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 ...

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.

Problems experiences with the construction of cement and lime stabilized layers and working solutions for these problems

CSIR Research Space (South Africa)

Botha, PB

2005-10-01

Full Text Available Stabilized layers are used extensively in South-Africa in the construction of roads. The layers are usually stabilized with hydrated road lime, cement, slag, fly-ash, bitumen emulsion, foamed asphalt or a combination of several of these agents...

Energy Efficient Microwave Hybrid Processing of Lime for Cement, Steel, and Glass Industries

Energy Technology Data Exchange (ETDEWEB)

Fall, Morgana L; Yakovlev, Vadim; Sahi, Catherine; Baranova, Inessa; Bowers, Johnney G; Esquenazi\t, Gibran L

2012-02-10

MAT in the US lime industry. This estimate showed that 7.3 TBTU/year could be saved, with reduction of 270 MMlbs of CO2 emissions, and $29 MM/year in economic savings. Taking into account estimates for MAT implementation in the US cement industry, an additional 39 TBTU/year, 3 Blbs of CO2 and $155 MM/year could be saved. One of the main remaining barriers to commercialization of MAT for the lime and cement industries is the sheer size of production. Through this project, it was realized that a production size MAT rotary calciner was not feasible, and a different approach was adapted. The concept of a microwave post heat section located in the upper portion of the cooler was devised and appears to be a more realistic approach for MAT implementation. Commercialization of this technology will require (1) continued pilot scale calcining demonstrations, (2) involvement of lime kiln companies, and (3) involvement of an industrial microwave equipment provider. An initial design concept for a MAT post-heat treatment section was conceived as a retrofit into the cooler sections of existing lime rotary calciners with a 1.4 year payback. Retrofitting will help spur implementation of this technology, as the capital investment will be minimal for enhancing the efficiency of current rotary lime kilns. Retrofits would likely be attractive to lime manufacturers, as the purchase of a new lime kiln is on the order of a $30 million dollar investment, where as a MAT retrofit is estimated on the order of $1 million. The path for commercialization lies in partnering with existing lime kiln companies, who will be able to implement the microwave post heat sections in existing and new build kilns. A microwave equipment provider has been identified, who would make up part of the continued development and commercialization team.

Lime mud from cellulose industry as raw material in cement mortars

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Modolo, R. C.E.

2014-12-01

Full Text Available This study reports the use of lime mud (LM in cement-based-mortars. Lime mud is a waste generated in the production of cellulose by the kraft mill process. It is mainly composed of CaCO3, a small amount of magnesium carbonate and other trace minerals. Mortars were prepared by adding different amounts of LM (10, 20 and 30% by weight of cement in dry weight. The mortar compositions were evaluated through rheology and flow table measurements, assuring that all the samples exhibited adequate conditions for testing in both equipments. The hardened state properties were also evaluated through mechanical strengths at 7, 28 and 90 days of curing. Following a waste management solution perspective, this work intend to provide a general evaluation of LM application in cement based mortars, looking at both fresh and hardened properties in order to guarantee that the final application requirements are not hindered.Este estudio revela el uso de lodo de carbonato (LM en morteros de cemento. El LM es un residuo compuesto principalmente por CaCO3 generado en la producción de pasta de papel por el método Kraft. Los morteros se prepararon a partir de la adición de diferentes niveles de LM (10, 20 y 30% en peso de cemento en peso seco. Las composiciones de los morteros fueron caracterizadas através de mediciones de reología de mesa y de flujo, asegurando que las muestras exhibían condiciones adecuadas para su caracterización en ambos equipamientos. Las propiedades en estado endurecido también se evaluaron através de resistencias mecánicas a los 7, 28 y 90 días de cura. Con objeto de gestión de residuos, este trabajo tiene la intención de proporcionar una visión general de la aplicación de LM en los morteros, haciendo hincapié en las propiedades con el fin de garantizar que los requisitos para su aplicación final no se vean obstaculizados.

Utilization of lime-dried sludge for eco-cement clinker production: effects of different feeding points.

Science.gov (United States)

Cao, Haihua; Liu, Wei; Xu, Jingcheng; Liu, Jia; Huang, Juwen; Huang, Xiangfeng; Li, Guangming

2018-02-01

Co-processing lime-dried sludge (LDS) in cement kilns is an appropriate technique to solve the problem of LDS disposal and promote the sustainable development for cement industry. However, there were limited studies that investigated the effects of feeding points on product quality and cement kiln emissions. In this study, simulated experiments were conducted by dividing the feeding points into high-temperature zones (HTZs) and raw mill (RM). Cement quality and major cement kiln emission characteristics were comprehensively investigated. The results showed that in terms of burnability, compressive strength and microstructure, the optimum co-processing amount of LDS were 9 wt% when feeding at RM, while 6% when feeding at HTZs. Meanwhile, the organic emissions of RM samples were mainly low environmental risk compounds of amides and nitrogenous heterocyclic compounds. Inorganic gaseous pollutions of NO X and SO 2 , respectively, were 8.11 mg/g DS and 12.89 mg/g DS, compared with 7.61 mg/g DS and 4.44 mg/g DS for HTZs. However, all the cement kiln emissions concentration were still much lower than standard requirements. Overall, RM had a bigger LDS co-processing capacity and higher, but acceptable, cement kiln emissions. Feeding LDS via RM could dispose larger amounts of sludge and provide more alternative materials for cement manufacturing.

Arsenic Encapsulation Using Portland Cement With Ferrous Sulfate/Lime And Terra-BondTM Technologies - Microcharacterization And Leaching Studies

Science.gov (United States)

This work reports the results of an investigation on the treatment and encapsulation of arsenic-containing materials by Portland cement with ferrous sulfate and lime (PFL) and Terra-BondTM, a commercially available patented technology. The arsenic materials treated we...

Natural radioactivity of the cement, lime and plaster in the Zacatecas State

International Nuclear Information System (INIS)

Mireles, F.; Davila, J. I.; Lopez, H.; Pinedo, J. L.; Rios, C.; Saucedo, S. A.; Cespedes, N.

2012-10-01

The construction materials are the main radiation gamma source inside the houses room and the buildings, followed by the terrestrial and cosmic radiation. The radioactivity levels of the construction materials were obtained to establish reference levels and of population exposure. In this work the study of 56 samples of construction materials is presented, 24 of cement, 20 of lime and 12 of plaster, of the marks more sold in the municipalities of Zacatecas and Guadalupe of the Zacatecas State, Mexico. The objective is the study of the concentration in activity of the radioisotopes 238 U, 232 Th, 40 K and 137 Cs, using a gamma rays spectrometry system based on a hyper pure germanium detector. The obtained results of activity concentration of the interest radioisotopes show similar values average to those published by UNSCEAR 1993. The population of the municipalities of Zacatecas and Guadalupe is exposed to the environmental gamma radiation coming from the contained radioisotopes in the construction materials; the annual equivalent effective dose by the cement is in the range of 116 at 562 μSv a -1 with an average of 340 μSv a -1 , of the lime is in the range of 36 at 212 μSv a -1 with an average of 87 μSv a -1 , and of the plaster is in the range of 16 at 27 μSv a -1 with an average of 22 μSv a -1 , this exposure does not represent any risk for the population's health. (Author)

Characteristics of ammonia emission during thermal drying of lime sludge for co-combustion in cement kilns.

Science.gov (United States)

Liu, Wei; Xu, Jingcheng; Liu, Jia; Cao, Haihua; Huang, Xiang-Feng; Li, Guangming

2015-01-01

Thermal drying was used to reduce sludge moisture content before co-combustion in cement kilns. The characteristics of ammonia (NH3) emission during thermal drying of lime sludge (LS) were investigated in a laboratory-scale tubular dry furnace under different temperature and time conditions. As the temperature increased, the NH3 concentration increased in the temperature range 100-130°C, decreased in the temperature range 130-220°C and increased rapidly at >220°C. Emission of NH3 also increased as the lime dosage increased and stabilized at lime dosages>5%. In the first 60 min of drying experiments, 55% of the NH3 was released. NH3 accounted for about 67-72% of the change in total nitrogen caused by the release of nitrogen-containing volatile compounds (VCs) from the sludge. X-ray photoelectron spectroscopy and Fourier-transform infrared spectroscopy revealed that the main forms of nitrogen in sludge were amides and amines. The addition of lime (CaO) could cause conversion of N-H, N-O or C-N containing compounds to NH3 during the drying process.

Studies on the Potential of Waste Soda Lime Silica Glass in Glass Ionomer Cement Production

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V. W. Francis Thoo

2013-01-01

Full Text Available Glass ionomer cements (GIC are produced through acid base reaction between calcium-fluoroaluminosilicate glass powder and polyacrylic acid (PAA. Soda lime silica glasses (SLS, mainly composed of silica (SiO2, have been utilized in this study as the source of SiO2 for synthesis of Ca-fluoroaluminosilicate glass. Therefore, the main objective of this study was to investigate the potential of SLS waste glass in producing GIC. Two glasses, GWX 1 (analytical grade SiO2 and GWX 2 (replacing SiO2 with waste SLS, were synthesized and then characterized using X-ray diffraction (XRD and energy dispersive X-ray (EDX. Synthesized glasses were then used to produce GIC, in which the properties were characterized using Fourier transform infrared spectroscopy (FT-IR and compressive test (from 1 to 28 days. XRD results showed that amorphous glass was produced by using SLS waste glass (GWX 2, which is similar to glass produced using analytical grade SiO2 (GWX 1. Results from FT-IR showed that the setting reaction of GWX 2 cements is slower compared to cement GWX 1. Compressive strengths for GWX 1 cements reached up to 76 MPa at 28 days, whereas GWX 2 cements showed a slightly higher value, which is 80 MPa.

Natural cement as the precursor of Portland cement: Methodology for its identification

International Nuclear Information System (INIS)

Varas, M.J.; Alvarez de Buergo, M.; Fort, R.

2005-01-01

When cements appeared in the 19th century, they took the place of traditional binding materials (lime, gypsum, and hydraulic lime) which had been used until that time. Early cements can be divided into two groups, natural and artificial (Portland) cements. Natural cements were introduced first, but their widespread usage was short-lived as they were quickly replaced by artificial cements (Portland), still the most important and predominant today. The main differences between natural and artificial cements arise during the manufacturing process. The final properties of the cements are greatly influenced by differences in the raw materials and burning temperatures employed. The aim of this paper is to assess the efficiency of traditional analytical techniques (petrographic microscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR)) used to differentiate natural and artificial cements

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...

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%.

Free lime quantitative determination by X ray diffraction, on anhiydrous and dried cement

Directory of Open Access Journals (Sweden)

Sagrera, J. L.

1987-09-01

Full Text Available In manufactured cements, and concerning the quality control, the fast determination of the contents of free lime is a necessary step. The measurement of the content is made taking the net altitude of one peak of the DRX which, on each case, is peculiar to the compound to be determined. So, a calibrating curve is drawn, using there synthetic samples prepared with original cement with addition of 1%, 3% and 5% in weight of calcium oxide prepared fusing at 1100 °C for two hours a Merkc precipitate calcium carbonate. This calibrating curve allows to know the free lime content in original cement, when the results obtained by X ray diffraction is carried to the calibrating curve.

En la fabricación de cementos, y dentro del control de su calidad, la determinación rápida del contenido de cal libre es un dato necesario. Esta determinación, según normativa (*, debe hacerse usando la vía química. Como método alternativo existe la técnica de difracción de rayos X que, en pocos minutos, puede determinar el contenido de cal libre, sin posibles interferencias de otros compuestos. La medida del contenido se hace midiendo la altura de un pico del difractograma de rayos X que, para cada caso, es privativo del compuesto que se quiere determinar. En el presente artículo se trata de explicar, paso a paso, el procedimiento para determinar cuantitativamente el contenido de cal libre que existe en un cemento anhidro y desecado a 110 °C. Para ello, se construye una curva de calibrado utilizando tres muestras sintéticas preparadas en el laboratorio partiendo del cemento utilizado, al que se le añade el 1%, 3% y 5% en peso de OXIDO DE CALCIO preparado calcinando a 1.100 °C durante dos horas CARBONATO DE CALCIO precipitado Merck. Dicha curva de calibrado permite conocer el contenido de cal libre, del cemento de partida, cuando el resultado obtenido por difracción de rayos X se lleva a la curva patrón obtenida.

Effect of hydrated lime and cement on moisture damage of recycled mixtures with foamed bitumen and emulsion

OpenAIRE

Nosetti, R.A.; Pérez Jiménez, Félix Edmundo; Martínez Reguero, Adriana Haydée; Miró Recasens, José Rodrigo

2016-01-01

Cold recycling with foamed bitumen can be used as a sustainable and cost-effective rehabilitation technique. This paper focuses on the evaluation of the resistance to the water action in mixtures with reclaimed asphalt pavement (RAP) and foamed bitumen by means of indirect tensile test, comparing the effect of two active fillers: cement and hydrated lime. Additionally, mixtures recycled with RAP and asphalt emulsions were also tested in order to compare the response of both technologies. Resu...

The effect of high curing temperature on the reaction kinetics in MK/lime and MK-blended cement matrices at 60 deg. C

International Nuclear Information System (INIS)

Rojas, Moises Frias; Sanchez de Rojas, M.I.

2003-01-01

It is well known that the pozzolanic reaction between metakaolin (MK) and calcium hydroxide produces CSH, C 2 ASH 8 (stratlingite), C 4 AH 13 and C 3 ASH 6 (hydrogarnet). However, the presence or absence of these hydrated phases depends on different parameters, such as curing temperature, matrix used, etc. This paper shows the results of a study in order to know the effect of high curing temperature (60 deg. C) on the kinetics of the pozzolanic reaction in different matrices. MK/lime (calcium hydroxide) and MK-blended cement matrices were studied in samples stored and cured at 60 deg. C and up to 123 days of hydration. The nature, sequence and crystallinity of the hydrated phases were analysed using differential thermal analysis (DTA) and X-ray diffraction (XRD) techniques. Results showed that the sequence and formation of the hydrated phases was different in both matrices cured at 60 deg. C. In an MK/lime matrix, C 2 ASH 8 , C 4 AH 13 and C 3 ASH 6 were the main hydrated phases; while in an MK-blended cement, stratlingite was the sole hydrated phase issued from pozzolanic reaction. The DTA and XRD data also reveal an important fact: there is no evidence of the presence of hydrogarnet in blended cements

New waste based clinkers: Belite and lime formulations

International Nuclear Information System (INIS)

Raupp-Pereira, Fabiano; Ball, Richard James; Rocha, Joao; Labrincha, Joao A.; Allen, Geoffrey C.

2008-01-01

This work describes the formulation of new belite-based (CR2) and lime-based (CR3) cementitious materials derived from industrial wastes, such as sludges (generated in the Al-anodising and surface coating industrial processes, potable water filtration/cleaning operations and in marble sawing processes) and foundry sand. Powder mixtures were prepared and fired at different temperatures. For comparison, similar formulations were prepared with pre-treated and commercially available natural raw materials and processed in similar conditions. The thermal process was followed by differential scanning calorimetry (DSC) and high-temperature powder X-ray diffraction (HT-XRD) studies. The CR2 clinker was found to contain belite as the main cementitious phase, the main polymorph being identified by NMR. The CR3 clinker contained common cementitious phases, such as C 3 A and C 3 S, but free lime and calcium aluminium oxide sulphates were also identified by high temperature XRD and NMR. Then the corresponding cement was prepared and the evolution of the mechanical strength with time was evaluated. The lime-based cement obtained from wastes shows a stronger hardening character than the standard material, which tends to show dusting phenomena due to the presence of a reasonable amount of free lime (as the result of its expansive reaction with ambient moisture). Some fluxing impurities (e.g. alkalis) present in the waste materials improve the overall reactivity of the mixture and induces the combination of the lime in CR3. Raman, XPS and FIB techniques were used to fully characterise the aged cements

Simple method of dynamic Young’s modulus determination in lime and cement mortars

Directory of Open Access Journals (Sweden)

Rosell, J. R.

2011-03-01

Full Text Available The present work explains a simple method to determine the dynamic Young module (MOE by inducing a set of small mechanical perturbation to samples of lime and cement mortars and correlating the results obtained with results determined using other techniques and methods. The procedure described herein follows the instructions stated in the UNE-EN ISO 12680-1 standard for refractory products although in this study the instructions are applied to standardized RILEM 4x4x16 cm test samples made of lime and cement mortars. In addition, MOE determinations are obtained by using ultrasonic impulse velocity while static Young's modulus determinations are obtained by performing conventional bending tests. The ability of this procedure to correlate with results from other techniques, along with its simplicity, suggests that it can be widely adapted to determine the deformability of mortars under load using standardized samples.

El presente trabajo muestra un método simple para determinar el módulo de Young dinámico (MOE a partir de pequeñas perturbaciones mecánicas producidas a probetas de mortero de cal y de cemento, correlacionando los resultados obtenidos con las correspondientes mediciones realizadas con otras técnicas. El procedimiento sigue básicamente las instrucciones fijadas en la norma UNE-EN ISO 12680-1 de productos refractarios, pero aplicándolo a probetas normalizadas RILEM 4x4x16 de morteros confeccionados con cal y cemento. Paralelamente se realizan determinaciones del MOE a partir de la velocidad de paso de impulsos ultrasónicos y determinaciones del módulo de Young estático a partir de ensayos de flexión convencionales. La simplicidad del método aplicado y la correlación de los resultados obtenidos con las variables medidas permiten concluir que esta metodología es de aplicación directa para determinar la deformabilidad bajo carga de los morteros a partir de probetas normalizadas.

Influence of supplementary cementitious materials on water transport kinetics and mechanical properties of hydrated lime and cement mortars

Directory of Open Access Journals (Sweden)

Ince, C.

2015-06-01

Full Text Available The purpose of this paper is an investigation of the possible role of supplementary cementitious materials (SCMs on water transport kinetics and mechanical properties of hydrated lime (CL90 and Portland cement (PC mortars. The properties of hydrated lime are significantly different from those of cement and therefore modifying fresh and hardened properties of these mortars are vital for mortar/substrate optimisation in masonry construction. The parameters investigated in this paper often are the main barriers to the use of hydrated lime in construction practice. The results show that transfer sorptivity and time to dewater freshly-mixed hydrated lime mortars can be modified when binder is partially replaced with SCMs. Compressive strength of CL90 mortars is increased systematically with the increased replacement levels of SCMs and the results are supported with the microstructural images. The ability to modify the water transport kinetics and mechanical properties allows compatibility between the mortar and the substrate unit in masonry construction.El objetivo de este artículo es investigar el papel de los materiales cementantes suplementarios (SCMs en la cinética de transporte del agua y en las propiedades mecánicas de los morteros de cal hidratada (CL90 y cemento Portland. Las propiedades de la cal hidratada son significativamente diferentes a las del cemento y por lo tanto el control de las propiedades de los morteros frescos y endurecidos es fundamental en la optimización mortero/substrato en albañilería. Los parámetros estudiados en este trabajo son a menudo las principales barreras para el uso de la cal hidratada en la práctica de la construcción. Los resultados indican que la absortividad y el tiempo necesario para deshidratar morteros de cal hidratada recién mezclados pueden ser controlados cuando el conglomerante es parcialmente remplazado por SCMs. La resistencia a compresión de los morteros CL90 aumenta sistem

Lunar cement

Science.gov (United States)

Agosto, William N.

1992-01-01

With the exception of water, the major oxide constituents of terrestrial cements are present at all nine lunar sites from which samples have been returned. However, with the exception of relatively rare cristobalite, the lunar oxides are not present as individual phases but are combined in silicates and in mixed oxides. Lime (CaO) is most abundant on the Moon in the plagioclase (CaAl2Si2O8) of highland anorthosites. It may be possible to enrich the lime content of anorthite to levels like those of Portland cement by pyrolyzing it with lunar-derived phosphate. The phosphate consumed in such a reaction can be regenerated by reacting the phosphorus product with lunar augite pyroxenes at elevated temperatures. Other possible sources of lunar phosphate and other oxides are discussed.

Use of demolition residues construction in soil-lime bricks

International Nuclear Information System (INIS)

Figueiredo, S.S.; Silva, C.G.; Silva, I.A.; Neves, G.A.

2011-01-01

Besides being responsible for several environmental damage caused by its residues, the construction industry is also considered the greatest natural resources consumer. When finely ground, such residues can exhibit cementing properties, which may replace part of the lime used in the manufacture of soil-lime bricks. This study aimed to verify the viability of using demolition residues (DR) in soil-lime bricks without structural function. For this, test specimens were prepared using mixes in a 1:10 ratio of lime:soil and embedding residue in partial replacement of lime in the proportions of 25%, 50% and 75%. The test specimens were submitted to curing periods of 28 and 52 days, then it was determined the compression strength. The results showed that when embedded on moderate percentages, demolition residues construction can be used in the production of soil-lime bricks. (author)

Recycled sand in lime-based mortars.

Science.gov (United States)

Stefanidou, M; Anastasiou, E; Georgiadis Filikas, K

2014-12-01

The increasing awareness of the society about safe guarding heritage buildings and at the same time protecting the environment promotes strategies of combining principles of restoration with environmentally friendly materials and techniques. Along these lines, an experimental program was carried out in order to investigate the possibility of producing repair, lime-based mortars used in historic buildings incorporating secondary materials. The alternative material tested was recycled fine aggregates originating from mixed construction and demolition waste. Extensive tests on the raw materials have been performed and mortar mixtures were produced using different binding systems with natural, standard and recycled sand in order to compare their mechanical, physical and microstructure properties. The study reveals the improved behavior of lime mortars, even at early ages, due to the reaction of lime with the Al and Si constituents of the fine recycled sand. The role of the recycled sand was more beneficial in lime mortars rather than the lime-pozzolan or lime-pozzolan-cement mortars as a decrease in their performance was recorded in the latter cases due to the mortars' structure. Copyright © 2014 Elsevier Ltd. All rights reserved.

Preparing hydraulic cement from oil-shale residue

Energy Technology Data Exchange (ETDEWEB)

1921-08-28

A process for preparation of hydraulic cement from oil-shale residue is characterized in that, as flux is used, rich-in-lime poor-in-sulfur portland-cement clinker, by which the usual gypsum addition, is avoided.

Economic evaluation of the industrial solar production of lime

International Nuclear Information System (INIS)

Meier, Anton; Gremaud, Nicolas; Steinfeld, Aldo

2005-01-01

The use of concentrated solar energy in place of fossil fuels for driving the endothermic calcination reaction CaCO 3 → CaO + CO 2 at above 1300 K has the potential of reducing CO 2 emissions by 20% in a state-of-the-art lime plant and up to 40% in a conventional cement plant. An economic assessment for an industrial solar calcination plant with 25 MW th solar input indicates that the cost of solar produced lime ranges between 128 and 157 $/t, about twice the current selling price of conventional lime. The solar production of high purity lime for special sectors in the chemical and pharmaceutical industry might be competitive with conventional fossil fuel based calcination processes at current fuel prices

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

Irreversible dilation of NaCl contaminated lime-cement mortar due to crystallization cycles

International Nuclear Information System (INIS)

Lubelli, B.; Hees, R.P.J. van; Huinink, H.P.; Groot, C.J.W.P.

2006-01-01

The mechanism of damage occurring in NaCl contaminated materials has not been clarified yet. Apart from crystallization pressure, other hypotheses have been proposed to explain the cause of decay. Irreversible dilation has been observed in a few cases but has never been studied in a more systematic way. The aim of the research is to contribute to the modeling of this phenomenon. In the present paper the effect of NaCl on the hydric and hygric behavior of a lime-cement mortar is extensively studied. The results indicate that NaCl influences the hydric and hygric dilation behavior of the material. The material contaminated with NaCl shrinks during dissolution and dilates during crystallization of the salt. This dilation is irreversible and sufficient to damage the material after few dissolution/crystallization cycles. This behavior is not restricted to NaCl, but is observed in the presence of other salts as well (NaNO 3 and KCl). Outcomes of electron microscopy studies suggest that salts causing irreversible dilation tend to crystallize as layers on the pore wall

The influence of additives on leaching of tritium of the immobilization matrices of contaminated oils by cementation

International Nuclear Information System (INIS)

Deneanu, N.; Dulama, M.; Baboescu, E.; Horhoianu, G.

2000-01-01

The research studies showed that the solidification of contaminated pump oils resulted from Cernavoda NPP operation can be done by using various immobilization matrices such as: cement with appropriate mineral additives sand of Aghires, lime and silicate accelerator. Research works and experiments were carried out on four groups: cement-emulsion, cement-emulsion-silicate accelerator, cement-emulsion-lime- silicate accelerator and cement-emulsion-sand of Aghires. The paper presents the author's research on immobilization of contaminated oil by cementation using Romanian emulsifiers. With both of the emulsifiers used, there were obtained reasonable compressive strengths and leaching rates. (author)

Historic lime-binders: An example of 19th Century Dutch Military plain concrete

NARCIS (Netherlands)

Nijland, T.G.; Copuroglu, O.; Heinemann, H.A.

2012-01-01

Before the general acceptance of Portland cement as the main binder for concrete in the late 19th century, other, locally available binders were occasionally used. In the case of the Netherlands, which did not produce Portland cement, traditional lime-based binders were not uncommon. With a strong

Historic lime-binders : An example of the 19th century Dutch military plain concrete

NARCIS (Netherlands)

Heinemann, H.A.; Copuroglu, O.; Nijland, T.G.

2012-01-01

Before the general acceptance of Portland cement as the main binder for concrete in the late 19th century, other, locally available binders were occasionally used. In the case of the Netherlands, which did not produce Portland cement, traditional lime-based binders were not uncommon. With a strong

Physicochemical characterization of cement kiln dust for potential reuse in acidic wastewater treatment

International Nuclear Information System (INIS)

Mackie, A.; Boilard, S.; Walsh, M.E.; Lake, C.B.

2010-01-01

Cement kiln dust (CKD) is a fine-grained material produced during the manufacture of cement. Current reuse options are limited and the bulk of CKD not reused in the cement manufacturing process is sent to landfills or stored on-site. Due to the calcium oxide (CaO) content of CKD, it has the potential to be used as a replacement for lime in treating acidic wastewaters such as acid rock drainage (ARD). This paper outlines the results of an examination of the physical and chemical properties of CKD samples collected from six cement plants. The CKD samples were analyzed for major oxides using X-ray diffraction (XRD), available lime, specific surface area, particle size, and morphology using scanning electron microscope (SEM) and compared with a commercial quicklime product. Conductivity, pH, and calcium concentrations of slaked CKD and quicklime solutions were used as indicators of reactivity of the CKD. Slaking of two of the CKD samples with the highest free lime contents (e.g., 34 and 37% free CaO) gave elevated pH values statistically comparable to those of the commercial quicklime sample that was characterized as having 87% available CaO. Acid neutralization trials indicate that even CKD samples with low free lime contents could be effective at neutralizing acidic wastewaters.

Changes in Properties of Cement and Lime Mortars When Incorporating Fibers from End-of-Life Tires

Directory of Open Access Journals (Sweden)

Lluís Gil

2016-02-01

Full Text Available This paper studies the addition of fibers from end-of-life tires to commercial mortar mixtures. Two different types of mortar, one lime-plastic and other cement-fluid, are mixed with different percentage of fibers ranging from 0% to 1%. The changes in bulk density, consistency, compressive and flexural strength, dynamic Young modulus and water absorption are studied. According to the results, consistency is the property that shows more relevant changes for an addition of 0.25% fibers. Consistency is related to workability and affects the water absorption and the Young modulus values. On the contrary, bulk density and mechanical properties did not change with the addition of fibers. The results prove that this fiber, considered a waste from recycling of end-of-life tires, can be used in commercial mixtures without losing strength. On the other hand, mortar workability limits the amount of fibers that can be included in the mixture and this parameter determines the performance of the mortar.

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

OpenAIRE

Beltagui, Hoda; Sonebi, Mohammed; Maguire, K.; Taylor, Susan

2018-01-01

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 ...

Evaluation of Cement, Lime, and Asphalt Amended Municipal Solid Waste Incinerator Residues

Science.gov (United States)

1989-09-01

the lime column over time ( Atlas & Bartha , 1987). Certainly, a more extensive evaluation of the lime amended residue’s microbial activity is required...4.02 ASTM D 1559 (1988) Annual Book of ASTM Standards: Road & Paving Materials; Traveled Surface Characteristics, Sec 4, Vol 4.03 Atlas , R. & R. Bartha ...1987) Microbial Ecology : Fundamentals & Applications, Benjamin-Cummings, Menlo, CA Barrow N., J. Bowden, A. Posner, & J. Quirk (1981) Describing the

Natural radioactivity of the cement, lime and plaster in the Zacatecas State; Radiactividad natural del cemento, cal y yeso en el Estado de Zacatecas

Energy Technology Data Exchange (ETDEWEB)

Mireles, F.; Davila, J. I.; Lopez, H.; Pinedo, J. L.; Rios, C.; Saucedo, S. A.; Cespedes, N., E-mail: fmireles@uaz.edu.mx [Universidad Autonoma de Zacatecas, Unidad Academica de Estudios Nucleares, Cipres No. 10, Fracc. La Penuela, 98068 Zacatecas (Mexico)

2012-10-15

The construction materials are the main radiation gamma source inside the houses room and the buildings, followed by the terrestrial and cosmic radiation. The radioactivity levels of the construction materials were obtained to establish reference levels and of population exposure. In this work the study of 56 samples of construction materials is presented, 24 of cement, 20 of lime and 12 of plaster, of the marks more sold in the municipalities of Zacatecas and Guadalupe of the Zacatecas State, Mexico. The objective is the study of the concentration in activity of the radioisotopes {sup 238}U, {sup 232}Th, {sup 40}K and {sup 137}Cs, using a gamma rays spectrometry system based on a hyper pure germanium detector. The obtained results of activity concentration of the interest radioisotopes show similar values average to those published by UNSCEAR 1993. The population of the municipalities of Zacatecas and Guadalupe is exposed to the environmental gamma radiation coming from the contained radioisotopes in the construction materials; the annual equivalent effective dose by the cement is in the range of 116 at 562 {mu}Sv a{sup -1} with an average of 340 {mu}Sv a{sup -1}, of the lime is in the range of 36 at 212 {mu}Sv a{sup -1} with an average of 87 {mu}Sv a{sup -1}, and of the plaster is in the range of 16 at 27 {mu}Sv a{sup -1} with an average of 22 {mu}Sv a{sup -1}, this exposure does not represent any risk for the population's health. (Author)

Characterization of cement-based ancient building materials in support of repository seal materials studies

International Nuclear Information System (INIS)

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

1983-12-01

Ancient mortars and plasters collected from Greek and Cypriot structures dating to about 5500 BC have been investigated because of their remarkable durability. The characteristics and performance of these and other ancient cementitious materials have been considered in the light of providing information on longevity of concrete materials for sealing nuclear waste geological repositories. The matrices of these composite materials have been characterized and classified into four categories: (1) gypsum cements; (2) hydraulic hydrated lime and hydrated-lime cements; (3) hydraulic aluminous and ferruginous hydrated-lime cements (+- siliceous components); and (4) pozzolana/hydrated-lime cements. Most of the materials investigated, including linings of ore-washing basins and cisterns used to hold water, are in categories (2) and (3). The aggregates used included carbonates, sandstones, shales, schists, volcanic and pyroclastic rocks, and ore minerals, many of which represent host rock types of stratigraphic components of a salt repository. Numerous methods were used to characterize the materials chemically, mineralogically, and microstructurally and to elucidate aspects of both the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical (mineralogical) and microstructural factors. Durability was found to be affected by matrix mineralogy, particle size and porosity, and aggregate type, grading, and proportioning, as well as method of placement and exposure conditions. Similar factors govern the potential for durability of modern portland cement-containing materials, which are candidates for repository sealing. 29 references, 29 figures, 6 tables

Performance of Portland cement mixes containing silica fume and mixed with lime-water

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Metwally A.A. Abd Elaty

2014-12-01

Test results show that using lime-water in mixing enhances consistency degree compared to the corresponding control mixes. Furthermore, it delays both initial and final setting times compared with traditional water due to the common ion effect principles. Moreover, combined use of lime-water and silica fume enhances the pozzolanic reaction that was identified by the strength development at both early and later ages. The existence of CH crystals for higher percentages of silica fume (up to 30% for further reaction at later ages was observed by XRD results. Moreover, combined use of silica fume and lime-water ensures a high alkaline media around steel bars from the moment of ingredients mixing as long as later ages despite of pozzolanic reaction that was identified from results of chloride attack.

Effect of lime addition during sewage sludge treatment on characteristics of resulting SSA when it is used in cementitious materials.

