -4 cm d -1 order of magnitude, in the later time of leaching, its rate rapidly declined, down to 10 -7 . Most of leached heavy metals are produced at early ages. The leaching concentration of heavy metals and leaching time has strong positive relationships. In factual utilizing circumstances, heavy metals' leaching from MSWI fly ash-cement hardened pastes is a very slow and gradually diluting process. The leaching toxicity of heavy metals is far lower than that of the National Standard of China, and minimum harmful matters can be contained and released in the environment. Reusing of MSWI fly ash as partial replacement for cement in concrete mixes is potentially feasible.

  3. Using locally available fly ash for modifying concrete properties

    International Nuclear Information System (INIS)

    Rizwan, S.A.; Toor, S.R.; Ahmad, H.

    2005-01-01

    This paper suggests the possible use of fly ash, a bye-product produced in our thermal power plants operating on coal as fuel for improvement of concrete quality. In the present investigation, locally available finely divided fly ash has been used for modification Presently, it is being used extensively in concrete in modem countries and is considered as waste material in general. Behavior of fly ash modified concrete in comparison to normal concrete having same mix proportions, aggregates, net water-cement ratio and similar curing conditions has been studied in short terms up to the age of 56 days during which the specimens were subjected to normal water curing method. Tests were carried out for compressive strength at 3, 7, 14,28 and 56 days, 24 hours % age water absorption at the age of 56 days and durability (resistance of concrete against N/2 solutions of both nitric acid and hydrochloric acid for one month) of concrete were also carried out at the age of 56 days. It was seen that the compressive strength of concrete modified with the available type of fly ash was less than the normal concrete. But so. far as the durability and % age water absorption are concerned, fly ash plays an important role here. 24 hours % age water absorption decreases with increase in fly ash content an admixture and as a cement replacement in concrete. But so far as durability is concerned, 20% replacement of fly ash with cement appears to be more effective than it is with 40%. The purpose of investigation was to introduce the use of fly ash in concretes to the Engineers and Architects in Pakistan. (author)

  4. Recycling and recovery routes for incinerated sewage sludge ash (ISSA): a review.

    Science.gov (United States)

    Donatello, Shane; Cheeseman, Christopher R

    2013-11-01

    The drivers for increasing incineration of sewage sludge and the characteristics of the resulting incinerated sewage sludge ash (ISSA) are reviewed. It is estimated that approximately 1.7 milliontonnes of ISSA are produced annually world-wide and is likely to increase in the future. Although most ISSA is currently landfilled, various options have been investigated that allow recycling and beneficial resource recovery. These include the use of ISSA as a substitute for clay in sintered bricks, tiles and pavers, and as a raw material for the manufacture of lightweight aggregate. ISSA has also been used to form high density glass-ceramics. Significant research has investigated the potential use of ISSA in blended cements for use in mortars and concrete, and as a raw material for the production of Portland cement. However, all these applications represent a loss of the valuable phosphate content in ISSA, which is typically comparable to that of a low grade phosphate ore. ISSA has significant potential to be used as a secondary source of phosphate for the production of fertilisers and phosphoric acid. Resource efficient approaches to recycling will increasingly require phosphate recovery from ISSA, with the remaining residual fraction also considered a useful material, and therefore further research is required in this area. Copyright © 2013 Elsevier Ltd. All rights reserved.

  5. Heat of hydration measurements on cemented radioactive wastes. Part 1: cement-water pastes

    International Nuclear Information System (INIS)

    Lee, D.J.

    1983-12-01

    This report describes the hydration of cement pastes in terms of chemical and kinetic models. A calorimetric technique was used to measure the heat of hydration to develop these models. The effects of temperature, water/cement ratio and cement replacements, ground granulated blast furnace slag (BFS) and pulverised fuel ash (PFA) on the hydration of ordinary Portland cement (OPC) is reported. The incorporation of BFS or PFA has a marked effect on the hydration reaction. The effect of temperature is also important but changing the water/cement ratio has little effect. Results from cement pastes containing only water and cement yield total heats of reaction of 400, 200 and 100 kJ/kg for OPC, BFS and PFA respectively. Using the results from the models which have been developed, the effect of major salts present in radioactive waste streams can be assessed. Values of the total heat of reaction, the time to complete 50 percent reaction, and the energy of activation, can be compared for different waste systems. (U.K.)

  6. The effect of steel slag as a coarse aggregate and Sinabung volcanic ash a filler on high strength concrete

    Science.gov (United States)

    Karolina, R.; Putra, A. L. A.

    2018-02-01

    The Development of concrete technology is continues to grow. The requisite for efficient constructions that are often viewed in terms of concrete mechanical behavior, application on the field, and cost estimation of implementation increasingly require engineers to optimize construction materials, especially for concrete materials. Various types of concrete have now been developed according to their needs, such as high strength concrete. On high strength concrete design, it is necessary to consider several factors that will affect the reach of the quality strength, Those are cement, water cement ratio (w/c), aggregates, and proper admixture. In the use of natural mineral, it is important for an engineer to keep an eye on the natural conditions that have been explored. So the selection of aggregates as possible is a material that is not causing nature destruction. On this experiment the use of steel slag from PT.Growth Sumatra Industry as a substitute of coarse and fine aggregate, and volcanic ash of mount Sinabung as microsilka in concrete mixture substituted to create high strength concrete that is harmless for the environment. The use of mount sinabung volcanic ash as microsilika coupled with the use of Master Glenium Sky 8614 superplasticizer. This experiment intend to compare high strength concrete based slag steel as the main constituent aggregates and high strength concrete with a conventional mixture. The research result for 28 days old concrete shows that conventional concrete compressive strength is 67.567 MPa, slag concrete 75.958 Mpa, conventional tensile strength 5.435 Mpa while slag concrete 5.053 Mpa, conventional concrete bending strength 44064.96 kgcm while concrete slag 51473.94 kgcm and modulus of conventional concrete fracture 124.978 kg / cm2 while slag concrete 145.956 kg / cm2. Both concrete slump values shows similar results due to the use of superplasticizer.

  7. Effect of Fly-Ash on Corrosion Resistance Characteristics of Rebar Embedded in Recycled Aggregate Concrete

    Science.gov (United States)

    Revathi, Purushothaman; Nikesh, P.

    2018-04-01

    In the frame of an extended research programme dealing with the utilization of recycled aggregate in concrete, the corrosion resistance characteristics of rebars embedded in recycled aggregate concrete is studied. Totally five series of concrete mixtures were prepared with fly-ash as replacement for cement in the levels of 10-30% by weight of cement. Corrosion studies by 90 days ponding test, linear polarization test and impressed voltage tests were carried out, in order to investigate whether corrosion behaviour of the rebars has improved due to the replacement of cement with fly-ash. Results showed that the replacement of cement with fly-ash in the range of 20-30% improves the corrosion resistance characteristics of recycled aggregate concrete.

  8. A review on the effect of fly ash characteristics and their variations on the synthesis of fly ash based geopolymer

    Science.gov (United States)

    Wattimena, Oswyn K.; Antoni, Hardjito, Djwantoro

    2017-09-01

    There are more than four decades since the last 1970s where geopolymers concrete was first introduced and developed to use as a replacement to conventional concrete material which uses cement as a binder. And since the last two decades, geopolymers which utilized fly ash as aluminosilicate source material, i.e. fly ash based geopolymers, have been investigated. Many researchers present how to produce the best fly ash based geopolymer with a various source of constituent material as well as mixing formula to achieve exceptional concrete performance. Although there is a similar trend towards factors affecting the result of fly ash based geopolymer synthesis, there is still remain a wide range in mixture proportion. The considerable variation in fly ash characteristics as source material in the synthesis can very likely be one of the causes of this problem. This paper attempts to identify the effect of source material variation of geopolymer concrete, particularly which use fly ash as source material and focuses on the variation of its characteristics and the effects to properties of concrete. From the reviews it concluded that different sources (and even the same source, but different batch) of fly ash materials will give some different characteristics of the fly ash, where it would affect the synthesis process of the fly ash based geopolymer concretes.

  9. Stabilize ash using Clemson's sintering process (Part 1 - Phase 1 results): Mixed waste fly ash stabilization. Innovative technology summary report

    International Nuclear Information System (INIS)

    1998-12-01

    Incineration of applicable Department of Energy (DOE) mixed wastes has produced a secondary waste stream of radioactive and Resource Conservation and Recovery Act (RCRA) hazardous fly ash that also requires treatment before land disposal. Unlike bottom ash, fly ash usually contains constituents making efficient stabilization difficult. For example, fly ash from the DOE Waste Experimental Reduction Facility (WERF) incinerator at the Idaho National Engineering and Environmental Laboratory (INEEL) contains volatile metals, metal salts, high concentrations of zinc, and unburned organic residues. All of these constituents can effect the stabilization process. The Department of Energy, and in particular the Mixed Waste Focus Area (MWFA) of EM-50, has stated the need for improved stabilization methods would accept a higher ash waste loading while meeting waste form disposal criteria. These alternative stabilization technologies should include delivery systems to minimize worker exposure and minimize secondary waste generation, while maximizing operational flexibility and radionuclide containment. Currently, the standard practice for stabilizing ash is mixing with Portland cement at room temperature. This standard practice produces a significant increase of waste material volume or has difficulty in adequately stabilizing the components in the fly ash to ensure regulatory requirements are consistently satisfied. To address these fly ash stabilization shortcomings, the MWFA, a DOE/EM-50 program, invested in the development of several fly ash stabilization alternatives, including the Clemson University sintering method

  10. Basalt waste added to Portland cement

    Directory of Open Access Journals (Sweden)

    Thiago Melanda Mendes

    2016-08-01

    Full Text Available Portland cement is widely used as a building material and more than 4.3 billion tons were produced in 2014, with increasing environmental impacts by this industry, mainly through CO2 emissions and consumption of non-removable raw materials. Several by-products have been used as raw materials or fuels to reduce environmental impacts. Basaltic waste collected by filters was employed as a mineral mixture to Portland cement and two fractions were tested. The compression strength of mortars was measured after 7 days and Scanning Electron Microscopy (SEM and Electron Diffraction Scattering (EDS were carried out on Portland cement paste with the basaltic residue. Gains in compression strength were observed for mixtures containing 2.5 wt.% of basaltic residue. Hydration products observed on surface of basaltic particles show the nucleation effect of mineral mixtures. Clinker substitution by mineral mixtures reduces CO2 emission per ton of Portland cement.

  11. FEATURES OF ASH OF THERMAL POWER PLANTS AS AGGREGATE FOR CONCRETES

    Directory of Open Access Journals (Sweden)

    M. A. Storozhuk

    2017-10-01

    Full Text Available Purpose. The scientific work is dedicated to development of scientific-technical bases of production and application of concrete on the basis of ashes of thermal power plants (TPP. Methodology. The properties of TPP ash, as well as the peculiarities of its behavior in a concrete mix as a fine aggregate, have been studied. It is shown that the hydrolysis and hydration of cement occur in the active environment of ash, which has a huge specific surface area. This significantly affects the course of these processes and the quality of the concrete produced. A new technology of application of ash of TPP for preparation of concrete mixes is offered. Vibrated and vibrovacuumized concretes of optimum composition from slag and ash, as well as from granite crushed stone and ash, are tested. The chara-cteristics of ordinary concrete (from granite crushed stone and quartz sand are given to compare. Findings. The results of the tests showed the possibility of obtaining concretes of class C20/25…C25/30 on the basis of slag and ash of TPP at a limited consumption of cement. It is shown that the concrete with traditional aggregates has a lower strength than the concrete, which has ash as fine aggregate. This research results contribute to the increased use of ash in construction that solves the problem of aggregates as well as thermal power plants waste recycling. Originality. New method and technology of application of TPP ashes in concrete are developed. Ash concrete mix has rational flowability, which produces the greatest strength of ash vacuum concrete. This strength is twice or more as large as the strength of vibrated ash concrete mix with flowability S1. Practical value. The physico-chemical properties of TPP ash as aggregate for concrete are presented. Significant difference of ash from ordinary aggregates is shown. Chemical activity of the ash is justified. The special conditions of cement hardening in the case of using ash as aggregate for concrete

  12. Fabrication of Phosphate Cement with High Integrity

    International Nuclear Information System (INIS)

    Yang, Jae Hwan; Lee, Chang Hwa; Heo, Cheol Min; Jeon, Min Ku; Kang, Kweon Ho

    2011-01-01

    As the development of industrial society has accelerated, hazardous wastes are generated as well. According to the 1986 statistics of U.S.A, each person made 40 tons of waste in America that year. Treatment of radioactive waste is one of the most important and serious problems related to waste treatments, because its radioactivity and decaying heat have harmful effects to human and environment for a long time. Nuclear developed countries have used conventional method of treatment such as vitrification or cementation in order to stabilize and solidify radioactive waste. Although the former guarantees the formation of high leaching resistant and durable waste form, it requires several hundred (or even more than one thousand) temperature to melt glass frit. This process generates secondary waste volatilized, as well as being non-economical. Cement technology played a role of immobilizing low and middle class wastes. It has advantages of low temperature setting, low cost, easy process, etc. The alkalinity of ordinary cement, however, constrains the utility of cement to the solidification of alkaline waste. In addition, leachability and mechanical strength of cements are not quite appropriate for the stabilization of high level waste. In this regard, chemically bonded phosphate cement(CBPC), which sets by an acid-base reaction, is a potentially expectable material for immobilization of radioactive waste. CBPC not only sets at room temperature, but also encapsulates various isotopes chemically. The performance of CBPC can be enhanced by the addition of fly ash, sand, wollastonite, etc. This study aims at fabricating the CBPC containing fly ash with high integrity. Morphology, microstructure, and compressive strength are evaluated using SEM, and digital compressing machine

  13. Evaluation of the suitability for concrete using fly ash in N.P.P. structures

    International Nuclear Information System (INIS)

    Cho, M. S.; Song, Y. C.; Kim, S. W.; Ko, K. T.