Science.gov (United States)

Vouk, D; Nakic, D; Štirmer, N; Baricevic, A

2017-02-01

Final disposal of sewage sludge is important not only in terms of satisfying the regulations, but the aspect of choosing the optimal wastewater treatment technology, including the sludge treatment. In most EU countries, significant amounts of stabilized and dewatered sludge are incinerated, and sewage sludge ash (SSA) is generated as a by product. At the same time, lime is one of the commonly used additives in the sewage sludge treatment primarily to stabilize the sludge. In doing so, the question arose how desirable is such addition of lime if the sludge is subsequently incinerated, and the generated ash is further used in the production of cementitious materials. A series of mortars were prepared where 10-20% of the cement fraction was replaced by SSA. Since all three types of analyzed SSA (without lime, with lime added during sludge stabilization and with extra lime added during sludge incineration) yielded nearly same results, it can be concluded that if sludge incineration is accepted solution, lime addition during sludge treatment is unnecessary even from the standpoint of preserving the pozzolanic properties of the resulting SSA. Results of the research carried out on cement mortars point to the great possibilities of using SSA in concrete industry.

Interpreting chemistry and technology of lime binders and implementing it in the conservation field

Directory of Open Access Journals (Sweden)

Georgia Zacharopoulou

2009-01-01

Full Text Available The objective of the paper is the compilation, review and dissemination of updated scientific knowledge on lime theory and technology in the field of heritage conservation. The strong evidence of the last decade's research on the positive effect of the - not demonstrable by a chemical equation – 'key' missing link of the maturation process is highlighted. It is demonstrated that the exceptional perfor -mance characteristics of durable lime based mortars predominately rely on the capacity for rapid, efficient and extensive carbonation of the air-hardening phase of limes, in particular when matured (nanoparticle wet slaked lime putties are used; and on the chemical and mechanical stability of the strength components (principally CSHs of the hydraulic phase of limes, which is higher in their more crystalline forms of historical lime-pozzolan mixtures than in their amorphous forms of modern cements. Hence, physicochemical adhesion and cohesion bonds both at the lime matrix and at the binder/aggregate interfaces are ensured imparting minimization of cracks and durability to lime based mortars and historic masonries. The comprehensive documentation of the former leads to optimal materials and procedures to preserve our cultural heritage.

Expansive cements for the manufacture of the concrete protective bandages

Science.gov (United States)

Yakymechko, Yaroslav; Voloshynets, Vladyslav

2017-12-01

One of the promising directions of the use of expansive cements is making the protective bandages for the maintenance of pipelines. Bandages expansive application of the compositions of the pipeline reinforce the damaged area and reduce stress due to compressive stress in the cylindrical area. Such requirements are best suited for expansive compositions obtained from portland cement and modified quicklime. The article presents the results of expansive cements based on quick lime in order to implement protective bandages pipelines.

Chemical composition, effective atomic number and electron density study of trommel sieve waste (TSW), Portland cement, lime, pointing and their admixtures with TSW in different proportions

International Nuclear Information System (INIS)

Kurudirek, Murat; Aygun, Murat; Erzeneoglu, Salih Zeki

2010-01-01

The trommel sieve waste (TSW) which forms during the boron ore production is considered to be a promising building material with its use as an admixture with Portland cement and is considered to be an alternative radiation shielding material, also. Thus, having knowledge on the chemical composition and radiation interaction properties of TSW as compared to other building materials is of importance. In the present study, chemical compositions of the materials used have been determined using a wavelength dispersive X-ray fluorescence spectrometer (WDXRFS). Also, TSW, some commonly used building materials (Portland cement, lime and pointing) and their admixtures with TSW have been investigated in terms of total mass attenuation coefficients (μ/ρ), photon interaction cross sections (σ t ), effective atomic numbers (Z eff ) and effective electron densities (N e ) by using X-rays at 22.1, 25 keV and γ-rays at 88 keV photon energies. Possible conclusions were drawn with respect to the variations in photon energy and chemical composition.

The effects of silica fume and hydrated lime on the strength development and durability characteristics of concrete under hot water curing condition

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Hamza Ali

2017-01-01

Full Text Available Sustainability is considered to be highly important for preserving continued industrial growth and human development. Concrete, being the world’s largest manufacturing material comprises cement as an essential binding component for strength development. However, excessive production of cement due to high degree of construction practices around the world frames cement as a leading pollutant of releasing significant amounts of CO2 in the atmosphere. To overcome this environmental degradation, silica fume and hydrated lime are used as partial replacements to cement. This paper begins with the examination of the partial replacement levels of hydrated lime and silica fume in concrete and their influence on the mechanical properties and durability characteristics of concrete. The effect of hot water curing on concrete incorporated with both silica fume and hydrated lime is also investigated in this paper. The results reported in this paper show that the use of silica fume as a partial replacement material improved both the mechanical properties and durability characteristics of concrete due to the formation of calcium silica hydrate crystals through the pozzolanic reaction. Although the hydrated lime did not significantly contribute in the development of strength, its presence enhanced the durability of concrete especially at long-term. The results also showed that hot water curing enhanced the strength development of concrete incorporated with silica fume due to the accelerated rate of both the hydration and pozzolanic reaction that takes place between silica fume and calcium hydroxide of the cement matrix particularly at early times. The results reported in this paper have significant contribution in the development of sustainable concrete. The paper does not only address the use of alternative binders as a partial replacement material in concrete but also suggest proper curing conditions for the proposed replacement materials. These practices

Combination of Palm Kernel Husk Ash (PKHA) and Free Lime (CaO ...

African Journals Online (AJOL)

Almost all admixtures used in concrete construction in Nigeria are imported. In this study, various proportions of free Lime (CaO), Palm Kernel Husk Ash (PKHA) and Ordinary Portland Cement (OPC) were mixed and the setting times of various mix proportions were determined and compared with that of only OPC.

Influence of natural pozzolana and lime additives on the temporal variation of soil compaction and shear strength

Science.gov (United States)

Harichane, Khelifa; Ghrici, Mohamed; Missoum, Hanifi

2011-06-01

Soil stabilization has been practiced for quite some time by adding mixtures, such as cement, lime and fly ash. The additives of lime (L), natural pozzolana (NP) or a combination of both were investigated here on the impact on the temporal variation of geotechnical characteristics of two cohesive soils. Lime and natural pozzolana were added at the content of 0-8% and 0-20%, respectively. The soil specimens were cured for 1, 7, 28 and 90 days and then tested for shear strength. Our data show that a combination of lime with natural pozzolana causes the increase in the maximum dry density but the decrease in the optimum moisture content in the gray soil, and vice verse in the red soil. The shear stress of both cohesive soils stabilized with lime or with the combination of lime and natural pozzolana was found to increase with time. The cohesion and the internal friction angle in lime-added samples were demonstrated to increase with time. The combination of lime with natural pozzolana exhibits a significant effect on the enhancement of the cohesion and the internal friction angle at later stages. The lime-natural pozzolana combination appears to produce higher shear parameters than lime or natural pozzolana used alone.

Instability improvement of the subgrade soils by lime addition at Borg El-Arab, Alexandria, Egypt

Science.gov (United States)

El Shinawi, A.

2017-06-01

Subgrade soils can affect the stability of any construction elsewhere, instability problems were found at Borg El-Arab, Alexandria, Egypt. This paper investigates geoengineering properties of lime treated subgrade soils at Borg El-Arab. Basic laboratory tests, such as water content, wet and dry density, grain size, specific gravity and Atterberg limits, were performed for twenty-five samples. Moisture-density (compaction); California Bearing Ratio (CBR) and Unconfined Compression Strength (UCS) were conducted on treated and natural soils. The measured geotechnical parameters of the treated soil shows that 6% lime is good enough to stabilize the subgrade soils. It was found that by adding lime, samples shifted to coarser side, Atterberg limits values of the treated soil samples decreased and this will improve the soil to be more stable. On the other hand, Subgrade soils improved as a result of the bonding fine particles, cemented together to form larger size and reduce the plastiCity index which increase soils strength. The environmental scanning electron microscope (ESEM) is point to the presence of innovative aggregated cement materials which reduce the porosity and increase the strength as a long-term curing. Consequently, the mixture of soil with the lime has acceptable mechanical characteristics where, it composed of a high strength base or sub-base materials and this mixture considered as subgrade soil for stabilizations and mitigation the instability problems that found at Borg Al-Arab, Egypt.

The role of curing period on the engineering characteristics of a cement-stabilized soil

Directory of Open Access Journals (Sweden)

Athanasopoulou Antonia

2016-07-01

Full Text Available Very often, pavements constructed in an economical manner or matching surface elevations of adjacent lanes cannot be designed for the soil conditions of the existing subgrade. Therefore, there is a need to stabilize the soil with an appropriate chemical substance in order to increase its strength to a satisfactory level. For the enhancement of subgrade soil strength characteristics, lime and cement are the most commonly used stabilizers. An experimental program was directed to the evaluation of a clayey soil and its mixtures with different cement contents performing tests on the index properties, the moisture-density relation, the unconfined compressive strength, and linear shrinkage. There is a definite improvement in strength. The time interval used to cure the prepared specimens affected positively both strength and plasticity features of the mixtures. A comparison with mixtures of the same soil with lime has been made, because of the wide use of lime in clay soil stabilization projects.

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

Science.gov (United States)

Sikora, Pawel; Augustyniak, Adrian; Cendrowski, Krzysztof; Horszczaruk, Elzbieta; Rucinska, Teresa; Nawrotek, Pawel; Mijowska, Ewa

2016-01-01

The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide) were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100%) to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed. PMID:28773823

Characterization of Mechanical and Bactericidal Properties of Cement Mortars Containing Waste Glass Aggregate and Nanomaterials

Directory of Open Access Journals (Sweden)

Pawel Sikora

2016-08-01

Full Text Available The recycling of waste glass is a major problem for municipalities worldwide. The problem concerns especially colored waste glass which, due to its low recycling rate as result of high level of impurity, has mostly been dumped into landfills. In recent years, a new use was found for it: instead of creating waste, it can be recycled as an additive in building materials. The aim of the study was to evaluate the possibility of manufacturing sustainable and self-cleaning cement mortars with use of commercially available nanomaterials and brown soda-lime waste glass. Mechanical and bactericidal properties of cement mortars containing brown soda-lime waste glass and commercially available nanomaterials (amorphous nanosilica and cement containing nanocrystalline titanium dioxide were analyzed in terms of waste glass content and the effectiveness of nanomaterials. Quartz sand is replaced with brown waste glass at ratios of 25%, 50%, 75% and 100% by weight. Study has shown that waste glass can act as a successful replacement for sand (up to 100% to produce cement mortars while nanosilica is incorporated. Additionally, a positive effect of waste glass aggregate for bactericidal properties of cement mortars was observed.

Investigation of Hydraulic Binding Characteristics of Lime Based Mortars Used in Historical Masonry Structures

Science.gov (United States)

Binal, Adil

2017-10-01

In the historic masonry structures, hard and large rock fragments were used as the construction materials. The hydraulic binder material prepared to keep this used material in its entirety is a different material than the cement used today. Khorasan mortar made by using aggregate and lime exhibits a more flexible structure than the concrete. This feature allows the historic building to be more durable. There is also a significant industrial value because of the use of Khorasan mortar in the restoration of historic masonry structures. Therefore, the calculation of the ideal mixture of Khorasan mortar and the determination of its mechanical and physical properties are of great importance regarding preserving historic buildings. In this study, the mixtures of different lime and brick fractions were prepared. It was determined that Khorasan mortar shows the highest compressive strength in mixtures with water/lime ratio of 0.55 and lime/aggregate ratio of 0.66. By keeping the mixing ratio constant, it was observed that the strengths of the samples kept in the humidity chamber for different curing times increased day by day. The early strength values of samples with the high lime/aggregate ratio (l/a: 0.83) were higher than those with the low lime/aggregate ratio (l/a: 0.5). For the samples with low lime/aggregate ratio, there was an increase in the strength values depending on the curing period. As the cure duration increases, a chemical reaction takes place between the lime and the brick fracture, and as a result of this reaction, the strength values are increased.

Encapsulation of ILW raffinate in the Dounreay cementation plant

International Nuclear Information System (INIS)

Sinclair, G.F.

1998-01-01

The Dounreay Cementation Plant has been designed and constructed to encapsulate the first cycle liquid raffinate arising from the reprocessing of irradiated Research Reactor fuel into a cementitious matrix. The acidic liquid waste is conditioned with sodium hydroxide prior to mixing with the cement powders (a 9:1 ratio of Blast Furnace Slag / Ordinary Portland Cement with 5% Lime). The complete cement mixing process is performed within the 500-liter drum, which provides the waste package primary containment. The plant has recently been commissioned and has commenced routine operation, processing stocks of existing raffinate that has been stored at Dounreay for up to 30 years. The waste loading per drum has been optimised within the constraints of the chemical composition of the raffinate, with an expected plant throughput of 2.5 m 3 /week. (author)

Performance of Low-Volume Roads with Wearing Course Layer of Silty Sandy Soil Modified with Rice Husk Ash and Lime

Energy Technology Data Exchange (ETDEWEB)

Behak Katz, L.; Musso Laespiga, M.

2016-07-01

Rice husk ash (RHA) is a by-product of rice milling. Its use as soil stabilizer is a way to replace the final disposal with environmental benefit. However, RHA is not cementitious itself but when mixed with lime forms cements which improve the soil properties. A research of performance of a silty sandy soil modified with RHA and lime as wearing course layer of low-volume roads was conducted through two full-scale test sections with different pavements built in Artigas, northern Uruguay. The alkaline reactivity of RHA is low because the husk burning is not controlled. The soil-RHA-lime mix design was conducted according to the Thompson’s Method. The pavement test sections were monitored through deflection measures by Benkelman beam and observations of surface condition. The deflections decreased over time in both test sections due to the development of cementation of the study materials. After one year, the dust emission was reduced, the wet skid resistance of pavement surfaces improved and there was not rutting. The researched pavements have had a good performance under the existing traffic and environmental conditions, demonstrating that wearing course layer of silty sand modified with RHA and lime is an alternative to improve the condition of low-volume roads and to replace the final disposal of RHA, with environmental, social and economic benefits. (Author)

Ageing of Dry Cement Mixes for Finishing Purposes

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Bronius VEKTARIS

2013-09-01

Full Text Available Dry building mixes, stored in the air, absorb water vapor and CO2 gas and ageing because properties of binding materials, mostly Portland cement, deteriorate after its prehydration and carbonation. In this paper the ageing singularities of dry cement mixes for finishing purposes and additives for retarding this process has been determinated. Ordinary and quickly hardening Portland cements absorb H2O and CO2 more than white cement – about 70 % – 75 % and 30 % – 38 % per month of innitial mass, respectively. White cement is more resistant to prehydration and carbonation, because it contains less C3A, C4AF and alkali, characterized initial activity. Dry mixes with white cement, although slower, but still worse after stored. Influence of routine dry mortar mixes ingredients and additives (methyl cellulose, pigments, sand and lime on prehydration properties of the mixes for finishing purpose is not substantial. Significant positive influence comes from the addition of fatty acid salts (zinc stearate or sodium oleate. The dry cement mixes for finishing purpose has been recomended to hydrophobisate with one of these additives, adding about 1 % by weight of cement during preducing mixes. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5243

Ageing of Dry Cement Mixes for Finishing Purposes

Directory of Open Access Journals (Sweden)

Bronius VEKTARIS

2013-09-01

Full Text Available Dry building mixes, stored in the air, absorb water vapor and CO2 gas and ageing because properties of binding materials, mostly Portland cement, deteriorate after its prehydration and carbonation. In this paper the ageing singularities of dry cement mixes for finishing purposes and additives for retarding this process has been determinated. Ordinary and quickly hardening Portland cements absorb H2O and CO2 more than white cement – about 70 % – 75 % and 30 % – 38 % per month of innitial mass, respectively. White cement is more resistant to prehydration and carbonation, because it contains less C3A, C4AF and alkali, characterized initial activity. Dry mixes with white cement, although slower, but still worse after stored. Influence of routine dry mortar mixes ingredients and additives (methyl cellulose, pigments, sand and lime on prehydration properties of the mixes for finishing purpose is not substantial. Significant positive influence comes from the addition of fatty acid salts (zinc stearate or sodium oleate. The dry cement mixes for finishing purpose has been recomended to hydrophobisate with one of these additives, adding about 1 % by weight of cement during preducing mixes. DOI: http://dx.doi.org/10.5755/j01.ms.19.3.5243

Strengthening Masonry Arches with Lime-Based Mortar Composite

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Valerio Alecci

2017-06-01

Full Text Available In recent decades, many strengthening interventions on masonry elements were performed by using fiber reinforced polymers (FRPs. These advanced materials proved to be effective to increase the load-carrying capacity of masonry elements and to improve their structural behavior, avoiding the most critical failure modes. Despite the advantages of this technique compared to more traditional methods, FRP systems have disadvantages related to their low resistance to high temperatures, impossibility of application on wet surfaces, low permeability, and poor compatibility with masonry supports. Therefore, composite materials made of a fiber textile embedded in an inorganic matrix were recently proposed as alternatives to FRPs for strengthening historic masonry constructions. These composite materials are easier to install, have higher resistance to high temperatures, and permit higher vapor permeability than FRPs. The inorganic matrix is frequently a cement-based mortar, and the composite materials made of a fiber textile embedded in a cement-based mortar are usually identified as FRCM (fabric reinforced cementitious matrix composites. More recently, the use of natural lime mortar as an inorganic matrix has been proposed as an alternative to cement-based mortars when historic compatibility with the substrate is strictly required, as in case of restoration of historic buildings. In this paper, the effectiveness of a fabric made of basalt fibers embedded in lime mortar matrix (Basalt-FRLM for the strengthening of masonry arches is investigated. An experimental investigation was performed on 1:2 scaled brick masonry arches strengthened at the extrados with a layer of Basalt-FRLM and tested under vertical load. The results obtained are compared with previous results obtained by the authors by testing masonry arches strengthened at their extrados with FRCM and FRP composites. This investigation highlights the effectiveness of Basalt-FRLM in increasing load

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.

Properties, sustainability and elevated temperature behavior of concrete containing Portland limestone cement

Science.gov (United States)

El-Hawary, Moetaz; Ahmed, Mahmoud

2017-09-01

The utilization of some type of cheap filler as partial cement replacement is an effective way of improving concrete sustainability. With the recent trends to reduce water to cement ratio and improve compaction, there is no enough space or water for complete hydration of cement. This means that actually, a portion of mixed cement acts as expensive filler. Replacing this portion with cheaper filler that requires less energy to produce is, therefore, beneficial. Crushed limestone is the most promising filler. This work is to investigate the effect of the amount of limestone fillers on the sustainability and the fresh and mechanical properties of the resulting concrete. A rich mix is designed with a low water/cement ratio of 0.4. Lime is introduced as a replacement percentage of cement. Ratios of 0, 10, 20 and 30% were used. Slump, compressive strength, specific gravity and water absorption are evaluated for every mix. In addition, the effect of the amount of lime on the residual strength of concrete subjected to elevated temperatures is also investigated. Samples are subjected to six different temperature stations of 20, 100, 200, 300, 500 and 700°C for six hours before being cooled and subsequently tested for compressive strength and specific gravity. Sustainability of the tested mixes is evaluated through reductions in the emitted carbon dioxide, energy and reduction in cost. Based on the annual use of concrete in Kuwait, the sustainability benefits resulting from the use of limestone filler in Kuwait are evaluated and assessed. The paper is concluded with the recommendation of the use of 15% limestone filler as partial cement replacement where the properties and the behavior under high temperature of the resulting concrete are almost the same as those of conventional concrete with considerable cost and sustainability benefits.

Preparation of cement from oil shale

Energy Technology Data Exchange (ETDEWEB)

1922-08-24

A process for preparing cement from oil shale is described. The simultaneous recovery of shale oil by heating the oil shale formed into briquets with finely ground lime or limestone in a stream of hot gases is characterized by the fact that live steam or fine drops of water as preserving and carbonization means is introduced into the furnace, at the place, where the temperature of the briquet reaches about 500 to 600/sup 0/ C.

Impact of coal and rice husk ash on the quality and chemistry of cement clinker

International Nuclear Information System (INIS)

Nawaz, S.; Kanwal, S.; Rahim, U.; Sheikh, N.; Shahzad, K.

2012-01-01

Utilization of rice husk as an alternative fuel for coal is of interest due to its availability in huge quantities in Pakistan and also because its combustion is environmental pollution friendly as it generates much less SOX due to its much lower sulphur content (0.1-0.3%) compared to sulphur content in coals, particularly indeginous coals ranging from 0.6-14.8%. The purpose of present study was to examine the impact of co-firing of rice husk and coal on the quality of cement clinker so as to substitute expensive imported coal with the abundantly available cheaper rice husk to reduce the cost of production of the cement. For this investigation raw feed mix (mixture of limestone, clay, bauxite and laterite in predetermined proportions) used for cement manufacture was mixed with predetermined varying proportions of coal ash and rice husk ash and placed inside a muffle furnace at 1200 degree C - 1500 degree C i-e the temperatures prevailing in the industrial cement kilns, for various periods of time to obtain cement clinker. The quality and chemistry of cement clinker thus produced in the laboratory was experimentally studied to ensure the quality of cement clinker that would be obtained by co-firing of rice husk and coal in different proportions in industrial cement kilns as the coal ash and rice husk ash produced during combustion will get mixed with cement clinker in industrial kilns. The results indicated that there was decrease in the Lime Saturation Factor, Free Lime and Tricalcium Silicate (C3S) content and increase in the Dicalcium Silicate (C2S) content by increasing the rice husk ash and decreasing the coal ash proportion in the clinker. (author)

29Si solid state NMR investigation of pozzolanic reaction occurring in lime-treated Ca-bentonite

International Nuclear Information System (INIS)

Pomakhina, Elena; Deneele, Dimitri; Gaillot, Anne-Claire; Paris, Michael; Ouvrard, Guy

2012-01-01

Lime is widely used as additive to improve the mechanical properties of natural soil used in earthworks. However, the physico-chemical mechanisms involved are yet not well understood. In order to develop and optimize this treatment method, a better understanding of the interaction between lime and the minerals of the soils, in particular clay minerals, is required. In this study, Ca-bentonite was treated with 2, 5 and 10 wt.% of lime during 1 to 98 days. Modifications in the Si local environment were then monitored by solid state nuclear magnetic resonance to investigate the pozzolanic reaction. All the soil mineral phases contribute to the release of Si and to the pozzolanic reaction, with a rapid and total consumption of Si-polymorph and an exacerbated dissolution of montmorillonite. Mechanism of C–S–H formation, function of the Ca content in the system, was found to match the sorosilicate-tobermorite model described in cement systems.

LIME REQUIREMENT DETERMINATION AND LIMING IMPACT ON SOIL NUTRIENT STATUS

Directory of Open Access Journals (Sweden)

Krunoslav Karalić

2010-06-01

Full Text Available The aim of conducted research was to determine the influence of liming, mineral and organic fertilization on soil chemical properties and nutrient availability in the soil, yield height and mineral composition of alfalfa. Results were used to create regression models for prediction of liming impact on soil chemical properties. Liming and fertilization experiment was sat up in 20 L volume plastic pots with two types of acid soils with different texture from two sites. Ten liming and fertilization treatments were applied in four repetitions. Lime treatments increased soil pH values and decreased hydrolytic acidity. Mineral and organic fertilization affected additional soil acidification. Application of lime intensified mineralization and humus decomposition, while organic fertilization raised humus content. The results showed significant increase of AL-P2O5 and K2O availability. The treatments increased soil Ca concentrations, but at the same time decreased exchangeable Mg concentrations. Soil pH increase resulted in lower Fe, Mn, Zn and Cu availability. Soil CEC was increased by applied treatments. Lime rates increased number and height of alfalfa plants, as well as yield of leaf, stalk increased concentrations of N, P, K and Ca in alfalfa leaf and stalk, but decreased leaf Mg and Fe, Mn, Zn and Cu concentrations. Regression computer models predicted with adequate accuracy P, Fe, Mn, Zn and Cu availability and final pH value as a result of liming and fertilization impact.

Examination of solidified and stabilized matrices as a result of solidification and stabilization process of arseniccontaining sludge with portland cement and lime

Directory of Open Access Journals (Sweden)

Tanapon Phenrat

2004-02-01

Full Text Available By solidification and stabilization (S/S with Portland cement and lime, it is possible to reduce arsenic concentration in leachate of the arsenic-containing sludge from arsenic removal process by coagulation with ferric chloride. From the initial arsenic concentration in leachate of unsolidified /unstabilized sludge which was around 20.75 mg/L, the arsenic concentrations in leachate of solidified/stabilized waste were reduced to 0.3, 0.58, 1.09, and 1.85 mg/L for the waste-to-binder ratios of 0.15, 0.25, 0.5, and 1, respectively, due tothe formation of insoluble calcium-arsenic compounds. To be more cost effective for the future, alternative uses of these S/S products were also assessed by measurement of compressive strength of the mortar specimens. It was found that the compressive strengths of these matrices were from 28 ksc to 461 ksc. In conclusion, considering compressive strength and leachability of the solidified matrices, some of these solidified/ stabilized products have potential to serve as an interlocking concrete paving block.

Microstructural analysis of the potential of sugarcane bagasse ash as a pozzolan material in cement composites

International Nuclear Information System (INIS)

Pereira, A.M.; Assuncao, C.C.; Guimaraes, L. de M.; Malmonge, J.A.; Tashima, M.M; Akasaki, J.L.

2016-01-01

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)

Lime-water consolidation effects on poor lime mortars

Czech Academy of Sciences Publication Activity Database

Drdácký, Miloš; Slížková, Zuzana

2012-01-01

Roč. 43, č. 1 (2012), s. 31-36 ISSN 0044-9466 R&D Projects: GA ČR(CZ) GA103/09/2067 Institutional support: RVO:68378297 Keywords : lime mortar s * lime -water consolidation * conservation Subject RIV: JN - Civil Engineering

Lime

Science.gov (United States)

Miller, M.

2006-01-01

In 2005, US lime production was 20 Mt with a value of $1.5 billion. Production was unchanged compared with 2004. Captive production was 1.4 Mt. US consumption was 20.2 Mt. Most of the US lime trade was with Canada and Mexico. Despite some disruptions due to hurricanes Katrina and Rita, normal sales activities remained healthy.

Full quantitative phase analysis of hydrated lime using the Rietveld method

Energy Technology Data Exchange (ETDEWEB)

Lassinantti Gualtieri, Magdalena, E-mail: magdalena.gualtieri@unimore.it [Dipartimento Ingegneria dei Materiali e dell' Ambiente, Universita Degli Studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41100 Modena (Italy); Romagnoli, Marcello; Miselli, Paola; Cannio, Maria [Dipartimento Ingegneria dei Materiali e dell' Ambiente, Universita Degli Studi di Modena e Reggio Emilia, Via Vignolese 905/a, I-41100 Modena (Italy); Gualtieri, Alessandro F. [Dipartimento di Scienze della Terra, Universita Degli Studi di Modena e Reggio Emilia, I-41100 Modena (Italy)

2012-09-15

Full quantitative phase analysis (FQPA) using X-ray powder diffraction and Rietveld refinements is a well-established method for the characterization of various hydraulic binders such as Portland cement and hydraulic limes. In this paper, the Rietveld method is applied to hydrated lime, a non-hydraulic traditional binder. The potential presence of an amorphous phase in this material is generally ignored. Both synchrotron radiation and a conventional X-ray source were used for data collection. The applicability of the developed control file for the Rietveld refinements was investigated using samples spiked with glass. The results were cross-checked by other independent methods such as thermal and chemical analyses. The sample microstructure was observed by transmission electron microscopy. It was found that the consistency between the different methods was satisfactory, supporting the validity of FQPA for this material. For the samples studied in this work, the amount of amorphous material was in the range 2-15 wt.%.

Full quantitative phase analysis of hydrated lime using the Rietveld method

International Nuclear Information System (INIS)

Lassinantti Gualtieri, Magdalena; Romagnoli, Marcello; Miselli, Paola; Cannio, Maria; Gualtieri, Alessandro F.

2012-01-01

Full quantitative phase analysis (FQPA) using X-ray powder diffraction and Rietveld refinements is a well-established method for the characterization of various hydraulic binders such as Portland cement and hydraulic limes. In this paper, the Rietveld method is applied to hydrated lime, a non-hydraulic traditional binder. The potential presence of an amorphous phase in this material is generally ignored. Both synchrotron radiation and a conventional X-ray source were used for data collection. The applicability of the developed control file for the Rietveld refinements was investigated using samples spiked with glass. The results were cross-checked by other independent methods such as thermal and chemical analyses. The sample microstructure was observed by transmission electron microscopy. It was found that the consistency between the different methods was satisfactory, supporting the validity of FQPA for this material. For the samples studied in this work, the amount of amorphous material was in the range 2–15 wt.%.

Experimental Study on Feasibility of Non Potable Water with Lime on Properties of Ppc

Science.gov (United States)

Reddy Babu, G.; Madhusudana Reddy, B.; Ramana, N. V.; Sudharshan Reddy, B.

2017-08-01

This research aimed to investigate feasibility of outlet water of water treatment plant and limewater on properties of Portland pozzolana cement (PPC). Twenty water treatment plants were found out in the Bhimavaram municipality region in West Godavari district, Andhra Pradesh, India. Approximately, each plant supplying potable water about 4000 to 5000 L/day. All plants are extracting ground water and treating through Reverse Osmosis (RO) process. At outlet, huge quantity of wasted water is being discharged into side drains in Bhimavaram municipality. One typical treatment plant was selected, and water at outlet was collected and Physical and chemical analysis was carried out as per producer described in APHA. The effect of plant outlet water(POW), lime water(LM), and plant outlet water with lime (POWL) on physical properties i.e., setting times, compressive strength, and flexural strength of Portland pozzolana Cement (PPC) were studied in laboratory and compared same with reference specimens i.e., made with Distilled Water (DW) as mixing water. No significant change was observed in initial and finial setting time in POW, LW, and (POWL) as compared with reference specimens made with distilled water (DW). Compressive strength was significantly increased with LW and (POWL) specimens compared to that of reference specimens. XRD technique was employed to study the mineralogical analysis.

3.7. Technical and economic aspects of the application of cement concretes obtained from local minerals

International Nuclear Information System (INIS)

Saidov, D.Kh.

2011-01-01

This article is devoted to technical and economic aspects of the application of cement concretes obtained from local minerals. The following composite materials obtained from local raw materials were considered: mineral (cement, lime), inorganic (phosphates, sodium silicate), organic (phenol formaldehyde, epoxide, urea-formaldehyde, carbamide, acryl, organosilicon, furfural aniline). It was concluded that from technical and economical points of view the most effective materials were: mineral composite materials, crude shale oils and ligno sulphonates.

The antifungal efficiency of carbide lime slurry compared with the commercial lime efficiency

Science.gov (United States)

Strigac, J.; Mikusinec, J.; Strigacova, J.; Stevulova, N.

2017-10-01

The article deals with studying the antifungal efficiency of carbide lime slurry compared to industrially manufactured commercial lime. Antifungal efficiency expressed as mould proofness properties was tested on the fungi using the procedure given in standard CSN 72 4310. A mixture of fungi Aspergillus niger, Chaetomium globosum, Penicillium funiculosum, Paecilomyces variotii and Gliocladium virens was utilized for testing. The scale for evaluating mould proofness properties according to CSN 72 4310 is from 0 to 5 in degree of fungi growth, where 0 means that no fungi growth occurs and the building products and materials possess fungistatic properties. The study confirms the fungistatic propeties of carbide lime slurry as well as industrially manufactured commercial lime. However, carbide lime slurry and industrially manufactured commercial lime possess no fungicidal effect.

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...

[Review of lime carbon sink.

Science.gov (United States)

Liu, Li Li; Ling, Jiang Hua; Tie, Li; Wang, Jiao Yue; Bing, Long Fei; Xi, Feng Ming

2018-01-01

Under the background of "missing carbon sink" mystery and carbon capture and storage (CCS) technology development, this paper summarized the lime material flow process carbon sink from the lime carbonation principles, impact factors, and lime utilization categories in chemical industry, metallurgy industry, construction industry, and lime kiln ash treatment. The results showed that the lime carbonation rate coefficients were mainly impacted by materials and ambient conditions; the lime carbon sink was mainly in chemical, metallurgy, and construction industries; and current researches focused on the mechanisms and impact factors for carbonation, but their carbon sequestration calculation methods had not been proposed. Therefore, future research should focus on following aspects: to establish a complete system of lime carbon sequestration accounting method in view of material flow; to calculate lime carbon sequestration in both China and the world and explain their offset proportion of CO 2 emission from lime industrial process; to analyze the contribution of lime carbon sequestration to missing carbon sink for clarifying part of missing carbon sinks; to promote the development of carbon capture and storage technology and provide some scientific bases for China's international negotiations on climate change.

Effect of Lime Powder and Metakaolin on Fresh and Hardened Properties of Self Compacting Concrete

Directory of Open Access Journals (Sweden)

Rizwan Ahmad Khan

2016-12-01

Full Text Available This study investigated the fresh and hardened properties of Self-Compacting Concrete (SCC with different types and amounts of admixtures. Six mixes were prepared by replacing 30% of cement with different percentages of fly ash (FA, lime powder (LP and metakaolin (MK. Water- Cement ratio was kept constant at 0.41 and superplasticizer dosage of 1% by weight of cement. The filling and passing ability were investigated through Slump Flow, J-Ring, V-funnel and L-box test before filling the moulds. The compressive strength of hardened SCC cubes was also measured after specified days of curing (7, 14, 28, 60 & 90 days. The workability test results showed that as FA was replaced by increasing percentages of LP and MK, the mixes became dense and hence less workable. It was observed that the compressive strength showed an increase with increasing percentage replacement of FA with LP and MK. This increase was higher for mixes with MK than that of mixes with LP.

Agricultural residues based composites part II: Hydration characteristics of cement- cellulosic fibers composites

International Nuclear Information System (INIS)

Hekal, E.E.; Kishar, E.A.; Abd-El-Khader, A.H.; Ibrahim, A.A.; Mobarak, F.M.

2005-01-01

The aim of this study is the utilization of the local agricultural wastes, such as ice straw bagasse, cotton stalks and linen fibers, which cause a big environmental problem. Different cement-fiber composites were prepared using 1.5, 3, 4.5 and 6% fibers by weight of cement. The lengths of the fibers used were 0.5, 0.8, and 1.25 mm. Hydration of the different, composites was carried out at room temperature for various lime intervals namely, 1.3,7 .28 and 90 days. Combined water contents, compressive strength and phase composition of the different prepared composites were examined

Dolomitic lime containing hydraulic additive

International Nuclear Information System (INIS)

Lagzdina, S.; Sedmalis, U.; Bidermanis, L.; Liepins, J.; Grosvalds, I.

1997-01-01

To obtain qualitative dolomitic lime the optimum calcination temperature of dolomite containing about 9 % of clayey substances is 900 deg C. The mechanical strength of dolomitic lime containing 30 % of brick waste additive after 6-9 months of hardening is 1.4-1.5 times higher than that of samples without hydraulic additive, for calcium lime - 2.2-2.6 times higher. Generally the mechanical strength of dolomitic lime is higher than that one of calcium lime. It can be explained by the active role of MgO in the hydration and hardening processes of dolomitic lime. Xray diffraction phase analysis was performed by X-ray diffractometer DPON-3M with Cu-K α emission filter

Sulfoaluminate-belite cement from low-calcium fly ash and sulfur-rich and other industrial by-products

Energy Technology Data Exchange (ETDEWEB)

Arjunan, P.; Silsbee, M.R.; Roy, D.M.

1999-08-01

The study describes the preparation and characterization of an environmentally friendly cement with performance characteristics similar to those of Portland cement, from a lime kiln bag house dust, a low-calcium fly ash, and a scrubber sludge. Promising preliminary results show the formation of relatively low-temperature phases calcium sulfoaluminate (4CaO{center{underscore}dot}3Al{sub 2}O{sub 3}{center{underscore}dot}SO{sub 3}) and dicalcium silicate (2CaO{center{underscore}dot}SiO{sub 2}) at {approximately} 1,250 C if nodulized raw means used for clinker preparation and at 1,175 C if powdered raw meal is used as compared to the {approximately} 1,500 C sintering temperature required for Portland cement. Phases of the developed cements were predicted using modified Bogue calculations. Isothermal calorimetric measurements indicate the hydration properties of the cements are comparable to ordinary Portland cement. Mechanical properties and microstructural evaluations also were carried out.

Front line of cement technolgy and control. Part 5. ; Baking process and chemical reactions. Cement saisentan sono gijutsu to kanri 5. ; Shosei katei to kagaku hanno

Energy Technology Data Exchange (ETDEWEB)

Hirai, M. (Ube Industries, Ltd., Yamaguchi (Japan))

1990-06-01

The baking process in cement production means the process that the raw materials which were mixed and pulverized in the raw material preparation process are charged into a reaction furnace which is called kiln, and clinders (intermediate product of cement) are generated. It is the process which affects quality as well as production cost of cement more significantly than anything else. In this article, an outline of the above baking facilities, how the raw materials change and clinkers are generated therein, and how they are controlled are introduced. Clinkers are composed of such products as alite, belite, aluminate and ferrite, etc. which were generated after decomposition reactions of such raw materials as lime stone, clay, silica rock and iron oxide in the above kiln. The essential ponts of the process control which makes the generation reactions of clinker compounds efficiently are such two points as well balanced raw materials to be charged into the baking facilities and stable operation of such facilities. The quality of cement which is required as finished goods is achieved by the quality control at each intermediate process and the quality tests of cement. 5 refs., 10 figs., 2 tabs.

Solidification of low-level radioactive wastes in masonry cement

International Nuclear Information System (INIS)

Zhou, H.; Colombo, P.

1987-03-01

Portland cements are widely used as solidification agents for low-level radioactive wastes. However, it is known that boric acid wastes, as generated at pressurized water reactors (PWR's) are difficult to solidify using ordinary portland cements. Waste containing as little as 5 wt % boric acid inhibits the curing of the cement. For this purpose, the suitability of masonry cement was investigated. Masonry cement, in the US consists of 50 wt % slaked lime (CaOH 2 ) and 50 wt % of portland type I cement. Addition of boric acid in molar concentrations equal to or less than the molar concentration of the alkali in the cement eliminates any inhibiting effects. Accordingly, 15 wt % boric acid can be satisfactorily incorporated into masonry cement. The suitability of masonry cement for the solidification of sodium sulfate wastes produced at boiling water reactors (BWR's) was also investigated. It was observed that although sodium sulfate - masonry cement waste forms containing as much as 40 wt % Na 2 SO 4 can be prepared, waste forms with more than 7 wt % sodium sulfate undergo catastrophic failure when exposed to an aqueous environment. It was determined by x-ray diffraction that in the presence of water, the sulfate reacts with hydrated calcium aluminate to form calcium aluminum sulfate hydrate (ettringite). This reaction involves a volume increase resulting in failure of the waste form. Formulation data were identified to maximize volumetric efficiency for the solidification of boric acid and sodium sulfate wastes. Measurement of some of the waste form properties relevant to evaluating the potential for the release of radionuclides to the environment included leachability, compression strengths and chemical interactions between the waste components and masonry cement. 15 refs., 19 figs., 9 tabs

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.

Alumina sludge's Influence on the physicochemical characteristics of CPJ55 cement

Directory of Open Access Journals (Sweden)

Dahhou M.

2018-01-01

Full Text Available Partial replacement of the Portland cement CPJ55 ingredients by various quantities of alumina sludge (AS, produced during drinking water plant sludge, was used in the preparation of mortar mold with dimensions 40×40×160 mm. The characterization of materials is carried out by X-ray fluorescence (XRF, Xray diffraction (XRD, free lime dosing, and the mechanical tests. Analysis of the chemical composition by XRF shows that the studied alumina sludge is mainly composed of aluminum oxide, silica, which is correlated with the principal mineral phases identified in the XRD analysis results. It is demonstrated that adding 5% of the alumina sludge in Portland cement does not affect the mineralogy of final product. Nevertheless, the compression and flexural strength tests (in 28 days conducted on mortar sample comprising 5% sludge elucidate that it belongs to cement mortar class of type 32.5 R.

Effect of a biodegradable natural polymer on the properties of hardened lime-based mortars

International Nuclear Information System (INIS)

Izaguirre, A.; Lanas, J.; Alvarez, J. I.

2011-01-01

As an environmentally friendly and energy-saving alternative to cement-based materials and to some chemically obtained water-reducers, a commercialized starch was incorporated into aerial lime-based matrix. Different dosages were tested in order to study the influence that the amount of additive exerted on the properties of the material. Density, shrinkage, water absorption through capillarity, water vapour permeability, mechanical strengths, porosity, pore size distribution, and durability in the face of freezing-thawing cycles were studied in the mortars. The tested starch acted as a thickener for dosages up to 0.30%, and changed its behaviour for the largest dosage (0.50%): in that case it behaved as a plasticizer, dispersing the lime through the fresh mass and generating a more workable material. As a result, the matrix of the hardened mortar presented great coherence, owing to its large density and low porosity, characteristics which led to lower capillarity and permeability, better mechanical properties and durability. (Author) 46 refs.

The influence of using volcanic ash and lime ash as filler on compressive strength in self compacting concrete

Science.gov (United States)

Karolina, Rahmi; Panatap Simanjuntak, Murydrischy

2018-03-01

Self Compacting Concrete (SCC) is a technology which is developing today in which concrete solidifies by itself without using vibrator. Casting conventional concrete which has a lot of reinforcement bars sometimes finds difficulty in achieving optimal solidity. The method used to solve this problem is by using SCC technology. SCC was made by using filler, volcanic ash, and lime ash as the filling materials so that the concrete became more solid and hollow space could be filled up. The variation of using these two materials was 10%, 15%, 20%, and 25% of the cementitious mass and using 1% of superplasticizer from cementitious material. The supporting testing was done by using the test when the concrete was still fluid and when it was solid. Malleable concrete was tested by using EFNARC 2002 standard in slump flow test, v-funnel test, l-shaped box test, and j-ring test to obtain filling ability and passing ability. In this malleable lime concrete test, there was the decrease, compared with normal SCC concrete without adding volcanic ash and lime ash. Testing was also done in solid concrete in compressive strength, tensile strength, and concrete absorption. The result of the testing showed that the optimum tensile strength in Variation 1, without volcanic ash and lime ash – with 1% of superplasticizer was 39.556 MPa, the optimum tensile strength in Variation 1, without volcanic ash and lime ash- with 1% of super-plasticizer was 3.563 MPa, while the value of optimum absorption which occurred in Variation 5 (25% of volcanic ash + 25% of lime ash + 50% of cement + 1% of superplasticizer) was 1.313%. This was caused by the addition of volcanic ash and lime ash which had high water absorption.

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

Rootstocks for 'Tahiti' lime

Directory of Open Access Journals (Sweden)

Stenzel Neusa Maria Colauto

2004-01-01

Full Text Available The 'Tahiti' lime (Citrus latifolia Tanaka is an important commercial citrus cultivar in Brazil. 'Rangpur' lime has being used as its main rootstock, but it is susceptible to root rot caused by Phytophthora, reducing tree longevity. An experiment was set up in a randomized block design, with three trees per plot of each rootstock and four replicates, and run for 12 years, aiming to compare the performance of 'IAC-5 Tahiti' lime, budded on 'Rangpur' lime (Citrus limonia Osb.; 'C-13' citrange (Citrus sinensis (L. Osb. × Poncirus trifoliata (L. Raf.; 'African' rough lemon (Citrus jambhiri Lush.; 'Volkamer' lemon (Citrus volkameriana Ten. & Pasq.; trifoliate orange (Poncirus trifoliata (L. Raf.; 'Sunki' mandarin (Citrus sunki Hort. ex Tan. and 'Cleopatra' mandarin (Citrus reshni Hort. ex Tan.. Eleven years after the establishment of the orchard, trees with the greatest canopy development were budded on 'C-13' citrange and 'African' rough lemon, and both differed significantly from trees budded on trifoliate orange, 'Sunki' and 'Cleopatra' mandarins, which presented the smallest canopy development. Trees budded on 'Rangpur' lime and 'C-13' citrange had the highest cumulative yields, and were different from trees budded on trifoliate orange, 'Cleopatra' and 'Sunki' mandarins. There was no rootstock effect on mean fruit weight and on the total soluble solid/acid ratio in the juice. The 'Rangpur' lime and the 'Cleopatra' mandarin rootstocks reduced longevity of plants.

A research of the mineralogy phases of clinker in a spanish cement using the method of Rietveld

International Nuclear Information System (INIS)

Castanon Ana M; Garcia Granda Santiago; Guerrero Ana M; Gomez Fernandez Fernando

2012-01-01

In order to introduce continuously a quality control method in a Spanish cement factory to improve the final product feature new research methodology is being developed. The Rietveld method [1] has been successfully used to analyze the composition of the main phases of clinker. Using this methodologies, research has been carried out to quantize appropriately the minor phase of free lime which is extremely important in the clinker quality. This method leads to satisfactory results on samples with contents in CaO from 3%. These results are possible combining X- ray diffraction and fluorescence techniques as well as the chemical analysis data. Clinker, the Rietveld method, free lime.

Improved control of sucrose losses and clarified juice turbidity with lime saccharate in hot lime clarification of sugarcane juice and other comparisons with milk of lime

Science.gov (United States)

A comparative investigation of adding milk of lime (MOL) versus lime saccharate (SACCH) in hot lime clarification of juice at a U.S. sugarcane factory was undertaken to quantify performance across the 2009 processing season after a preliminary factory study in 2008. SACCH was prepared by adding hyd...

Mineral Resource of the Month: Lime

Science.gov (United States)

Corathers, Lisa A.

2015-01-01

Lime is the common term for several chemicals in three major categories: quicklime, hydrated lime and refractory dead-burned dolomite. Lime is almost never found naturally. It is primarily manufactured by burning limestone in kilns, followed by hydration when necessary. 

Arsenic removal by lime softening

DEFF Research Database (Denmark)

Kaosol, T.; Suksaroj, C.; Bregnhøj, Henrik

2002-01-01

This paper focuses on the study of arsenic removal for drinking water by lime softening. The initial arsenic (V) concentration was 500 and 1,000 ug/L in synthetic groundwater. The experiments were performed as batch tests with varying lime dosages and mixing time. For the synthetic groundwater......, arsenic (V) removal increased with increasing lime dosage and mixing time, as well as with the resulting pH. The residual arsenic (V) in all cases was lower than the WHO guideline of 10 ug/L at pH higher than 11.5. Kinetic of arsenic (V) removal can be described by a first-order equation as C1 = C0*e......^-k*t. The relation between the constant (k value) and increasing lime dosage was found to be linear, described by k = 0.0034 (Dlime). The results support a theory from the literature that the arsenic (V) was removed by precipitation af Ca3(AsO4)2. The results obtained in the present study suggest that lime...

Importance of granulometry on phase evolution and phase-to-phase relationships of experimentally burned impure limestones intended for production of hydraulic lime and/or natural cement

Science.gov (United States)

Kozlovcev, Petr; Přikryl, Richard; Přikrylová, Jiřina

2015-04-01

In contrast to modern ordinary Portland cement production from finely ground raw material blends, ancient burning of hydraulic lime was conducted by burning larger pieces of natural raw material. Due to natural variability of raw material composition, exploitation of different beds from even one formation can result the product with significantly different composition and/or properties. Prague basin (Neoproterozoic to pre-Variscan Palaeozoic of the central part of the Bohemian Massif - the so-called Barrandian area, Czech Republic) represents a classical example of the limestone-rich region with long-term history of limestone burning for quick lime and/or various types of hydraulic binders. Due to the fact that burning of natural hydraulic lime has been abandoned in this region at the turn of 19th/20th c., significant gap in knowledge on the behavior of various limestone types and on the influence of minor variance in composition on the quality of burned product is encountered. Moreover, the importance of employment of larger pieces of raw material for burning for the development of proper phase-to-phase relationships (i.e. development of hydraulic phases below sintering temperature at mutual contacts of minerals) has not been examined before. To fill this gap, a representative specimens of major limestone types from the Prague basin have been selected for experimental study: Upper Silurian limestone types (Přídolí and Kopanina Lms.), and Lower Devonian limestones (Radotín, Kotýs, Řeporyje, Dvorce-Prokop, and Zlíchov Lms.). Petrographic character of the experimental material was examined by polarizing microscopy, cathodoluminescence, scanning electron microscopy with an energy dispersive spectrometer (SEM-EDS), and X-ray diffraction (XRD) of insoluble residue. Based on the data from wet silicate analyses, modal composition of studied impure limestones was computed. Experimental raw material was burned in laboratory electric furnace at 1000 and 1200°C for 3

RE-UTILIZATION OF INORGANIC SOLID WASTE (LIME MUD AS FOREST ROAD STABILIZER FROM THE CHEMICAL RECOVERY PROCESS IN KRAFT PULP MILL

Directory of Open Access Journals (Sweden)

Habip Eroğlu

2005-04-01

Full Text Available Waste handling is a concern in all pulp and paper mills. Best available techniques for reducing waste is to minimize the generation of solid waste and/or reuse these materials, wherever practicable. One of the most important solid wastes is lime mud which is generated from the kraft pulping in its chemical recovery process. This paper explores the composition of lime mud resulting from the chemical recovery unite of kraft pulp mill and investigation of this waste for re-using beneficially on sub grade and pavement of forest road as a alternative disposal method. Lime mud obtained from the re-causticising process in SEKA pulp mill that utilizes wheat straw and reed as the principal raw material was supplied with % 47 water content and its chemical and physical characterisations was performed according to standard methods. Dried waste to environmental condition was mixed with certain amount to composite cement for using on pavement and sandy clay, loamy clay and clay soils for enriching forest road sub grade properties. In order to investigate the lime mud addition on pavement and sub grade properties necessary physical tests were performed. As a consequence this study reveals that while waste of lime mud causes environmental and economical problem with conventional disposal techniques and/or abandoning to environment, this waste can be used as good stabilisation materials on forest road sub-grade and pavement without any environmental problem.

Earth mortars and earth-lime renders

Directory of Open Access Journals (Sweden)

Maria Fernandes

2008-01-01

Full Text Available Earth surface coatings play a decorative architectural role, apart from their function as wall protection. In Portuguese vernacular architecture, earth mortars were usually applied on stone masonry, while earth renders and plasters were used on indoors surface coatings. Limestone exists only in certain areas of the country and consequently lime was not easily available everywhere, especially on granite and schist regions where stone masonry was a current building technique. In the central west coast of Portugal, the lime slaking procedure entailed slaking the quicklime mixed with earth (sandy soil, in a pit; the resulting mixture would then be combined in a mortar or plaster. This was also the procedure for manufactured adobes stabilized with lime. Adobe buildings with earth-lime renderings and plasters were also traditional in the same region, using lime putty and lime wash for final coat and decoration. Classic decoration on earth architecture from the 18th-19th century was in many countries a consequence of the François Cointeraux (1740-1830 manuals - Les Cahiers d'Architecture Rurale" (1793 - a French guide for earth architecture and building construction. This manual arrived to Portugal in the beginning of XIX century, but was never translated to Portuguese. References about decoration for earth houses were explained on this manual, as well as procedures about earth-lime renders and ornamentation of earth walls; in fact, these procedures are exactly the same as the ones used in adobe buildings in this Portuguese region. The specific purpose of the present paper is to show some cases of earth mortars, renders and plasters on stone buildings in Portugal and to explain the methods of producing earth-lime renders, and also to show some examples of rendering and coating with earth-lime in Portuguese adobe vernacular architecture.

Ectomycorrhizal activity as affected by soil liming

Energy Technology Data Exchange (ETDEWEB)

Andersson, Solbritt

1996-05-01

Acidification of the forest soils in southern Sweden due to atmospheric deposition has become evident during recent decades. To counteract further acidification, liming of forests in the most affected areas has been proposed. Most forest trees in the temperate and boreal forest ecosystems live in symbiosis with ectomycorrhizal fungi, and their uptake of mineral nutrients from the soil is greatly influenced by the symbiosis. In this thesis effects of liming on ectomycorrhiza have been studied in relation to effects on root colonization, fungal growth and nitrogen uptake. In field experiments the effects of liming on ectomycorrhizal colonization of root tips were variable, possibly due to different soil types and climatic variations. However, a changed mycorrhizal community structure could be detected. Laboratory studies also showed that the substrate may influence the outcome of lime applications; the nutrient status of the substrate had a marked effect on how mycelial growth was affected by liming. Under the experimental conditions used in the studies presented in this thesis, liming reduced the uptake of nitrogen and phosphorus by both mycorrhizal and non-mycorrhizal plants. The amount of extractable nitrogen and phosphorus in the peat was also reduced by liming. The latter could be due to either microbial or chemical immobilization. The lime induced decrease in nitrogen uptake was stronger in non-mycorrhizal plants than in mycorrhizal plants. Thus, the mycorrhizal plants had a higher ability to deal with the negative effects of liming on nitrogen availability. This was not the case for phosphorus. The lime induced decrease in phosphorus uptake was stronger for mycorrhizal plants, and in the highest lime treatment there was no significant difference between the mycorrhizal and the non-mycorrhizal spruce plants. 76 refs, 2 figs, 1 tab

Incorporation of trace elements in Portland cement clinker: Thresholds limits for Cu, Ni, Sn or Zn

International Nuclear Information System (INIS)

Gineys, N.; Aouad, G.; Sorrentino, F.; Damidot, D.

2011-01-01

This paper aims at defining precisely, the threshold limits for several trace elements (Cu, Ni, Sn or Zn) which correspond to the maximum amount that could be incorporated into a standard clinker whilst reaching the limit of solid solution of its four major phases (C 3 S, C 2 S, C 3 A and C 4 AF). These threshold limits were investigated through laboratory synthesised clinkers that were mainly studied by X-ray Diffraction and Scanning Electron Microscopy. The reference clinker was close to a typical Portland clinker (65% C 3 S, 18% C 2 S, 8% C 3 A and 8% C 4 AF). The threshold limits for Cu, Ni, Zn and Sn are quite high with respect to the current contents in clinker and were respectively equal to 0.35, 0.5, 0.7 and 1 wt.%. It appeared that beyond the defined threshold limits, trace elements had different behaviours. Ni was associated with Mg as a magnesium nickel oxide (MgNiO 2 ) and Sn reacted with lime to form a calcium stannate (Ca 2 SnO 4 ). Cu changed the crystallisation process and affected therefore the formation of C 3 S. Indeed a high content of Cu in clinker led to the decomposition of C 3 S into C 2 S and of free lime. Zn, in turn, affected the formation of C 3 A. Ca 6 Zn 3 Al 4 O 15 was formed whilst a tremendous reduction of C 3 A content was identified. The reactivity of cements made with the clinkers at the threshold limits was followed by calorimetry and compressive strength measurements on cement paste. The results revealed that the doped cements were at least as reactive as the reference cement.

Cement and concrete options paper

International Nuclear Information System (INIS)

1999-10-01

Greenhouse gas emissions associated with the production of concrete are projected to increase from 10.5 million tonnes in 1990 to almost 14 million tonnes in 2010. Over half of this amount will be non-energy related emissions of carbon dioxide resulting from the conversion of limestone to lime. According to this report by industry experts, the industry has an excellent record of improving energy efficiency and there are few easy gains remaining. Nevertheless, improvements in energy efficiency and fuel use, increased use of concrete where it can be shown to result in net reduction of GHG emissions, and partial replacement of cement by supplementary cementitious materials that involve no additional generation of GHGs, could yield an approximate reduction in carbon dioxide emissions of nearly seven million tons in 2010. The industry proposes three measures to realise these benefits: (1) encouraging replacement of fossil fuels by otherwise waste material, (2) encouraging increased use of concrete in constructing houses and roads, and (3) encouraging increased use of supplementary cementing materials. The industry is opposed to carbon or energy taxes that increase the cost of doing business, on the grounds that such taxes would adversely affect the industry's competitive position internationally. tabs

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.

Comparative evaluation of aerial lime mortars for architectural conservation

OpenAIRE

Faria, Paulina; Henriques, Fernando M.A.; Rato, Vasco

2008-01-01

Journal of Cultural Heritage 9 (2008) 338-346 International bibliography on conservation usually refers that mortars made with lime putty with long extinction periods behave better than others made with the current dry hydrated limes. In order to evaluate this assess, an experimental study of lime mortars was carried out, using dry hydrated lime and two lime putties. It becomes clear that the use of lime putties with long extinction periods in mortars allow better performances, pa...

Formulation of calcium dialuminate (CaO·2Al2O3 refractory cement from local bauxite

Directory of Open Access Journals (Sweden)

A.B. Tchamba

2015-06-01

Full Text Available Three types of bauxites containing aluminum hydroxide of 58.1% gibbsite and 19.3% boehmite for BX3, 95.5% of gibbsite for BX55 and 84.5% of gibbsite for BX8 were used with lime at 95% of CaO through solid state sintering in one stage to prepare a refractory clinker at 1550 °C. The powder obtained after grinding the clinker showed in the XRD curves the presence of CaO·2Al2O3 and CaO·TiO2 phases in the cement samples. The density of cement powder varied between 2.95 and 3.17 g/cm3 and the specific area of powder obtained after grinding was between 0.72 and 0.85 m2/g. The properties of hydrated cement, W/C = 0.33, after stabilization of cement components for 48 h at 105 °C were showed by XRD, DTA, DTG and SEM (C3AH6, AH3, CA2 and CaO·TiO2. The Young's modulus of the cement made varied between 35.5 and 39.4 GPa, and these Young's moduli were compared to conventional CA14M cement.

Durability of air lime mortar

DEFF Research Database (Denmark)

Nielsen, Anders

2016-01-01

This contribution deals with the physical and chemical reasons why pure air lime mortars used in masonry of burned bricks exposed to outdoor climate have shown to be durable from the Middle Ages to our days. This sounds strange in modern times where pure air lime mortars are regarded as weak...... materials, which are omitted from standards for new masonry buildings, where use of hydraulic binders is prescribed. The reasons for the durability seam to be two: 1. The old mortars have high lime contents. 2. The carbonation process creates a pore structure with a fine pored outer layer and coarser pores...

Modification of Lime Mortars with Synthesized Aluminosilicates

Science.gov (United States)

Loganina, Valentina I.; Sadovnikova, Marija E.; Jezierski, Walery; Małaszkiewicz, Dorota

2017-10-01

The increasing attention for restoration of buildings of historical and architectural importance has increased the interest for lime-based binders, which could be applied for manufacturing repair mortars and plasters compatible with historical heritage. Different additives, admixtures or fibers may be incorporated to improve mechanical and thermal features of such materials. In this study synthesized aluminosilicates (SA) were applied as an additive for lime mortar. The technology of synthesis consisted in the deposition of aluminosilicates from a sodium liquid glass by the aluminum sulphate Al2(SO4)3. The goal of this investigation was developing a new method of aluminosilicates synthesis from a sodium liquid glass and using this new material as a component for a lime mortar. Aluminosilicates were precipitated from the solution of aluminum sulphate Al2(SO)3 and sodium silicate. SA were then used as an additive to calcareous compositions and their influence was tested. Mortars were prepared with commercial air lime and siliceous river sand. Air lime binder was replaced by 5 and 10 wt.% of SA. Calcareous composition specimens were formed at water/lime ratio 1.0. The following analyses were made: grain size distribution of SA, X-ray diffraction analysis (XRD), sorption properties, plastic strength and compressive strength of lime mortars. XRD pattern of the SA shows the presence of thenardite, gibbsite and amorphous phase represented by aggregate of nano-size cristobalite-like crystallites. Application of SA leads to increase of compressive strength after 90 days of hardening by 28% and 53% at SA content 5 and 10% respectively comparing to specimens without this additive. Contents of chemically bound lime in the reference specimens after 28 days of hardening in air-dry conditions was 46.5%, while in specimens modified with SA contained 50.0-55.3% of bound lime depending on filtrate pH. This testifies to high activity of calcareous composition. The new blended lime

27 CFR 9.27 - Lime Kiln Valley.

Science.gov (United States)

2010-04-01

... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Lime Kiln Valley. 9.27... OF THE TREASURY LIQUORS AMERICAN VITICULTURAL AREAS Approved American Viticultural Areas § 9.27 Lime Kiln Valley. (a) Name. The name of the viticultural area described in this section is “Lime Kiln Valley...

Effect of addition of Sikament-R superplasticizer on the hydration characteristics of portland cement pastes

Directory of Open Access Journals (Sweden)

Safaa.M. El Gamal

2012-08-01

Full Text Available The effect of addition of Sikament-R superplasticizer (modified lignosulphonate base on the hydration characteristics of hardened Portland cement pastes were studied at different curing conditions. Four mixtures were prepared using 0, 0.2, 0.4 and 0.6 wt% addition of Sikament-R superplasticizer (SR of cement. These pastes were hydrated under two different conditions; (i normal curing at room temperature; 25 °C up to 90 days periods and (ii hydrothermal curing at a pressure of 8 atm. of saturated steam up to 24 h. The compressive strength, combined water content, free lime content, gel/space ratio and microstructure of hardened cement pastes were studied. The results revealed that addition of SR superplasticizer promote the dispersion of cement particles and interacts with Ca(OH2. The addition of SR superplasticizer exhibits Portland cement better workability during the preparation of pastes. In addition, amore compact structure were obtained leading to higher values of compressive strength for all the hardened hydrated pastes under both normal and hydrothermal curing. The results indicated that the addition of SR superplasticizer to Portland cement does not alter the types of hydration products formed during normal or hydrothermal conditions; only it caused a decrease in the degree of the porosity of the formed pastes.

Wetland vegetation responses to liming an Adirondack watershed

Energy Technology Data Exchange (ETDEWEB)

Mackun, I.R.

1993-01-01

Watershed liming as a long-term mitigation strategy to neutralize lake acidity, from increasing acid deposition, was initiated in North America at Woods Lake in the west central Adirondack region of New York. In October 1989, a dose of 10 MT lime (83.5% CaCO[sub 3]) ha[sup [minus]1] was aerially applied to 48% of the watershed. The wetlands adjacent to Woods Lake showed two distinct community types: one dominated by Chamaedaphne calyculata, and one dominated by graminoids and other herbaceous species. Within two years, liming did not alter the structure of either community type, and changed the cover or frequency of only 6 of 64 individual taxa. Most of these changes occurred in the herbaceous community type. The only strong positive response to liming was a nearly threefold increase in cover of the rhizomatous sedge Cladium mariscoides. The cover of Carex interior and Sphagnum spp. benefited from lime addition, while cover of Drosera intermedia and Muhlenbergia uniflora, and frequency of Hypericum canadense responded negatively to lime. Liming influenced the competitive release of only three taxa, all forbs with small growth forms. The tissue chemistry of foliage and twigs of Myrica gale, Chamaedaphne calyculata, and Carex stricta in the Chamaedaphne calyculata community type clearly illustrated species-specific patterns of nutrient accumulation and allocation both before and after liming. Concentrations of 17 of 20 elements responded to liming, although the responses varied among species and plant parts. Carex foliage was least responsive to liming, and Chamaedaphne twigs were most responsive. Elemental changes in plant tissues will be reflected in litter and many influence long-term nutrient dynamics in the wetland community.

Phytochemical fingerprints of lime honey collected in serbia.

Science.gov (United States)

Gašić, Uroš; Šikoparija, Branko; Tosti, Tomislav; Trifković, Jelena; Milojković-Opsenica, Dušanka; Natić, Maja; Tešić, Živoslav

2014-01-01

Composition of phenolic compounds and the sugar content were determined as the basis for characterization of lime honey from Serbia. Particular attention was given to differences in phytochemical profiles of ripe and unripe lime honey and lime tree nectar. Melissopalynological analysis confirmed domination of Tilia nectar in all analyzed samples. Phenolic acids, abscisic acid, flavonoids, and flavonoid glycosides were determined by means of ultra-HPLC coupled with a hybrid mass spectrometer (UHPLC-OrbiTrap). Sugar content was determined using high-performance anion-exchange chromatography with amperometric detection. Similar phenolic compounds characterized unripe and ripe honeys, while the lime tree nectar profile showed notable differences. Compared to lime tree nectar, a high amount of chrysin, pinocembrin, and galangin were detected in both ripe and unripe lime honey. Fructose and glucose were the major constituents of all investigated samples, and amounts were within the limits established by European Union legislation. Sucrose content in the nectar sample was up to two-fold higher when compared to all honey samples. Isomaltose and gentiobiose with turanose content were different in analyzed production stages of lime honey.

Study of the creep of lime-stabilised zirconia

International Nuclear Information System (INIS)

Saint-Jacques, Robert G.