    2002-01-01

    The nuclear power plant structures constructed in Korea has been generally used type V cement(sulfate-resisting Portland cement), but according to the study results reported recently, it shows that type V cement is superior the resistance of sulfate attack, but the resistance of salt damage is weaker than type I cement. It is increased the demands on the use of mineral admixtures such as fly ash, ground granulated blast-furnace slag instead of type V cement in order to improve the durability of concrete structures. But the study on concrete mixed with fly ash in Korea has been mainly performed on rheology and strength properties of the concrete. Therefore, this study is to improve the durability of concrete structures of N.P.P. as using fly ash cement instead of type V cement. As a results, the concrete containing fly ash is improved the resistance to salt attack, sulfate attack and freezing-thawing and is deteriorated the carbonation. But if it is used the concrete with high strength or low water-powder ratio, the concrete have not problem on the durability

  14. Moessbauer Studies of Thermal Power Plant Coal and Fly Ash

    International Nuclear Information System (INIS)

    Taneja, S. P.

    2004-01-01

    Iron-57 Moessbauer spectroscopic studies were carried out at room temperature on samples of coal, slag (bottom ash) and mechanical ash collected from Bhatinda (India) thermal power plant. Hyperfine parameters such as isomer shift, quadrupole splitting and total internal magnetic field of 57 Fe nuclei were used to characterize various iron-bearing minerals. The observed parameters indicate the presence of pyrite, siderite and ankerite in coal sample while magnetic fractions of mechanical ash and slag samples show the formation of hematite and Al-substituted magnesio-ferrite. The non-magnetic fraction of slag ash shows the dominance of Fe 2+ phases while that of mechanical ash demonstrates the formation of both Fe 2+ and Fe 3+ phases. These findings are compared with Moessbauer and magnetic susceptibility studies on fly ash samples of Panipat (India) thermal power plant reported earlier.

  15. A Study on the Evaluation of Field Application of High-Fluidity Concrete Containing High Volume Fly Ash

    OpenAIRE

    Choi, Yun-Wang; Park, Man-Seok; Choi, Byung-Keol; Oh, Sung-Rok

    2015-01-01

    In the recent concrete industry, high-fluidity concrete is being widely used for the pouring of dense reinforced concrete. Normally, in the case of high-fluidity concrete, it includes high binder contents, so it is necessary to replace part of the cement through admixtures such as fly ash to procure economic feasibility and durability. This study shows the mechanical properties and field applicability of high-fluidity concrete using mass of fly ash as alternative materials of cement. The high...

  16. Utilization of coal fly ash in solidification of liquid radioactive waste from research reactor.

    Science.gov (United States)

    Osmanlioglu, Ahmet Erdal

    2014-05-01

    In this study, the potential utilization of fly ash was investigated as an additive in solidification process of radioactive waste sludge from research reactor. Coal formations include various percentages of natural radioactive elements; therefore, coal fly ash includes various levels of radioactivity. For this reason, fly ashes have to be evaluated for potential environmental implications in case of further usage in any construction material. But for use in solidification of radioactive sludge, the radiological effects of fly ash are in the range of radioactive waste management limits. The results show that fly ash has a strong fixing capacity for radioactive isotopes. Specimens with addition of 5-15% fly ash to concrete was observed to be sufficient to achieve the target compressive strength of 20 MPa required for near-surface disposal. An optimum mixture comprising 15% fly ash, 35% cement, and 50% radioactive waste sludge could provide the solidification required for long-term storage and disposal. The codisposal of radioactive fly ash with radioactive sludge by solidification decreases the usage of cement in solidification process. By this method, radioactive fly ash can become a valuable additive instead of industrial waste. This study supports the utilization of fly ash in industry and the solidification of radioactive waste in the nuclear industry.

  17. Disposal of low-level radioactive waste using high-calcium fly ash. Final report

    International Nuclear Information System (INIS)

    Cogburn, C.O.; Hodgson, L.M.; Ragland, R.C.

    1986-04-01

    The feasibility of using calcium-rich fly ash from coal-fired power plants in the disposal of low-level radioactive waste was examined. The proposed areas of use were: (1) fly-ash cement as a trench lining material; (2) fly ash as a backfill material; and (3) fly ash as a liquid waste solidifier. The physical properties of fly-ash cement were determined to be adequate for trench liner construction, with compressive strengths attaining greater than 3000 psi. Hydraulic conductivities were determined to be less than that for clay mineral deposits, and were on the order of 10 -7 cm/sec, with some observed values as low as 10 -9 cm/sec. Removal of radioisotopes from acidified solutions by fly ash was good for all elements tested except cesium. The removal of cesium by fly ash was similar to that of montmorillonite clay. The corrosive effects on metals in fly ash environments was determined to be slight, if not non-existent. Coatings at the fly-ash/metal interfaces were observed which appeared to inhibit or diminish corrosion. The study has indicated that high-calcium fly ash appears to offer considerable potential for improved retention of low-level radioactive wastes in shallow land disposal sites. Further tests are needed to determine optimum methods of use. 8 refs., 4 figs., 7 tabs

  18. Assessing fly ash treatment: Remediation and stabilization of heavy metals

    DEFF Research Database (Denmark)

    Lima, A.T.; Ottosen, Lisbeth M.; Ribeiro, Alexandra B.

    2012-01-01

    Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through the electrodialy......Fly ashes from Municipal Solid Waste (MSW), straw (ST) and co-combustion of wood (CW) are here analyzed with the intent of reusing them. Two techniques are assessed, a remediation technique and a solidification/stabilization one. The removal of heavy metals from fly ashes through...... the electrodialytic process (EDR) has been tried out before. The goal of removing heavy metals has always been the reuse of fly ash, for instance in agricultural fields (BEK). The best removal rates are here summarized and some new results have been added. MSW fly ashes are still too hazardous after treatment to even...... consider application to the soil. ST ash is the only residue that gets concentrations low enough to be reused, but its fertilizing value might be questioned. An alternative reuse for the three ashes is here preliminary tested, the combination of fly ash with mortar. Fly ashes have been substituted...

  19. Fundamental study of low-NOx combustion fly ash utilization

    International Nuclear Information System (INIS)

    Suuberg, Eric M.; Hurt, Robert H.

    1998-01-01

    This study is principally concerned with characterizing the organic part of coal combustion fly ashes. High carbon fly ashes are becoming more common as by-products of low-NOx combustion technology, and there is need to learn more about this fraction of the fly ash. The project team consists of two universities, Brown and Princeton, and an electrical utility, New England Power. A sample suite of over fifty fly ashes has been gathered from utilities across the United States, and includes ashes from a coals ranging in rank from bituminous to lignite. The characterizations of these ashes include standard tests (LOI, Foam Index), as well as more detailed characterizations of their surface areas, porosity, extractability and adsorption behavior. The ultimate goal is, by better characterizing the material, to enable broadening the range of applications for coal fly ash re-use beyond the current main market as a pozzolanic agent for concretes. The potential for high carbon-content fly ashes to substitute for activated carbons is receiving particular attention. The work performed to date has already revealed how very different the surfaces of different ashes produced by the same utility can be, with respect to polarity of the residual carbon. This can help explain the large variations in acceptability of these ashes as concrete additives

  20. Lightweight Brick by Carbon Ash from The Mixed Plastic Waste Treatment Plant

    Directory of Open Access Journals (Sweden)

    Chen Kuo-Wei

    2016-01-01

    Full Text Available This study was designed to investigate the mixed plastic waste from the production of light carbon ash bricks performance. The mixed waste plastic pyrolysis process generated waste - Carbon ash. After extrusion, a Lightweight brick was made by carbon ash, additive and Cement mortar. In general, the set compressive strength and insulation effect of lightweight bricks with carbon ash proportion for significant impact. The set water absorption and thermal conductivity of lightweight bricks with carbon ash proportion for significant impact. The set density of lightweight brick ameliorates with M3824 additive and CM3 cement mortar for significant impact. Under conditions of technology and economic, the results of this study as reference for market-oriented marketing and commercialization of production.

  1. Corrosion of metal containers containing cemented radioactive wastes

    International Nuclear Information System (INIS)

    Duffo, G.S.; Farina, S.B.; Schulz, F.M.; Marotta, F

    2010-01-01

    Nuclear activities generate different kinds of radioactive wastes. In the case of Argentina, wastes classified as low and medium level are conditioned in metal drums for final disposal in a repository whose design is based on the use of multiple and independent barriers. Nuclear energy plants generate a large volume of mid-level radioactive wastes, consisting mainly of ion-exchange resins contaminated by fission products. Other contaminated products such as gloves, papers, clothing, rubber and plastic tubing, can be incinerated and the ashes from the combustion also constitute wastes that must be disposed of. These wastes (resins and ashes) must be immobilized in order to avoid the release of radionuclides into the environment. The wastes usually undergo a process of cementing to immobilize them. This work aims to systematically study the process of degradation by corrosion of the steel drums in contact with the cemented resins and with the ashes cemented with the addition of different types and concentrations of aggressive compounds (chloride and sulfate). The specimens are configured so that the parameters of interest for the steel in contact with the cemented materials can be measured. The variables of corrosion potential, electric resistivity of the matrix and polarization resistance (PR) were monitored and show that the presence of chloride increases the susceptibility to corrosion of the drum steel that is in contact with the cement resin matrix

  2. The use of bottom ash for replacing fine aggregate in concrete paving blocks

    Directory of Open Access Journals (Sweden)

    Antoni

    2017-01-01

    Full Text Available Bottom ash that results from coal burning for electrical generation is still much underutilized in Indonesia and it is necessary to increase the usage of this waste. The manufacture of paving blocks using bottom ash, which is normally associated with high water absorption due to its high porosity and carbon content, was examined in this study with the aim to increase the usage of this waste material. The study was done in three phases: (1 the mixture of cement and bottom ash passing sieves of 2 and 5 mm were done with ratios of 1:3, 1:4, and 1:5; from the best proportion, fly ash was used to replace the cement material from 10–80%, and (3 samples with 30% and 50% fly ash replacement ratios were used in combination with 5 mm and 10 mm sieved bottom ash. Compressive strength, water absorption, and abrasion resistance tests were conducted to assess the properties of the resultant paving block. From the result, bottom ash is used to replace natural sand in making paving blocks. By optimizing the particle packing density and using fly ash as a cement replacement, the compressive strength of paving blocks can exceed 40 MPa.

  3. Influence of fly-ashes on properties of ordinary concretes

    Directory of Open Access Journals (Sweden)

    Rutkowska Gabriela

    2016-03-01

    Full Text Available Influence of fly-ashes on properties of ordinary concretes. Care of the environment in accordance with the principles of sustainable development introduces the possibility and need for waste recycling. The construction and building materials industry has the greatest potential for reuse of waste. The article presents the results of investigations of selected properties (consistency, water absorbability, compressive strength and tensile strength after 28 and 56 days of curing, depth of penetration of ordinary concretes and concretes containing fly-ashes - calcareous and siliceous ash − in their composition. To make the samples, the Portland cement CEM I 42.5 R and natural aggregate with graining of 0-16 mm were used. The concrete with siliceous and calcareous admixtures was made in three lots where the ash was added in the quantity of 15, 20 and 30% of the cement mass. After the tests, it was stated that the fly-ash admixture does not increase the air content in the mix, it increases the compressive strength in time and the siliceous ash improves the splitting tensile strength.

  4. Biomass ash utilization

    Energy Technology Data Exchange (ETDEWEB)

    Bristol, D.R.; Noel, D.J.; O`Brien, B. [HYDRA-CO Operations, Inc., Syracuse, NY (United States); Parker, B. [US Energy Corp., Fort Fairfield, ME (United States)

    1993-12-31

    This paper demonstrates that with careful analysis of ash from multiple biomass and waste wood fired power plants that most of the ash can serve a useful purpose. Some applications require higher levels of consistency than others. Examples of ash spreading for agricultural purposes as a lime supplement for soil enhancement in Maine and North Carolina, as well as a roadbase material in Maine are discussed. Use of ash as a horticultural additive is explored, as well as in composting as a filtering media and as cover material for landfills. The ash utilization is evaluated in a framework of environmental responsibility, regulations, handling and cost. Depending on the chemical and physical properties of the biomass derived fly ash and bottom ash, it can be used in one or more applications. Developing a program that utilizes ash produced in biomass facilities is environmentally and socially sound and can be financially attractive.

  5. Research of magnesium phosphosilicate cement

    Science.gov (United States)

    Ding, Zhu

    Magnesium phosphosilicate cement (MPSC) is a novel phosphate bonded cement, which consists mainly of magnesia, phosphate and silicate minerals. The traditional magnesium phosphate cements (MPCs) usually composed by ammonium phosphate, and gaseous ammonia will emit during mixing and in service. There is no noxious ammonia released from MPSC, furthermore, it can recycle a large volume of the non-hazardous waste. The goal of this research is to investigate the composition, reaction products, reaction mechanism, microstructure, properties, durability and applications of the MPSC. MPSC sets rapidly and has high early strength. It reacts better with solid industrial waste when compared to Portland cement. Many solid industrial wastes, such as fly ash, steel slag, coal gangue, red coal gangue, red mud, barium-bearing slag, copper slag, silica fume, and ground granulated blast furnace slag, have been used as the main component (40% by weight) in MPSC. The research has found that these aluminosilicate (or ironsilicate, or calciumsilicate) minerals with an amorphous or glass structure can enhance the performance of MPSC. The disorganized internal structure of amorphous materials may make it possess higher reactivity compared to the crystalline phases. Chemical reaction between phosphate and these minerals may form an amorphous gel, which is favorable to the cementing. Borax, boric acid and sodium tripolyphosphate have been used as retardants in the MPSC system. It is found that boric acid has a higher retarding effect on the setting of cement, than borax does. However, sodium polyphosphate accelerates the reaction of MPSC. The hydration of MPSC is exothermic reaction. The heat evolution may prompt hydrates formation, and shorten the setting process. Modern materials characterization techniques, XRD, DSC, TG-DTA FTIR, XPS, MAS-NMR, SEM, TEM, MIP, etc. were used to analyze the phase composition, micro morphology, and microstructure of hardened MPSC. The main hydration product

  6. Cement technology for plugging boreholes in radioactive waste repository sites. Progress report, October 1, 1977--September 30, 1978

    International Nuclear Information System (INIS)

    Moore, J.G.; Morgan, M.T.; McDaniel, E.W.; Greene, H.B.; West, G.A.

    1979-08-01

    Experiments are in progress using 34 batches of cements from 13 different locales, representing 11 types of cement, and 17 batches of fly ash from 14 suppliers. Data are being obtained from physical and chemical test methods and from measurements made in parametric studies involving cement--fly-ash concretes and saltcretes. Addition of 10 wt % salt to a standard mortar will double the initial and final set times. The set time of the saltcrete can be increased or decreased by a lignite fly ash or bituminous fly ash respectively. The compressive strengths of mortars were measured at 7, 28, and 91 days. The compressive strengths of cement--fly-ash concretes were found to vary with curing time and the fly ash composition. The strengths of saltcretes decreased with increasing salt concentration but increased with the addition of fly ash; the effect of the fly ash composition was apparently negligible. The thermal conductivities of cementitious solids, were found to increase with density and with sand and/or salt concentration. Thermal conductivities of saltcretes decreased with increasing temperature but remained almost constant in neat cement pastes. The conductivity values ranged from 0.4 W/m.K for a neat cement paste to 1.8 W/m.K for a salcrete. Results for a number of saltcretes under the same drying conditions showed that the apparent liquid permeability decreased with increasing salt content. Shrinkage of neat pastes and saltcretes varied approximately linearly with time, while cement--fly-ash solids showed a high rate in the first few weeks followed by a lower rate for a longer time period

  7. Asymmetric Ashes

    Science.gov (United States)

    2006-11-01

    , it is. "This has some impact on the use of Type Ia supernovae as standard candles," says Ferdinando Patat. "This kind of supernovae is used to measure the rate of acceleration of the expansion of the Universe, assuming these objects behave in a uniform way. But asymmetries can introduce dispersions in the quantities observed." "Our discovery puts strong constraints on any successful models of thermonuclear supernova explosions," adds Wang. Models have suggested that the clumpiness is caused by a slow-burn process, called 'deflagration', and leaves an irregular trail of ashes. The smoothness of the inner regions of the exploding star implies that at a given stage, the deflagration gives way to a more violent process, a 'detonation', which travels at supersonic speeds - so fast that it erases all the asymmetries in the ashes left behind by the slower burning of the first stage, resulting in a smoother, more homogeneous residue.

  8. Radioisotope conveyor ash meter

    International Nuclear Information System (INIS)

    Savelov, V.D.

    1994-01-01

    Radioisotope conveyor ash meter realizes persistent measuring of ashiness of coal and products of its enrichment on the belt conveyor without contact. The principle of ash meter acting is based on functional dependence of the gamma radiation flows backscattering intensity of radioisotope sources from the ash volume content in the controlled fuel. Facility consists from the ashiness transducer and the processing and control device

  9. Improvement of coal fly ash pozzolanic activity by different physical methods

    Directory of Open Access Journals (Sweden)

    Jovanović I.

    2014-01-01

    Full Text Available This paper presents the results of laboratory investigations performed in order to determine the possibility of improving the pozzolanic activity of coal fly ash from two Serbian Thermal Power Plants. The initial samples of fly ash were treated by different physical processes (mechanical activation, grinding and classification. On the obtained samples, the pozzolanic activity was determined using standard methods (with lime and Portland cement. It was found that the above procedures can significantly improve the pozzolanic activity of fly ash, and the best results were achieved when the fly ash was treated by mechanical activation process in the laboratory ring mill.

  10. Alternative Fuel for Portland Cement Processing

    Energy Technology Data Exchange (ETDEWEB)

    Schindler, Anton K; Duke, Steve R; Burch, Thomas E; Davis, Edward W; Zee, Ralph H; Bransby, David I; Hopkins, Carla; Thompson, Rutherford L; Duan, Jingran; ; Venkatasubramanian, Vignesh; Stephen, Giles

    2012-06-30

    The production of cement involves a combination of numerous raw materials, strictly monitored system processes, and temperatures on the order of 1500 °C. Immense quantities of fuel are required for the production of cement. Traditionally, energy from fossil fuels was solely relied upon for the production of cement. The overarching project objective is to evaluate the use of alternative fuels to lessen the dependence on non-renewable resources to produce portland cement. The key objective of using alternative fuels is to continue to produce high-quality cement while decreasing the use of non-renewable fuels and minimizing the impact on the environment. Burn characteristics and thermodynamic parameters were evaluated with a laboratory burn simulator under conditions that mimic those in the preheater where the fuels are brought into a cement plant. A drop-tube furnace and visualization method were developed that show potential for evaluating time- and space-resolved temperature distributions for fuel solid particles and liquid droplets undergoing combustion in various combustion atmospheres. Downdraft gasification has been explored as a means to extract chemical energy from poultry litter while limiting the throughput of potentially deleterious components with regards to use in firing a cement kiln. Results have shown that the clinkering is temperature independent, at least within the controllable temperature range. Limestone also had only a slight effect on the fusion when used to coat the pellets. However, limestone addition did display some promise in regards to chlorine capture, as ash analyses showed chlorine concentrations of more than four times greater in the limestone infused ash as compared to raw poultry litter. A reliable and convenient sampling procedure was developed to estimate the combustion quality of broiler litter that is the best compromise between convenience and reliability by means of statistical analysis. Multi-day trial burns were conducted

  11. The influence of blast furnace slag, fly ash and silica fume on corrosion of reinforced concrete in marine environment

    NARCIS (Netherlands)

    Polder, R.B.

    1996-01-01

    Chloride penetration from sea water may cause corrosion of reinforcement in concrete structures. Adding reactive inorganic materials such as blast furnace slag, fly ash or silica fume to the cement matrix improves the resistance against chloride penetration as compared to Portland cement concrete. A

  12. Fourth international conference on fly ash, silica fume, slag, and natural pozzolans in concrete: Supplemental proceedings

    International Nuclear Information System (INIS)

    Berry, E.E.; Hemmings, R.T.; Zhang, M.H.; Malhotra, V.M.

    1992-03-01

    This report consists of four papers presented at a special session on high volume fly ash (HVFA) concrete. These four papers summarize an EPRI research project currently in progress that is investigating HVFA concretes. This objective of this research is to commercialize the HVFA concrete technology through: (1) an extensive measurement of basic engineering and durability properties; (2) an examination of the binder microstructure and cementation hydration reactions; and (3) technology transfer to industry and the construction community. Overall the data from the project that are summarized in these papers, show that commercial quality structural grade concrete (up to 50 MPa compressive strength at 90 days) can be made from a wide range of fly ashes and cements available throughout the USA. It has been shown in this project that fly ash is a reactive participant with the Portland cement in the cementing process, and also serves as a microaggregate in a multiphase composite binder formed during curing. The properties of the binder were found to significantly influence strength development, elastic modulus, and the stress-strain behavior of HVFA concrete. Overall, the data presented show that regardless of the type of fly ash (from the nine US ashes evaluated) and the two cements used, that air-entrained HVFA concrete exhibits excellent durability in all respects except under application of deicing salts where some surface scaling has been observed in the laboratory

  13. Leaching of solidified TRU-contaminated incinerator ash

    International Nuclear Information System (INIS)

    Fuhrmann, M.; Colombo, P.

    1984-01-01

    Leach rate and cumulative fractional releases of plutonium were determined for a series of laboratory-scale waste forms containing transuranic (TRU) contaminated incinerator ash. The solidification agents from which these waste forms were produced are commercially available materials for radioactive waste disposal. The leachants simulate groundwaters with chemical compositions that are indiginous to different geological media proposed for repositories. In this study TRU-contaminated ash was incorporated into waste forms fabricated with portland type I cement, urea-formaldehyde, polyester-styrene or Pioneer 221 bitumen. The ash was generated at the dual-chamber incinerator at the Rocky Flats Plant. These waste forms contained between 1.25 x 10 -2 and 4.4 x 10 -2 Ci (depending on the solidification agent) of mixed TRU isotopes comprised primarily of 239 Pu and 240 Pu. Five leachant solutions were prepared consisting of: (1) demineralized water, (2) simulated brine, (3) simplified sodium-dominated groundwater (30 meq NaCl/liter), (4) simplified calcium-dominated groundwater (30 meq CaCl 2 /liter), and (5) simplified bicarbonate-dominated groundwater (30 meq NaHCO 3 /liter). Cumulative fractional releases were found to vary significantly with different leachants and solidification agents. In all cases waste forms leached in brine gave the lowest leach rates. Urea-formaldehyde had the greatest release of radionuclides while polyester-styrene and portland cement had approximately equivalent fractional releases. Cement cured for 210 days retained radionuclides three times more effectively than cement cured only 30 days

  14. physico-chemical studies on polymer impregnated blending cement mortar composite

    International Nuclear Information System (INIS)

    Abdel-Rahman, H.A.

    2001-01-01

    as the increasing of the demand on a specific performance characteristics in concrete such as improved strength, low heat, sulfate resistance, improved impermeability and certain other applications. some of the industrial waste materials such as the blast-furnace slag, silica fume and fly ash were mixed with the cement clinker to produce blended cement . the use of these materials modifies the strength, pore structure and permeability of hardened cement mortar or concrete. the incorporation of blast furnace slag and silica fume in the hardened blended cement mortar or concrete is a common practice recently due to technological, economical and environmental benefits

  15. Application of tracer technique in cement industry

    International Nuclear Information System (INIS)

    Baran'ai, L.

    1979-01-01

    Application is stated of the radioisotope indication method in the cement industry. The method was applied in three directions. In the first direction, by means of labelling of 300 steel mill balls by cobalt-60, wear of them was examined. The degree of wear of milling balls in the process of milling was determined according to the decrease of their weight. Radioactive label served only for tracing controll balls. In the second direction, according to the natural radioactivity being presented in ashes by radioisotopes radium-226 and thorium-229, amount of ashes in the products of cement milling was determined (in the mill product, cement product, flying dust and back loading groats). In the third direction, by means of labelling of definite fractions of mille by radioisotope gold-198, optimization of technological parameters of silos were raw meal is homogenization. The following technological parameters have been established: amount of homogenized material; time of homogenization and frequency of intensity changing of supplied compressed air jet [ru

  16. Experimental Study on Rise Husk Ash & Fly Ash Based Geo-Polymer Concrete Using M-Sand

    Science.gov (United States)

    Nanda Kishore, G.; Gayathri, B.