1971-09-01

This research thesis reports the study of creep of stabilised zirconia containing between 13 and 20 per cent of lime, at temperatures between 1.200 and 1.400 C, and under compression stresses between 500 and 4.000 pounds by square inch. Specimens are polycrystalline with an average grain diameter between 7 and 29 microns. The author notably shows that the creep rate of lime-stabilised zirconia is directly proportional to the applied stress, and that the creep apparent activation energy is close to activation energy of volume self-diffusion of calcium and zirconium in lime-stabilised zirconia. Results of creep tests show that, in the studied conditions, the creep rate is directly proportional to the inverse of the grain average diameter, and this is in compliance with the Gifkins and Snowden theory of creep by sliding at grain boundaries. The author also shows that the creep rate of the lime stabilised zirconia varies with lime content, and reaches a maximum when zirconia contains about 15 per cent of lime. Lower creep rates obtained for higher and lower lime contents are explained [fr

Energy efficiency opportunity guide in the lime industry

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

The lime industry processes limestone, an abundant inorganic mineral, for metallurgical, industrial and chemical, environmental, and construction applications. The energy the industry uses results in greenhouse gas emissions and the Canadian Lime Institute, in collaboration with Natural Resources Canada, sponsored the development of this guidebook which is intended to provide ideas for saving energy in the lime industry. This document is a practical source of information and can be used to develop self-audit and evaluation techniques to monitor energy usage. The report first provides an overview of the lime industry, then presents its energy costs. General energy efficiency methodologies are highlighted and, in conclusion, advice on improving energy efficiency in general and specifically for lime industry operations is given. This guidebook provides useful information for lime industry operators who are trying to improve the energy efficiency of their operations.

Durability Properties of Self Compacting Concrete containing Fly ash, Lime powder and Metakaolin

Directory of Open Access Journals (Sweden)

Rizwan Ahmad Khan

2016-01-01

Full Text Available This paper investigates the durability properties of Self-compacting concrete (SCC, with different amounts of fly ash (FA, lime powder (LP and metakaolin (MK. A total of 6 mixes were prepared that have a constant water-binder ratio (w/b of 0.41 and superplasticizer dosage of 1% by weight of cement. In addition to compressive strength, the durability properties of SCC mixes were determined by means of Initial surface absorption test (ISAT and Capillary suction test. The test results indicated that the durability properties of the mixes appeared to be very dependent on the type and amount of the mineral admixture used; the mixes containing MK were found to have considerably higher permeability resistance. Good co-relation between strength and absorption were achieved.

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)

Recycle of fired phosphogypsum waste product as a cement replacement and its role on the hydration and strength development of pastes

International Nuclear Information System (INIS)

Tantawi, S.H.

2005-01-01

The effect of Partially up to fully substituted of treated phosphogypsum x(PG) for natural gypsum on the physico- mechanical as well as kinetic of hydration of ordinary Portland cement has been discussed . The results show that by increasing PG % the water to cement ratio decreased while the initial and final setting times increased So PG acts as a retarder and water reducer . The retardation effect may be attributed to formation of ettringite layer which formed on the surface of C3A of cement pastes . The chemically combined water, free lime content and bulk density increased with curing time and with PG content for all cement pastes up to 90 days due to increasing of the rate of hydration. The compressive strength increased by increasing of PG % due to formation of anhydrite , changes in major oxides content and reduction of impurities . X-Ray Diffraction, SEM and DTA of some samples have been studied

Corrosion effects on soda lime glass

NARCIS (Netherlands)

Veer, F.A.; Rodichev, Y.M.

2010-01-01

Although soda lime glass is the most common used transparent material in architecture, little is known about the corrosion effects on long term strength and the interaction between corrosion and defects. Extensive testing on soda lime bars under different environmental conditions and different

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

Science.gov (United States)

1965-09-01

the authors: (a) Portland cement mixed with CaSO4 and the dried hydratioQ products of lime and burnt kaolin (Budnikov and Kosuirevu[1 5i); it is...expansive ef- fects are strongly influenced by the amount of mixing water and by the nature of the alu.minous component; that is, kaolin , slag and bauxite...mechanical proper- ties of high-molecular system dispersion ." Colloidal Rev., Acad. Opement Sci. USSR, vol XVII, No. 2 (1955). .MI, 43. Mikhailov, V

Engineering Properties of Bentonite Stabilized with Lime and Phosphogypsum

Directory of Open Access Journals (Sweden)

Kumar Sujeet

2014-12-01

Full Text Available Engineering properties such as compaction, unconfined compressive strength, consistency limits, percentage swell, free swell index, the California bearing ratio and the consolidation of bentonite stabilized with lime and phosphogypsum are presented in this paper. The content of the lime and phosphogypsum varied from 0 to 10 %. The results reveal that the dry unit weight and optimum moisture content of bentonite + 8 % lime increased with the addition of 8 % phosphogypsum. The percentage of swell increased and the free swell index decreased with the addition of 8 % phosphogypsum to the bentonite + 8 % lime mix. The unconfined compressive strength of the bentonite + 8 % lime increased with the addition of 8 % phosphogypsum as well as an increase in the curing period up to 14 days. The liquid limit and plastic limit of the bentonite + 8 % lime increased, whereas the plasticity index remained constant with the addition of 8 % phosphogypsum. The California bearing ratio, modulus of subgrade reaction, and secant modulus increased for the bentonite stabilized with lime and phosphogypsum. The coefficient of the consolidation of the bentonite increased with the addition of 8 % lime and no change with the addition of 8 % phosphogypsum.

First evidence of lime burning in southern Scandinavia: lime kilns found at the royal residence on the west bank of Lake Tissø

DEFF Research Database (Denmark)

Henriksen, Peter Steen; Holst, Sandie

2015-01-01

In connection with investigations of the aristocratic residence at Tissø from the Viking Age, the earliest evidence so far of lime burning in Denmark has been excavated. The excavations unearthed traces of up to five lime kilns which were subsequently dated to the end of the ninth century....... This corresponds well with the dating of the erection of the hall in the third construction phase at Fugledegård. Finds of mud-and-wattle with whitewashing show that the lime was used to whitewash the halls at Tissø in both the Germanic Iron Age and the Viking Age. Analyses of lime from the lime kilns...... and the whitewashed mud-and-wattle demonstrate that the raw material for the lime burning was mainly travertine deposited in spring water, but that bryozoan limestone was also used. The lime kilns were just under 2 m in diameter with stone-built edges, and there are indications that the superstructure may have been...

Lime stabilization of expansive soil from Sergipe - Brazil

Directory of Open Access Journals (Sweden)

Leite Rafaella

2016-01-01

Full Text Available Expansive soils are characterized by volumetric changes caused by variations in moisture. They can cause several damages to civil constructions, especially to lightweight structures, including cracks and fissures. Chemical stabilization through addition of lime is one of the most effective techniques used to treat this type of soil. Due to cationic exchanges, lime can significantly reduce swell potential. This research studied a disturbed sample of expansive soil collected in Nossa Senhora do Socorro – Sergipe, Brazil, through the following laboratory tests: sieve and hydrometer tests, Atterberg Limits, compaction, free swell and swell pressure. All direct and indirect methods mentioned in this paper indicated that the natural soil presented high to very high degree of expansion, which reached approximately 20% of free swell and nearly 200 kPa of swell pressure. In order to evaluate the effect of lime, the same tests were conducted in soil-lime mixtures, using lime contents of 3%, 6% and 9%. The results confirmed the efficiency of lime stabilization. It was noted that, as lime content increased, there was reduction of clay fraction and increment of silt fraction; plasticity index decreased to nearly its half; compaction curve was displaced; and free swell and swell pressure reduced significantly.

Ring Formation in Lime Kilns; Ringbildning i Mesaugnar II

Energy Technology Data Exchange (ETDEWEB)

Dhak, Janice [AaF-Process AB, Stockholm (Sweden)

2003-07-15

The key to a cost efficient and high performance pulp production is low variations in the production level. Despite the fact that all pulp mills always work with improvements to eliminate problems with ring formations, AaF has at several mill seen that the operation of a lime kiln still often is disturbed by ring formation. In 1999 AAF made an extensive investigation of more than 10 lime kilns in Sweden, considering operational data, kiln data and lime chemical analyzes. The result pointed out the importance of how the lime kiln is operated and that dead load and contaminants in the lime was less important. The report suggested that it is the difference in the temperature between the flue gas and the lime that is of importance. There are no quantified process values available that guides for a 'best practice' way to run a lime kiln to avoid ring formation. The goal with this project has been to develop a strategy for operation of a kiln in a way that lowers the risk for ring formation. The results from simulations of a number of lime kilns in this project could not proof that a low difference in the temperature between the flue gas and the lime was the main cause of problems with ring formation and thus it was not possible to quantify the optimal difference to avoid rings. Probably the most important information from the simulations was that it is not the temperature difference in number of degrees that is of importance, rather the fact that the temperature difference in the kalcining zone varies, and time to time reach below the critical level were lime occasionally is cooled down. It can be the case if the temperature profile of the flue gas temporarily changes or if the lime mud temperature profile is changed. The reason for changes in the temperature profile is discussed in the report. The most important factors discussed are: Variations in the energy input e.g. oil and methanol/strong gases in cocombustion. One single fuel is easier to control

Effect of the preparation of lime putties on their properties.

Science.gov (United States)

Navrátilová, Eva; Tihlaříková, Eva; Neděla, Vilém; Rovnaníková, Pavla; Pavlík, Jaroslav

2017-12-08

In the study of lime as the basic component of historical mortars and plasters, four lime putties prepared from various kinds of lime of various granulometry and by various ways of preparation were evaluated. The rheological properties and micro-morphologic changes, growing of calcite crystals, and rate of carbonation were monitored. The lime putty prepared from lump lime achieves the best rheological properties, yield stress 214.7 Pa and plastic viscosity 2.6 Pa·s. The suitability of this lime putty was checked by testing the development of calcium hydroxide and calcite crystals using scanning electron microscopy and environmental scanning electron microscopy. The disordered crystals of calcium hydroxide exhibit better carbonation resulting in the large crystals of calcite; therefore, the mortar prepared from the lump lime has the highest flexural strength and compressive strength 0.8/2.5 MPa, its carbonation is the fastest and exhibits the longest durability. Also, thanks to the micro-morphological characterization of samples in their native state by means of environmental scanning electron microscopy, the new way of lime putty preparation by mixing was proven. The preparation consists in the mechanical crash of the lime particles immediately after hydration. This enables the properties of putty prepared from lump lime to be nearly reached.

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.

2018-06-01

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.

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.

Freeze concentration of lime juice

Directory of Open Access Journals (Sweden)

Ampawan Tansakul

2008-11-01

Full Text Available The main objective of this research was to study the effects of processing conditions, i.e. cooling medium temperature (-6, -12 and -18C and scraper blade rotational speed (50, 100 and 150 rpm on the freeze concentration of lime juice. The initial soluble solid content of lime juice was 7.6 Brix. Results showed that soluble solid content of lime juice increased as cooling medium temperature decreased while scraper blade rotational speed increased. It was also found that the processing condition with -18˚C cooling medium temperature and 150 rpm rotational speed of the scraper blade was the best among all studied conditions, although the loss of the soluble solids with ice crystals during ice separation was relatively high at 35%.

Removal of phosphate from greenhouse wastewater using hydrated lime.

Science.gov (United States)

Dunets, C Siobhan; Zheng, Youbin

2014-01-01

Phosphate (P) contamination in nutrient-laden wastewater is currently a major topic of discussion in the North American greenhouse industry. Precipitation of P as calcium phosphate minerals using hydrated lime could provide a simple, inexpensive method for retrieval. A combination of batch experiments and chemical equilibrium modelling was used to confirm the viability of this P removal method and determine lime addition rates and pH requirements for greenhouse wastewater of varying nutrient compositions. Lime: P ratio (molar ratio of CaMg(OH)₄: PO₄‒P) provided a consistent parameter for estimating lime addition requirements regardless of initial P concentration, with a ratio of 1.5 providing around 99% removal of dissolved P. Optimal P removal occurred when lime addition increased the pH from 8.6 to 9.0, suggesting that pH monitoring during the P removal process could provide a simple method for ensuring consistent adherence to P removal standards. A Visual MINTEQ model, validated using experimental data, provided a means of predicting lime addition and pH requirements as influenced by changes in other parameters of the lime-wastewater system (e.g. calcium concentration, temperature, and initial wastewater pH). Hydrated lime addition did not contribute to the removal of macronutrient elements such as nitrate and ammonium, but did decrease the concentration of some micronutrients. This study provides basic guidance for greenhouse operators to use hydrated lime for phosphate removal from greenhouse wastewater.

Reducing CO2-Emission by using Eco-Cements

Science.gov (United States)

Voit, K.; Bergmeister, K.; Janotka, I.

2012-04-01

CO2 concentration in the air is rising constantly. Globally, cement companies are emitting nearly two billion tonnes/year of CO2 (or around 6 to 7 % of the planet's total CO2 emissions) by producing portland cement clinker. At this pace, by 2025 the cement industry will be emitting CO2 at a rate of 3.5 billion tones/year causing enormous environmental damage (Shi et al., 2011; Janotka et al., 2012). At the dawn of the industrial revolution in the mid-eighteenth century the concentration of CO2 was at a level of ca. 280 ppm. 200 years later at the time of World War II the CO2 level had risen to 310 ppm what results in a rate of increase of 0,15 ppm per year for that period (Shi et al., 2011). In November 2011 the CO2 concentration reached a value of 391 ppm (NOAA Earth System Research Laboratory, 2011), a rise of ca. 81 ppm in 66 years and an increased rate of around 1,2 ppm/year respectively. In the same period cement production in tons of cement has multiplied by a factor of ca. 62 (Kelly & Oss, US Geological Survey, 2010). Thus new CO2-saving eco-cement types are gaining in importance. In these cement types the energy-consuming portland cement clinker is partially replaced by latent hydraulic additives such as blast furnace slag, fly ash or zeolite. These hydraulic additives do not need to be fired in the rotary furnace. They ony need to be pulverized to the required grain size and added to the ground portland cement clinker. Hence energy is saved by skipping the engery-consuming firing process, in addition there is no CO2-degassing as there is in the case of lime burning. Therefore a research project between Austria and Slovakia, funded by the EU (Project ENVIZEO), was initiated in 2010. The main goal of this project is to develop new CEM V eco-types of cements and certificate them for common usage. CEM V is a portland clinker saving cement kind that allows the reduction of clinker to a proportion of 40-64% for CEM V/A and 20-39% for CEM V/B respectively by the

Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars

International Nuclear Information System (INIS)

Manfroi, E.P.; Cheriaf, M.; Rocha, J.C.

2010-01-01

Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

Performance Characteristics of Waste Glass Powder Substituting Portland Cement in Mortar Mixtures

Science.gov (United States)

Kara, P.; Csetényi, L. J.; Borosnyói, A.

2016-04-01

In the present work, soda-lime glass cullet (flint, amber, green) and special glass cullet (soda-alkaline earth-silicate glass coming from low pressure mercury-discharge lamp cullet and incandescent light bulb borosilicate glass waste cullet) were ground into fine powders in a laboratory planetary ball mill for 30 minutes. CEM I 42.5N Portland cement was applied in mortar mixtures, substituted with waste glass powder at levels of 20% and 30%. Characterisation and testing of waste glass powders included fineness by laser diffraction particle size analysis, specific surface area by nitrogen adsorption technique, particle density by pycnometry and chemical analysis by X-ray fluorescence spectrophotometry. Compressive strength, early age shrinkage cracking and drying shrinkage tests, heat of hydration of mortars, temperature of hydration, X-ray diffraction analysis and volume stability tests were performed to observe the influence of waste glass powder substitution for Portland cement on physical and engineering properties of mortar mixtures.

Experimental Research for the Application of Mining Waste in the Trench Cutting Remixing Deep Wall Method

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Yan Chao

2015-01-01

Full Text Available This paper focuses on the use of fly ash (FA or ground granulated blast slag (GGBS and reactive lime blends for cement-stabilized Nanjing clay, comparing them with Portland cement (PC for enhanced technical performance. A range of tests were conducted to investigate the properties of stabilized soils, including macrostrength (UCS, permeability, and microstructure analyses by scanning electron microscopy (SEM. The influence of PC : (FA + lime ratio, PC : (GGBS + lime ratio and curing time was addressed. The UCS and permeability results revealed that PC-FA-lime was more efficient than PC-GGBS-lime as a binder for soil stabilization, with an optimum proportion of PC : (FA + lime = 3 : 7 at 25% binder content, varying with curing time. The microstructure analysis reveals that fly ash mainly changes the pore volume distribution, which ranges between 0.01 μm and 1 μm, and produces more CSH/CASH bonding and fissures due to the secondary hydration and pozzolanic reactions. Based on the favourable results obtained, it can be concluded that the soft soils can be successfully stabilized by the combined action of cement, fly ash, and lime. Since fly ash is much cheaper than cement, the addition of fly ash and lime in cement-soil mix may particularly become attractive and can result in cost reduction of construction.

Simple Analysis of Historical Lime Mortars

Science.gov (United States)

Pires, Joa~o

2015-01-01

A laboratory experiment is described in which a simple characterization of a historical lime mortar is made by the determination of its approximate composition by a gravimetric method. Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD) are also used for the qualitative characterization of the lime mortar components. These…

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.

Comparative study of engineering properties of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7

Science.gov (United States)

Tiecheng, Yan; Xingyuan, Zhang; Hongping, Yang

2018-03-01

This study describes an analytical comparison of the engineering characteristics of two-lime waste tire particle soil and soil with lime/loess ratio of 3:7 using density measurements, results of indoor consolidation tests, and direct shear tests to examine the strength and deformation characteristics. It investigates the engineering performance of collapsible loess treated with waste tire particles and lime. The results indicate that (1) the shear strength of the two-lime waste tire particle soils increases continuously with soil age; and (2) the two-lime waste tire particle soils are light-weight, strong, and low-deformation soils, and can be applied primarily to improve the foundation soil conditions in areas with collapsible loess soils. This could address the problem of used tire disposal, while providing a new method to consider and manage collapsible loess soils.

CEMENT SLURRIES FOR GEOTHERMAL WELLS CEMENTING

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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.

Lime treatment of stabilized leachates

International Nuclear Information System (INIS)

Renou, S.; Poulain, S.; Givaudan, J. G.; Sahut, C.; Moulin, P.

2009-01-01

Reverse Osmosis is the most widely used method for treating municipal solid waste landfill leachates, since it produces a permeate in compliance with reject requirements. However, the efficiency of this process at the industrial scale is limited mainly because of membrane fouling and the high osmotic pressures involved. Although lime precipitation is traditionally used to eliminate the temporary hardness of water by de-carbonation, it has also been shown to be highly efficient in removing humic substances which are known to have strong fouling potential towards membranes. Our objective is to study the lime/leachate physico-chemistry, in order to determine the potential of the lime precipitation as pre-treatment for reverse osmosis. The results show that the lime treatment makes it possible (i) to act efficiently on the inorganic fraction of leachates through a de-carbonation mechanism which entails massive precipitation of the carbonates under the form of CaCO 3 , (ii) to eliminate by co-precipitation the high Molecular Weight (MW) organic macromolecules (≥ 50, 000 g.mol -1 ) such as humic acids, and (iii) to generate a stable residue that can be easily stored at a landfill. The reverse osmosis step will be facilitated through significant reduction of the osmotic pressures and prevention of membrane fouling. (authors)

A Hybrid Multidimensional Approach to Select a Country for Global Cement Plant Location

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Muhammad Khurram Ali

2015-04-01

Full Text Available The globalization and saturated domestic markets force international firms to gradually expand their businesses across the borders to capture potential emerging markets. The decision to select a country for a new cement plant location demands analysis of a large number of factors. It is a multifaceted problem which requires investigation and prioritization of factors in a hierarchical way.This paper uses an FAHP (Fuzzy Analytic Hierarchy Process based procedure proposing a practical framework for solution of the GCPLP (Global Cement Plant Location Problem. It deals with real world ambiguities and handles a broader spectrum of influencing factors. The criteria for selection of a country for a new cement plant installation are prioritized from the FAHP based evaluation made by experts. Different global databases including the World Bank are used for the fuzzy ratings of the alternatives. It has been learnt in this particular problem that cement specific and cost related factors are the most sensitive while legal regulations and economic conditions are relatively less sensitive for the decision makers. Therefore, the countries having strong lime stone reserves, cheaper fuel costs and good internal marketing positions are higher in ranking. The paper concludes with different rankings of the four countries analyzed which assist the strategic managers in making decisions on the basis of mathematically computed results.

A hybrid multidimensional approach to select a country for global cement plant location

International Nuclear Information System (INIS)

Ali, M.K.

2015-01-01

The globalization and saturated domestic markets force international firms to gradually expand their businesses across the borders to capture potential emerging markets. The decision to select a country for a new cement plant location demands analysis of a large number of factors. It is a multifaceted problem which requires investigation and prioritization of factors in a hierarchical way. This paper uses an FAHP (Fuzzy Analytic Hierarchy Process) based procedure proposing a practical framework for solution of the GCPLP (Global Cement Plant Location Problem). It deals with real world ambiguities and handles a broader spectrum of influencing factors. The criteria for selection of a country for a new cement plant installation are prioritized from the FAHP based evaluation made by experts. Different global databases including the World Bank are used for the fuzzy ratings of the alternatives. It has been learnt in this particular problem that cement specific and cost related factors are the most sensitive while legal regulations and economic conditions are relatively less sensitive for the decision makers. Therefore, the countries having strong lime stone reserves, cheaper fuel costs and good internal marketing positions are higher in ranking. The paper concludes with different rankings of the four countries analyzed which assist the strategic managers in making decisions on the basis of mathematically computed results. (author)

Solidification/stabilization of dredged marine sediments for road construction.

Science.gov (United States)

Wang, Dong Xing; Abriak, Nor Edine; Zentar, Rachid; Xu, WeiYa

2012-01-01

Cement/lime-based solidification is an environmentally sound solution for the management of dredged marine sediments, instead of traditional solutions such as immersion. Based on the mineralogical composition and physical characteristics of Dunkirk sediments, the effects of cement and lime are assessed through Atterberg limits, modified Proctor compaction, unconfined compressive strength and indirect tensile strength tests. The variation of Atterberg limits and the improvement in strength are discussed at different binder contents. The potential of sediments solidified with cement or lime for road construction is evaluated through a proposed methodology from two aspects: I-CBR value and material classification. The test results show the feasibility of solidified dredged sediments for beneficial use as a material in road construction. Cement is superior to lime in terms of strength improvement, and adding 6% cement is an economic and reasonable method to stabilize fine sediments.

Improvement of poor subgrade soils using cement kiln dust

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Ahmed Mancy Mosa

2017-12-01

Full Text Available Construction of pavements layers on subgrade with excellent to good properties reduces the thickness of the layers and consequently reduces the initial and maintenance cost of highways and vice versa. However, construction of pavements on poor subgrade is unavoidable due to several constrains. Improvement of subgrade properties using traditional additives such as lime and Portland cement adds supplementary costs. Therefore, using by-products in this domain involves technical, economic, and environmental advantages. Cement kiln dust (CKD is generated in huge quantities as a by-product material in Portland cement plants. Therefore, it can be considered as an excellent alternative in this domain. In Iraq, Portland cement plants generate about 350000 tons of CKD annually which is available for free. Therefore, Iraq can be adopted as a case study. This paper covers using CKD to improve the properties of poor subgrade soils based on series of California Bearing Ration (CBR tests on sets of untreated samples and samples treated with different doses of CKD in combination with different curing periods to investigate their effects on soil properties. The results exhibited that adding 20% of CKD with curing for 14 days increases the CBR value from 3.4% for untreated soil to 48% for treated soil; it, also, decreases the swelling ratio. To determine the effects of using this dose under the mentioned curing period on the designed thicknesses of pavements layers, a case study was adopted. The case study results exhibited that treatment of the subgrade soil by 20% of CKD with curing for 14 days reduces the cost of the pavements by $25.875 per square meter.

Lime in gold and uranium mining

International Nuclear Information System (INIS)

Van Staden, C.M.

1979-01-01

In this article the author discusses the role of lime in gold and uranium extraction and looks more closely at the industry's efforts to improve the environment by vegetation of sand dumps and slimes dams. He then comes to the conclusion that lime has been and still is the most effective, practical and cheapest chemical that can be used in the South African gold and uranium mining industry to settle pulps, protect cyanide solutions, aid the vegetation of dumps and neutralise acidic waters and residues. The gold and uranium industry is very pollution concious, and in South Africa the importance of the role that lime plays in combating air and water pollution cannot be over emphasised

Calcium hydroxide poisoning

Science.gov (United States)

Hydrate - calcium; Lime milk; Slaked lime ... Calcium hydroxide ... These products contain calcium hydroxide: Cement Limewater Many industrial solvents and cleaners (hundreds to thousands of construction products, flooring strippers, brick cleaners, cement ...

Solid recovered fuels in the cement industry with special respect to hazardous waste.

Science.gov (United States)

Thomanetz, Erwin

2012-04-01

Cements with good technical properties have been produced in Europe since the nineteenth century and are now worldwide standardized high-quality mass products with enormous production numbers. The basic component for cement is the so-called clinker which is produced mainly from raw meal (limestone plus clay plus sands) in a rotary kiln with preheater and progressively with integrated calciner, at temperatures up to 1450 °C. This process requires large amounts of fossil fuels and is CO₂-intensive. But most CO₂ is released by lime decomposition during the burning process. In the 1980s the use of alternative fuels began--firstly in the form of used oil and waste tyres and then increasingly by pre-conditioned materials from commercial waste and from high calorific industrial waste (i.e. solid recovered fuel (SRF))--as well as organic hazardous waste materials such as solvents, pre-conditioned with sawdust. Therefore the cement industry is more and more a competitor in the waste-to-energy market--be it for municipal waste or for hazardous waste, especially concerning waste incineration, but also for other co-incineration plants. There are still no binding EU rules identifying which types of SRF or hazardous waste could be incinerated in cement kilns, but there are some well-made country-specific 'positive lists', for example in Switzerland and Austria. Thus, for proper planning in the cement industry as well as in the waste management field, waste disposal routes should be considered properly, in order to avoid surplus capacities on one side and shortage on the other.

Time evolution of pore system in lime - Pozzolana composites

Science.gov (United States)

Doleželová, Magdaléna; Čáchová, Monika; Scheinherrová, Lenka; Keppert, Martin

2017-11-01

The lime - pozzolana mortars and plasters are used in restoration works on building cultural heritage but these materials are also following the trend of energy - efficient solutions in civil engineering. Porosity and pore size distribution is one of crucial parameters influencing engineering properties of porous materials. The pore size distribution of lime based system is changing in time due to chemical processes occurring in the material. The present paper describes time evolution of pore system in lime - pozzolana composites; the obtained results are useful in prediction of performance of lime - pozzolana systems in building structures.

Lime and gypsum application on the wheat crop

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Caires Eduardo Fávero

2002-01-01

Full Text Available Root growth and crop yield can be affected by chemical modifications of the soil profile owing to lime and gypsum applications. A field trial was carried out on a dystrophic Clayey Rhodic Hapludox at Ponta Grossa, PR, Brazil, aiming to evaluate lime (without or with incorporation into the soil and gypsum effects on root growth, mineral nutrition and grain yield of wheat (cv. OR 1. A randomized complete block design was used, with three replications, in a split-plot experiment. Treatments with dolomitic limestone (without lime and 4.5 t ha-1 of lime applied on the surface, in total rate and 1/3 of the requirement per year during 3 years, or incorporated into the soil were applied in July 1998 (main plots and the rates of gypsum (0, 3, 6 and 9 t ha-1 in October 1998 (subplots. Wheat was evaluated in the 2000 winter season. In conditions of water deficit absence, there was no limitation in root growth in depth, for exchangeable Ca of 6 mmol c dm-3. Lime incorporation of lime increased the Mg concentration in the leaves, but wheat yield was not influenced by the correction of soil acidity through liming treatments. Gypsum increased the concentrations of Ca and S in wheat leaves, with significant effects on grain yield. The critical level of S-SO4(2- in the 0-20 cm soil layer, extracted by ammonium acetate 0.5 mol L-1 in acetic acid 0.25 mol L-1, was 25.8 mg dm-3.

Balancing guava nutrition with liming and fertilization

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Amanda Hernandes

2012-12-01

Full Text Available Guava response to liming and fertilization can be monitored by tissue testing. Tissue nutrient signature is often diagnosed against nutrient concentration standards. However, this approach has been criticized for not considering nutrient interactions and to generate numerical biases as a result of data redundancy, scale dependency and non-normal distribution. Techniques of compositional data analysis can control those biases by balancing groups of nutrients, such as those involved in liming and fertilization. The sequentially arranged and orthonormal isometric log ratios (ilr or balances avoid numerical bias inherent to compositional data. The objectives were to relate tissue nutrient balances with the production of "Paluma" guava orchards differentially limed and fertilized, and to adjust the current patterns of nutrient balance with the range of more productive guava trees. It was conducted one experiment of 7-yr of liming and three experiments of 3-yr with N, P and K trials in 'Paluma' orchards on an Oxisol. Plant N, P, K, Ca and Mg were monitored yearly. It was selected the [N, P, K | Ca, Mg], [N, P | K], [N | P] and [Ca | Mg] balances to set apart the effects of liming (Ca-Mg and fertilizers (N-K on macronutrient balances. Liming largely influenced nutrient balances of guava in the Oxisol while fertilization was less influential. The large range of guava yields and nutrient balances allowed defining balance ranges and comparing them with the critical ranges of nutrient concentration values currently used in Brazil and combined into ilr coordinates.

46 CFR 148.04-23 - Unslaked lime in bulk.

Science.gov (United States)

2010-10-01

... 46 Shipping 5 2010-10-01 2010-10-01 false Unslaked lime in bulk. 148.04-23 Section 148.04-23... HAZARDOUS MATERIALS IN BULK Special Additional Requirements for Certain Material § 148.04-23 Unslaked lime in bulk. (a) Unslaked lime in bulk must be transported in unmanned, all steel, double-hulled barges...

Effect of lime concentration on gelatinized maize starch dispersions properties.

Science.gov (United States)

Lobato-Calleros, C; Hernandez-Jaimes, C; Chavez-Esquivel, G; Meraz, M; Sosa, E; Lara, V H; Alvarez-Ramirez, J; Vernon-Carter, E J

2015-04-01

Maize starch was lime-cooked at 92 °C with 0.0-0.40% w/w Ca(OH)2. Optical micrographs showed that lime disrupted the integrity of insoluble remnants (ghosts) and increased the degree of syneresis of the gelatinized starch dispersions (GSD). The particle size distribution was monomodal, shifting to smaller sizes and narrower distributions with increasing lime concentration. X-ray patterns and FTIR spectra showed that crystallinity decreased to a minimum at lime concentration of 0.20% w/w. Lime-treated GSD exhibited thixotropic and viscoelastic behaviour. In the linear viscoelastic region the storage modulus was higher than the loss modulus, but a crossover between these moduli occurred in the non-linear viscoelastic region. The viscoelastic properties decreased with increased lime concentration. The electrochemical properties suggested that the amylopectin-rich remnants and the released amylose contained in the continuous matrix was firstly attacked by calcium ions at low lime levels (<0.20% w/w), disrupting the starch gel microstructure. Copyright © 2014 Elsevier Ltd. All rights reserved.

[Study on Archaeological Lime Powders from Taosi and Yinxu Sites by FTIR].

Science.gov (United States)

Wei, Guo-feng; Zhang, Chen; Chen, Guo-liang; He, Yu-ling; Gao, Jiang-tao; Zhang, Bing-jian

2015-03-01

Archaeological lime powders samples from Taosi and Yinxu sites, natural limestone and experimentally prepared lime mortar were investigated by means of Fourier transform infrared spectrometry (FTIR) to identify the raw material of lime powders from Taosi and Yinxu sites. Results show that ν2/ν4 ratio of calcite resulted from carbonation reaction of man-made lime is around 6.31, which is higher than that of calcite in natural limestone and reflects the difference in the disorder of calcite crystal structure among the natural limestone and prepared lime mortar. With additional grinding, the values of v2 and ν4 in natural limestone and prepared lime mortar decrease. Meanwhile, the trend lines of ν2 versus ν4 for calcite in experimentally prepared lime mortar have a steeper slope when compared to calcite in natural limestone. These imply that ν2/ν4 ratio and the slope of the trend lines of ν2 versus ν4 can be used to determine the archaeological man-made lime. Based on the experiment results, it is possible that the archaeological lime powder from Taosi and Yinxu sites was prepared using man-made lime and the ancient Chinese have mastered the calcining technology of man-made lime in the late Neolithic period about 4 300 years ago.

Effects of corn cob ash on lime stabilized lateritic soil

Science.gov (United States)

Nnochiri, Emeka Segun

2018-03-01

This study assesses the effects of Corn Cob Ash (CCA) on lime-stabilized lateritic soil. Preliminary tests were carried out on the natural soil sample for purpose of identification and classification. Lime being the main stabilizing material was thoroughly mixed with the soil sample to determine the optimum lime requirement of the sample as a basis for evaluating the effects of the CCA. The optimum lime requirement was 10%. The CCA was thereafter added to the lime stabilized soil in varying proportions of 2, 4, 6, 8 and 10%. Unsoaked CBR increased from 83% at 0% CCA to highest value of 94% at 4% CCA. Unconfined Compressive Strength (UCS) values increased from 1123kN/m2 at 0% CCA to highest value of 1180kN/m2 at 4% CCA. It was therefore concluded that CCA can serve as a good complement for lime stabilization in lateritic soil.