    2017-08-01

    Serious environmental problems by means of increasing the production of Ordinary Portland cement (OPC), which is conventionally used as the primary binder to produce cement concrete. An attempt has been made to reduce the use of ordinary Portland cement in cement concrete. There is no standard mix design of geo-polymer concrete, an effort has been made to know the physical, chemical properties and optimum mix of geo-polymer concrete mix design. Concrete cubes of 100 x 100 x 100 mm were prepared and cured under steam curing for about 24 hours at temperature range of 40°C to 60°C. Fly ash is replaced partially with rice husk ash at percentage of 10%, 15% and 25%. Sodium hydroxide and sodium silicate are of used as alkaline activators with 5 Molar and 10 Molar NaOH solutions. Natural sand is replaced with manufacture sand. Test results were compared with controlled concrete mix of grade M30. The results shows that as the percentage of rice husk ash and water content increases, compressive strength will be decreases and as molarity of the alkaline solution increases, strength will be increases.

  17. Effect of high volume of fly ash from 5 sources on compressive strength and acid resistance of concrete

    Directory of Open Access Journals (Sweden)

    Vivatanachang, N.

    2004-03-01

    Full Text Available The purpose of this research was to examine the effect of high volume of fly ash from various sources on compressive strength and acid resistance of concrete. Fly ashes from 5 sources were collected and classified by an air classifier into 3 groups of different degree of fineness; low, medium, and high fineness. Portland cement type I was replaced by fly ash at the rate of 50% by weight of cementitious materials (Portland cement type I and fly ash to cast concrete cylinders of 10 cm in diameter and 20 cm in height. After fly ash concreteswere cured in water for 28 days, they were tested to determine the compressive strength. In addition, the specimens were immersed in 3% of sulfuric acid solution and the weight losses of concretes were measured from 3 to 90 days. It was found that the compressive strengths of fly ash concretes were more than 77% of the control concrete when the high fineness fly ashes were used. Each source of the fly ash had different effect on the compressive strength as well as on the sulfuric acid resistance of concrete. The compressive strength of fly ash concrete was improved with the use of high fineness fly ash; however, the sulfuric acid resistance of the concrete tended to decrease as the fineness of fly ash increased.

  18. Cements research progress. 1988

    International Nuclear Information System (INIS)

    Anon.

    1990-01-01

    This book reviews a survey of the literature on the science of cements published during 1988. The book focuses on an aspect of cement utilization of increasing importance, the immobilization of nuclear wastes

  19. Mechanical and Durability Properties of Fly Ash Based Concrete Exposed to Marine Environment

    Science.gov (United States)

    Kagadgar, Sarfaraz Ahmed; Saha, Suman; Rajasekaran, C.

    2017-06-01

    Efforts over the past few years for improving the performance of concrete suggest that cement replacement with mineral admixtures can enhance the strength and durability of concrete. Feasibility of producing good quality concrete by using alccofine and fly ash replacements is investigated and also the potential benefits from their incorporation were looked into. In this study, an attempt has been made to assess the performance of concrete in severe marine conditions exposed upto a period of 150 days. This work investigates the influence of alccofine and fly ash as partial replacement of cement in various percentages (Alccofine - 5% replacement to cement content) and (fly ash - 0%, 15%, 30%, 50% & 60% to total cementitious content) on mechanical and durability properties (Permit ion permeability test and corrosion current density) of concrete. Usage of alccofine and high quantity of fly ash as additional cementitious materials in concrete has resulted in higher workability of concrete. Inclusion of alccofine shows an early strength gaining property whereas fly ash results in gaining strength at later stage. Concrete mixes containing 5% alccofine with 15% fly ash replacement reported greater compressive strength than the other concrete mixes cured in both curing conditions. Durability test conducted at 56 and 150 days indicated that concrete containing higher percentages of fly ash resulted in lower permeability as well lesser corrosion density.

  20. Mechanical and Durability Properties of Fly Ash Based Concrete Exposed to Marine Environment

    Directory of Open Access Journals (Sweden)

    Kagadgar Sarfaraz Ahmed

    2017-06-01

    Full Text Available Efforts over the past few years for improving the performance of concrete suggest that cement replacement with mineral admixtures can enhance the strength and durability of concrete. Feasibility of producing good quality concrete by using alccofine and fly ash replacements is investigated and also the potential benefits from their incorporation were looked into. In this study, an attempt has been made to assess the performance of concrete in severe marine conditions exposed upto a period of 150 days. This work investigates the influence of alccofine and fly ash as partial replacement of cement in various percentages (Alccofine - 5% replacement to cement content and (fly ash - 0%, 15%, 30%, 50% & 60% to total cementitious content on mechanical and durability properties (Permit ion permeability test and corrosion current density of concrete. Usage of alccofine and high quantity of fly ash as additional cementitious materials in concrete has resulted in higher workability of concrete. Inclusion of alccofine shows an early strength gaining property whereas fly ash results in gaining strength at later stage. Concrete mixes containing 5% alccofine with 15% fly ash replacement reported greater compressive strength than the other concrete mixes cured in both curing conditions. Durability test conducted at 56 and 150 days indicated that concrete containing higher percentages of fly ash resulted in lower permeability as well lesser corrosion density.

  1. High-volume use of self-cementing spray dry absorber material for structural applications

    Science.gov (United States)

    Riley, Charles E.

    Spray dry absorber (SDA) material, or spray dryer ash, is a byproduct of energy generation by coal combustion and sulfur emissions controls. Like any resource, it ought to be used to its fullest potential offsetting as many of the negative environmental impacts of coal combustion as possible throughout its lifecycle. Its cementitious and pozzolanic properties suggest it be used to augment or replace another energy and emissions intensive product: Portland cement. There is excellent potential for spray dryer ash to be used beneficially in structural applications, which will offset CO2 emissions due to Portland cement production, divert landfill waste by further utilizing a plentiful coal combustion by-product, and create more durable and sustainable structures. The research into beneficial use applications for SDA material is relatively undeveloped and the material is highly underutilized. This dissertation explored a specific self-cementing spray dryer ash for use as a binder in structural materials. Strength and stiffness properties of hydrated spray dryer ash mortars were improved by chemical activation with Portland cement and reinforcement with polymer fibers from automobile tire recycling. Portland cement at additions of five percent of the cementitious material was found to function effectively as an activating agent for spray dryer ash and had a significant impact on the hardened properties. The recycled polymer fibers improved the ductility and toughness of the material in all cases and increased the compressive strength of weak matrix materials like the pure hydrated ash. The resulting hardened materials exhibited useful properties that were sufficient to suggest that they be used in structural applications such as concrete, masonry block, or as a hydraulic cement binder. While the long-term performance characteristics remain to be investigated, from an embodied-energy and carbon emissions standpoint the material investigated here is far superior to

  2. Sulfur polymer cement concrete

    International Nuclear Information System (INIS)

    Weber, H.H.; McBee, W.C.

    1990-01-01

    Sulfur-based composite materials formulated using sulfur polymer cement (SPC) and mineral aggregates are described and compared with conventional portland cement based materials. Materials characteristics presented include mechanical strength, chemical resistance, impact resistance, moisture permeation, and linear shrinkage during placement and curing. Examples of preparation and placement of sulfur polymer cement concrete (SC) are described using commercial scale equipment. SC applications presented are focused into hostile chemical environments where severe portland cement concrete (PCC) failure has occurred

  3. Corrosion-resistant Foamed Cements for Carbon Steels

    Energy Technology Data Exchange (ETDEWEB)

    Sugama T.; Gill, S.; Pyatina, T., Muraca, A.; Keese, R.; Khan, A.; Bour, D.

    2012-12-01

    The cementitious material consisting of Secar #80, Class F fly ash, and sodium silicate designed as an alternative thermal-shock resistant cement for the Enhanced Geothermal System (EGS) wells was treated with cocamidopropyl dimethylamine oxide-based compound as foaming agent (FA) to prepare numerous air bubble-dispersed low density cement slurries of and #61603;1.3 g/cm3. Then, the foamed slurry was modified with acrylic emulsion (AE) as corrosion inhibitor. We detailed the positive effects of the acrylic polymer (AP) in this emulsion on the five different properties of the foamed cement: 1) The hydrothermal stability of the AP in 200 and #61616;C-autoclaved cements; 2) the hydrolysis-hydration reactions of the slurry at 85 and #61616;C; 3) the composition of crystalline phases assembled and the microstructure developed in autoclaved cements; 4) the mechanical behaviors of the autoclaved cements; and, 5) the corrosion mitigation of carbon steel (CS) by the polymer. For the first property, the hydrothermal-catalyzed acid-base interactions between the AP and cement resulted in Ca-or Na-complexed carboxylate derivatives, which led to the improvement of thermal stability of the AP. This interaction also stimulated the cement hydration reactions, enhancing the total heat evolved during cement’s curing. Addition of AP did not alter any of the crystalline phase compositions responsible for the strength of the cement. Furthermore, the AP-modified cement developed the porous microstructure with numerous defect-free cavities of disconnected voids. These effects together contributed to the improvement of compressive-strength and –toughness of the cured cement. AP modification of the cement also offered an improved protection of CS against brine-caused corrosion. There were three major factors governing the corrosion protection: 1) Reducing the extents of infiltration and transportation of corrosive electrolytes through the cement layer deposited on the underlying CS

  4. Development of Classified Fly Ash as a Pozzolanic Material

    Science.gov (United States)

    Rukzon, Sumrerng; Chindaprasirt, Prinya

    This research studies the potential for using classified fly ash from Mae Moh power plant in Thailand as a pozzolanic material. Three different fly ash finenesses viz., coarse Original Fly Ash (OFA), Medium Fly Ash (MFA) and Fine Fly Ash (FFA) were used for the study. Ordinary Portland Cement (OPC) was partially replaced with fly ash at 20 and 40% by weight of binder. The water to binder ratio was kept constant at 0.5 and the flow of mortar was maintained at 110±5% with the aid of superplasticizer (SP). Compressive strength, carbonation depth and porosity test of mortars were determined. FFA has a high potential to be used as a good pozzolanic material. The use of FFA produces mortars with good strength and low porosity. The resistance to carbonation of mortar improves with partial replacement of FFA in comparison with the normal coarse fly ash. The use of FFA results in a strong and dense mortar which is due to better dispersion and filling effect as well as an increase in the pozzolanic reaction.

  5. Change in re-use value of incinerated sewage sludge ash due to chemical extraction of phosphorus.

    Science.gov (United States)

    Li, Jiang-Shan; Chen, Zhen; Wang, Qi-Ming; Fang, Le; Xue, Qiang; Cheeseman, C R; Donatello, Shane; Liu, Lei; Poon, Chi Sun

    2018-04-01

    The potential of six different extractants to recover phosphorus (P) from incinerated sewage sludge ash (ISSA) was evaluated. Secondary effects such as the co-dissolution of Zn and Cu were also considered. The residual ISSA from each study was assessed in particular detail, focusing on the leachability of remaining Zn and Cu, major element composition, crystalline phases and overall degree of crystallinity and particle size distribution. The residual ISSA was also evaluated as a pozzolanic material using a Strength Activity Index (SAI) test with mortars containing Portland cement with a 20% substitution by ISSA. All results were compared to tests with untreated ISSA. Overall, the use of 3 of the 6 extractants could be ruled out due to poor P recovery potential and/or a serious compromise of the potential reuse of residual ISSA in Portland cement-based materials. The results highlight the added value of considering the potential reuse of residual ISSA when trying to optimize P recovery from ISSA by wet methods. Copyright © 2018 Elsevier Ltd. All rights reserved.

  6. Melting and Sintering of Ashes

    DEFF Research Database (Denmark)

    Hansen, Lone Aslaug

    1997-01-01

    , the biggest deviations being found for salt rich (i.e. straw derived) ashes.A simple model assuming proportionality between fly ash fusion and deposit formation was found to be capable of ranking deposition rates for the different straw derived fly ashes, whereas for the fly ashes from coal/straw co......-firing, the model only had a qualitative agreement with the measured ash deposit formation rates.Sintering measurements were carried out by means of compression strength testing of ash pellets. This method showed to not be applicable for the salt rich fly ash derived from straw combustion. For the fly ashes...... have been employed in a simple model for prediction of ash deposit formation, the results of which have been compared to ash deposition formation rates measured at the respective boilers.The ash fusion results were found to directly reflect the ash compositional data:a) Fly ashes and deposits from...

  7. Investigation of the Strength Properties of Palm Kernel Shell Ash Concrete

    Directory of Open Access Journals (Sweden)

    F. A. Olutoge

    2012-01-01

    Full Text Available Many researchers have studied the use of agro-waste ashes as constituents in concrete. These agro-waste ashes are siliceous or aluminosiliceous materials that, in finely divided form and in the presence of moisture, chemically react with the calcium hydroxide released by the hydration of Portland cement to form calcium silicate hydrate and other cementitious compounds. Palm kernel shell ash (PKSA is a by-product in palm oil mills. This ash has pozzolanic properties that enables it as a partial replacement for cement but also plays an important role in the strength and durability of concrete. The use of palm kernel shell ash (PKSA as a partial replacement for cement in concrete is investigated. The objective of this paper is to alleviate the increasing challenges of scarcity and high cost of construction materials used by the construction industry in Nigeria and Africa in general, by reducing the volume of cement usage in concrete works. Collected PKSA was dried and sieved through a 45um sieve. The fineness of the PKSA was checked by sieving through 45um sieve. The chemical properties of the ash are examined whereas physical and mechanical properties of varying percentage of PKSA cement concrete and 100% cement concrete of mix 1:2:4 and 0.5 water-cement ratios are examined and compared. A total of 72 concrete cubes of size 150 × 150 × 150 mm³ with different volume percentages of PKSA to Portland cement in the order 0:100, 10:90 and 30:70 and mix ratio of 1:2:4 were cast and their physical and mechanical properties were tested at 7, 14, 21 and 28 days time. Although the compressive strength of PKSA concrete did not exceed that of OPC, compressive strength tests showed that 10% of the PKSA in replacement for cement was 22.8 N/mm2 at 28 days; which was quite satisfactory with no compromise in compressive strength requirements for concrete mix ratios 1:2:4. This research showed that the use of PKSA as a partial replacement for cement in concrete

  8. Testing and evaluation of polyethylene and sulfur cement waste forms

    International Nuclear Information System (INIS)

    Franz, E.M.; Kalb, P.D.; Colombo, P.

    1985-01-01

    This paper discusses the results of recent studies related to the use of polyethylene and modified sulfur cement as new binder materials for the improved solidification of low-level wastes. Waste streams selected for this study include those which result from advanced volume reduction technologies (dry evaporator concentrate salts and incinerator ash) and those that remain problematic for solidification using contemporary agents (ion-exchange resins). Maximum waste loadings were determined for each waste type. Recommended waste loadings of 70 wt % sodium sulfate, 50 wt % boric acid, 40 wt % incinerator ash and 30 wt % ion exchange resins, which are based on process control and waste form performance considerations are reported for polyethylene. For sulfur cement the recommended waste loadings of 40 wt % sodium sulfate and boric acid salts and 43 wt % incinerator ash are reported. However, incorporation of ion-exchange resin waste in modified sulfur cement is not recommended due to poor waste form performance. The work presented in this paper will, in part, present data that can be used to assess the acceptability of polyethylene and modified sulfur cement waste forms to meet the requirements of 10 CFR 61. 8 refs., 10 figs., 6 tabs

  9. Physical and Chemical Character of Fly Ash of Coal Fired Power Plant in Java

    Science.gov (United States)

    Triwulan; Priadana, K. A.; Ekaputri, J. J.; Bayuaji, R.

    2017-11-01

    Quality of fly ash is varying widely in the field, it depends on the combustion process and the quality of the basic ingredients, namely coal. It will affect the physical and mechanical properties of the concrete mixtures used. This study used 12 samples of fly ash. The physical and chemical properties and finesse modulus were analyzed. The fly ash was mixed with OPC (Ordinary Portland Cement) with the proportion of 20% fly ash and 80% OPC. The specimens were form with mortar dimension of 5cm x 5 cm. The test was affected by the correlation of fly ash fineness modulus to compressive strength, correlation density of fly ash to compressive strength, and correlation of carbon content to the compressive strength.

  10. Utilization of power plant bottom ash as aggregates in fiber-reinforced cellular concrete.

    Science.gov (United States)

    Lee, H K; Kim, H K; Hwang, E A

    2010-02-01

    Recently, millions tons of bottom ash wastes from thermoelectric power plants have been disposed of in landfills and coastal areas, regardless of its recycling possibility in construction fields. Fiber-reinforced cellular concrete (FRCC) of low density and of high strength may be attainable through the addition of bottom ash due to its relatively high strength. This paper focuses on evaluating the feasibility of utilizing bottom ash of thermoelectric power plant wastes as aggregates in FRCC. The flow characteristics of cement mortar with bottom ash aggregates and the effect of aggregate type and size on concrete density and compressive strength were investigated. In addition, the effects of adding steel and polypropylene fibers for improving the strength of concrete were also investigated. The results from this study suggest that bottom ash can be applied as a construction material which may not only improve the compressive strength of FRCC significantly but also reduce problems related to bottom ash waste.

  11. COMPRESSIVE STRENGTH AND MICROSTRUCTURE STUDIES ON CEMENT ADDED GEOPOLYMER CONCRETE

    OpenAIRE

    Vanga Renuka; Kolluri Dharani

    2017-01-01

    Geopolymer results from the reaction of a source material that is rich in silica and alumina with alkaline liquid. It is essentially cement free concrete. This material is being studied extensively and shows promise as a greener substitute for Ordinary Portland Cement concrete in some applications. Research is shifting from the chemistry domain to engineering applications and commercial production of geopolymer concrete. It has been found that geopolymer concrete has good engineering properti...

  12. Aggregate material formulated with MSWI bottom ash and APC fly ash for use as secondary building material

    International Nuclear Information System (INIS)

    Valle-Zermeño, R. del; Formosa, J.; Chimenos, J.M.; Martínez, M.; Fernández, A.I.

    2013-01-01

    Highlights: ► A concrete formulation was optimized using Bottom Ash and APC ash. ► 10% of APC ash achieves good compromise between economic and performance aspects. ► The crushed concrete was evaluated as secondary building granular material. ► The environmental behavior allows its use as secondary material. ► The abrasion resistance is not good enough for its use as a road sub-base material. - Abstract: The main goal of this paper is to obtain a granular material formulated with Municipal Solid Waste Incineration (MSWI) bottom ash (BA) and air pollution control (APC) fly ash to be used as secondary building material. Previously, an optimum concrete mixture using both MSWI residues as aggregates was formulated. A compromise between the environmental behavior whilst maximizing the reuse of APC fly ash was considered and assessed. Unconfined compressive strength and abrasion resistance values were measured in order to evaluate the mechanical properties. From these results, the granular mixture was not suited for certain applications owing to the high BA/APC fly ash content and low cement percentages used to reduce the costs of the final product. Nevertheless, the leaching test performed showed that the concentrations of all heavy metals were below the limits established by the current Catalan legislation for their reutilization. Therefore, the material studied might be mainly used in embankments, where high mechanical properties are not needed and environmental safety is assured

  13. Procedure for ash-poor cokes

    Energy Technology Data Exchange (ETDEWEB)

    Geissler

    1945-04-01

    This article was composed of four sections which dealt with de-ashing processes or uses of ash-poor coke. The general procedure for de-ashing started with 1 mm coal grains mixed with dilute HCl and then decanted from a concentrator. The thick paste was crushed finely and pasted with tar from the Low Temperature Carbonization (LTC). The paste was kneaded, washed, and then formed. The resulting briquettes were dried, crushed, and reformed. The LTC then took place at 550/sup 0/C followed by coking at 900/sup 0/C. The oven dimensions were given as 3.25 m tall, 0.65 wide, and 4 m deep for the LTC sections, and 3.25 m x 0.60 m x 4 m for the coking section. These dimensions were designed for 100 kg coke per hour. Methods were discussed for decreasing costs of coke production by substitution of a cheaper binding tar than that of the LTC recycle. CS/sub 2/ production was proposed using coke processed by the above de-ashing procedure. This process which substituted coke for the usual charcoal was shown to work, but was very sensitive to ash and solids content in the coke. Coke substitution for reducing charcoal in the production of light metals was tested. It was found that the iron content of the coke product has to be less than 0.05%, so that the coal used must have only slight traces of iron. Experiments were carried out to use de-ashed cokes as fuel to power automibiles, where a major difficulty was found in the tendency of the coke briquettes to flake and crumble. Different methods and binders were tried for briquetting, thus eliminating many difficulties. For the production of electrode cokes, flotation, separation, and lye treatment preceeded the de-ashing procedure outlined above. It was concluded that the properties of the cokes were greatly influenced by the quality of the briquette binder. It was intended to research and classify the types of binders.

  14. CHH Cement Composite

    Science.gov (United States)

    Cwirzen, A.; Habermehl-Cwirzen, K.; Nasibulina, L. I.; Shandakov, S. D.; Nasibulin, A. G.; Kauppinen, E. I.; Mudimela, P. R.; Penttala, V.

    The compressive strength and electrical resistivity for hardened pastes produced from nanomodified Portland SR cement (CHH- Carbon Hedge Hog cement) were studied. The nanomodification included growing of carbon nanotubes (CNTs) and carbon nanofibers (CNFs) on the cement particles. Pastes having water to binder ratio of 0.5 were produced. The obtained hardened material was characterized by increased compressive strength in comparison with the reference specimens made from pristine SR cement, which was attributed to reinforcing action of the CNTs and CNFs. The electrical resistivity of CHH composite was lower by one order of magnitude in comparison with reference Portland cement paste.

  15. ULTRA-LIGHTWEIGHT CEMENT

    Energy Technology Data Exchange (ETDEWEB)

    Fred Sabins

    2001-04-15

    The objective of this project is to develop an improved ultra-lightweight cement using ultralight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Problems and Task 3: Test Ultra-Lightweight Cements. Results reported this quarter include a review and summary of Halliburton Energy Services (HES) and BJ Services historical performance data for lightweight cement applications. These data are analyzed and compared to ULHS cement and foamed cement performances. Similar data is expected from Schlumberger, and an analysis of this data will be completed in the following phases of the project. Quality control testing of materials used to formulate ULHS cements in the laboratory was completed to establish baseline material performance standards. A testing protocol was developed employing standard procedures as well as procedures tailored to evaluate ULHS and foamed cement. This protocol is presented and discussed. Results of further testing of ULHS cements are presented along with an analysis to establish cement performance design criteria to be used during the remainder of the project. Finally, a list of relevant literature on lightweight cement performance is compiled for review during the next quarter.

  16. Properties of cement based composites modified using diatomaceous earth

    Science.gov (United States)

    Pokorný, Jaroslav; Pavlíková, Milena; Záleská, Martina; Pavlík, Zbyšek

    2017-07-01

    Diatomite belongs among natural materials rich on amorphous silica (a-SiO2). When finely milled, it can potentially substitute part of cement binder and positively support formation of more dense composite structure. In this connection, two types of diatomaceous earth applied as a partial substitution of 5, 10, 15, and 20 mass% of Portland cement in the composition of cement paste were studied. In the tested mixtures with cement blends, the amount of batch water remained same, with water/binder ratio 0.5. For fresh paste mixtures, initial and final setting times were measured. First, hardened pastes cured 28 days in water were characterized by their physical properties such as bulk density, matrix density and open porosity. Then, their mechanical and thermophysical parameters were assessed. Obtained results gave clear evidence of setting time shortening for pastes with diatomite what brought negative effect with respect to the impaired workability of fresh mixtures. On the other hand, there was observed strength improvement for mixtures containing diatomite with higher amount of SiO2. Here, the increase in mechanical resistivity was distinct up to 15 mass% of cement replacement. Higher cement substitution by diatomite resulted in an increase in porosity and thus improvement of thermal insulation properties.

  17. Review of palm oil fuel ash and ceramic waste in the production of concrete

    Science.gov (United States)

    Natasya Mazenan, Puteri; Sheikh Khalid, Faisal; Shahidan, Shahiron; Shamsuddin, Shamrul-mar

    2017-11-01

    High demand for cement in the concrete production has been increased which become the problems in the industry. Thus, this problem will increase the production cost of construction material and the demand for affordable houses. Moreover, the production of Portland cement leads to the release of a significant amount of CO2 and other gases leading to the effect on global warming. The need for a sustainable and green construction building material is required in the construction industry. Hence, this paper presents utilization of palm oil fuel ash and ceramic waste as partial cement replacement in the production of concrete. Using both of this waste in the concrete production would benefit in many ways. It is able to save cost and energy other than protecting the environment. In short, 20% usage of palm oil fuel ash and 30% replacement of ceramic waste as cement replacement show the acceptable and satisfactory strength of concrete.

  18. Mechanical behavior of cementitious composites with processed sugar cane bagasse ashes

    International Nuclear Information System (INIS)

    Bezerra, Augusto C.S.; Saraiva, Sergio L.C.; Sena, Natalia O.; Pereira, Gabriela M.; Rodrigues, Conrado S.; Ferreira, Maria C.N.F.; Castro, Laurenn W.A.; Silva, Marcos V.M.S.; Gomes, Romero C.; Aguilar, Maria T.P.

    2014-01-01

    Sugar cane bagasse is waste from the sugar and ethanol industry and is primarily intended for burning in boilers to generate energy. As waste from the cogeneration of energy, sugar cane bagasse ashes (SCBA) are produced with no honorable destination. This paper studies the use of SCBA to partially replace Portland cement in producing cementitious composites. The ashes were processed by reburning and grinding, and after processing were characterized by a scanning electron microscope, x-ray diffraction, laser granulometry, and x-ray fluorescence spectrometry. After characterization, cement compounds were fashioned, replacing 0, 10, 20 and 30% of the cement with SCBA. The composites were mechanically evaluated by means of compression strength tests, tensile strength tests by bending. The results proved significant, indicating the possible use of SCBA when added to the cement on manufacture. (author)

  19. Alpha radioactivity in Indian cement samples

    International Nuclear Information System (INIS)

    Nain, M.; Chauhan, R. P.; Chakarvarti, S. K.