PERFORMANCE OF CEMENT MORTARS REPLACED BY GROUND WASTE BRICK IN DIFFERENT AGGRESSIVE CONDITIONS

Directory of Open Access Journals (Sweden)

ILHAMI DEMIR

2011-09-01

Full Text Available This article investigates the sulphate resistance of cement mortars when subjected to different exposure conditions. Cement mortars were prepared using ground waste brick (GWB as a pozzolanic partial replacement for cement at replacement levels of 0%, 2.5%, 5%, 7.5, 10%, 12.5 and 15%. Mortar specimens were stored under three different conditions: continuous curing in lime-saturated tab water (TW, continuous exposure to 5% sodium sulphate solution (SS, and continuous exposure to 5% ammonium nitrate solution (AN, at a temperature of 20 ± 3 ºC, for 7, 28, 90, and 180 days. Prisms with dimensions of 25×25×285 mm, to determine the expansions of the mortar samples; and another set of prisms with dimensions of 40×40×160 mm, were prepared to calculate the compressive strength of the samples. It was determined that the GWB replacement ratios between 2.5% and 10% decreased the 180 days expansion values. The highest compressive strength values were found for the samples with 10% replacement ratio in the TW, SS, and AN conditions for 180 days. The microstructure of the mortars were investigated using scanning electron microscopy (SEM and the Energy dispersive X-ray (EDX.

Soil stabilization 1982

Science.gov (United States)

Barenberg, E. J.; Thompson, M. R.; Tayabji, S. D.; Nussbaum, P. J.; Ciolko, A. T.

Seven papers cover the following areas: design, construction and performance of lime, fly ash, and slag pavement; evaluation of heavily loaded cement stabilized bases; coal refuse and fly ash compositions; potential highway base course materials; lime soil mixture design considerations for soils of southeastern United States; short term active soil property changes caused by injection of lime and fly ash; soil cement for use in stream channel grade stabilization structures; and reaction products of lime treated southeastern soils.

Optimization of lime treatment processes

International Nuclear Information System (INIS)

Zinck, J. M.; Aube, B. C.

2000-01-01

Lime neutralization technology used in the treatment of acid mine drainage and other acidic effluents is discussed. Theoretical studies and laboratory experiments designed to optimize the technology of lime neutralization processes and to improve the cost efficiency of the treatment process are described. Effluent quality, slaking temperature, aeration, solid-liquid separation, sludge production and geochemical stability have been studied experimentally and on site. Results show that through minor modification of the treatment process, costs, sludge volume generated, and metal released to the environment can be significantly reduced. 17 refs., 4 figs

Characteristic Asphalt Concrete Wearing Course (ACWC) Using Variation Lime Filler

Science.gov (United States)

Permana, R. A.; Pramesti, F. P.; Setyawan, A.

2018-03-01

This research use of lime filler Sukaraja expected add durability layers of concrete pavement is asphalt damage caused by the weather and load traffic. This study attempts to know how much value characteristic Marshall on a mixture of concrete asphalt using lime filler. This research uses experimental methods that is with a pilot to get results, thus will look filler utilization lime on construction concrete asphalt variation in filler levels 2 %, 3 %, 4 %.The results showed that the use of lime filler will affect characteristic a mixture of concrete asphalt. The more filler chalk used to increase the value of stability. On the cretaceous filler 2 % value of stability is 1067,04 kg. When lime filler levels added to the levels of filler 4 %, the value of stability increased to 1213,92 kg. The flexibility increased the number of filler as levels lime 2 % to 4 % suggests that are conducted more stiff mix.

Liming as a method to remedy lakes contaminated by radiostrontium

International Nuclear Information System (INIS)

Haakanson, Lars

2003-01-01

This work has identified the characteristics regulating lake sensitivity to 90 Sr-contamination and why certain lakes are likely to respond positively to lake liming (Ca-treatment) and when this would not be a feasible or economic remedial measure to lower 90 Sr-levels in fish. The results demonstrate that liming would work best in (1) small, (2) low-productive, (3) oligohumic, (4) acid lakes with (5) low initial Ca-concentrations. It is important to start the liming as soon as possible after the fallout. The liming model discussed in this work can be used to calculate the changes in lake Ca-concentrations and the duration of the liming. The Sr-model can be used to calculate changes in Sr-levels in water, sediments and fish. At best, these simulations indicate that it is realistic to expect that lake liming can reduce peak levels of 90 Sr in fish by 25-40%

Short-term responses of wetland vegetation after liming of an Adirondack watershed

Energy Technology Data Exchange (ETDEWEB)

Mackun, I.R.; Leopold, D.J.; Raynal, D.J. (State Univ. of New York, Syracuse, NY (United States))

1994-08-01

Watershed liming has been suggested as a long-term mitigation strategy for lake acidity, particularly in areas subject to high levels of acidic deposition. However, virtually no information has been available on the impacts of liming on wetland vegetation. In 1989, 1100 Mg of limestone (83.5% CaCO[sub 3]) were aerially applied to 48% (100 ha) of the Woods Lake watershed in the west-central Adirondack region of New York as part of the first comprehensive watershed liming study in North America. We inventoried wetland vegetation in 1.0-m[sup 2] plots before liming and during the subsequent 2 yr. Within this period liming influenced the cover, frequency, or importance values of only 6 of 64 wetland taxa. The cover of Sphagnum spp. and of the cespitose sedge Carex interior decreased in control relative to limed plots, and cover of the rhizomatous sedge Cladium mariscoides increased nearly threefold in limed areas. These two sedges, which are relatively tall, are characteristic of more calcareous habitats. Cover of the grass Muhlenbergia uniflora, cover and importance were adversely affected or inhibited by lime. It is unclear whether liming directly inhibited the growth of these three small-statured species, or whether the adverse effects of lime were mediated through shifts in competitive interactions with other species. The limited responses that we observed to liming, along with changes that occurred in control plots over the study period, may indicate that in the short term watershed liming was no more of a perturbation than the environmental factors responsible for natural annual variation in wetland communities.

Liming impacts on soils, crops and biodiversity in the UK: A review.

Science.gov (United States)

Holland, J E; Bennett, A E; Newton, A C; White, P J; McKenzie, B M; George, T S; Pakeman, R J; Bailey, J S; Fornara, D A; Hayes, R C

2018-01-01

Fertile soil is fundamental to our ability to achieve food security, but problems with soil degradation (such as acidification) are exacerbated by poor management. Consequently, there is a need to better understand management approaches that deliver multiple ecosystem services from agricultural land. There is global interest in sustainable soil management including the re-evaluation of existing management practices. Liming is a long established practice to ameliorate acidic soils and many liming-induced changes are well understood. For instance, short-term liming impacts are detected on soil biota and in soil biological processes (such as in N cycling where liming can increase N availability for plant uptake). The impacts of liming on soil carbon storage are variable and strongly relate to soil type, land use, climate and multiple management factors. Liming influences all elements in soils and as such there are numerous simultaneous changes to soil processes which in turn affect the plant nutrient uptake; two examples of positive impact for crops are increased P availability and decreased uptake of toxic heavy metals. Soil physical conditions are at least maintained or improved by liming, but the time taken to detect change varies significantly. Arable crops differ in their sensitivity to soil pH and for most crops there is a positive yield response. Liming also introduces implications for the development of different crop diseases and liming management is adjusted according to crop type within a given rotation. Repeated lime applications tend to improve grassland biomass production, although grassland response is variable and indirect as it relates to changes in nutrient availability. Other indicators of liming response in grassland are detected in mineral content and herbage quality which have implications for livestock-based production systems. Ecological studies have shown positive impacts of liming on biodiversity; such as increased earthworm abundance that

Action time effect of lime on its depressive ability for pyrite

Institute of Scientific and Technical Information of China (English)

Tichang Sun

2004-01-01

Two sample groups of bulk concentrates consisting mainly of pyrite and chalcopyrite from Daye and Chenghchao Mines in Hubei Province of China were used to investigate the effect of the action time of lime on its depressive ability for pyrite. The experimental results conducted with different samples and collectors showed that the action time between lime and pyrite markedly influences the depressive ability of lime. The depressive ability of lime increased with the action time increasing. It was also proved that the depressive results obtained at a large lime dosage after a shorter action time are similar to those obtained at a small lime dosage after a longer action time. The increase of depressive ability of lime after a longer action time is because that there are different mechanisms in different action time. The composition on the surface of pyrite acted for different time with lime was studied by using ESCA (Electron Spectroscopic Chemical Analysis). The results showed that iron hydroxide and calcium sulphate formed on the pyrite surface at the presence of lime in the pulp but the amounts of iron hydroxide and calcium sulphate were different at different action time. At the beginning action time the compound formed on the pyrite surface was mainly calcium sulphate and almost no iron hydroxide formed; but with the action time increasing, iron hydroxide formed. The longer the action time, the more iron hydroxide and the less calcium sulphate formed. It was considered that the stronger depressive ability of lime after a longer action time is because more iron hydroxide forms on the pyrite surface.

Experimental investigation and constitutive model for lime mudstone.

Science.gov (United States)

Wang, Junbao; Liu, Xinrong; Zhao, Baoyun; Song, Zhanping; Lai, Jinxing

2016-01-01

In order to investigate the mechanical properties of lime mudstone, conventional triaxial compression tests under different confining pressures (0, 5, 15 and 20 MPa) are performed on lime mudstone samples. The test results show that, from the overall perspective of variation law, the axial peak stress, axial peak strain and elastic modulus of lime mudstone tend to gradually increase with increasing confining pressure. In the range of tested confining pressure, the variations in axial peak stress and elastic modulus with confining pressure can be described with linear functions; while the variation in axial peak strain with confining pressure can be reflected with a power function. To describe the axial stress-strain behavior in failure process of lime mudstone, a new constitutive model is proposed, with the model characteristics analyzed and the parameter determination method put forward. Compared with Wang' model, only one parameter n is added to the new model. The comparison of predicted curves from the model and test data indicates that the new model can preferably simulate the strain softening property of lime mudstone and the axial stress-strain response in rock failure process.

Hydration products of lime-metakaolin pastes at ambient temperature with ageing

Energy Technology Data Exchange (ETDEWEB)

Gameiro, A., E-mail: agameiro@lnec.pt [National Laboratory of Civil Engineering, Materials Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Santos Silva, A., E-mail: ssilva@lnec.pt [National Laboratory of Civil Engineering, Materials Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Veiga, R., E-mail: rveiga@lnec.pt [National Laboratory of Civil Engineering, Buildings Department, Av. do Brasil, 101, 1700 Lisbon (Portugal); Velosa, A., E-mail: avelosa@ua.pt [Department of Civil Engineering, Geobiotec, University of Aveiro, Campus Universitario de Santiago, 3810-193 Aveiro (Portugal)

2012-05-10

Highlights: Black-Right-Pointing-Pointer We study the compounds formed in lime/MK blended pastes and their stability over time. Black-Right-Pointing-Pointer Different mixes of lime/MK pastes show different reaction kinetics during curing time, being the pozzolanic compounds formed directly proportional to the lime by MK replacement. Black-Right-Pointing-Pointer Some pozzolanic products are found to be unstable during the hydration reaction employed in our study. - Abstract: Mortars constituted of lime mixtures with pozzolanic additions have been extensively used in the past for the construction of historic and traditional buildings. This paper presents the results of blended pastes of lime and metakaolin (MK), namely compounds formed and their stability over time. This research is part of an extensive study aiming at the formulation of lime based mortars for restoration purposes. It has been shown for several years that MK has been applied in inorganic binders due to its capacity to react vigorously with calcium hydroxide (CH). In the presence of water originating a series of major hydrated phases, namely tetra calcium aluminate hydrate (C{sub 4}AH{sub 13}), calcium silicates hydrates (CSH) and calcium aluminium silicate hydrates (stratlingite - C{sub 2}ASH{sub 8}). Several blended pastes of lime and MK, with different substitution rates of lime by MK (wt%) were prepared and cured at a temperature of 20 Degree-Sign C and relative humidity RH > 95%. The phase composition of the formed hydrated phases was determined by X-ray diffraction (XRD) and simultaneous thermal analysis (TG-DTA). The obtained results showed that lime/MK pastes compositions displayed different reaction kinetics during curing time, being the pozzolanic products content directly proportional to the substitution rate of lime by MK. Also, a relationship between the increase stratlingite content and the MK substitution rate of lime by MK was found.

Investigation into the use of cement kiln dust in high density sludge (HDS) treatment of acid mine water.

Science.gov (United States)

Mackie, Allison L; Walsh, Margaret E

2015-11-15

The purpose of this study was to investigate the potential to replace lime with cement kiln dust (CKD) in high density sludge (HDS) treatment of acid mine drainage (AMD). The bench-scale study used two water samples: AMD sampled from a lead-zinc mine with high concentrations of iron (Fe), zinc (Zn), and arsenic (As) (Fe/Zn-AMD) and a synthetic AMD solution (Syn-AMD) spiked with ferric sulfate (Fe2(SO4)3). Arsenic was found to be significantly reduced with CKD-HDS treatment of Fe/Zn-AMD compared to lime-HDS treatment, to concentrations below the stringent mine effluent discharge regulation of 0.10 mg As/L (i.e., 0.04 ± 0.02 mg/L). Both CKD- and lime-HDS treatment of the two AMD samples resulted in settled water Fe concentrations above the stringent discharge guideline of 0.3 mg Fe/L. CKD addition in the HDS process also resulted in high settled water turbidity, above typical discharge guidelines of 15 mg TSS/L. CKD-HDS treatment was found to result in significantly improved settled solids (i.e., sludge) quality compared to that generated in the lime-HDS process. HDS treatment with CKD resulted in 25-88% lower sludge volume indices, 2 to 9 times higher % wet solids, and 10 to 20 times higher % dry solids compared to lime addition. XRD and XPS testing indicated that CKD-HDS sludge consisted of mainly CaCO3 and SiO2 with Fe(3+) precipitates attached at particle surfaces. XRD and XPS testing of the lime-HDS generated sludge showed that it consisted of non-crystalline Fe oxides typical of sludge formed from precipitates with a high water concentration. Increased sedimentation rates were also found for CKD (1.3 cm/s) compared to lime (0.3 cm/s). The increased solids loading with CKD addition compared to lime addition in the HDS process was suggested to both promote surface complexation of metal precipitates with insoluble CKD particles and increase compression effects during Type IV sedimentation. These mechanisms collectively contributed to the reduced water content of

Plasticity, Swell-Shrink, and Microstructure of Phosphogypsum Admixed Lime Stabilized Expansive Soil

OpenAIRE

James, Jijo; Pandian, P. Kasinatha

2016-01-01

The study involved utilization of an industrial waste, Phosphogypsum (PG), as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL), optimum lime content (OLC), and less than ICL (LICL), were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil for stabilization. The effect of stabilization was studied by performing index tests, namely, liquid limit, plastic lim...

Towards the industrial solar production of lime

Energy Technology Data Exchange (ETDEWEB)

Meier, A.; Bonaldi, E. [QualiCal SA, Bergamo (Italy); Cella, G.M. [QualiCal SA, Bergamo (Italy); Lipinski, W.; Palumbo, R.; Steinfeld, A. [ETH Zuerich (Switzerland) and PSI; Wieckert, C.; Wuillemin, D.

2002-03-01

A new industrial concept that aims at the development of the chemical engineering technology for the solar production of lime is being examined. To establish the technical feasibility, a 10 kW solar reactor has been designed, constructed, and experimentally tested at a high-flux solar furnace. The quality of the produced solar lime meets industrial standards. (author)

Hydrogen Chloride Reaction with Lime and Limestone

DEFF Research Database (Denmark)

Erik Weinell, Claus; Jensen, Peter I.; Dam-Johansen, Kim

1992-01-01

The capacity of solid slaked lime and limestone for binding HCl from a gas phase has been investigated in the temperature range 60-1000 °C. The binding capacity is largest in the range 500-600 °C. However, for slaked lime in the presence of water, a large binding capacity is observed also below 150...

Identification and stabilization methods for problematic silt soils : a laboratory evaluation of modification and stabilization additives.

Science.gov (United States)

2003-07-01

The instability and pumping response of non-plastic, high silt (and fine sand) soils was investigated. Common reagents, i.e., lime, lime-fly ash, Portland cement, and slag cement were included as admixtures with three high silt (and fine sand) soils....

Effects of Palm Kernel Shell Ash on Lime-Stabilized Lateritic Soil

Science.gov (United States)

Nnochiri, Emeka Segun; Ogundipe, Olumide M.; Oluwatuyi, Opeyemi E.

2017-09-01

The research investigated the effects of palm kernel shell ash (PKSA) on lime-stabilized lateritic soil. Preliminary tests were performed on three soil samples, i.e., L1, L2 and L3 for identification; the results showed that L1 was A-7-6, L2 was A-7-6, and L3 was A-7-6. The optimum amount of lime for each of the soil samples was achieved. The optimum amount for L1 was 10%, for L2, 8% and for L3, 10%; at these values they recorded the lowest plasticity indexes. The further addition of PKSA was performed by varying the amount of PKSA and lime added to each of the soil samples. The addition of 4% PKSA+ 6% lime, the addition of 4% PKSA + 4% lime, and the addition of 4% PKSA + 6% lime increased the California Bearing Ratio (CBR) to the highest values for L1, L2 and L3 from 8.20%. It was concluded that PKSA can be a suitable complement for lime stabilization in lateritic soil.

Origin of C. latifolia and C. aurantiifolia triploid limes: the preferential disomic inheritance of doubled-diploid 'Mexican' lime is consistent with an interploid hybridization hypothesis.

Science.gov (United States)

Rouiss, H; Bakry, F; Froelicher, Y; Navarro, L; Aleza, P; Ollitrault, P

2018-03-05

Two main types of triploid limes are produced worldwide. The 'Tahiti' lime type (Citrus latifolia) is predominant, while the 'Tanepao' type (C. aurantiifolia) is produced to a lesser extent. Both types result from natural interspecific hybridization involving a diploid gamete of C. aurantiifolia 'Mexican' lime type (itself a direct interspecific C. micrantha × C. medica hybrid). The meiotic behaviour of a doubled-diploid 'Mexican' lime, the interspecific micrantha/medica recombination and the resulting diploid gamete structures were analysed to investigate the possibility that 'Tahiti' and 'Tanepao' varieties are derived from natural interploid hybridization. A population of 85 tetraploid hybrids was established between a doubled-diploid clementine and a doubled-diploid 'Mexican' lime and used to infer the genotypes of 'Mexican' lime diploid gametes. Meiotic behaviour was studied through combined segregation analysis of 35 simple sequenbce repeat (SSR) and single nucleotide polymorphismn (SNP) markers covering the nine citrus chromosomes and cytogenetic studies. It was supplemented by pollen viability assessment. Pollen viability of the doubled-diploid Mexican lime (64 %) was much higher than that of the diploid. On average, 65 % of the chromosomes paired as bivalents and 31.4 % as tetravalents. Parental heterozygosity restitution ranged from 83 to 99 %. Disomic inheritance with high preferential pairing values was deduced for three chromosomes. Intermediate inheritances, with disomic trend, were found for five chromosomes, and an intermediate inheritance was observed for one chromosome. The average effective interspecific recombination rate was low (1.2 cM Mb-1). The doubled-diploid 'Mexican' lime had predominantly disomic segregation, producing interspecific diploid gamete structures with high C. medica/C. micrantha heterozygosity, compatible with the phylogenomic structures of triploid C. latifolia and C. aurantiifolia varieties. This disomic trend limits

Elemental analysis of Taiwanese areca nut and limes with INAA

International Nuclear Information System (INIS)

Wei, Y.Y.; Chung, C.

1997-01-01

The popular areca nuts were sampled and their stuffed white and red lime were collected simultaneously from four marketplaces in Taiwan in different growing seasons. Samples of areca nut were treated via homogenizer prior to freeze drying, about 100-150 mg each of the areca nut and lime were packed into PE bag. Samples were irradiated with neutron flux about 10 12 n x cm -2 x s -1 . A total of 17, 18, and 13 elements was analyzed with INAA for white lime, red lime, and areca nut, respectively. The results indicated that Ca have the highest concentration in both limes. Most elements in collected samples have wide range of concentrations among different seasons and marketplaces. It is suggested that the elemental concentration of areca nut and limes exists in divergence originated from various farms in Taiwan. In addition, four elements of Ca, Fe, Mg, and Sc are probably overtaken by persons having chewing habit of areca nut and their effects on oral cancer are discussed. (author)

Using the low-temperature plasma in cement production

International Nuclear Information System (INIS)

Sazonova, N A; Skripnikova, N K

2015-01-01

The calculation of the raw-material mixtures and mineralogical composition of the cement clinkers which are synthezed on their base taking into account the disbalanced crystallization of the melting and glassing under conditions of the low-temperature plasma was performed. The difference of the actual values from the calculated ones is 0.69-3.73%. The composition which is characterized as the saturation coefficient 0,88; the silicate module - 3.34, the alumina module - 2.52 in melting of which the alite in amount 78.7%; 3CaO·SiO 2 - 4%; 3CaO·Al 2 O 3 - 9.8%; 12CaO·7Al 2 O 3 -2.9%; CaO free - 1% formed using the lime-stone from the quarry «Pereval» in the town of Slyudyanka and the clay from the deposit «Maximovski» in Irkutsk Region is considered as the optimal one. The structure of the melted clinker is represented as the metastable minerals of alite in the lamellar form with the dimensions up to (3-20)×(80-400) μm and the ratio of length to width 26.6-133. The elongated crystal form may stipulate the high cement activity based on the melted clinkers, which is 82.7-84.2 MPa. Valid- ing the revealed high activity of the viscous substance was confirmed by the results of the scanning electronic microscopy, X-ray phase analysis, with using of which the quantitative and qualitative analyses of the clinker minerals having the deformed crystalic lattice; were performed the morphology of the minerals in the clinker and cement stone, received on its ground, was studied. (paper)

Red mud addition in the raw meal for the production of Portland cement clinker.

Science.gov (United States)

Tsakiridis, P E; Agatzini-Leonardou, S; Oustadakis, P

2004-12-10

The aim of the present research work was to investigate the possibility of adding red mud, an alkaline leaching waste, which is obtained from bauxite during the Bayer process for alumina production, in the raw meal for the production of Portland cement clinker. For that reason, two samples of raw meals were prepared: one with ordinary raw materials, as a reference sample ((PC)Ref), and another with 3.5% red mud ((PC)R/M). The effect on the reactivity of the raw mix was evaluated on the basis of the unreacted lime content in samples sintered at 1350, 1400 and 1450 degrees C. Subsequently, the clinkers were produced by sintering the two raw meals at 1450 degrees C. The results of chemical and mineralogical analyses as well as the microscopic examination showed that the use of the red mud did not affect the mineralogical characteristics of the so produced Portland cement clinker. Furthermore, both clinkers were tested by determining the grindability, setting time, compressive strength and expansibility. The hydration products were examined by XRD analysis at 2, 7, 28 and 90 days. The results of the physico-mechanical tests showed that the addition of the red mud did not negatively affect the quality of the produced cement.

Manufacture of stabilized phosphogypsum blocks for underwater massives in the Gulf of Gabès

Directory of Open Access Journals (Sweden)

Koubaa Lobna

2014-04-01

Studies show that the treatment of PH in the crushed sand and cement or cement and lime gives the best results in terms of ultrasonic speed and compressive strength. Also, they indicate that the addition of cement and lime can absorb huge amounts of PH (92 %. Resistance obtained is sufficient for possible use blocks of PH made for the construction of massive underwater.

Managing ecosystems without prior knowledge: pathological outcomes of lake liming

Directory of Open Access Journals (Sweden)

David G. Angeler

2017-12-01

Full Text Available Management actions often need to be taken in the absence of ecological information to mitigate the impact of pressing environmental problems. Managers counteracted the detrimental effects of cultural acidification on aquatic ecosystems during the industrial era using liming to salvage biodiversity and ecosystem services. However, historical contingencies, i.e., whether lakes were naturally acidic or degraded because of acidification, were largely unknown and therefore not accounted for in management. It is uncertain whether liming outcomes had a potentially detrimental effect on naturally acidic lakes. Evidence from paleolimnological reconstructions allowed us to analyze community structure in limed acidified and naturally acidic lakes, and acidified and circumneutral references. We analyzed community structure of phytoplankton, zooplankton, macroinvertebrates (littoral, sublittoral, profundal, and fish between 2000 and 2004. Naturally acidic limed lakes formed communities that were not representative of the other lake types. The occurrence of fish species relevant for ecosystem service provisioning (fisheries potential in naturally acidic limed lakes were confounded by biogeographical factors. In addition, sustained changes in water quality were conducive to harmful algal blooms. This highlights a pathological outcome of liming lakes when their naturally acidic conditions are not accounted for. Because liming is an important social-ecological system, sustained ecological change of lakes might incur undesired costs for societies in the long term.

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

Water Utility Lime Sludge Reuse – An Environmental Sorbent ...

Science.gov (United States)

Lime sludge can be used as an environmental sorbent to remove sulfur dioxide (SO2) and acid gases, by the ultra-fine CaCO3 particles, and to sequester mercury and other heavy metals, by the Natural Organic Matter and residual activated carbon. The laboratory experimental set up included a simulated flue gas preparation unit, a lab-scale wet scrubber, and a mercury analyzer system. The influent mercury concentration was based on a range from 22 surveyed power plants. The reactivity of the lime sludge sample for acid neutralization was determined using a method similar to method ASTM C1318-95. Similar experiments were conducted using reagent calcium carbonate and calcium sulfate to obtain baseline data for comparing with the lime sludge test results. The project also evaluated the techno-economic feasibility and sustainable benefits of reusing lime softening sludge. If implemented on a large scale, this transformative approach for recycling waste materials from water treatment utilities at power generation utilities for environmental cleanup can save both water and power utilities millions of dollars. Huge amounts of lime sludge waste, generated from hundreds of water treatment utilities across the U.S., is currently disposed in landfills. This project evaluated a sustainable and economically-attractive approach to the use of lime sludge waste as a valuable resource for power generation utilities.

Effect of gamma radiation on chemical composition and storability of lime RTS

International Nuclear Information System (INIS)

Pandey, S.K.; Bisen, A.; Dwivedi, V.

2008-01-01

In the present investigation, the RTS was irradiated with different doses of gamma radiation to study their effect on chemical composition and storability of lime RTS and vitamin C content only was influenced significantly by 50 Gy gamma radiation during storage (16 days) without adversely affecting the quality of lime fruits, whereas, under control and higher doses of gamma radiation, the quality of lime RTS was deteriorated. The irradiation of lime with 50 Gy gamma radiation may be useful for extending storability of lime of RTS and stabilizing the market demand. (author)

Lime utilization in the laboratory, field, and design of pavement layers : final report.

Science.gov (United States)

2017-01-01

The objective of this study was to review and report the best practices of using lime (i.e., granulated lime, hydrated lime, and slurry lime) to dry soil, in working tables, and in pavement applications. The project also reviewed and documented the i...

Use of Fiber-Reinforced Cements in Masonry Construction and Structural Rehabilitation

Directory of Open Access Journals (Sweden)

Ece Erdogmus

2015-02-01

Full Text Available The use of fiber reinforcement in traditional concrete mixes has been extensively studied and has been slowly finding its regular use in practice. In contrast, opportunities for the use of fibers in masonry applications and structural rehabilitation projects (masonry and concrete structures have not been as deeply investigated, where the base matrix may be a weaker cementitious mixture. This paper will summarize the findings of the author’s research over the past 10 years in these particular applications of fiber reinforced cements (FRC. For masonry, considering both mortar and mortar-unit bond characteristics, a 0.5% volume fraction of micro fibers in type N Portland cement lime mortar appear to be a viable recipe for most masonry joint applications both for clay and concrete units. In general, clay units perform better with high water content fiber reinforced mortar (FRM while concrete masonry units (CMUs perform better with drier mixtures, so 130% and 110% flow rates should be targeted, respectively. For earth block masonry applications, fibers’ benefits are observed in improving local damage and water pressure resistance. The FRC retrofit technique proposed for the rehabilitation of reinforced concrete two-way slabs has exceeded expectations in terms of capacity increase for a relatively low cost in comparison to the common but expensive fiber reinforced polymer applications. For all of these applications of fiber-reinforced cements, further research with larger data pools would lead to further optimization of fiber type, size, and amount.

Influence of lime juice on the severity of sickle cell anemia.

Science.gov (United States)

Adegoke, Samuel Ademola; Shehu, Umar Abdullahi; Mohammed, Lasisi Oluwafemi; Sanusi, Yunusa; Oyelami, Oyeku Akibu

2013-06-01

The pain in sickle cell anemia (SCA) is often triggered by dehydration, acidosis, and fever that are usually due to malaria. Intake of lime juice was recently demonstrated to facilitate clearance of the malaria parasite. It was therefore sought to determine whether regular intake of lime juice will ameliorate crisis, especially recurrent bone pain. In this preliminary, open-labeled, randomized study, the effects of lime juice on the clinical and some laboratory characteristics of children with SCA were tested. Among the 113 children with SCA studied in two hospitals, the 58 receiving lime treatment had lower rates of significant painful episodes than the 55 without lime (37 versus 83 crises in 6 months, and 0.64±0.11 versus 1.51±0.34 average rates per child, plime did not cause any significant side-effect. Regular intake of lime juice may be of great therapeutic and nutritional relevance in children with SCA.

Development of a three-dimensional CFD model for rotary lime kilns

Energy Technology Data Exchange (ETDEWEB)

Lixin Tao; Blom, Roger (FS Dynamics Sweden AB, Goeteborg (Sweden)); Nordgren, Daniel (Innventia, Stockholm (Sweden))

2010-11-15

In the calcium loop of the recovery cycle in a Kraft process of pulp and paper production, rotary lime kilns are used to convert the lime mud, mainly CaCO3, back to quick lime, CaO, for re-use in the causticizing process. The lime kilns are one of the major energy consumption devices for paper and pulp industry. Because of the rising oil price and new emission limits, the pulp mills have been forced to look for alternative fuels for their lime kilns. One interesting alternative to oil, often easily available at pulp mills, is biofuels such as sawdust and bark. However the practical kiln operation often encounters some difficulties because of the uncertainties around the biofuel impact on the lime kiln performance. A deeper understanding of the flame characteristics is required when shifting from oil to biofuels. Fortunately recent advances in modern Computational Fluid Dynamics, CFD, have provided the possibility to study and predict the detailed flame characteristics regarding the lime kiln performance. In this project a three-dimensional CFD model for rotary lime kilns has been developed. To simulate a rotary lime kiln the developed CFD model integrates the three essential sub-models, i.e. the freeboard hot flow model, the lime bed model and the rotating refractory wall model and it is developed based on the modern CFD package: FLUENT which is commercially available on the market. The numerical simulations using the developed CFD model have been performed for three selected kiln operations fired with three different fuel mixtures. The predicted results from the CFD modelling are presented and discussed in order to compare the impacts on the kiln performance due to the different firing conditions. During the development, the lime kiln at the Soedra Cell Moensteraas mill has been used as reference kiln. To validate the CFD model, in-plant measurements were carried out in the Moensteraas lime kiln during an experiment campaign. The results obtained from the

Hygroscopic slaking of lime with steam or humid air. New energy effective lime slaking technology in kraft pulping; Hygroskopisk slaeckning av kalk med aanga eller fuktig luft. Ny energieffektiv teknik foer slaeckning av mesakalk i sulfatmassaindustrin

Energy Technology Data Exchange (ETDEWEB)

Lundqvist, Roland

2005-12-15

Lime stone is widely used in chemical recovery for regeneration of white liquor in kraft pulping. Slaked (hydrated) lime is used to convert (causticize) sodium carbonate into sodium hydroxide, whereby lime mud (calcium carbonate) precipitates from the solution. Lime mud is dried and reburned in a lime kiln, where burned lime (calcium oxide) is formed. The circle is closed when lime is slaked (hydrated) in green liquor in an exotherm reaction. Problems with traditional slaking method is that heat is recovered at low temperatures. With the method described in this report there is potential to increase heat recovery in the causticizing plant. The forecasted method means that lime is slaked with steam or humid air, for example combined with a lime mud drier and a lime kiln. The task has included slaking of burned lime with steam or humid hot air, on purpose to test a specific machine equipment in pilote scale, and to investigate temperatures and hydratization rates able to reach. Also the lime slaked with steam/humid air should be compared with burned lime slaked in green liquor when green liquor is causticized, and to investigate the dewatering properties of formed lime mud. The target group is pulp and paper industry using the kraft process. The tests have been performed at SMA Svenska Mineral AB plant (lime burning) at Sandarne Sweden in years 2004-2005. Hydrated lime of varying slaking rates has been produced at temperatures up to 270 deg C. Caustizicing being performed show that dewatering properties of lime mud formed is quite up to the standard of lime mud from burned lime slaked in green liquor. The apprehension, that the hygroscopic slaked lime should result in lime mud difficult to dewater, has not become true. Important experiences have come out which could be used as a base in further investigations.

Vitrified medical wastes bottom ash in cement clinkerization. Microstructural, hydration and leaching characteristics.

Science.gov (United States)

Papamarkou, S; Christopoulos, D; Tsakiridis, P E; Bartzas, G; Tsakalakis, K

2018-04-19

The present investigation focuses on the utilization of medical wastes incineration bottom ash (MBA), vitrified with soda lime recycled glass (SLRG), as an alternative raw material in cement clinkerization. Bottom ash is recovered from the bottom of the medical wastes incineration chamber, after being cooled down through quenching. It corresponds to 10-15 wt% of the initial medical wastes weight and since it has been classified in the category of hazardous wastes, its safe management has become a major environmental concern worldwide. MBA glasses of various syntheses were initially obtained during the MBA vitrification simultaneously with various amounts of silica scrap (20, 25 and 30 wt% correspondingly). The produced MBA glasses were in turn used for the production of Portland cement clinker, after sintering at 1400 °C, thus substituting traditional raw materials. Both evaluation of vitrification and sintering products was carried out by chemical and mineralogical analyses along with microstructure examination. The final cements were prepared by clinkers co-grinding in a laboratory ball mill with appropriate amounts of gypsum (≈5.0 wt%) and the evaluation of their quality was carried out by determining setting times, standard consistency, expansibility and compressive strength at 2, 7, 28 and 90 days. Finally, the leaching behaviour of the vitrified MBA and hydrated cements, together with the corresponding of the "as received" MBA, was further examined using the standard leaching tests of the Toxicity Characteristic Leaching Procedure (TCLP) and the EN 12457-2. According to the obtained results, the quality of the produced cement clinkers was not affected by the addition of the vitrified MBA in the raw meal, with the trace elements detected in all leachates measured well below the corresponding regulatory limits. Copyright © 2018 Elsevier B.V. All rights reserved.

Effects of experimental acidification on mobilisation of metals from sediments of limed and non-limed lakes

International Nuclear Information System (INIS)

Waellstedt, Teresia; Borg, Hans

2003-01-01

In order to study the influence of pH on the mobilisation of metals from lake sediments, intact sediment cores with overlying water were sampled from one lime treated lake and one acidified lake. The overlying water of two cores from each lake was successively acidified to pH 4.2 over a period of 3 months. In the acid treated samples from the limed lake, the initial concentrations of Al, Cd, Mn, Pb and Zn in the overlying water were generally lower and the final concentrations were higher than in the acid treated samples from the acidified lake. The labile inorganic fraction of Al (Al i ) was increasingly dominating as pH decreased. Redox potential and pH in the sediment indicated that the upper two centimetres were involved in the exchange reactions. The experiment showed that mobilisation of metals from sediments can occur and the results indicated that mobilisation could contribute to increased concentrations of metals in lake water during reacidification of formerly lime treated lakes. - Reacidification leads to mobilisation of metals from lake sediments

Plasticity, Swell-Shrink, and Microstructure of Phosphogypsum Admixed Lime Stabilized Expansive Soil

Directory of Open Access Journals (Sweden)

Jijo James

2016-01-01

Full Text Available The study involved utilization of an industrial waste, Phosphogypsum (PG, as an additive to lime stabilization of an expansive soil. Three lime dosages, namely, initial consumption of lime (ICL, optimum lime content (OLC, and less than ICL (LICL, were identified for the soil under study for stabilizing the soil. Along with lime, varying doses of PG were added to the soil for stabilization. The effect of stabilization was studied by performing index tests, namely, liquid limit, plastic limit, shrinkage limit, and free swell test, on pulverized remains of failed unconfined compression test specimens. The samples were also subjected to a microstructural study by means of scanning electron microscope. Addition of PG to lime resulted in improvement in the plasticity and swell-shrink characteristics. The microstructural study revealed the formation of a dense compact mass of stabilized soil.

Kaffir lime leaves extract inhibits biofilm formation by Streptococcus mutans.

Science.gov (United States)

Kooltheat, Nateelak; Kamuthachad, Ludthawun; Anthapanya, Methinee; Samakchan, Natthapon; Sranujit, Rungnapa Pankla; Potup, Pachuen; Ferrante, Antonio; Usuwanthim, Kanchana

2016-04-01

Although kaffir lime has been reported to exhibit antioxidant and antileukemic activity, little is known about the antimicrobial effect of kaffir lime extract. Because Streptococcus mutans has been known to cause biofilm formation, it has been considered the most important causative pathogen of dental caries. Thus, the effective control of its effects on the oral biofilm is the key to the prevention of dental caries. The aims of the present study were to investigate the effect of kaffir lime leaves extract on biofilm formation and its antibacterial activity on S. mutans. We examined the effect of kaffir lime leaves extract on growth and biofilm formation of S. mutans. For the investigation we used a kaffir lime extract with high phenolic content. The minimum inhibitory concentration of the extract was determined by broth microdilution assay. The inhibitory effect of the test substances on biofilm formation was also investigated by biofilm formation assay and qRT-PCR of biofilm formation-associated genes. Kaffir lime leaves extract inhibits the growth of S. mutans, corresponding to the activity of an antibiotic, ampicillin. Formation of biofilm by S. mutans was also inhibited by the extract. These results were confirmed by the down-regulation of genes associated with the biofilm formation. The findings highlight the ability of kaffir lime leaves extract to inhibit S. mutans activity, which may be beneficial in the prevention of biofilm formation on dental surface, reducing dental plaque and decreasing the chance of dental carries. Copyright © 2016 Elsevier Inc. All rights reserved.

Liming the acid lake Hovvatn, Norway: a whole-ecosystem study

Energy Technology Data Exchange (ETDEWEB)

Raddum, G G; Brettum, P; Matzow, D; Nilssen, J P; Skov, A; Sveaelv, T; Wright, R F

1986-12-01

Hovvatn, a 1 sq. km. chronically-acidified lake in southernmost Norway, was treated with 200 tonne of powdered limestone in March 1981. An additional 40 tonne were added to a 0.046 sq km pond (Pollen) draining into Hovvatn. The lakes were stocked with brown trout in June 1981 and in each subsequent year. At ice-out pH rose from 4.4 to 6.3 (Hovvatn) and 7.5 (Pollen), Ca and alkalinity increased, and total Al decreased by 120 ..mu..g/l. None of the other major ions exhibited significant changes in concentration. Total organic C and P increased after liming. The phytoplankton community was dominated by chrysophytes and did not change significantly following liming. The zooplankton community was typical of acid lakes prior to liming. There was a clear succession in species dominance following treatment, although no new species immigrated to the lakes. Zoobenthos changed from a community characterized by low abundance and reduced number of species to increased abundance of oligochaetes, mayflies and chironomids. Hovvatn and Pollen were barren of fish prior to stocking. The stocked fish showed remarkably high growth rate during the first years. Liming apparently improved conditions for zoobenthos, enhancing the processing of fine detritus which in turn resulted in elevated levels of TOC and P in the lakewaters during the first year after liming. The oligotrophication process typical of acid lakes was temporarily reversed by liming. The interactions between groups of organisms in Hovvatn and Pollen indicates that many years are required before a new steady-state can be attained following liming. 61 references.

A research of the mineralogy phases of clinker in a spanish cement using the method of Rietveld

International Nuclear Information System (INIS)

Castanon, Ana M; Garcia, Granda Santiago; Guerrero, Ana M; Gomez Fernandez, Fernando

2012-01-01

In order to introduce continuously a quality control method in a Spanish cement factory to improve the final product feature new research methodology is being developed. The Rietveld method [1] has been successfully used to analyze the composition of the main phases of clinker. Using this methodologies, research has been carried out to quantize appropriately the minor phase of free lime which is extremely important in the clinker quality. This method leads to satisfactory results on samples with contents in CaO from 3%. These results are possible combining X- ray diffraction and fluorescence techniques as well as the chemical analysis data.

Hygroscopic slaking of lime with steam or humid air. New energy effective lime slaking technology in kraft pulping; Hygroskopisk slaeckning av kalk med aanga eller fuktig luft. Ny energieffektiv teknik foer slaeckning av mesakalk i sulfatmassaindustrin

Energy Technology Data Exchange (ETDEWEB)

Lundqvist, Roland

2003-07-15

Lime stone is widely used in chemical recovery for regeneration of white liquor in kraft pulping. Slaked (hydrated) lime is used to convert (causticize) sodium carbonate into sodium hydroxide, whereby lime mud (calcium carbonate) precipitates from the solution. Lime mud is dried and reburned in a lime kiln, where burned lime (calcium oxide) is formed. The circle is closed when lime is slaked (hydrated) in green liquor in an exotherm reaction. Problems with traditional slaking method is that heat is recovered at low temperatures. With the method described in this report there is potential to increase heat recovery in the causticizing plant. The forecasted method means that lime is slaked with steam or humid air, for example combined with a lime mud drier and a lime kiln. The task has included slaking of burned lime with steam or humid hot air, on purpose to test a specific machine equipment in pilote scale, and to investigate temperatures and hydratization rates able to reach. Also the lime slaked with steam/humid air should be compared with burned lime slaked in green liquor when green liquor is causticized, and to investigate the dewatering properties of formed lime mud. The target group is pulp and paper industry using the kraft process. The tests have been performed at SMA Svenska Mineral AB plant (lime burning) at Sandarne Sweden in years 2004-2005. Project owner has been the Swedish company Torkapparater AB, and the project is performed inside the 'Vaermeforsk Program for Pulp and Paper Industry 2004-2005'. Other partners, besides SMA Svenska Mineral AB, has been Stora Enso Skoghalls Bruk, Carnot AB, AaF Process AB and KTH Energiprocesser. Hydrated lime of varying slaking rates has been produced at temperatures up to 270 deg C. Caustizicing being performed show that dewatering properties of lime mud formed is quite up to the standard of lime mud from burned lime slaked in green liquor. The apprehension, that the hygroscopic slaked lime should result

Steam slaking of lime - kinetics and technology. New energy effective lime slaking technology in kraft pulping; Aangslaeckning av kalk - kinetik och teknik. Ny energieffektiv teknik foer slaeckning av mesakalk i sulfatmassaindustrin

Energy Technology Data Exchange (ETDEWEB)

Lundqvist, Roland

2008-06-15

Lime stone is widely used in chemical recovery for regeneration of white liquor in kraft pulping. Slaked (hydrated) lime is used to convert (causticize) sodium carbonate into sodium hydroxide, whereby lime mud (calcium carbonate) precipitates from the solution. Lime mud is dried and reburned in a lime kiln, where burned lime (calcium oxide) is formed. The circle is closed when lime is slaked (hydrated) in green liquor in an exotherm reaction. Problems with traditional lime burning and slaking methods are that heat recovery is bad and heat is recovered at low temperatures. With the method described in this report there is potential to increase heat recovery in the causticizing plant, and to recover heat at higher temperatures. The forecasted method means that lime is slaked with water vapour, for example combined with an indirect heated lime mud drier and a lime kiln. This project is a follow-up to pilot tests performed in a specific machine equipment at year 2006. The target group is pulp and paper industry using the kraft process. The owner of this new project is Carnot AB and the project is performed inside the Vaermeforsk Program for Pulp and Paper Industry 2006-2008. Partners and advisers in project group have been KTH Energy Processes, CTH Energy and Environment, LTH Chemical Technology, SMA Mineral AB, and reference group from STORA Enso Skoghall, Sodra Cell, M-Real Husum and SCA Packaging Piteaa. The task in this stage has included market investigations and laboratory tests. Contacts have been made with suppliers, preliminary dimensioning of process equipment and budget offers are received. Economic calculations have been made out of the offers. The laboratory tests are done as an examination paper at KTH Energiprocesser on the reactivity of burned lime from kraft lime kiln when it is slaked with water vapour instead of green liquor. The vapour intended to be used is at atmospheric pressure or even down to 0,2 atm. Complementary addition to these laboratory

Acid-base properties of a limed pyritic overburden during simulated weathering

Energy Technology Data Exchange (ETDEWEB)

Doolittle, J.J.; Hossner, L.R. [South Dakota State University, Brookings, SD (United States). Plant Science Dept.

1997-11-01

Surface-mine reclamation is often hindered by the formation of acid mine soil and acid mine drainage from FeS{sub 2} oxidation. Surface soils containing FeS{sub 2} are often treated with crushed limestone (predominately CaCO{sub 3}) to prevent aid minesoil formation. The main objective of this study was to evaluate the long-term effectiveness of liming pyritic minesoil to prevent the formation of acid minesoil and acid mine drainage. Pyritic minesoils that did not receive lime became acidic very rapidly and produced acidic leachate. Almost all of the FeS{sub 2} in this treatment oxidized during the first 200 d. The addition of lime at a rate of 25% of the theoretical acid-base account (ABA) significantly slowed FeS{sub 2} oxidation, but rapid oxidation ensued after the added lime was neutralized. Treatments receiving a liming rate of 50% ABA or greater remained neutral to alkaline throughout the study. Acid-base values and residual FeS{sub 2}-CO{sub 3} data, however, indicate that the lime was dissolving from the system faster than the FeS{sub 2} was oxidizing, and all the treatments would eventually become acidic. The results indicate that the liming of a pyritic overburden to an ABA of 125% is not a sustainable solution to preventing acid minesoil and acid mine drainage. 25 refs., 6 figs., 3 tabs.

Stabilization of expansive soil using bagasse ash & lime | Wubshet ...

African Journals Online (AJOL)

7-5 soil on the AASHTO classification was stabilized using 3% lime, 15% bagasse ash and 15% bagasse ash in combination with 3% lime by dry weight of the soil. The effect of the additives on the soil was investigated with respect to plastcity, ...

Soil Stabilization with Lime for the Construction of Forest Roads

Directory of Open Access Journals (Sweden)

Reginaldo Sérgio Pereira

2018-02-01

Full Text Available ABSTRACT The mechanical performance of soil stabilization using lime to improve forest roads was assessed. This study was conducted with lateritic soil (LVAd30 using lime content of 2% in the municipality of Niquelândia, Goiás state, Brazil. Geotechnical tests of soil characterization, compaction, and mechanical strength were performed applying different compaction efforts and curing periods. The results showed that lime content significantly changed the mechanical performance of natural soil, increasing its mechanical strength and load-carrying capacity. Compaction effort and curing time provided different responses in the unconfined compressive strength (UCS and California Bearing Ratio (CBR tests. The best UCS value (786.59 kPa for the soil-lime mixture was achieved with modified compaction effort and curing time of 28 days. In the CBR test, soil-lime mixtures compacted at intermediate and modified efforts and cured for 28 days were considered for application as subbase material of flexible road pavements, being a promising alternative for use in layers of forest roads.

LIME EFFECTIVENESS OF SOME FERTILIZERS IN A TROPICAL ACID ALFISOL

Directory of Open Access Journals (Sweden)

Mercy Omogbohu Anetor

2007-11-01

Full Text Available Liming increases production costs and environmentally unfriendly. Effectiveness of crystalliser (CRYS, single super phosphate (SSP and organic fertilizer (OF for liming was evaluated by determining pH and phosphorus- (P- availability in an acid alfisol incubated with the amendments, Ca(OH2 being reference. Treatments were replicated thrice in completely randomised design. Un-amended soil remained acidic (pH 4.8 but liming raised pH (6.1-6.6, enhancing maximum (15.09-17.33 mg kg-1 P–release (un-amended having 4.24-7.09 mg P kg-1. Lime (L and L+P treatments resulted in maximum pH increases (7.0-7.2, decreasing with incubation. Fertilizer treatments also raised pH (5.0-5.5 for OF, CRYS or SSP; 5.6-5.8 for CRYS +SSP, CRYS+OF and OF+SSP relative to control (5.2. Acid soil infertility-ameliorating potential of CRYS and OF was revealed. They could be used multi-purposely as lime and P fertilizers by poor-resource farmers challenged by acid soil infertility factors.

Lime treatment of liquid waste containing heavy metals, radionuclides and organics

International Nuclear Information System (INIS)

DuPont, A.

1990-01-01

This paper reports on lime treatment of liquid waste containing heavy metals, radio nuclides and organics. Lime is wellknown for its use in softening drinking water the treatment of municipal wastewaters. It is becoming important in the treatment of industrial wastewater and liquid inorganic hazardous waste; however, there are many questions regarding the use of lime for the treatment of liquid hazardous waste

A modified PMMA cement (Sub-cement) for accelerated fatigue testing of cemented implant constructs using cadaveric bone.

Science.gov (United States)

Race, Amos; Miller, Mark A; Mann, Kenneth A

2008-10-20

Pre-clinical screening of cemented implant systems could be improved by modeling the longer-term response of the implant/cement/bone construct to cyclic loading. We formulated bone cement with degraded fatigue fracture properties (Sub-cement) such that long-term fatigue could be simulated in short-term cadaver tests. Sub-cement was made by adding a chain-transfer agent to standard polymethylmethacrylate (PMMA) cement. This reduced the molecular weight of the inter-bead matrix without changing reaction-rate or handling characteristics. Static mechanical properties were approximately equivalent to normal cement. Over a physiologically reasonable range of stress-intensity factor, fatigue crack propagation rates for Sub-cement were higher by a factor of 25+/-19. When tested in a simplified 2 1/2-D physical model of a stem-cement-bone system, crack growth from the stem was accelerated by a factor of 100. Sub-cement accelerated both crack initiation and growth rate. Sub-cement is now being evaluated in full stem/cement/femur models.

[Effects of Lime on Seedling Growth,Yield and Volatile Constituents of Atractylodes lancea].

Science.gov (United States)

Zhang, Yan; Miki, Sakurai; Chen, Mei-lan; Takeda, Xiuji; Zhao, Dong-yue; Kang, Li-ping; Guo, Lan-ping

2015-03-01

To investigate the effects of different amounts of lime on yield and quality of Atractylodes lancea, and to provide reference for the herb growing site soil improvement and self-poisoning ease. Add different gradients of lime, and then measure their growth targets, yield and four kinds of volatile constituents content(hinesol, atractylone, β-eudesmol and atractylodin). Volatile constituents yield per plant was calculated. Adding 160 g/m2 lime had a significant role in promoting the growth and yield of herb; Adding 80 g/m2 lime was conducive to the volatile constituents production, and adding lime decreased the atractylone and atractylodin content, while increased the hinesol and β-eudesmol content; Adding 160 g/m2 lime promoted the volatile constituents yield per plant. Adding lime plays a role of neutralize soil pH, antibacteria and prevention incognita, and has a certain degree of ease autotoxicity and obstacle,and then promotes the yield and volatile constituents production of Atractylodes lancea.

Lime helps establish crownvetch on coal-breaker refuse

Science.gov (United States)

Miroslaw M. Czapowskyj; Edward A. Sowa

1976-01-01

A study was begun in 1965 to determine the effect of lime fertilizer, and mulch on the establishment and growth of crownvetch crowns planted on anthracite coal-breaker refuse. After 7 years the lime application had by far the strongest effect. Both 2.5 and 5.0 tons per acre increased survival and ground cover manyfold, and both treatments were equally beneficial from...

Models for predicting the mass of lime fruits by some engineering properties.

Science.gov (United States)

Miraei Ashtiani, Seyed-Hassan; Baradaran Motie, Jalal; Emadi, Bagher; Aghkhani, Mohammad-Hosein

2014-11-01

Grading fruits based on mass is important in packaging and reduces the waste, also increases the marketing value of agricultural produce. The aim of this study was mass modeling of two major cultivars of Iranian limes based on engineering attributes. Models were classified into three: 1-Single and multiple variable regressions of lime mass and dimensional characteristics. 2-Single and multiple variable regressions of lime mass and projected areas. 3-Single regression of lime mass based on its actual volume and calculated volume assumed as ellipsoid and prolate spheroid shapes. All properties considered in the current study were found to be statistically significant (ρ lime based on minor diameter and first projected area are the most appropriate models in the first and the second classifications, respectively. In third classification, the best model was obtained on the basis of the prolate spheroid volume. It was finally concluded that the suitable grading system of lime mass is based on prolate spheroid volume.

Chemical Modification of Uniform Soils and Soils with High/Low Plasticity Index

OpenAIRE

Li, Xuanchi; Tao, Fei; Bobet, Antonio

2015-01-01

Lime and/or cement are used to treat weak subgrade soils during construction of highways. These chemicals are mixed with the soil to improve its workability, compactability and engineering properties. INDOT (Indiana Department of Transportation) has been using chemical modification of native soils for the past 20 years. In fact, 90% of current subgrade is treated, typically with quick lime, lime byproducts or cement. For pavement design, it is customary to not include any improvement of the s...

Characterization of historic lime mortars by neutron scattering and mercury porosimetry

International Nuclear Information System (INIS)

Zouridakis, N.; Stefanopoulos, K.L.; Treimer, W.

1999-01-01

Complete text of publication follows. Lime mortars were commonly used in building from ancient Greek times through to the beginning of the nineteenth century [1]. In the past few years, the increased interest in conservation and restoration of historic monuments requires a better knowledge of the structure and composition of lime mortars resulting from the various additives, as well as the preparation technique each time used. Lime mortars from ancient Greek monuments have been dated by using the radiocarbon method [2]. Furthermore, a wide selection of lime mortars from known historic periods and monuments in Greece has been examined by mercury porosimetry. It was found that their structure depends on the utilization of the monument which come from. In specific, lime mortars coming from residences have more or less the same structure, whereas the preparation technique differs for lime mortars coming from tombs and walls. The weathering effects on the porous system of the mortars are studied by neutron scattering. (author) [1] Brown, P.W., and Clifton, J.R., 'Air pollution and conservation', eds. J. Roswall and S. Aleby, 225 (1988), Elsevier, Amsterdam.; [2] N. Zouridakis, J.F. Sliege, A. Person et al., Archaeometry, 60 (1987) 29

Suitability of a lime source high in manganese as a feed ingredient ...

African Journals Online (AJOL)

plasma enzyme levels, mineral concentrations in plasma, faeces and kidneys, mineral content of livers, haematology, hislopathol- ogy of livers and kidneys and bone measurements.It is concluded that the Ouplaas lime, .... Table 1 Mineral composition of the pure lime sources (dry basis). Lime sources. Na. (vo). Mg. (vo). K.

Phylogenetic origin of limes and lemons revealed by cytoplasmic and nuclear markers.

Science.gov (United States)

Curk, Franck; Ollitrault, Frédérique; Garcia-Lor, Andres; Luro, François; Navarro, Luis; Ollitrault, Patrick

2016-04-01

The origin of limes and lemons has been a source of conflicting taxonomic opinions. Biochemical studies, numerical taxonomy and recent molecular studies suggested that cultivated Citrus species result from interspecific hybridization between four basic taxa (C. reticulata,C. maxima,C. medica and C. micrantha). However, the origin of most lemons and limes remains controversial or unknown. The aim of this study was to perform extended analyses of the diversity, genetic structure and origin of limes and lemons. The study was based on 133 Citrus accessions. It combined maternal phylogeny studies based on mitochondrial and chloroplastic markers, and nuclear structure analysis based on the evaluation of ploidy level and the use of 123 markers, including 73 basic taxa diagnostic single nucleotide polymorphism (SNP) and indel markers. The lime and lemon horticultural group appears to be highly polymorphic, with diploid, triploid and tetraploid varieties, and to result from many independent reticulation events which defined the sub-groups. Maternal phylogeny involves four cytoplasmic types out of the six encountered in the Citrus genus. All lime and lemon accessions were highly heterozygous, with interspecific admixture of two, three and even the four ancestral taxa genomes. Molecular polymorphism between varieties of the same sub-group was very low. Citrus medica contributed to all limes and lemons and was the direct male parent for the main sub-groups in combination with C. micrantha or close papeda species (for C. aurata, C. excelsa, C. macrophylla and C. aurantifolia--'Mexican' lime types of Tanaka's taxa), C. reticulata(for C. limonia, C. karna and C. jambhiri varieties of Tanaka's taxa, including popular citrus rootstocks such as 'Rangpur' lime, 'Volkamer' and 'Rough' lemons), C. aurantium (for C. limetta and C. limon--yellow lemon types--varieties of Tanaka's taxa) or the C. maxima × C. reticulate hybrid (for C. limettioides--'Palestine sweet' lime types--and C

Liming of acid tropical soils: practice, prospects and constraints ...

African Journals Online (AJOL)

But the incidental inclusion of liming materials in fertilizers has not been effective and sustainable due to the intensive land use activities, constant application of acid-forming chemical fertilizers, leaching losses of bases and crop removal. Liming materials themselves vary in their calcium and magnesium contents and ...

Incorporation of turmeric-lime mixture during the preparation of ...

African Journals Online (AJOL)

GREGO

2007-03-19

Mar 19, 2007 ... behaviour) of 2 min-blanched samples (both treated and control) were the maximum among other corresponding puree samples. Thus, 2 min blanching time may be preferred for the preparation of this new type of turmeric-lime treated tomato puree product. Key words: Turmeric-lime, Lycopersicon ...

Characterization of the Lime Mortars of the Rui Barbosa House Museum in Rio De Janeiro, Brazil

Directory of Open Access Journals (Sweden)

Daniele Pereira da Silva Dalto

2018-02-01

Full Text Available The aim of this research is to characterize the mortars of the Rui Barbosa House Museum, built in 1850, in the city of Rio de Janeiro, Brazil, using X-ray diffraction (XRD, gel-CSH determination, Fourier Transform Infrared spectrometry (FTIR, Wavelength-Dispersive X-ray Fluorescence spectrometry (WDXRF, Thermo gravimetric analysis (TG-DTG, and granulometric analysis. Also, petrographic and physical characteristics such as porosity, water absorption, and apparent density of the mortars were used to identify the raw materials employed in their preparation. Mineralogical associations found are similar (quartz, calcite, kaolinite, microcline, muscovite, and albite for the majority of samples and only vary in their proportions; the most prominent phases are quartz and calcite. The collected data, indicating that the binder is hydrated lime, lead us to conclude that the analyzed samples are lime mortars, discarding the possibility of cement as the binder material. Two samples, located on the corner of the building, which underwent repairs, present a differentiated behavior, with high levels of dolomite and the presence of pozzolanic material, with greater water absorption and higher density, indicating the use of a different mortar type. In addition, it was verified that the WDXRF and XRD methods are able to determine the trace element composition with comparable precision with respect to the methodological approach proposed by Teutonico (1988. In addition, it has been verified that the major pollutant causing degradation of building are sulfur emitted by the vehicles and saline spray.

40 CFR 180.1231 - Lime; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Lime; exemption from the requirement... From Tolerances § 180.1231 Lime; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of lime. [70 FR 33363, June 8, 2005] ...

Lime-Stabilized Black Cotton Soil and Brick Powder Mixture as Subbase Material

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S. Srikanth Reddy

2018-01-01

Full Text Available Various researchers, for the past few decades, had tried to stabilize black cotton soil using lime for improving its shrinkage and swelling characteristics. But these days, the cost of lime has increased resulting in increase in need for alternative and cost effective waste materials such as fly ash and rice husk ash. Brick powder, one among the alternative materials, is a fine powdered waste that contains higher proportions of silica and is found near brick kilns in rural areas. The objective of the study is to investigate the use of lime-stabilized black cotton soil and brick powder mixture as subbase material in flexible pavements. Black cotton soil procured from the local area, tested for suitability as subbase material, turned out to be unsuitable as it resulted in very less CBR value. Even lime stabilization of black cotton soil under study has not showed up the required CBR value specified for the subbase material of flexible pavement by MORTH. Hence the lime-stabilized black cotton soil is proportioned with brick powder to obtain optimum mixture that yields a better CBR value. The mixture of 20% brick powder and 80% lime-stabilized black cotton soil under study resulted in increase in the CBR value by about 135% in comparison with lime-stabilized black cotton soil. Thus it is promising to use the mixture of brick powder and lime-stabilized black cotton soil as subbase material in flexible pavements.

Effect of a biodegradable natural polymer on the properties of hardened lime-based mortars; Efecto de un polimero natural biodegradable en las propiedades de morteros de cal en estado endurecido

Energy Technology Data Exchange (ETDEWEB)

Izaguirre, A.; Lanas, J.; Alvarez, J. I.

2011-07-01

As an environmentally friendly and energy-saving alternative to cement-based materials and to some chemically obtained water-reducers, a commercialized starch was incorporated into aerial lime-based matrix. Different dosages were tested in order to study the influence that the amount of additive exerted on the properties of the material. Density, shrinkage, water absorption through capillarity, water vapour permeability, mechanical strengths, porosity, pore size distribution, and durability in the face of freezing-thawing cycles were studied in the mortars. The tested starch acted as a thickener for dosages up to 0.30%, and changed its behaviour for the largest dosage (0.50%): in that case it behaved as a plasticizer, dispersing the lime through the fresh mass and generating a more workable material. As a result, the matrix of the hardened mortar presented great coherence, owing to its large density and low porosity, characteristics which led to lower capillarity and permeability, better mechanical properties and durability. (Author) 46 refs.

Fly ash aggregates. Vliegaskunstgrind

Energy Technology Data Exchange (ETDEWEB)

1983-03-01

A study has been carried out into artificial aggregates made from fly ash, 'fly ash aggregates'. Attention has been drawn to the production of fly ash aggregates in the Netherlands as a way to obviate the need of disposal of fly ash. Typical process steps for the manufacturing of fly ash aggregates are the agglomeration and the bonding of fly ash particles. Agglomeration techniques are subdivided into agitation and compaction, bonding methods into sintering, hydrothermal and 'cold' bonding. In sintering no bonding agent is used. The fly ash particles are more or less welded together. Sintering in general is performed at a temperature higher than 900 deg C. In hydrothermal processes lime reacts with fly ash to a crystalline hydrate at temperatures between 100 and 250 deg C at saturated steam pressure. As a lime source not only lime as such, but also portland cement can be used. Cold bonding processes rely on reaction of fly ash with lime or cement at temperatures between 0 and 100 deg C. The pozzolanic properties of fly ash are used. Where cement is applied, this bonding agent itself contributes also to the strength development of the artificial aggregate. Besides the use of lime and cement, several processes are known which make use of lime containing wastes such as spray dry absorption desulfurization residues or fluid bed coal combustion residues. (In Dutch)

The Strength Behaviour of Lime Stabilized Organic Clay Soil Modified by Catalyst Additeives

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Khitam Abdulhussein Saeed

2016-12-01

Full Text Available The organic clay soil can be found in many large size reclaimed lands. These soils present enormously high settlement potential and low strength that needs to be improved by means of effective ground improvement techniques. One of the low cost techniques is to modify the soil with lime in-situ to make it suitable for construction and allow it to increase in strength by pozzolanic reactions between lime and clay minerals. Lime is known to be an effective stabilization material for clayey soil. Nevertheless, its effectiveness may be less with organic clay due to low effective strength properties. Thus, this study concerns the addition of catalyst i.e. zeolite which may improve the performance of lime stabilization to accelerate lime-organic clay reactions. The unconfined compressive test (UCT is conducted on remoulded samples (38mm x 80mm for 0, 7, 14 , 28, and 90 days of curing period. The addition of synthetic zeolite in lime-organic stabilized soil has increased the soil strength by 185% at 90 days curing period at the design mix of organic clay + 10% lime +10% zeolite. The higher value of UCS indicates that zeolite is an effective catalyst to enhance lime stabilization.

The use of hydrated lime in acid mine drainage treatment

Science.gov (United States)

Othman, Anuar; Sulaiman, Azli; Sulaiman, Shamsul Kamal

2017-05-01

Hydrated lime also known as calcium hydroxide with chemical formula Ca(OH)2 was used in this study as neutralization agent in acid mine drainage (AMD) treatment. Hydrated lime that is used to treat pool water samples from tin tailings located in Pengkalan Hulu, Perak was obtained from Simpang Pulai, Perak. The pH of water sample was around 2.6 to 2.8. Ten different variables of hydrated lime weights were used to treat 1 L of water sample. The weights of hydrated lime used were 0.2 g, 0.4 g, 0.6 g, 0.8 g, 1.0 g, 1.2 g, 1.4 g, 1.6 g, 1.8 g and 2.0 g. Time interval used was every 5 minutes up to minutes 30. Jar test method was used in this study. The maximum pH value of 5.93 ± 0.03 most approaches standard A and had complied standard B have been obtained using 2.0 g hydrated lime in 30-minute time interval. The concentration of arsenic, cadmium and chromium had decreased but only cadmium concentration did not comply with Standards A and B.