    2006-01-01

    The essential constituents of radioactive and each of cements like lime, silica and alumina are derived from earth's crust in which radioactive elements like uranium, thorium etc are also present in varying amounts almost everywhere. These two elements are considered as the parent elements of uranium and thorium radioactive decay series in which radon and thoron are produced respectively as decay products. In the present study the samples of ordinary Portland cement , Portland pozzolana cement and some other cementious finishing materials like white cement, Plaster of Paris , cement putty etc were collected and analysed for radium and radon concentrations along with radon exhalation rates. Materials and Methods: Alpha sensitive LR-115 Type II plastic track detectors commonly known as S olid State Nuclear Track Detectors w ere used to measure the radium and radon concentration. The alpha particles emitted from the radon causes the radiation damaged tracks. The Chemical etching in NaOH at 60 C for about 90 minutes was done to reveal these latent tracks, which were then scanned and counted by an optical microscope of suitable magnification. By calculating the track density of registered tracks, the radon and radium concentrations along with exhalation rate of radon, were determined using required formulae. Results: The radon and radium concentration in various brands of cements found to vary from 333±9.9 to 506±13.3 Bq m-3 and from 3.7±0.1 to 5.6±0.2 Bq k g-1 while in various cementious finishing materials used in the construction, these were found to vary from 378±19.7 to 550±9.8 Bq m-3 and from 4.2±0.2 to 6.1±0.1 Bq Kg-1, respectively. Based on the data the mass and surface exhalation rates were also calculated Conclusion: The measurements indicate that there is marginal variation of the concentration of radium and radon in various brands of cements in India with lower levels in the cement samples having red oxide and higher levels in fly ash based cement

  20. Utilization of waste tires as alternative fuel in cement plant

    OpenAIRE

    Pezdirc, Andrej

    2016-01-01

    Cement industry is regulated by legislation in which various measures are specified for prevention and reduction of air pollution as well as protection of human health, due to atmospheric emissions, which occur during cement production. Legislation also holds emission limit values for co-incineration of wastes i.e. alternative fuels. Waste tires as an alternative fuel can be co-incinerated i.e. co-processed in cement plants, where the high calorific value of the rubber is used to substitute f...

  1. Energy optimization and reduction of carbon footprint in cement manufacturing

    Energy Technology Data Exchange (ETDEWEB)

    Gallestey, Eduardo; Crosley, Gabriela; Wilson, Andrew; Maier, Urs; Hoppler, Rolf; Boerrnert, Thomas

    2010-09-15

    Cement producers are large consumers of thermal and electrical energy, which are only available at steadily increasing costs. Efforts to reduce demands by using higher efficiency equipment and substituting -fuels and raw materials to lower production costs have been addressed in recent years. Under the Kyoto Protocol industrialised countries agreed to reduce their collective greenhouse gas emissions. Cement producers as some of the largest emitters of CO2 have been especially challenged to find new and innovative ways to reduce greenhouse gas emissions. This paper summarise some ABB technologies developed to assist the cement industry to meet these goals.

  2. MECHANICAL PROPERTIES AND SULFURIC ACID RESISTANCE OF HIGH VOLUME CLASS C FLY ASH CONCRETE

    Directory of Open Access Journals (Sweden)

    Halit YAZICI

    2005-03-01

    Full Text Available In this study, some physical and mechanical properties of concrete mixtures containing high volume Class C fly ash have been investigated. Two different curing conditions, standard curing in water and curing in air were applied to the specimens in which 40 to 70 % cement was replaced with fly ash. Compressive strength, splitting tensile strength, modulus of elasticity and sulfuric acid resistance of concrete mixes, the volume stability of mortar bar specimens and setting times of pastes were investigated. Test results are presented comparatively with control specimens which have only Portland cement as a binder.

  3. MODIFICATION OF FOAMED CEMENT-CLAY MORTARS BY STABILIZERS

    Directory of Open Access Journals (Sweden)

    Panfilova Marina Ivanovna

    2012-10-01

    by-product generated in the course of combustion of crossties, and reduction of the cement consumption rate. The authors have identified that ash added into the injection does not cause any deterioration of the mortar strength; rather, it assures its structural stability and prevents any leaching of heavy metals that it contains. The authors have identified that adding 20 to 26 % of flue ash into the injection reduces the mortar hardening time by 30 %, while the strength of the mortar that has 20 % of ash is almost equal to the one of the benchmark sample. However, any higher ash content causes deterioration of the hardening strength of the mortar. Therefore, the authors have discovered that 20 % of the cement may be replaced by the ash generated in the course of combustion of waste crossties. This replacement is to be performed in the course of preparation of mortars, and it is aimed at the strengthening of the soil. This operation is to be performed in the incinerator to preserve the solution properties. This technology reduces the amount of hazardous by-products through their recycling.

  4. Characterization and environmental evaluation of Atikokan coal fly ash for environmental applications

    Energy Technology Data Exchange (ETDEWEB)

    Yeheyis, M.B.; Shang, J.Q.; Yanful, E.K. [Western Ontario Univ., London, ON (Canada). Dept. of Civil and Environmental Engineering

    2008-09-15

    Coal fly ash from thermal power generating stations has become a valuable byproduct in various commercial and environmental applications due to its cementitious, alkaline, and pozzolanic properties. It is used as a raw material in cement production, and also as a replacement for cement in concrete production. This study provided physical, chemical, and mineralogical characterizations of fresh and landfilled coal fly ash from a thermal generation station in Ontario. Fly ash behaviour under various environmental conditions was examined. Tests were conducted to characterize fly ash acid neutralization capacity and heavy metal sorption capacity. The study showed that fresh and landfilled fly ash samples showed significant variations in morphology, mineralogy, and chemical composition. X-ray diffraction studies demonstrated that weathering of the fly ash caused the formation of secondary minerals. The study also showed that the heavy metals from both fresh and landfilled fly ash samples were below leachate criteria set by the provincial government. It was concluded that both fresh and landfilled fly ash are suitable for various environmental and engineering applications. 55 refs., 5 tabs., 11 figs.

  5. Use of petroleum code as fuel in the cement industry

    International Nuclear Information System (INIS)

    Nawaz, S.

    2006-01-01

    The Cement industry is a very energy intensive industry. Each ton of cement produced requires 60 to 130 kilograms of fuel oil or an equivalent fuelling amount also requires an average 110 kWh of electricity as well over 40% of total production cost is the energy requirements in the cement industry (i.2). Normally oil, gas or coal is fired in cement kilns as traditional fuels. However use of waste, both as alternative fuels and raw materials is now common practice in many cement companies. Many different types of wastes are burnt today in cement kilns like used tyres, rubber, paper waste, waste oils, waste wood, paper sludge, sewage, animal meal and animal remains (i,4). The choice of fuel for the purpose is normally based on price and availability considering different properties of the fuel as energy contents, ash contents, moisture and volatiles contents. Petcoke is not yet produced in any petroleum refinery in Pakistan but it is abundantly available in the market worldwide as it is obtained as a waste product during the refining processes. The purpose of the current research is to figure out the suitability of petroleum coke as a fuel for cement industry both on technical and economic basis. (author)

  6. STABILIZATION OF DRY SLUDGE OF LIQUID WASTE OF LEATHER TREATMENT BY USING FLY ASH

    Directory of Open Access Journals (Sweden)

    Cahya Widiyati

    2010-06-01

    Full Text Available The experiment of solidification of dry sludge of liquid waste of leather treatment are containing chrome (Cr by using fly ash has been done.  The experiment objective are immobilize Cr in the solid waste by using pozzoland cement was made of fly ash in order to stable in the repository.  The experiment were carried out by solidification of solid waste are containing total chrome of 1480.5 mg/kg sum of 2 - 10 weight % of (water + pozzoland cement by using pozzoland cement was made from the mixture of fly ash and calcite were burned at 1000 oC temperature for 2 hours.  The characterization of the solid composite of stabilization result consist of the compressive strength test and the leaching test by American Nuclear Society (ANS-16.1 method.  The experiment result were shown that pozzoland cement  can binding solid waste sum of 10 weight % of (water + pozzoland cement became the composite of waste concrete with the compressive strength of 577 ton/m2 and the chrome leaching test for 14 days of 0.059 mg/l.  The composite of waste concrete according to Bapedal rule for solidification of toxic waste with minimum compressive strength of 10 ton/m2 and maximum leached chrome of 5 mg/L.   Keywords: stabilization, solid waste, leather treatment, fly ash.

  7. Reactivity of fly ashes in a spray dryer FGD process

    Energy Technology Data Exchange (ETDEWEB)

    Davis, W.T.; Reed, G.D.

    1983-05-01

    During the period 1981-1982, a study was performed to determine the ability of various fly ashes to retain sulfur dioxide in a pilot plant spray dryer/fabric filter flue gas desulfurization system. This knowledge would provide design engineers with the necessary data to determine whether the fly ash from a particular utility could be used as an effective supplement or substitute for slaked lime in a spray dryer system. The study commenced with the collection of 22 fly ashes from lignite, subbituminous, and bituminous eastern and western coals. The ashes were contacted with the flue gas entering the pilot plant by two different techniques. In the first, the ashes were slurried in water and injected into the spray dryer through a spinning disk atomizer. In the second, the ashes were injected as a dry additive into the flue gas upstream of the spray dryer. Analyses were conducted to determine the ability of each ash to retain sulfur dioxide in the system followed by statistical correlations of the sulfur retention with the physical/chemical properties of each ash. 17 references, 32 figures, 19 tables.

  8. Properties of Palm Oil Fuel Ash (POFA) Geopolymer Mortar Cured at Ambient Temperature

    OpenAIRE

    Olivia Monita; Mona Tambunan Lora; Saputra Edy

    2017-01-01

    Geopolymer material needs high temperature curing to produce good microstructure, high strength, and durable product. However, curing at ambient temperature is more preferable and practical in application for cast in situ geopolymer. In order to allow curing at ambient temperature, the geopolymer is mixed with mineral additives that has high calcium content such as slag, Ordinary Portland Cement (OPC) and high calcium fly ash. In this study, the Ordinary Portland Cement (OPC) was added in the...

  9. Cement for Oil Well Cementing Operations in Ghana

    African Journals Online (AJOL)

    Michael

    performance of three locally manufactured cement samples and imported class G cement sample for oil and gas well ... cement. 2 Materials and Methods. 2.1 Materials. Three brands of cement available on the Ghanaian market and commonly used by Ghanaians for construction ..... Cement Slurry using Factorial Design”,.

  10. Substitutional analysis

    CERN Document Server

    Rutherford, Daniel Edwin

    2013-01-01

    Classic monograph, suitable for advanced undergraduates and graduate students. Topics include calculus of permutations and tableaux, semi-normal representation, orthogonal and natural representations, group characters, and substitutional equations. 1968 edition.

  11. Trace elements in coal ash

    Science.gov (United States)

    Deonarine, Amrika; Kolker, Allan; Doughten, Michael W.

    2015-01-01

    Coal ash is a residual waste product primarily produced by coal combustion for electric power generation. Coal ash includes fly ash, bottom ash, and flue-gas desulfurization products (at powerplants equipped with flue-gas desulfurization systems). Fly ash, the most common form of coal ash, is used in a range of products, especially construction materials. A new Environmental Protection Agency ruling upholds designation of coal ash as a non-hazardous waste under Subtitle D of the Resource Conservation and Recovery Act, allowing for the continued beneficial use of coal ash and also designating procedures and requirements for its storage.

  12. Incorporation of treated straw and wood fly ash into clay building brick

    DEFF Research Database (Denmark)

    Chen, Wan; Ottosen, Lisbeth M.; Jensen, Pernille Erland

    2016-01-01

    High Cd content in straw and wood fly ash, generated from biomass-fired power plants, prohibits its recycling as fertilizer spreading on the landfilled. To improve and alter the current mainstream of fly ash treatment by landfilling, different approaches were tried for treatment of straw and wood...... absorption, porosity, density, compressive strength and leaching behavior, and compared with the 100% clay bricks. It’s promising to use the treated ash as a secondary building material....... in the treated ash, suggests the possibility of the ash reuse in sintered clay bricks. In this study, the straw and wood fly ash treated by washing and EDR was incorporated into yellow clay bricks at different substitution rates. The properties of the clay-ash bricks were studied in terms of shrinkage, water...