Analysis on soil compressibility changes of samples stabilized with lime

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Elena-Andreea CALARASU

2016-12-01

Full Text Available In order to manage and control the stability of buildings located on difficult foundation soils, several techniques of soil stabilization were developed and applied worldwide. Taking into account the major significance of soil compressibility on construction durability and safety, the soil stabilization with a binder like lime is considered one of the most used and traditional methods. The present paper aims to assess the effect of lime content on soil geotechnical parameters, especially on compressibility ones, based on laboratory experimental tests, for several soil categories in admixture with different lime dosages. The results of this study indicate a significant improvement of stabilized soil parameters, such as compressibility and plasticity, in comparison with natural samples. The effect of lime stabilization is related to an increase of soil structure stability by increasing the bearing capacity.

Liming effect in the degradation of 14C-glyphosate in soils

International Nuclear Information System (INIS)

Arantes, Sayonara A.C.M.; Lavorenti, Arquimedes

2007-01-01

Liming is soil fertility management practice essential in tropical soils, in general extremely acidic. This practice, by influencing physical, chemical and biological features of soils may influence the behavior of organic molecules in soils. The glyphosate is one the most widely used pesticides in Brazil in several cultures to pest management control. Studies on its fate in soil are still incipient, mainly under the effect of liming practice The objective of the present study was to verify the effect of liming practice in the degradation of glyphosate in Red Latosol (LE) and Quartzarenic Neosol (RQ) soils and also in the microbial activity of the same soils. The experiment was conducted in a completely randomized design in a 2 x 2 factorial scheme, corresponding to two soils and two management conditions (with liming and without liming), with four replicates. The Radiometric technique was utilized to evaluate the evolution the 14 CO 2 at intervals of 7 days, during 70 days. The study of microbial activity was conducted parallel to the degradation experiment, using the methodology of radiolabelled glucose ( 14 C-glucose), which was measured at intervals of fourteen days, during 70 days. The results showed that in the studied soils, the liming increased the 14 C-glyphosate mineralization and the microbial activity. (author)

Effect of Lime Stabilization on Vertical Deformation of Laterite Halmahera Soil

Science.gov (United States)

Saing, Zubair; Djainal, Herry

2018-04-01

In this paper, the study was conducted to determine the lime effect on vertical deformation of road base physical model of laterite Halmahera soil. The samples of laterite soil were obtained from Halmahera Island, North Maluku Province, Indonesia. Soil characteristics were obtained from laboratory testing, according to American Standard for Testing and Materials (ASTM), consists of physical, mechanical, minerals, and chemical. The base layer of physical model testing with the dimension; 2m of length, 2m of width, and 1.5m of height. The addition of lime with variations of 3, 5, 7, an 10%, based on maximum dry density of standard Proctor test results and cured for 28 days. The model of lime treated laterite Halmahera soil with 0,1m thickness placed on subgrade layer with 1,5m thickness. Furthermore, the physical model was given static vertical loading. Some dial gauge is placed on the lime treated soil surface with distance interval 20cm, to read the vertical deformation that occurs during loading. The experimentals data was analyzed and validated with numerical analysis using finite element method. The results showed that the vertical deformation reduced significantly on 10% lime content (three times less than untreated soil), and qualify for maximum deflection (standard requirement L/240) on 7-10% lime content.

Efficacy and phytotoicity of lime sulphur in organic apple production

NARCIS (Netherlands)

Holb, I.J.; Jong, de P.F.; Heijne, B.

2003-01-01

Curative and preventive efficacy and phytotoxicity of lime sulphur spray schedules, based on a warning system, were evaluated in the Netherlands during two growing seasons under field conditions. In most cases, lime sulphur treatments applied either curatively or preventively resulted in

Lime application methods, water and bottom soil acidity in fresh water fish ponds

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Queiroz Julio Ferraz de

2004-01-01

Full Text Available Although some methods for determining lime requirement of pond soils are available and commonly used, there is still no consensus on whether it is more effective to apply liming materials to the bottoms of empty ponds or to wait and apply them over the water surface after ponds are filled. There is also little information on how deep lime reacts in pond sediment over time, and whether the depth of reaction is different when liming materials are applied to the water or to the soil. Therefore, three techniques for treating fish ponds with agricultural limestone were evaluated in ponds with clayey soils at a commercial fish farm. Amounts of agricultural limestone equal to the lime requirement of bottom soils were applied to each of three ponds by: direct application over the pond water surface; spread uniformly over the bottom of the empty pond; spread uniformly over the bottom of the empty pond followed by tilling of the bottom. Effectiveness of agricultural limestone applications did not differ among treatment methods. Agricultural limestone also reacted quickly to increase total alkalinity and total hardness of pond water to acceptable concentrations within 2 weeks after application. The reaction of lime to increase soil pH was essentially complete after one to two months, and lime had no effect below a soil depth of 8 cm. Tilling of pond bottoms to incorporate liming materials is unnecessary, and tilling consumes time and is an expensive practice; filled ponds can be limed effectively.

Advanced treatment of swine wastewater using an agent synthesized from amorphous silica and hydrated lime.

Science.gov (United States)

Tanaka, Yasuo; Hasegawa, Teruaki; Sugimoto, Kiyomi; Miura, Keiichi; Aketo, Tsuyoshi; Minowa, Nobutaka; Toda, Masaya; Kinoshita, Katsumi; Yamashita, Takahiro; Ogino, Akifumi

2014-01-01

Advanced treatment using an agent synthesized from amorphous silica and hydrated lime (M-CSH-lime) was developed and applied to swine wastewater treatment. Biologically treated wastewater and M-CSH-lime (approximately 6 w/v% slurry) were fed continuously into a column-shaped reactor from its bottom. Accumulated M-CSH-lime gradually formed a bed layer. The influent permeated this layer and contacted the M-CSH-lime, and the treatment reaction progressed. Treated liquid overflowing from the top of the reactor was neutralized with CO₂gas bubbling. The colour removal rate approximately exceeded 50% with M-CSH-lime addition rates of > 0.15 w/v%. The removal rate of PO(3⁻)(4) exceeded 80% with the addition of>0.03 w/v% of M-CSH-lime. The removal rates of coliform bacteria and Escherichia coli exceeded 99.9% with > 0.1 w/v%. Accumulated M-CSH-lime in the reactor was periodically withdrawn from the upper part of the bed layer. The content of citric-acid-soluble P₂O₅ in the recovered matter was>15% when the weight ratio of influent PO(3⁻)(4) -P to added M-CSH-lime was > 0.15. This content was comparable with commercial phosphorus fertilizer. The inhibitory effect of recovered M-CSH-lime on germination and growth of leafy vegetable komatsuna (Brassica rapa var. perviridis) was evaluated by an experiment using the Neubauer's pot. The recovered M-CSH-lime had no negative effect on germination and growth. These results suggest that advanced water treatment with M-CSH-lime was effective for simultaneous removal of colour, [Formula: see text] and coliform bacteria at an addition rate of 0.03-0.15 w/v%, and that the recovered M-CSH-lime would be suitable as phosphorus fertilizer.

Expansion reduction of clayey soils through Surcharge application and Lime Treatment

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T. López-Lara

2017-12-01

Full Text Available Expansive clayey soils produce heaving and cracking of floor slabs and walls. Expansive soils owe their characteristics to the presence of swelling clay minerals. This soil expands and contracts due to changes in the moisture content of the soil. In this study the surcharge required to counteract soil expansion was measured in natural expansive soils (untreated soils and lime treated soils starting at 19.61 kPa (2 Ton/m2 and continuing with increments of 19.61 kPa. Additionaly in lime treated soils the amount of lime was determined under different surcharges in order to reduce the expansion. The test results indicated that the surcharges applied to untreated soils were not proportional to the decrease of expansion which is probably due to the increase of soil density. In fact, only the initial surcharge of 19.61 kPa significantly decreased the expansion. According to the results, the soil expansion was considerably reduced (1.54% with the surcharge of 78.45 kPa, therefore this surcharge can be considered as the Swelling pressure. On the other hand the soil tested (high compressibility clay was stabilized with 6% of lime (without surcharges which was determined with the lowest value of liquid limit and plastic index as well as expansion test. After the application of surcharges and lime treatment to expansive soil, the surcharges of 39.22 kPa and 58.84 kPa decreased expansion and increased their resistance. This was concluded by similar low values of expansion (without settlements under both surcharges of each treated soil tested (2, 4 and 6% of lime. It can be concluded that the surcharge contributed to the decrease of soil expansion due to the decrease of the amount of lime required (6% without surcharge. So, 4% of lime was enough for the surcharge of 19.61 kPa and 2% of lime required the surcharge minimum of 39.22 kPa. This shows that the surcharge of a house on expansive soil reduces soil expansion and therefore reduces costs of any

CHEMICAL SOIL ATTRIBUTES AS AFFECTED BY LIME AND GYPSUM SURFACE APPLICATION

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A. Mantovani

2017-10-01

Full Text Available The gypsum is a soil condition end it has to function contribute to the elimination or reduction of aluminum in the soil in depth. Still, it can contribute to the distribution of nutrients in the soil profile more uniformly and thus increasing the productivity of crops. This study aimed to evaluate the influence of gypsum application, with and without lime, on soil chemical properties and soybean yield, in a no-till system. The experiment was carried in Campos Novos, Santa Catarina State, Brazil, with a randomized block design and split plot design with four replications, the main portion was distributed gypsum doses (1000, 2000, 4000 and 6000 kg ha-1 without incorporation, and the split plot (with and without lime and the liming was 2,000 kg ha-1. We evaluated the performance of components and productivity of soybeans. It was also analyzed the soil pH and Ca, Mg, S and Al at 0-20 and 20-40 cm. The application of gypsum at the rates tested surface with and without lime did not affect the yield components and soybean productivity. At 0-20 cm soil depth lime application increased soil pH by 0.3 units on the average rates of gypsum, but in the 20-40 cm layer was not found effect of lime and gypsum in pH ground due to the short time between application and evaluation. In areas with and without lime contents of Ca and S in the two layers evaluated increased with increasing rates of gypsum, since Mg has difference with the lime application on a 0-20 cm to dose 4000 kg ha-1 and the lime in the gypsum rates and Al decreased with increasing dose gypsum average in the 20-40 cm layer depth. The application of gypsum and limestone softened the negative effects of soil acidity and the increase mainly of calcium and sulfur at 0-20 cm, with less efficient effects in the 20-40 cm layer due to the soil is clayey and the period between the implementation and evaluation be 120 days.

Producer gas and its use for the manufacture of lime

Energy Technology Data Exchange (ETDEWEB)

Gupta, A K; Kumar, S

1976-04-01

An analysis of available data indicates that coal-based producer gas is superior to coal or wood as a fuel for lime kilns and much more readily available than oil or natural gas. With producer gas, chemical-grade lime is obtained, and the kiln capacity is increased, so that a smaller unit can be used or more lime obtained. With a mixture of coal and wood as the fuel, the lime produced is contaminated with ash. The added cost of the gas-producer unit can be paid out in one year owing to the greater demand for and the consequent higher prices obtainable for the chemical-grade product. In addition, the flue gases from the kiln can be used in place of steam to heat the gas producer, but experimental studies are needed to determine the magnitude of the savings in fuel consumption. 15 references.

Lime sulfur toxicity to broad mite, to its host plants and to natural enemies.

Science.gov (United States)

Venzon, Madelaine; Oliveira, Rafael M; Perez, André L; Rodríguez-Cruz, Fredy A; Martins Filho, Sebastião

2013-06-01

An acaricidal effect of lime sulfur has not been demonstrated for Polyphagotarsonemus latus. However, lime sulfur can cause toxicity to natural enemies and to host plants. In this study, the toxicity of different concentrations of lime sulfur to P. latus, to the predatory mite Amblyseius herbicolus and to the predatory insect Chrysoperla externa was evaluated. Additionally, the phytotoxicity of lime sulfur to two P. latus hosts, chili pepper and physic nut plants, was determined. Lime sulfur at a concentration of 9.5 mL L(-1) restrained P. latus population growth. However, this concentration was deleterious to natural enemies. The predatory mite A. herbicolus showed a negative value of instantaneous growth rate, and only 50% of the tested larvae of C. externa reached adulthood when exposed to 10 mL L(-1) . Physic nut had severe injury symptoms when sprayed with all tested lime sulfur concentrations. For chili pepper plants, no phytoxicity was observed at any tested concentration. Lime sulfur might be used for P. latus control on chili pepper but not on physic nut owing to phytotoxicity. Care should be taken when using lime sulfur in view of negative effects on natural enemies. Selective lime sulfur concentration integrated with other management tactics may provide an effective and sustainable P. latus control on chili pepper. © 2012 Society of Chemical Industry.

A novel eco-friendly technique for efficient control of lime water softening process.

Science.gov (United States)

Ostovar, Mohamad; Amiri, Mohamad

2013-12-01

Lime softening is an established type of water treatment used for water softening. The performance of this process is highly dependent on lime dosage. Currently, lime dosage is adjusted manually based on chemical tests, aimed at maintaining the phenolphthalein (P) and total (M) alkalinities within a certain range (2 P - M > or = 5). In this paper, a critical study of the softening process has been presented. It has been shown that the current method is frequently incorrect. Furthermore, electrical conductivity (EC) has been introduced as a novel indicator for effectively characterizing the lime softening process.This novel technique has several advantages over the current alkalinities method. Because no chemical reagents are needed for titration, which is a simple test, there is a considerable reduction in test costs. Additionally, there is a reduction in the treated water hardness and generated sludge during the lime softening process. Therefore, it is highly eco-friendly, and is a very cost effective alternative technique for efficient control of the lime softening process.

Aging and Curing Temperature Effects on Compressive Strength of Mortar Containing Lime Stone Quarry Dust and Industrial Granite Sludge

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Muhammad Nasir Amin

2017-06-01

Full Text Available In this study, the researchers investigated the potential use of locally available waste materials from the lime stone quarry and the granite industry as a partial replacement of cement. Quarry sites and granite industry in the eastern province of Saudi Arabia produces tons of powder wastes in the form of quarry dust (QD and granite sludge (GS, respectively, causing serious environmental problems along with frequent dust storms in the area. According to ASTM C109, identical 50-mm3 specimens were cast throughout this study to evaluate the compressive strength development of mortars (7, 28 and 91 days containing these waste materials. Experimental variables included different percentage replacement of cement with waste materials (GS, QD, fineness of GS, various curing temperatures (20, 40 and 60 °C as local normal and hot environmental temperatures and curing moisture (continuously moist and partially moist followed by air curing. Finally, the results of mortar containing waste materials were compared to corresponding results of control mortar (CM and mortar containing fly ash (FA. The test results indicated that under normal curing (20 °C, moist cured, the compressive strength of mortar containing the different percentage of waste materials (QD, GS, FA and their combinations remained lower than that of CM at all ages. However, the compressive strength of mortar containing waste materials slightly increased with increased fineness of GS and significantly increased under high curing temperatures. It was recommended that more fineness of GS be achieved to use its high percentage replacement with cement (30% or more incorporating local environmental conditions.

Investigation of Copper Sorption by Sugar Beet Processing Lime Waste

Science.gov (United States)

In the western United States, sugar beet processing for sugar recovery generates a lime-based waste product (~250,000 Mg yr-1) that has little liming value in the region’s calcareous soils. This area has recently experienced an increase in dairy production, with dairi...

Some studies on the reaction between fly ash and lime

Indian Academy of Sciences (India)

Unknown

Blain's air permeability apparatus was used for ... Pulverized lime with high per- centage of CaO (> 80 ... kept in a low-pressure autoclave at an average steam pressure and ... ing the solubility of lime in a solvent containing 1 part by volume of ...

Nutritional characteristics of two pigeon pea hybrids – Liming and phosphated fertilization

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Marcia Atauri Cardelli de Lucena

2012-12-01

Full Text Available The use of legumes in animal production systems can be a sustainable alternative as a protein source in rotational grazing system and/or as a protein bank. Pigeon pea (Cajanus cajan (L. Millsp. figure as an example of success of this use on animal nutrition. The development of this species can be limited by the high acidity and low soil phosphorus content. There is a lack of scientific information on the effects of liming and phosphorus fertilization on some nutritional variables of two pigeon pea new hybrids. This study was conducted in pots containing 5 kg of soil in a greenhouse at the Instituto de Zootecnia, Nova Odessa, São Paulo State. There were studied two pigeon pea hybrids, H1 and H2, and the treatments involved agronomic practices: 1 No liming and without phosphorus (control, 2 Liming (L, 3 Phosphorus fertilization (P and 4 Liming plus phosphorus. Liming was proposed to increase soil base saturation to 50%, it was used dolomite lime PRNT = 90%, in an amount corresponding to 4.5 t/ha. Phosphorus fertilization (as superphosphate rate was 60 kg/ha of PO25. The experimental units were allocated according to a complete randomised block design, with five replications. We analyzed the levels of crude protein (CP, neutral detergent fiber (NDF, acid detergent fiber (ADF, in pigeon pea shoot at 45 days of age. Statistical analyzes were performed using the software SISVAR, averages were compared using test for multiple comparisons Student Newman-Keuls - SNK test (P < 0.05. The H1 hybrid had the highest content of CP, by applying P, lime plus P and the control treatment compared to H2 hybrid. The association lime plus P resulted in higher content of CP mainly due to the increased availability of P for plants. Smaller values were observed for NDF in H2 with P application. Lower values of ADF were observed in H1 in both control treatment and P application. The ADF values were lower for the hybrid H2 only for the treatment lime plus P. The two

Liming effect in the degradation of 14C-glyphosate in soils

Energy Technology Data Exchange (ETDEWEB)

Arantes, Sayonara A.C.M.; Lavorenti, Arquimedes [Universidade de Sao Paulo (USP), Piracicaba, SP (Brazil). Escola Superior de Agricultura Luiz de Queiroz]. E-mails: samoreno@esalq.usp.br; alavoren@esalq.usp.br; Tornisielo, Valdemar L. [Centro de Energia Nuclear na Agricultura (CENA), Piracicaba, SP (Brazil)]. E-mail: vltornis@cena.usp.br

2007-07-01

Liming is soil fertility management practice essential in tropical soils, in general extremely acidic. This practice, by influencing physical, chemical and biological features of soils may influence the behavior of organic molecules in soils. The glyphosate is one the most widely used pesticides in Brazil in several cultures to pest management control. Studies on its fate in soil are still incipient, mainly under the effect of liming practice The objective of the present study was to verify the effect of liming practice in the degradation of glyphosate in Red Latosol (LE) and Quartzarenic Neosol (RQ) soils and also in the microbial activity of the same soils. The experiment was conducted in a completely randomized design in a 2 x 2 factorial scheme, corresponding to two soils and two management conditions (with liming and without liming), with four replicates. The Radiometric technique was utilized to evaluate the evolution the {sup 14}CO{sub 2} at intervals of 7 days, during 70 days. The study of microbial activity was conducted parallel to the degradation experiment, using the methodology of radiolabelled glucose ({sup 14}C-glucose), which was measured at intervals of fourteen days, during 70 days. The results showed that in the studied soils, the liming increased the {sup 14}C-glyphosate mineralization and the microbial activity. (author)

Long-term field-scale experiment on using lime filters in an agricultural catchment.

Science.gov (United States)

Kirkkala, Teija; Ventelä, Anne-Mari; Tarvainen, Marjo

2012-01-01

The River Yläneenjoki catchment in southwest Finland is an area with a high agricultural nutrient load. We report here on the nutrient removal performance of three on-site lime-sand filters (F1, F2, and F3), established within or on the edge of the buffer zones. The filters contain burnt lime (CaO) or spent lime [CaO, Ca(OH), and CaCO]. Easily soluble lime results in a high pH level (>11) and leads to an efficient precipitation of soluble phosphorus (P) from the runoff. Water samples were taken from the inflow and outflow of each site in different hydrological situations. The length of the monitoring period was 4 yr for F1, 6 yr for F2, and 1.5 yr for F3. F1 and F2 significantly reduced the suspended solids (SS), total P (PTOT), and dissolved reactive P (DRP) in the treated water. The proportional reduction (%) varied but was usually clearly positive. Filter F3 was divided into two equal parts, one containing burnt lime and the other spent lime. Both filter parts removed PTOT and SS efficiently from the water; the burnt-lime part also removed DRP. The mixed-lime part removed DRP for a year, but then the efficiency decreased. The effect of filters on nitrogen compounds varied. We conclude that sand filters incorporating lime can be used together with buffer zones to reduce both P and SS load to watercourses. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Influence of Lime and Phosphorus Application Rates on Growth of Maize in an Acid Soil

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Peter Asbon Opala

2017-01-01

Full Text Available The interactive effects of lime and phosphorus on maize growth in an acid soil were investigated in a greenhouse experiment. A completely randomized design with 12 treatments consisting of four lime levels, 0, 2, 10, and 20 t ha−1, in a factorial combination with three phosphorus rates, 0, 30, and 100 kg ha−1, was used. Maize was grown in pots for six weeks and its heights and dry matter yield were determined and soils were analyzed for available P and exchangeable acidity. Liming significantly reduced the exchangeable acidity in the soils. The effect of lime on available P was not significant but available P increased with increasing P rates. There was a significant effect of lime, P, and P by lime interactions on plant heights and dry matter. Without lime application, dry matter increased with increasing P rates but, with lime, dry mattes increased from 0 to 30 kg P ha−1 but declined from 30 to 100 kg P ha−1. The highest dry matter yield (13.8 g pot−1 was obtained with a combined 2 t ha−1 of lime with 30 kg P ha−1 suggesting that lime application at low rates combined with moderate amounts of P would be appropriate in this soil.

Efficacy of road bond and condor as soil stabilizers : final report.

Science.gov (United States)

2013-08-01

The Oklahoma Department of Transportation (ODOT) uses lime-based stabilizers including quick lime, hydrated lime, Class C fly ash (CFA) and cement kiln dust (CKD) to increase bearing capacity of fine-grained subgrade soils within the state of Oklahom...

Cermet cements.

Science.gov (United States)

McLean, J W

1990-01-01

Cermet ionomer cements are sintered metal/glass powders, which can be made to react with poly(acids). These new cements are significantly more resistant to abrasion than regular glass ionomer cements and are widely accepted as core build-up materials and lining cements. They can strengthen teeth and provide the clinician with an opportunity to treat early dental caries.

Imperial Limes - Projections in Medieval Imperial Idea

Directory of Open Access Journals (Sweden)

Z.Z. Zhekov

2015-08-01

Full Text Available Roman imperial limes from I - V BC was the first state border in world history, which in some sense corresponds to the modern concept of political boundary. It represents sustainable political, military and economic barrier between the Romans and the rest of the world. With minor modifications it retains their basic strategic concept during the period as expressed from the emperors Augustus and Tiberius. Limes become powerful barrier that separates cultural Roman Hellenistic world of the wild barbarian but at the same time limits the constructed infrastructure of roads, forts and towns became a natural cultural, commercial and political mediator between these two initially hostile worlds. In border towns developed a lively trade between Romans and barbarians. Roman traders penetrate inside the barbarian lands getting to know their culture and history. Studying foreign peoples and countries they convey information gathered imperial legate of the Roman population. The same process was developed and of course in the opposite direction. Exchange of information on the other promotes mutual understanding and open living on both sides of the Roman Limes.

A SYSTEM AND A METHOD FOR PREDICTION OF NOx EMISSION AND/OR FREE LIME CONCENTRATION IN A CEMENT KILN

DEFF Research Database (Denmark)

2008-01-01

The invention relates to a method (and corresponding soft sensor) for determining one or more cement kiln process parameters, the method comprising the steps of collecting at least one process measurement representing at least one process parameter and collecting at least one item of image data r...

The effect of reuse of unhairing-liming residual floats through ...

African Journals Online (AJOL)

STORAGESEVER

2008-09-03

Sep 3, 2008 ... Key words: Unhairing-liming process, reusing, leather industry, environment, bacterial and fungal numbers. INTRODUCTION .... 4.0 x101. -: No growth. Chemical analysis of samples. Chemical analyses of sodium sulphide and lime were done for the regeneration of ULP residual liquors. While preparing ...

40 CFR 180.1232 - Lime-sulfur; exemption from the requirement of a tolerance.

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 23 2010-07-01 2010-07-01 false Lime-sulfur; exemption from the... Exemptions From Tolerances § 180.1232 Lime-sulfur; exemption from the requirement of a tolerance. An exemption from the requirement of a tolerance is established for residues of lime-sulfur. [70 FR 33363, June...

A possible medieval lighthouse at Mul Dwarka (Kodinar) Saurashtra Coast, India

Digital Repository Service at National Institute of Oceanography (India)

Gaur, A.S.; Sundaresh; Rao, B.R.; Tripati, S.; Khedekar, V.D.

) of the ancient Mesopotamia (Woolley, 1939). Then lime mortars were used in the masonry work worldwide from ancient times until usage of modern cements (Portland) in the late 19th century. SEM-EDS analysis of the sample suggests that the major component.... The composition in modern Portland cement includes two third parts calcium oxide and ~20 % of silica. However, while preparing cement mortar a certain proportion of sand is added whereas lime mortar was directly used for construction purpose in ancient times...

Audiovisual Documentation of an International Seminar : Case: LIME

OpenAIRE

Tikkanen, Kirsti; Rönnberg, Mira

2013-01-01

The aim of this Bachelor’s thesis is to create a documentary video of an international seminar held in Kerava, Finland, in June 2013. The seminar was called Learning on Immigration and Multicultural Education (LIME) and it was conducted by Kerava Adult Education Center (later Keravan Opisto). LIME was a two-year intercultural project funded by the European Union. Different non-governmental organizations and adult education centers from eight European countries took part on the project. The ai...

DEVELOPMENT OF TECHNIQUES FOR QUANTITATIVE ANALYSIS OF LIME FLOWERS

Directory of Open Access Journals (Sweden)

Demyanenko DV

2016-03-01

Full Text Available Introduction. The article is devoted to the development of techniques for quantitative analysis of lime flower in order to make amendments to existing pharmacopoeian monographs for this herbal drug. Lime inflorescences contain lipophilic biologically active substances (BAS causing notable antimicrobial and anti-inflammatory effects and also more polar phenolic compounds with antiulcer activity. Considering this, it’s necessary to regulate all these groups of BAS quantitatively. Materials and methods. For this study six batches of lime flowers harvested in 2008-2009 yrs. in Kharkiv, Rivno and Zhitomir regions were used as crude herbal drug. Loss on drying was determined by routine pharmacopoeian procedures. Total content of lipophilic substances was determined gravimetrically after Soxhlet extraction of samples 1, 5, 7 and 10 g in weight with methylene chloride, considering that by its extracting ability this solvent is close to liquefied difluorochloromethane (freon R22 used by us for obtaining of lipophilic complexes. The duration of complete analytical extraction was determined by infusion of six 10 g assays of lime flowers during 1, 2, 3, 4, 5, 6 hours, then quantity of lipophilic extractives was revealed gravimetrically. Quantity of essential oil in lime flowers was evaluated under the procedure of ЕР7, 2.8.12. Weight of the herbal drug sample was 200 g, distillation rate – 2,5- 3,5 ml/min, volume of distillation liquid (water – 500 ml, volume of xylene in the graduated tube – 0,50 ml. Total flavonoid content recalculated to quercetin was determined after hydrolysis with acidified acetone, withdrawing of flavonoid aglycones with ethylacetate and by further spectrophotometry of their complexes with aluminium chloride. All quantitative determinations were replicated five times for each assay. All chemicals and reagents were of analytical grade. Results and discussion. It was found that adequate accuracy of the analysis of lipophilic

Enhanced inhibition of Aspergillus niger on sedge (Lepironia articulata) treated with heat-cured lime oil.

Science.gov (United States)

Matan, N; Matan, N; Ketsa, S

2013-08-01

This study aimed to examine heat curing effect (30-100°C) on antifungal activities of lime oil and its components (limonene, p-cymene, β-pinene and α-pinene) at concentrations ranging from 100 to 300 μl ml(-1) against Aspergillus niger in microbiological medium and to optimize heat curing of lime oil for efficient mould control on sedge (Lepironia articulata). Broth dilution method was employed to determine lime oil minimum inhibitory concentration, which was at 90 μl ml(-1) with heat curing at 70°C. Limonene, a main component of lime oil, was an agent responsible for temperature dependencies of lime oil activities observed. Response surface methodology was used to construct the mathematical model describing a time period of zero mould growth on sedge as functions of heat curing temperature and lime oil concentration. Heat curing of 90 μl ml(-1) lime oil at 70°C extended a period of zero mould growth on sedge to 18 weeks under moist conditions. Heat curing at 70°C best enhanced antifungal activity of lime oil against A. niger both in medium and on sedge. Heat curing of lime oil has potential to be used to enhance the antifungal safety of sedge products. © 2013 The Society for Applied Microbiology.

Liming Poultry Manures to Kill Pathogens and Decrease Soluble Phosphorus

International Nuclear Information System (INIS)

Maguire, R.; Hesterberg, D.; Gernat, A.; Anderson, K.; Wineland, M.; Grimes, J.

2006-01-01

Received for publication September 9, 2005. Stabilizing phosphorus (P) in poultry waste to reduce P losses from manured soils is important to protect surface waters, while pathogens in manures are an emerging issue. This study was conducted to evaluate CaO and Ca(OH) 2 for killing manure bacterial populations (pathogens) and stabilizing P in poultry wastes and to investigate the influence on soils following amendment with the treated wastes. Layer manure and broiler litter varying in moisture content were treated with CaO and Ca(OH) 2 at rates of 2.5, 5, 10, and 15% by weight. All treated wastes were analyzed for microbial plate counts, pH, and water-soluble phosphorus (WSP), while a few selected layer manures were analyzed by phosphorus X-ray absorption near edge structure (XANES). A loamy sand and a silt loam were amended with broiler litter and layer manure treated with CaO at rates of 0, 2.5, 5, 10, and 15% and soil WSP and pH were measured at times 1, 8, and 29 d. Liming reduced bacterial populations, with greater rates of lime leading to greater reductions; for example 10% CaO applied to 20% solids broiler litter reduced the plate counts from 793 000 to 6500 mL -1 . Liming also reduced the WSP in the manures by over 90% in all cases where at least 10% CaO was added. Liming the manures also reduced WSP in soils immediately following application and raised soil pH. The liming process used successfully reduced plate counts and concerns about P losses in runoff following land application of these limed products due to decreased WSP

Preparation of Lime by Roasting the Limestone Deposits of Strezovci (Republic of Kosovo and Its Use for the Aluminothermic Production of Calcium Metal

Directory of Open Access Journals (Sweden)

Hoda, S.

2013-03-01

Full Text Available The goal of producing and processing limestone ore (mostly CaCO3 is to obtain high-quality refractory materials based on lime (CaO. Lime is the raw material for obtaining calcium metal as a strategic and fundamental component in lead metallurgy (production of refined lead, Pb-Ca alloys in the battery and cable industry, ferroalloys production with the addition of silicon and calcium, production of alloy steel and high-quality steel. This paper explores the preparation of lime by roasting the limestone deposits of Strezovci (Republic of Kosovo and its use for obtaining calcium through the aluminothermic process. Through research and analysis of the chemical composition of certain types of lime, its suitabi- lity for obtaining calcium metal was determined, and by analyzing the samples of the slag, determined was the possibility of its use in the production of fire-resistant cement for which the evaluation is needed. Based on previous research, the following was chosen: optimal composition of the cast, volume of added reducing agents, and conditions of the reduction process performance: temperature-time and initial vacuum. According to the authors’ knowledge, not one Southeast European country has applied this method, and it includes the use of by-products (slag, which can cause environmental pollution. The goal of this research was to prepare lime by roasting limestone of domestic origin in order to obtain calcium metal through the aluminothermic process. The procedure of calcium metal production includes the following operations: decarbonatization of limestone ore (CaCO3 , grinding of the obtained lime (CaO, homogenization of CaO and alumina, agglomeration, and aluminothermic reduction in vacuum furnaces. For the efficiency of the process, the most important technological operations are decarbonatization and reduction, provided the other operations are performed correctly. The estimated total world capacity for production of calcium metal is 25

Classical Methods and Calculation Algorithms for Determining Lime Requirements

Directory of Open Access Journals (Sweden)

André Guarçoni

Full Text Available ABSTRACT The methods developed for determination of lime requirements (LR are based on widely accepted principles. However, the formulas used for calculation have evolved little over recent decades, and in some cases there are indications of their inadequacy. The aim of this study was to compare the lime requirements calculated by three classic formulas and three algorithms, defining those most appropriate for supplying Ca and Mg to coffee plants and the smaller possibility of causing overliming. The database used contained 600 soil samples, which were collected in coffee plantings. The LR was estimated by the methods of base saturation, neutralization of Al3+, and elevation of Ca2+ and Mg2+ contents (two formulas and by the three calculation algorithms. Averages of the lime requirements were compared, determining the frequency distribution of the 600 lime requirements (LR estimated through each calculation method. In soils with low cation exchange capacity at pH 7, the base saturation method may fail to adequately supply the plants with Ca and Mg in many situations, while the method of Al3+ neutralization and elevation of Ca2+ and Mg2+ contents can result in the calculation of application rates that will increase the pH above the suitable range. Among the methods studied for calculating lime requirements, the algorithm that predicts reaching a defined base saturation, with adequate Ca and Mg supply and the maximum application rate limited to the H+Al value, proved to be the most efficient calculation method, and it can be recommended for use in numerous crops conditions.