  13. Remedial processing of oil shale fly ash (OSFA) and its value-added conversion into glass-ceramics.

    Science.gov (United States)

    Zhang, Zhikun; Zhang, Lei; Li, Aimin

    2015-12-01

    Recently, various solid wastes such as sewage sludge, coal fly ash and slag have been recycled into various products such as sintered bricks, ceramics and cement concrete. Application of these recycling approaches is much better and greener than conventional landfills since it can solve the problems of storage of industrial wastes and reduce exploration of natural resources for construction materials to protect the environment. Therefore, in this study, an attempt was made to recycle oil shale fly ash (OSFA), a by-product obtained from the extracting of shale oil in the oil shale industry, into a value-added glass-ceramic material via melting and sintering method. The influence of basicity (CaO/SiO2 ratio) by adding calcium oxide on the performance of glass-ceramics was studied in terms of phase transformation, mechanical properties, chemical resistances and heavy metals leaching tests. Crystallization kinetics results showed that the increase of basicity reduced the activation energies of crystallization but did not change the crystallization mechanism. When increasing the basicity from 0.2 to 0.5, the densification of sintering body was enhanced due to the promotion of viscous flow of glass powders, and therefore the compression strength and bending strength of glass-ceramics were increased. Heavy metals leaching results indicated that the produced OSFA-based glass-ceramics could be taken as non-hazardous materials. The maximum mechanical properties of compression strength of 186 ± 3 MPa, bending strength of 78 ± 6 MPa, good chemical resistances and low heavy metals leaching concentrations showed that it could be used as a substitute material for construction applications. The proposed approach will be one of the potential sustainable solutions in reducing the storage of oil shale fly ash as well as converting it into a value-added product. Copyright © 2015 Elsevier Ltd. All rights reserved.

  14. Production of mineral ash-wool

    International Nuclear Information System (INIS)

    Micevic, Z.; Djekic, S.

    1996-01-01

    The project entitled 'Production of Mineral Ash-Wool' presents a new technology of possible use of the fly ash, generated as a waste product from the fossil fueled power plants, as a basic raw material for manufacturing of different products from a new mineral ash-wool. The wide area of mineral ash-wool application (civil engineering, industry, power generation, etc.) and the advantages of this new technology (important raw material obtained free of charge, substitution of expensive silicate stone, use of electric energy for melting instead for coke, vicinity of factory location close to the fossil fueled power plant, lower product price, reduction of environmental pollution, etc.) have resulted in the performance of the bench scale tests. Positive results have been obtained, as a good initial base for the realization of this project. The named study as an detailed analysis has been carried out for the assessment of: supply and sales market, analysis of possible and selection of an optimal location of the factory in the frame of fossil fueled power plant 'Kosovo', selection of the production capacity and alternative preliminary technical designs of the factory for the mineral ash-wool production. For the studied alternatives, specifications and capital investments evaluations for equipment and works (mechanical, civil engineering and electromechanical part) have been made as well as assessments of production costs. Based on the performed economical and financial analyses, as well as the sensitivity analyses one could be concluded that the investments in the factory for the mineral ash-wool production is highly economically acceptable. (author). 1 fig., 1 tab., 3 refs

  15. Controlled release from bio ash spread on forest soils; Styrd utlakning ur bioaska som sprids i skogsmark

    Energy Technology Data Exchange (ETDEWEB)

    Fjaellberg, Leif; Lagerblad, Bjoern; Moosberg Bustnes, Helena [Swedish Cement and Concrete Research Inst., Stockholm (Sweden); Bjurstroem, Henrik [AaF-Process AB, Stockholm (Sweden)

    2005-10-01

    In order to minimize the costs for forestry, recycling ashes from biofuels should be done on freshly logged locations. A condition is that the ash that is spread on forest soils is well stabilized, with a negligible leakage of nutrients during a few years. However, these nutrients should be released when vegetation can take them up, about 15 years after replanting. In this report are presented the results of a prestudy on the possibilities to stabilize ash and to coat ash pellets with a protective layer that provides the desired delay in leaching. The chemistry of ashes is complex and similar to that of cement. In this prestudy, we tried to utilize the ash chemistry and investigated the balance between calcium oxide and silicon dioxide as well as its effect on cementing properties. The hypothesis is that by combining different ashes and/or by adding components a more stable product that is less prone to leaching may be obtained. Alkali such as potassium salts could be immobilized in silicates. Samples of ca 10 ashes were collected from plants in order to create a variety of compositions. The ashes have been characterized with regard to chemical and mineralogical composition, particle size distribution. Their binding properties have been investigated. Ashes from fluidized bed combusters bonded best and fastest. The results would have been clearer if most ashes had not been slaked when they reached the laboratory, although they were taken out dry from the plants. Some weakly bonding ashes were mixed with strongly bonding ashes, and with silica fume in one experiment. The weak ashes could be stabilized to a product with a satisfactory compressive strength. The mineralogy of the hydrated ashes was studied. Several leaching tests were performed: by mixing an ash yielding high concentration of salts in the leachate with an ash yielding low concentrations a halving of the concentration could be obtained. Silica fume yielded similar results. Attempts to coat ash pellets

  16. Optimum feeding rate of solid hazardous waste in a cement kiln burner

    OpenAIRE

    Ariyaratne, W. K. Hiromi; Melaaen, Morten Christian; Tokheim, Lars-André

    2013-01-01

    Solid hazardous waste mixed with wood chips (SHW) is a partly CO2 neutral fuel, and hence is a good candidate for substituting fossil fuels like pulverized coal in rotary kiln burners used in cement kiln systems. SHW is used in several cement plants, but the optimum substitution rate has apparently not yet been fully investigated. The present study aims to find the maximum possible replacement of coal by SHW, without negatively affecting the product quality, emissions and overall operation of...

  17. Hybrid cement based on the alkali activation of by-products of coal

    OpenAIRE

    Rivera,Jhonathan F; Mejia,Johanna M; Mejia de Gutierrez,Ruby; Gordillo,Marisol

    2014-01-01

    This study focuses on the production of an alternative cementitious material with low environmental impact through the evaluation of two-coal combustion by-products. Hybrid cements based on the alkali activation of fly ash, (FA) and boiler slag (BS) blend with a proportion of Portland cement (OPC) up to 30% were produced. FA and BS contain an unburned material up to 16%. Response Surface Methodology (RSM) was used to optimize the compressive strength. BS geopolymer achieved high compressive s...

  18. The Effects of Design Strength, Fly Ash Content and Curing Method on Compressive Strength of High Volume Fly Ash Concrete: A Design of Experimental

    Directory of Open Access Journals (Sweden)

    Solikin Mochamad

    2017-01-01

    Full Text Available High volume fly ash concrete becomes one of alternatives to produce green concrete as it uses waste material and significantly reduces the utilization of Portland cement in concrete production. Although using less cement, its compressive strength is comparable to ordinary Portland cement (hereafter OPC and the its durability increases significantly. This paper reports investigation on the effect of design strength, fly ash content and curing method on compressive strength of High Volume Fly Ash Concrete. The experiment and data analysis were prepared using minitab, a statistic software for design of experimental. The specimens were concrete cylinder with diameter of 15 cm and height of 30 cm, tested for its compressive strength at 56 days. The result of the research demonstrates that high volume fly ash concrete can produce comparable compressive strength which meets the strength of OPC design strength especially for high strength concrete. In addition, the best mix proportion to achieve the design strength is the combination of high strength concrete and 50% content of fly ash. Moreover, the use of spraying method for curing method of concrete on site is still recommended as it would not significantly reduce the compressive strength result.

  19. Protecting black ash from the emerald ash borer

    Science.gov (United States)

    Les Benedict

    2010-01-01

    Black ash (Fraxinus nigra) is an important resource for Tribes in the Northeast and Great Lakes regions of the North American continent. Ash in North America is being threatened with widespread destruction as a result of the introduction of emerald ash borer beetle (Agrilus planipennis) in 2002. Measures are being taken to slow the spread of emerald ash borer beetle....

  20. Current Methods to Detoxify Fly Ash from Waste Incineration

    Energy Technology Data Exchange (ETDEWEB)

    Hallgren, Christine; Stroemberg, Birgitta [TPS Termiska Processer AB, Nykoeping (Sweden)

    2004-07-01

    Fly ash from waste incineration contains large amounts of heavy metals and dioxins, which will cause a significant disposal problem within the coming years. The amount of fly ash produced in Sweden is currently approximately 60,000 tons/y. New technological options for the decontamination and/or inertization of incinerator fly ash are being developed with the objective of rendering a product that can be reused or, at least, be deposited at standard landfill sites with no risk. Many of these technologies have been tested at industrial scale or in pilot projects. The proposed alternatives include: Thermal treatments; Immobilization/stabilization by cement based techniques; Wet chemical treatments (extractions, immobilizations); Microbiological treatments. Of these, thermal treatments are the most promising solution. Depending on the temperature thermal treatments are classified in two main types: 1) low temperature (below 600 deg C) thermal treatments and 2) high temperature (above 1200 deg C) thermal treatments (vitrification). Most dioxins can be successfully destroyed at temperatures up to 400 deg C under oxygen deficient conditions and at temperatures up to 600 deg C under oxidising conditions. However most heavy metals remain in the fly ash after low temperature treatment. At a temperature of 900 deg C most heavy metals can also be removed in a 10% HCl atmosphere by forming volatile metal chlorides (CT-Fluapur process). During vitrification processes the fly ash melts and forms an inert glassy slag. The product does not leach any significant amount of heavy metals and is free from dioxin. The volume of the fly ash is significantly reduced. The product can be land filled at low costs or used as construction material. The properties of the product depend on the cooling process and on additives such as sand, limestone or waste glass. A series of vitrification methods at industrial size or in pilot scale using different furnaces are studied. Among these, plasma

  1. SCC with high volume of fly ash content

    Directory of Open Access Journals (Sweden)

    Bakhrakh Anton

    2017-01-01

    Full Text Available Self-compacting concrete is a very perspective building material. It provides great benefits during the construction of heavily reinforced buildings. SCC has outstanding properties such as high flowability, dense structure and high strength due to specific quality of aggregates, fillers, their proportion in mix, use of polycarboxylate-based superplasticizers. Main disadvantages of SCC are high price and the difficulty of obtaining a proper mix. Use of fillers, such as fly ash type F, is a way to make SCC cheaper by replacing part of cement. Fly ash also provides some technological and operating advantages. In this paper the influence of high volume (60% from cement fly ash type F on the properties of concrete mixture and hardened concrete is investigated. The result of the work shows the possibility of reduction the cost of SCC using ordinary fillers and high amount of fly ash. The investigated SCC has low speed of hardening (7-day compressive strength at the range of 41.8 MPa and high volume of entrained air content (3.5%.

  2. Chemical constitution, physical properties, and biocompatibility of experimentally manufactured Portland cement.

    Science.gov (United States)

    Hwang, Yun-Chan; Kim, Do-Hee; Hwang, In-Nam; Song, Sun-Ju; Park, Yeong-Joon; Koh, Jeong-Tae; Son, Ho-Hyun; Oh, Won-Mann

    2011-01-01

    An experimental Portland cement was manufactured with pure raw materials under controlled laboratory conditions. The aim of this study was to compare the chemical constitution, physical properties, and biocompatibility of experimentally manufactured Portland cement with those of mineral trioxide aggregate (MTA) and Portland cement. The composition of the cements was determined by scanning electron microscopy (SEM) and energy-dispersive x-ray analysis (EDAX). The setting time and compressive strength were tested. The biocompatibility was evaluated by using SEM and XTT assay. SEM and EDAX revealed the experimental Portland cement to have a similar composition to Portland cement. The setting time of the experimental Portland cement was significantly shorter than that of MTA and Portland cement. The compressive strength of the experimental Portland cement was lower than that of MTA and Portland cement. The experimental Portland cement showed a similar biocompatibility to MTA. The experimental Portland cement might be considered as a possible substitute for MTA in clinical usage after further testing. Copyright © 2011 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

  3. Hard x-ray nanotomography of amorphous aluminosilicate cements.

    Energy Technology Data Exchange (ETDEWEB)

    Provis, J. L.; Rose, V.; Winarski, R. P.; van Deventer, J. S. J. (Advanced Photon Source); ( CNM)

    2011-08-01

    Nanotomographic reconstruction of a sample of low-CO{sub 2} 'geopolymer' cement provides the first three-dimensional view of the pore structure of the aluminosilicate geopolymer gel, as well as evidence for direct binding of geopolymer gel onto unreacted fly ash precursor particles. This is central to understanding and optimizing the durability of concretes made using this new class of binder, and demonstrates the value of nanotomography in providing a three-dimensional view of nanoporous inorganic materials.

  4. Shedding of ash deposits

    DEFF Research Database (Denmark)

    Zbogar, Ana; Frandsen, Flemming; Jensen, Peter Arendt

    2009-01-01

    . Deposit shedding can be defined as the process of deposit removal from the heat transfer surfaces. Mechanical and thermal shock devices for deposit removal can be implemented within into the boiler, which can be then referred to as artificial shedding. Sootblowing is one such process, where a pressurized...... on the ash characteristics and the boiler operation. Different deposit characteristics will govern the ash deposit behaviour, and thus the mechanism of deposit shedding. The deposit strength will influence the erosion and gravity shedding mechanisms. The ash viscosity and the melting behaviour will govern...

  5. Mechanical and durability performance of rice husk ash concrete of grade 30, 40 and 50

    International Nuclear Information System (INIS)

    Erawati, M.; Nik Anisah, N.N.; Nurdiyana, M.H.; Noor Arbaiyah, M.Y.; Kartini, K.

    2010-01-01

    Cement is produce and manufactured on a large scale from the silicate industry and used mostly in building homes, industrial buildings and other structures. Cements are produce from raw naturally occurring materials and the production involved both mining and manufacturing components, and it is a major source of greenhouse gas emission. For sustainability, and to reduce the greenhouse gas emission cause by cement production, therefore it is highly time to look into the other possibility of replacing this cementitious material. Research had shown that small amounts of inert filler have always been acceptable as cement replacements, what more if the fillers have the pozzolanic properties, in which it will not only impart technical advantages to the resulting concrete but also enable larger quantities of cement replacement to be achieved. In this millennium due to constantly increasing amount of industry by products, concretes made almost completely of waste materials should be produced in large scale. Extensive studies have been carried out and have indicated that the incinerator ash can be beneficially utilize, however, in Malaysia the utilization of this ash is not routinely practiced or mandated. This paper highlighted the possibility of using rice husk ash as cement replacement for sustainability in making concrete of grade 30, 40 and 50. The strength and durability tests will conducted to validate the possibility of it uses. Studies conducted have shown that rice husk ash has the pozzolanic properties, achieved the target strength and improved its permeability. Thus, not only give technical advantage to the resulting concrete but it also reduces cement consumption and on top of that the conservation of resources. (author)

  6. classical optimization of bagasse ash content in cement-stabilized ...

    African Journals Online (AJOL)

    Optimization of construction materials with laboratory data is a very possible way of minimizing waste of resources (materials and cost). There had been several successful attempts of optimization of construction materials. However, optimization in soil stabilization for road-work has been very rare because of its complexities ...

  7. Enhanced properties of graphene/fly ash geopolymeric composite cement

    Energy Technology Data Exchange (ETDEWEB)

    Saafi, Mohamed, E-mail: m.bensalem.saafi@strath.ac.uk [Department of Civil and Environmental Engineering, University of Strathclyde, G4 0NG (United Kingdom); Tang, Leung [Agilent Technologies, EH12 9DJ (United Kingdom); Fung, Jason; Rahman, Mahbubur [Department of Civil and Environmental Engineering, University of Strathclyde, G4 0NG (United Kingdom); Liggat, John [Department of Pure and Applied Chemistry, University of Strathclyde, G4 0NG (United Kingdom)

    2015-01-15

    This paper reports for the first time the incorporation of in-situ reduced graphene oxide (rGO) into geopolymers. The resulting rGO–geopolymeric composites are easy to manufacture and exhibit excellent mechanical properties. Geopolymers with graphene oxide (GO) concentrations of 0.00, 0.10, 0.35 and 0.50% by weight were fabricated. The functional groups, morphology, void filling mechanisms and mechanical properties of the composites were determined. The Fourier transform infrared (FTIR) spectra revealed that the alkaline solution reduced the hydroxyl/carbonyl groups of GO by deoxygenation and/or dehydration. Concomitantly, the spectral absorbance related to silica type cross-linking increased in the spectra. The scanning electron microscope (SEM) micrographs indicated that rGO altered the morphology of geopolymers from a porous nature to a substantially pore filled morphology with increased mechanical properties. The flexural tests showed that 0.35-wt.% rGO produced the highest flexural strength, Young's modulus and flexural toughness and they were increased by 134%, 376% and 56%, respectively.

  8. Strength and durability performance of alkali-activated rice husk ash geopolymer mortar.

    Science.gov (United States)

    Kim, Yun Yong; Lee, Byung-Jae; Saraswathy, Velu; Kwon, Seung-Jun

    2014-01-01

    This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm(2) and 45 N/mm(2), respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete.

  9. Strength and Durability Performance of Alkali-Activated Rice Husk Ash Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Yun Yong Kim

    2014-01-01

    Full Text Available This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2 and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4 environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete.

  10. Retention of crowns cemented on implant abutments with temporary cements.

    Science.gov (United States)

    Nagasawa, Yuko; Hibino, Yasushi; Nakajima, Hiroshi

    2014-01-01

    This study was to examine the retentive force of crowns to implant abutments with commercial temporary cements. Six different temporary cements were investigated. Cast crowns were cemented to the abutments using each cement and their retentive forces to abutments were determined 7 or 28 days after cementing (n=10). The retentive force of the cements to abutments varied widely among the products [27-109 N (7-day), 18-80 N (28-days)]. The retentive force of all the cements was not reduced as the time elapsed, except for two products tested. The polycarboxylate cements and paste-mixing type eugenol-free cements revealed comparable retentive force after 28 days of storage. The powder-liquid type cements showed a positive correlation (pcement between the retentive force and compressive strength. Mechanical strength of temporary cements could not be a prominent predicting factor for retention of the crowns on the abutments.

  11. Utilization of Palm Oil Clinker as Cement Replacement Material.

    Science.gov (United States)

    Kanadasan, Jegathish; Abdul Razak, Hashim

    2015-12-16

    The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with palm oil clinker powder as a binder material in self-compacting mortar. The fresh, hardened and microstructure properties were evaluated throughout this study. In addition, sustainability component analysis was also carried out to assess the environmental impact of introducing palm oil clinker powder as a replacement material for cement. It can be inferred that approximately 3.3% of cement production can be saved by substituting palm oil clinker powder with cement. Reducing the utilization of cement through a high substitution level of this waste material will also help to reduce carbon emissions by 52%. A cleaner environment free from pollutants can be created to ensure healthier living. Certain industries may benefit through the inclusion of this waste material as the cost and energy consumption of the product can be minimized.

  12. Utilization of Palm Oil Clinker as Cement Replacement Material

    Directory of Open Access Journals (Sweden)

    Jegathish Kanadasan

    2015-12-01

    Full Text Available The utilization of waste materials from the palm oil industry provides immense benefit to various sectors of the construction industry. Palm oil clinker is a by-product from the processing stages of palm oil goods. Channelling this waste material into the building industry helps to promote sustainability besides overcoming waste disposal problems. Environmental pollution due to inappropriate waste management system can also be drastically reduced. In this study, cement was substituted with palm oil clinker powder as a binder material in self-compacting mortar. The fresh, hardened and microstructure properties were evaluated throughout this study. In addition, sustainability component analysis was also carried out to assess the environmental impact of introducing palm oil clinker powder as a replacement material for cement. It can be inferred that approximately 3.3% of cement production can be saved by substituting palm oil clinker powder with cement. Reducing the utilization of cement through a high substitution level of this waste material will also help to reduce carbon emissions by 52%. A cleaner environment free from pollutants can be created to ensure healthier living. Certain industries may benefit through the inclusion of this waste material as the cost and energy consumption of the product can be minimized.

  13. Review of the interactions between bentonite and cement

    International Nuclear Information System (INIS)

    Duerden, S.L.

    1992-01-01

    Properties of bentonite may be significantly affected by reaction with cement. This report reviews the literature to identify the reactions that may occur and considers their effects on the performance of bentonite in these applications. The dominant reactions expected under alkaline conditions prevalent in an underground repository where cement is used extensively are zeolitization, beidellitization, and ion exchange. Zeolitisation will occur at high temperatures (200 o C) or after long periods (500-1000 years) when the pH is high (pH>9). Beidellitization may occur at high pH (pH>9). The silica may reprecipitate in situ due to low hydraulic conductivity or in regions of low pH or temperature. This may result in reduced porosity/permeability and plasticity. Ion exchange reactions are virtually instantaneous. The rate of the reaction depends on the concentration and rate of access of ground water. Substitution of Ca 2+ ions from cement for Na + ions in sodium-bentonites will result in reduced swelling pressure and plasticity, and increased hydraulic conductivity of the bentonite. The effect of Na-bentonite on the properties of cement is the formation of an Al-substituted 11A tobermorite, which results in improved Cs + sorption. In cements reacted with Calcium-bentonite the main product was found to be a hydroxyapatite layer on the cement surface. (author)

  14. DURABILITY PROPERTIES OF FIBRE-REINFORCED POND ASH-MODIFIED CONCRETE

    Directory of Open Access Journals (Sweden)

    A. SOFI

    2016-10-01

    Full Text Available This paper presents an experimental study on the durability properties of pond ash-modified concrete randomly reinforced with steel fibres. Durability properties such as drying shrinkage, water absorption, permeable voids and acid attack were studied. The specimens were cast with three different pond ash contents of 10%, 20% and 30% by weight of cement. Grooved type steel fibres were added as 0.5%, 1% and 2% by volume of concrete to all the specimens. The results obtained were compared with those obtained with the conventional concrete. Change in length was measured for time periods of 1 day, 7 days, 14 days, 28 days, 56 days, 90 days and 180 days. The results indicated that drying shrinkage decreased with increase in pond ash content and fibre content. A pond ash content of 30% yielded good values of water absorption and permeable voids. Acid attack studies revealed that weight loss significantly decreased with increasing pond ash content and fibre content.

  15. Power station fly ash. A review of value-added utilization outside of the construction industry

    International Nuclear Information System (INIS)

    Iyer, R.S.; Scott, J.A.

    2001-01-01

    The disposal of fly ash from coal-fired power stations causes significant economic and environmental problems. A relatively small percentage of the material finds application as an ingredient in cement and other construction products, but the vast majority of material generated each year is held in ash dams or similar dumps. This unproductive use of land and the associated long-term financial burden of maintenance has led to realization that alternative uses for fly ash as a value-added product beyond incorporation in construction materials are needed. Utilization of fly ash in such areas as novel materials, waste management, recovery of metals and agriculture is reviewed in this article with the aim of looking at new areas that will expand the positive reuse of fly ash, thereby helping to reduce the environmental and economic impacts of disposal

  16. Chemical and thermal analysis of biomass ash from wooden chips and wheat straw combustion

    Science.gov (United States)

    Jankovský, Ondřej; Sedmidubský, David; Luxa, Jan; Bartůněk, Vilém; Záleská, Martina; Pavlíková, Milena; Pavlík, Zbyšek

    2017-07-01

    In this paper, we would like to demonstrate that biomass ash with appropriate composition can be used for the fabrication of high performance composites. Biomass ash from wooden chips and packed wheat straw was characterized using XRF and XRD. While the biomass ash contained high amount of carbon, it was thermally treated in order to reduce carbon content. The chemical and phase composition of treated biomass ash was again analyzed in detail by XRF and XRD. Moreover, the thermal treatment process was analyzed using STA. In the next step, the pozzolanic activity was analyzed using Frattini test. Potentiometric method was used for pH measurement. Since the both biomass ashes were pozzolana active, they are potentially suitable as a pozzolana active admixture in the cement, lime and alkali activated aluminosilicate composites.

  17. Solvent substitution

    International Nuclear Information System (INIS)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general ''Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated

  18. Solvent substitution

    Energy Technology Data Exchange (ETDEWEB)

    1990-01-01

    The DOE Environmental Restoration and Waste Management Office of Technology Development and the Air Force Engineering and Services Center convened the First Annual International Workshop on Solvent Substitution on December 4--7, 1990. The primary objectives of this joint effort were to share information and ideas among attendees in order to enhance the development and implementation of required new technologies for the elimination of pollutants associated with industrial use of hazardous and toxic solvents; and to aid in accelerating collaborative efforts and technology transfer between government and industry for solvent substitution. There were workshop sessions focusing on Alternative Technologies, Alternative Solvents, Recovery/Recycling, Low VOC Materials and Treatment for Environmentally Safe Disposal. The 35 invited papers presented covered a wide range of solvent substitution activities including: hardware and weapons production and maintenance, paint stripping, coating applications, printed circuit boards, metal cleaning, metal finishing, manufacturing, compliance monitoring and process control monitoring. This publication includes the majority of these presentations. In addition, in order to further facilitate information exchange and technology transfer, the US Air Force and DOE solicited additional papers under a general Call for Papers.'' These papers, which underwent review and final selection by a peer review committee, are also included in this combined Proceedings/Compendium. For those involved in handling, using or managing hazardous and toxic solvents, this document should prove to be a valuable resource, providing the most up-to-date information on current technologies and practices in solvent substitution. Individual papers are abstracted separated.

  19. Sugar Substitutes

    Science.gov (United States)

    ... and drinks. You may have heard them called “artificial sweeteners” or “non-caloric sweeteners.” They can be used ... a food or drink contains. What sugar substitutes/artificial sweeteners are approved by the FDA? The following sugar ...

  20. First international ash marketing and technology conference

    Energy Technology Data Exchange (ETDEWEB)

    1978-01-01

    A total of 42 papers were presented in sessions with the following headings: production and disposal of ash - an international review; environmental, health, safety, and legal aspects of ash handling; marketing of ash; development of new uses for ash; cementitious use of ash; ash in manufactured products; and geotechnical uses of ash.