ULTRA-LIGHTWEIGHT CEMENT

International Nuclear Information System (INIS)

Fred Sabins

2001-01-01

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

Cement-latex grouting mortar for cementing boreholes

Energy Technology Data Exchange (ETDEWEB)

Kateev, I S; Golyshkina, L A; Gorbunova, I V; Kurochkin, B M; Vakula, Ya V

1980-01-01

The need for the development of cement-latex grouting mortar for the purpose of separating strata when reinforcing boreholes at deposits in the Tatar Associated SSR is evaluated. Results of studies of the physical and mechanical properties of cement-latex grouting mortar systems (mortar plus brick) are presented. Formulas for preparing cement-latex grouting mortor are evaluated and results of industrial tests of such mortars shown.

76 FR 82295 - Central Power & Lime LLC; Notice of Filing

Science.gov (United States)

2011-12-30

... DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket Nos. EL12-18-000; QF82-207-007] Central Power & Lime LLC; Notice of Filing December 23, 2011. Take notice that on December 22, 2011, Central Power & Lime LLC, pursuant to sections 18 CFR 292.205(c) and 385.207 of the Federal Energy...

A nano approach to consolidation of degraded historic lime mortars

Czech Academy of Sciences Publication Activity Database

Drdácký, Miloš; Slížková, Zuzana; Ziegenbalg, G.

2009-01-01

Roč. 8, č. 2 (2009), s. 13-22 ISSN 1662-5250 R&D Projects: GA ČR(CZ) GA103/06/1609 Institutional research plan: CEZ:AV0Z20710524 Keywords : lime water * calcium hydroxide nanosuspension * lime mortar Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 0.571, year: 2009

Differences in the rheological properties of calcitic and dolomitic lime slurries: influence of particle characteristics and practical implications in lime-based mortar manufacturing

Directory of Open Access Journals (Sweden)

Arizzi, A.

2012-06-01

Full Text Available The study of the rheological properties of lime suspensions is a useful means to evaluate the workability of lime mortars. In this work, we studied the flow behaviour of two industrial hydrated limes, one of calcitic and the other of dolomitic composition, by means of two types of rheometer with different geometry and setup mode. The obtained results were interpreted taking into account the differences in microstructure and surface properties of the suspended particles. Calcitic lime dry particles are formed by angular and polydisperse clusters and, once dispersed in water, they behave like thixotropic materials. On the other hand, the dolomitic lime is formed by nanoparticles and small round cluster and it shows a pronounced plastic behaviour in suspension. This fundamental difference between the two materials explains the traditional preference for dolomitic lime mortars for plastering and rendering applications.

El estudio de las propiedades reológicas de suspensiones de cal es una herramienta muy útil para evaluar la trabajabilidad de morteros de cal. En este trabajo se ha estudiado el comportamiento en suspensión de dos cales hidratadas, de composición calcítica y dolomítica, mediante dos tipos de reómetros con geometría y modalidades distintas de medida. Los resultados obtenidos se han interpretado teniendo en cuenta las diferencias en la microestructura y las propiedades de superficie de las partículas en suspensión. Las partículas de cal calcítica están formadas por aglomerados angulares y polidispersos y, una vez dispersadas en agua, presentan un comportamiento tixotrópico. Por su parte, la cal dolomítica está formada por nanopartículas y pequeños agregados redondeados y muestra en suspensión un pronunciado comportamiento plástico. Esta importante diferencia entre las dos cales explica la preferencia tradicional de morteros de cal dolomítica para aplicaciones en revocos.

Study on Cr(VI) Leaching from Cement and Cement Composites

Science.gov (United States)

Palascakova, Lenka; Kanuchova, Maria

2018-01-01

This paper reports an experimental study on hexavalent chromium leaching from cement samples and cement composites containing silica fume and zeolite additions that were subjected to various leaching agents. The water-soluble Cr(VI) concentrations in cements ranged from 0.2 to 3.2 mg/kg and represented only 1.8% of the total chromium content. The presence of chromium compounds with both chromium oxidation states of III and VI was detected in the cement samples by X-ray photoelectron spectroscopy (XPS). Leaching tests were performed in a Britton-Robinson buffer to simulate natural conditions and showed increased dissolution of Cr(VI) up to 6 mg/kg. The highest amount of leached hexavalent chromium was detected after leaching in HCl. The findings revealed that the leaching of chromium from cements was higher by 55–80% than that from the cement composites. A minimum concentration was observed for all cement samples when studying the relationship between the soluble Cr(VI) and the cement storage time. PMID:29690550

A study on engineering characteristics of asphalt concrete using filler with recycled waste lime.

Science.gov (United States)

Sung Do, Hwang; Hee Mun, Park; Suk keun, Rhee

2008-01-01

This study focuses on determining the engineering characteristics of asphalt concrete using mineral fillers with recycled waste lime, which is a by-product of the production of soda ash (Na(2)CO(3)). The materials tested in this study were made using a 25%, 50%, 75%, and 100% mixing ratio based on the conventional mineral filler ratio to analyze the possibility of using recycled waste lime. The asphalt concretes, made of recycled waste lime, hydrated lime, and conventional asphalt concrete, were evaluated through their fundamental engineering properties such as Marshall stability, indirect tensile strength, resilient modulus, permanent deformation characteristics, moisture susceptibility, and fatigue resistance. The results indicate that the application of recycled waste lime as mineral filler improves the permanent deformation characteristics, stiffness and fatigue endurance of asphalt concrete at the wide range of temperatures. It was also determined that the mixtures with recycled waste lime showed higher resistance against stripping than conventional asphalt concrete. It was concluded from various test results that a waste lime can be used as mineral filler and, especially, can greatly improve the resistance of asphalt concrete to permanent deformation at high temperatures.

Utilization of slaked lime for the regulation of pH value in the process of copper

Directory of Open Access Journals (Sweden)

Petković Aleksandar V.

2009-01-01

Full Text Available The investigations of used lime at plant from company Messer-Tehnogas, Belgrade, were in the aim to improvement technologically results from flotation concentration of copper minerals in flotation plant Veliki Krivelj. This paper shows usage of slaked lime, which is waste in the process of technical gas production, for regulation of pH value in the process of copper minerals flotation concentration. It is important to point out that slaked lime is a waste material that is not dangerous. Preparation and dosage includes preparation procedures, which enable introduction into flotation process with the aim of achieving better results. Lime from Limekiln Zagrađe is brought into four storage places in flotation. Volume of each storage place is 80 m3. Lime in pieces from storage place is added by airbladders on transportation line and by system of transportation lines lime gets to the ball mill. At the mill entrance water is added and then follows lime grinding. Milk glass of lime thus prepared goes to the pump basket from where is transported by pipeline to conditioner, and then by manual and (or automatic valves it is dosed to the flotation concentration of copper minerals process. Prospect of advancement and rationalization of the used lime in flotation plant Bor, Veliki Krivelj and Majdanpek as well as a way to link different branches of industry was demonstrated. Total cost of lime supplying, transporting, preparation and distribution related slaked lime is lower for 2.955 din/kg. Particularly, using lime from Messer in content of 2.1 g/l value of pH 11.82 is possible to obtain.

Cement-in-cement acetabular revision with a constrained tripolar component.

Science.gov (United States)

Leonidou, Andreas; Pagkalos, Joseph; Luscombe, Jonathan

2012-02-17

Dislocation of a total hip replacement (THR) is common following total hip arthroplasty (THA). When nonoperative management fails to maintain reduction, revision surgery is considered. The use of constrained acetabular liners has been extensively described. Complete removal of the old cement mantle during revision THA can be challenging and is associated with significant complications. Cement-in-cement revision is an established technique. However, the available clinical and experimental studies focus on femoral stem revision. The purpose of this study was to present a case of cement-in-cement acetabular revision with a constrained component for recurrent dislocations and to investigate the current best evidence for this technique. This article describes the case of a 74-year-old woman who underwent revision of a Charnley THR for recurrent low-energy dislocations. A tripolar constrained acetabular component was cemented over the primary cement mantle following removal of the original liner by reaming, roughening the surface, and thoroughly irrigating and drying the primary cement. Clinical and radiological results were good, with the Oxford Hip Score improving from 11 preoperatively to 24 at 6 months postoperatively. The good short-term results of this case and the current clinical and biomechanical data encourage the use of the cement-in-cement technique for acetabular revision. Careful irrigation, drying, and roughening of the primary surface are necessary. Copyright 2012, SLACK Incorporated.

ULTRA-LIGHTWEIGHT CEMENT

International Nuclear Information System (INIS)

Fred Sabins

2001-01-01

The objective of this project is to develop an improved ultra-lightweight cement using ultra-lightweight hollow glass spheres (ULHS). Work reported herein addresses Task 1: Assess Ultra-Lightweight Cementing Issues, Task 2: Review Russian Ultra-Lightweight Cement Literature, Task 3: Test Ultra-Lightweight Cements, and Task 8: Develop Field ULHS Cement Blending and Mixing Techniques. Results reported this quarter include: preliminary findings from a literature review focusing on problems associated with ultra-lightweight cements; summary of pertinent information from Russian ultra-lightweight cement literature review; laboratory tests comparing ULHS slurries to foamed slurries and sodium silicate slurries for two different applications; and initial laboratory studies with ULHS in preparation for a field job

Admixture of lime in connection with deep rotary cultivation for short rotation energy forest

Energy Technology Data Exchange (ETDEWEB)

Danfors, B; Stambeck, A; Aasberg, G

1985-01-01

Spaghnum soils, which could be used for production of short rotation energy forests (Salix), require lime for the adjustment of the pH-level to obtain production at acceptable levels. It is necessary that the lime is distributed uniformly in the soil profile to a depth of at least 40-50 cm. The investigation has studied three methods of spreading and incorporating lime in the uppermost layer of soil. The first method concerned ploughing of peat soil with a conventional agricultural plough, the second method concerned rotovation with an agricutural rotovator to maximally 20 cm depth. In both cases the lime has been spread with a centrifugal broadcaster before the soil tillage. The third method implied simultaneous spreading of the lime and rotovation of the peat to a depth of maximally 50 cm, JTI has built and constructed a machine for this purpose. Ploughing as the only method of soil tillage of peat soils before planting of short rotation energy forests is rejected for two reasons. 1. Certain peat soils which have such mechanical properties that they immediately completely clog a plough. 2. The deficient distribution of lime in the ploughed layer. Rotovation with an agricultural rotovator has been done with good results. The delivery of lime in connection with the rotovation works well provided that the lime is dry. The peat is efficiently disintegrated and the lime gets a sufficiently uniform admixture. The cultivation depth, 40-50 cm, appears to be sufficient for the Salix plants to cope with the water supply during the summer. Limitations which should be discussed concern the cost of such an intensive and deep tillage of the peat.

Nutrient leaching potential following application of papermill lime-sludge to an acidic clay soil

Directory of Open Access Journals (Sweden)

S. C. Vettorazzo

2001-09-01

Full Text Available This experiment was carried out under greenhouse conditions with soil pots during 210 days, to evaluate the effect of calcitic papermill lime-sludge application (at the rates 0, 773, 1.547, and 2.320 mg kg-1 or respective equivalents to control, 2, 4, and 6 t ha-1, on chemical composition of soil leachate and its effects on eucalypt growth and yield. Highest soil leachate pH, SO4, and Na concentrations occurred in the 4 and 6 t ha-1 treatments. Soil leachate nitrate concentrations decreased with increasing lime-sludge rate. Soil leachate phosphate remained low (below the detection limit in all treatments until 120 days, while the concentration increased in the lime-sludge treatments at 210 days (last sampling in about 600 mg L-1. Lime-sludge decreased leachate Mg concentration, but had no significant effect among rates. Soil leachate Ca, K, B, Cu, Fe, and Zn did not change significantly for any lime-sludge application rates. The maximum NO3, Ca, Mg, K, and Na concentrations in the soil leachate occurred at 60 days after lime-sludge application (leaching equivalent to 1 pore volume, but for pH and SO4, the maximum occurred at 210 days (leaching equivalent to 4 pore volumes. Lime-sludge application decreased the concentration of exchangeable Al in the soil. Plant diameter growth and dry matter yield were increased with increasing lime-sludge rate. Beneficial effects on mineral nutrition (P, K, Ca, B, and Zn of eucalypts were also obtained by the application of 4 and 6 t ha-1 of lime-sludge.

Terrestrial liming benefits birds in an acidified forest in the northeast.

Science.gov (United States)

Pabian, Sarah E; Brittingham, Margaret C

2007-12-01

Studies in Europe have reported negative effects of acid deposition on forest birds, and research in North America has identified links between forest bird abundance and rates of acid deposition. We examined the bird community in an acidified forest in central Pennsylvania (USA) and evaluated the effects of terrestrial lime application on birds. We used a before-after control-impact (BACI) study design, with one year of observation before (2003) and three years after lime application (2004, 2005, and 2006). Between the 2003 and 2004 field seasons, 4500 kg/ha of dolomitic lime were applied to two of four 100-ha watersheds. Each year, we monitored bird abundance and Ovenbird (Seiurus aurocapilla) eggshell thickness and territory size. Soil and snail abundance data were also collected. The bird community and territory size results indicated that the study area may be providing low-quality habitat for forest birds, perhaps as a result of acid deposition. We found lower forest bird abundances than have been found in less acidified areas of Pennsylvania, and larger Ovenbird territory sizes than have been found in other studies. We found a significant positive relationship between soil calcium and bird abundance, indicating that soil calcium may affect bird abundance. Liming increased soil calcium and pH and led to increased snail and bird abundances. After liming, bird abundance was positively related to snail abundance. No significant changes occurred in Ovenbird territory size or eggshell thickness. Our results suggest that acid deposition could be responsible for reduced bird abundance, and that liming is a potential mitigation technique.

Experimental Effects of Lime Application on Aquatic Macrophytes: 2. Growth Response Versus Treatment Time and Lime Concentration

National Research Council Canada - National Science Library

James, William F; Barko, John W

2006-01-01

This research investigated the effects of applying lime (as calcium hydroxide; Ca(OH)2) either early or later in the life cycle on the growth, survivorship, and reproductive success of Sago Pondweed...

Experimental study on compressive strength of sediment brick masonry

Science.gov (United States)

Woen, Ean Lee; Malek, Marlinda Abdul; Mohammed, Bashar S.; Chao-Wei, Tang; Tamunif, Muhammad Thaqif

2018-02-01

The effects of pre-wetted unit bricks, mortar type and slenderness ratio of prisms on the compressive strength and failure mode of newly developed sediment brick have been evaluated and compared to clay brick and cement-sand bricks. The results show that pre-wetted sediment brick masonry exhibits higher compressive strength of up to 20% compared to the dry sediment masonry. Using cement-lime mortar leads to lower compressive strength compared to cement mortar. However, the sediment brick masonry with the cement lime mortar exhibit higher compressive strength in comparison with cement mortar masonry. More of diagonal shear cracks have been observed in the failure mode of the sediment bricks masonry compared to clay and cement-sand bricks masonry that show mostly vertical cracks and crushing. The sediment unit bricks display compressive strength in between clay and cement-sand bricks.

Effects of hydrated lime on radionuclides stabilization of Hanford tank residual waste.

Science.gov (United States)

Wang, Guohui; Um, Wooyong; Cantrell, Kirk J; Snyder, Michelle M V; Bowden, Mark E; Triplett, Mark B; Buck, Edgar C

2017-10-01

Chemical stabilization of tank residual waste is part of a Hanford Site tank closure strategy to reduce overall risk levels to human health and the environment. In this study, a set of column leaching experiments using tank C-104 residual waste were conducted to evaluate the leachability of uranium (U) and technetium (Tc) where grout and hydrated lime were applied as chemical stabilizing agents. The experiments were designed to simulate future scenarios where meteoric water infiltrates through the vadose zones into the interior of the tank filled with layers of grout or hydrated lime, and then contacts the residual waste. Effluent concentrations of U and Tc were monitored and compared among three different packing columns (waste only, waste + grout, and waste + grout + hydrated lime). Geochemical modeling of the effluent compositions was conducted to determine saturation indices of uranium solid phases that could control the solubility of uranium. The results indicate that addition of hydrated lime strongly stabilized the uranium through transforming uranium to a highly insoluble calcium uranate (CaUO 4 ) or similar phase, whereas no significant stabilization effect of grout or hydrated lime was observed on Tc leachability. The result implies that hydrated lime could be a great candidate for stabilizing Hanford tank residual wastes where uranium is one of the main concerns. Published by Elsevier Ltd.

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......−liquid reactions are discussed, as are the influences of particles sizes on clinker phase formation. Furthermore, a mechanism for clinker phase formation in an industrial rotary kiln reactor is outlined....

Effect of Lime on characteristics of consolidation, strength, swelling and plasticity of fine grained soil

Science.gov (United States)

Estabragh, A. R.; Bordbar, A. T.; Parsaee, B.; Eskandari, Gh.

2009-04-01

Using Lime as an additive material to clayey soil is one of the best effective technique in building the soil structures to get some purposes such as soil stabilization, soil reinforcement and decreasing soil swelling. In this research the effect of Lime on geotechnical characteristics of a clayey soil was investigated. Soil specimen types used in this study were consisted of clayey soil as the control treatment and clay mixed with different weight fractions of lime, 4, 6, 8 & 10 percent. Some experiments such as CBR, atterburg limits, compaction, consolidation and swelling was conducted on specimens. Results revealed that adding lime to soil would change its physical and mechanical properties. Adding lime increase the compression strength and consolidation coefficient and decrease swelling potential and maximum dry density. According to the results, Atterburg experiments show that presence of lime in soil increase the liquid limit of low plasticity soil and decrease the liquid limit of high plasticity soil, but totally it decreases the plasticity index of soils. Key words: soil stabilization, lime, compression strength, swelling, atterburg limits, compaction

Arsenic immobilization by calcium-arsenic precipitates in lime treated soils

International Nuclear Information System (INIS)

Moon, Deok Hyun; Dermatas, Dimitris; Menounou, Nektaria

2004-01-01

Lime-based stabilization/solidification (S/S) can be an effective remediation alternative for the immobilization of arsenic (As) in contaminated soils and sludges. However, the exact immobilization mechanism has not been well established. Based on previous research, As immobilization could be attributed to sorption and/or inclusion in pozzolanic reaction products and/or the formation of calcium-arsenic (Ca-As) precipitates. In this study, suspensions of lime-As and lime-As-kaolinite were studied in an attempt to elucidate the controlling mechanism of As immobilization in lime treated soils. Aqueous lime-As suspensions (slurries) with varying Ca/As molar ratios (1:1, 1.5:1, 2:1, 2.5:1 and 4:1) were prepared and soluble As concentrations were determined. X-Ray diffraction (XRD) analyses were used to establish the resulting mineralogy of crystalline precipitate formation. Depending on the redox state of the As source, different As precipitates were identified. When As (III) was used, the main precipitate formation was Ca-As-O. With As(V) as the source, Ca 4 (OH) 2 (AsO 4 ) 2 ·4H 2 O formed at Ca/As molar ratios greater than 1:1. A significant increase in As (III) immobilization was observed at Ca/As molar ratios greater than 1:1. Similarly, a substantial increase in As (V) immobilization was noted at Ca/As molar ratios greater than or equal to 2.5:1. This observation was also confirmed by XRD. Lime-As-kaolinite slurries were also prepared at different Ca/As molar ratios. These slurries were used to specifically investigate the possibility of forming pozzolanic reaction products. Such products would immobilize As by sorption and/or inclusion along with the formations of different As precipitates. Toxicity Characteristic Leaching Procedure (TCLP) tests were used to evaluate As leachability in these slurries. XRD analyses revealed no pozzolanic reaction product formation. Instead, As immobilization was found to be precipitation controlled. The same Ca-As precipitate, Ca

Acidic deposition: State of science and technology. Report 15. Liming acidic surface waters. Final report

International Nuclear Information System (INIS)

Olem, H.; Thornelof, E.; Sandoy, S.; Schreiber, R.K.

1990-09-01

The document describes the science and technology of aquatic liming--a method for improving the water quality of acidic surface waters to restore or enhance fisheries. The report is a comprehensive compilation of years of research in North America and Europe by dozens of scientists. Several mitigation technologies--including those that have only been proposed--are critically evaluated along with the effects of liming on water chemistry and aquatic biota. Through these evaluations, the state of the science and technology of aquatic liming is identified for the reader. Whole-lake liming is now recognized as a valuable management tool for acidic surface waters and their fisheries. However, some liming technologies are considered experimental and will need further evaluation. Distinctions between technologies are included--as is the distinction between liming acidic surface waters and reducing acidifying emissions

Characterization of cutting soda-lime glass sludge for the formulation of red ceramic products

International Nuclear Information System (INIS)

Filogonio, P.H.C.; Reis, A.S.; Louzada, D.M.; Della, V.P.

2014-01-01

Considering previous works that have demonstrated the feasibility of soda-lime glass incorporation into red ceramics, this paper aims to determine the potential for incorporation of cutting soda-lime glass sludge in red ceramic manufacturing. Therefore, the waste was characterized by X-ray fluorescence, X-ray diffraction, particle size distribution and thermal behavior. The results confirm the chemical and mineralogical similarity between waste and soda-lime glass. Because of this similarity, it is concluded that the soda-lime glass waste has the capability to be used in the manufacturing of red ceramics. (author)

Study of lime vs. no lime in cold in-place recycled asphalt concrete pavements : final report.

Science.gov (United States)

1991-09-01

The resilient characteristics of cold in-place recycled asphalt concrete with and without lime were examined. Six core samples were obtained from a site two months after construction; six months later, six additional core samples were obtained from t...

Self-healing of lime based mortars: Microscopy observations on case studies

NARCIS (Netherlands)

Lubelli, B.; Nijland, T.G.; Hees, R.P.J. van

2011-01-01

Lime mortars have, up to a certain extent, a self-healing capacity which may contribute to their durability. Self-healing in lime mortars consists of a process of dissolution, transport and re-precipitation of calcium compounds to heal cracks and fissures. The spontaneous occurrence of self-healing

Self-healing of lime based mortars : Microscopy observations on case studies

NARCIS (Netherlands)

Lubelli, B.; Nijland, T.G.; Van Hees, R.P.J.

2011-01-01

Lime mortars have, up to a certain extent, a self-healing capacity which may contribute to their durability. Self-healing in lime mortars consists of a process of dissolution, transport and re-precipitation of calcium compounds to heal cracks and fissures. The spontaneous occurrence of self-healing

A Twofold Comparison between Dual Cure Resin Modified Cement and Glass Ionomer Cement for Orthodontic Band Cementation.

Science.gov (United States)

Attar, Hanaa El; Elhiny, Omnia; Salem, Ghada; Abdelrahman, Ahmed; Attia, Mazen

2016-12-15

To test the solubility of dual cure resin modified resin cement in a food simulating solution and the shear bond strength compared to conventional Glass ionomer cement. The materials tested were self-adhesive dual cure resin modified cement and Glass Ionomer (GIC). Twenty Teflon moulds were divided into two groups of tens. The first group was injected and packed with the modified resin cement, the second group was packed with GIC. To test the solubility, each mould was weighed before and after being placed in an analytical reagent for 30 days. The solubility was measured as the difference between the initial and final drying mass. To measure the Shear bond strength, 20 freshly extracted wisdom teeth were equally divided into two groups and embedded in self-cure acrylic resin. Four mm sections of stainless steel bands were cemented to the exposed buccal surfaces of teeth under a constant load of 500 g. Shear bond strength was measured using a computer controlled materials testing machine and the load required to deband the samples was recorded in Newtons. GIC showed significantly higher mean weight loss and an insignificant lower Shear bond strength, compared to dual cure resin Cement. It was found that dual cure resin modified cement was less soluble than glass ionomer cement and of comparable bond strength rendering it more useful clinically for orthodontic band cementation.

The mechanical effect of the existing cement mantle on the in-cement femoral revision.

LENUS (Irish Health Repository)

Keeling, Parnell

2012-08-01

Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct.

Nanosecond (ns) laser transfer of silver nanoparticles from silver-exchanged soda-lime glass to transparent soda-lime glass and shock waves formation

International Nuclear Information System (INIS)

Sow, Mohamed Chérif; Blondeau, Jean-Philippe; Sagot, Nadine; Ollier, Nadège; Tite, Teddy

2015-01-01

Highlights: • Silver nanoparticles growth by nanosecond laser irradiation of silver exchanged soda-lime glasses. • Silver nanoparticles transfer. • Nanosecond laser induced shock waves formation on glass. - Abstract: In this contribution, we showed for the first time in our knowledge a single-step process for silver clusters and nanoparticles growth and transfer from silver-exchanged soda-lime glass to un-exchanged soda-lime glass (transparent glass in visible and NIR domain) by nanosecond (ns) laser irradiation. The transferred silver nanoparticles in transparent glass are strongly linked to the glass surface. In addition, we point out the formation of shock waves, with selective silver clustering on the top wave. This technique provides an alternative and simple way to obtain metallic nanoparticles in different media which can be traversed by laser wavelength used. Moreover, this experiment is made at room temperature and air environment. It is worth noting that our technique requires a glass previously doped with the corresponding silver ions

Impact of lime treated soils performance on design of earthfill dikes

Directory of Open Access Journals (Sweden)

Nerincx Nicolas

2016-01-01

Full Text Available Nowadays soil treatment with lime in civil engineering is widespread in many countries on all continents, within several construction fields. The interest of the hydraulic works community regarding this technique is currently growing. It has been indeed shown during the last decade that appropriate treatment technologies provide lime treated soils with high level properties such as excellent homogeneity, low permeability, internal and external erosion resistance and mechanical stability. Those have been shown in laboratory and for some properties with full scale experiments. The so conferred soil properties can lead to innovative earthfill dams and dikes designs by addressing some of the typical designer’s problems, such as stability, watertightness, internal erosion, surface protection and flood control. However, lime treated soil external erosion resistance is still to be quantified in the field for proper designing and dimensioning of lime treated soil external erosion protection or spillways. With this purpose, an experimental earthfill dike has been built along the river Vidourle (France in July 2015, in the frame of the French R&D program “DigueELITE”. This 50 m long and 3,5 m high dike is made of lime treated silt and is provided with sensors (succion, water content and temperature and piezometer in order to be monitored. It will also be tested against surface erosion. The final objective of this R&D program is to provide guidelines for designing innovative overflow resistant earthfill dikes. This article describes the performance reached by lime treated soils and associated design requirements and application; the experimental dike construction and lessons learned; the monitoring program; the dike design perspectives opened by soil treatment.

Compressibility of soft Iraqi soil stabilized with traditional Iraqi stabilizers (cement and lime

Directory of Open Access Journals (Sweden)

Baqir Husam

2018-01-01

Full Text Available This study shows an improvement of two types of clay soil brought from different parts of Iraq. The first soil (A from Al - Zaafaraniya site in Baghdad governorate. The second soil (B from Garma Ali site in the Al Basra governorate, Iraq. Soft clayey soils were treated by a combination of sulphate resistance Portland cement (PC and Quicklime (LQ to modify and stability. PC was added in percentages of 2,4,6,8 and 10%, as well as, LQ was added to 2 and 4%, of dry weight. Laboratory tests to determine specific gravity, Atterbergs limits and standard proctor test were conducted. Also, the main objective of this research is the concentrating on compression ratio (CR, the Rebound (Swelling ratio (RR and the stiffness during the modulus of elasticity (Es for treated and natural soils procreation from consolidation test. The results from laboratory tests shows high ability on the enhancing in terms of reduction in plasticity index (greatly increased workability, reduction in compression ratio (CR, reduction in the Rebound (Swelling ratio (RR, increase in the modulus of elasticity (Es. The change in moisture-density relationships resulting in lower maximum dry densities, higher optimum water content, and less variation of dry density from the maximum over a much wider range of water contents.

REMOVAL OF BERYLLIUM FROM DRINKING WATER BY CHEMICAL COAGULATION AND LIME SOFTENING

Science.gov (United States)

The effectiveness of conventional drinking water treatment and lime softening was evaluated for beryllium removal from two drinking water sources. ar test studies were conducted to determine how common coagulants (aluminum sulfate and ferric chloride and lime softening performed ...

Evaluation of the amount of excess cement around the margins of cement-retained dental implant restorations: the effect of the cement application method.

Science.gov (United States)

Chee, Winston W L; Duncan, Jesse; Afshar, Manijeh; Moshaverinia, Alireza

2013-04-01

Complete removal of excess cement from subgingival margins after cementation of implant-supported restorations has been shown to be unpredictable. Remaining cement has been shown to be associated with periimplant inflammation and bleeding. The purpose of this study was to investigate and compare the amount of excess cement after cementation with 4 different methods of cement application for cement-retained implant-supported restorations. Ten implant replicas/abutments (3i) were embedded in acrylic resin blocks. Forty complete veneer crowns (CVCs) were fabricated by waxing onto the corresponding plastic waxing sleeves. The wax patterns were cast and the crowns were cemented to the implant replicas with either an interim (Temp Bond) or a definitive luting agent (FujiCEM). Four methods of cement application were used for cementation: Group IM-Cement applied on the internal marginal area of the crown only; Group AH-Cement applied on the apical half of the axial walls of the crown; Group AA-Cement applied to all axial walls of the interior surface of the crown, excluding the occlusal surface; and Group PI-Crown filled with cement then seated on a putty index formed to the internal configuration of the restoration (cementation device) (n=10). Cement on the external surfaces was removed before seating the restoration. Cement layers were applied on each crown, after which the crown was seated under constant load (80 N) for 10 minutes. The excess cement from each specimen was collected and measured. One operator performed all the procedures. Results for the groups were compared, with 1 and 2-way ANOVA and the Tukey multiple range test (α=.05). No significant difference in the amount of excess/used cement was observed between the 2 different types of cements (P=.1). Group PI showed the least amount of excess cement in comparison to other test groups (P=.031). No significant difference was found in the amount of excess cement among groups MI, AH, and AA. Group AA showed the

76 FR 76760 - Gray Portland Cement and Cement Clinker From Japan

Science.gov (United States)

2011-12-08

... and Cement Clinker From Japan Determination On the basis of the record \\1\\ developed in the subject... duty order on gray Portland cement and cement clinker from Japan would be likely to lead to... and Cement Clinker from Japan: Investigation No. 731- TA-461 (Third Review). By order of the...

A Comparison between Lime and Alkaline Hydrogen Peroxide Pretreatments of Sugarcane Bagasse for Ethanol Production

Science.gov (United States)

Rabelo, Sarita C.; Filho, Rubens Maciel; Costa, Aline C.

Pretreatment procedures of sugarcane bagasse with lime (calcium hydroxide) or alkaline hydrogen peroxide were evaluated and compared. Analyses were performed using 2 × 2 × 2 factorial designs, with pretreatment time, temperature, and lime loading and hydrogen peroxide concentration as factors. The responses evaluated were the yield of total reducing sugars (TRS) and glucose released from pretreated bagasse after enzymatic hydrolysis. Experiments were performed using the bagasse as it comes from an alcohol/ sugar factory and bagasse in the size range of 0.248 to 1.397 mm (12-60 mesh). The results show that when hexoses and pentoses are of interest, lime should be the pretreatment agent chosen, as high TRS yields are obtained for nonscreened bagasse using 0.40 g lime/g dry biomass at 70 °C for 36 h. When the product of interest is glucose, the best results were obtained with lime pretreatment of screened bagasse. However, the results for alkaline peroxide and lime pretreatments of nonscreened bagasse are not very different.

An introduction to LIME 1.0 and its use in coupling codes for multiphysics simulations.

Energy Technology Data Exchange (ETDEWEB)

Belcourt, Noel; Pawlowski, Roger Patrick; Schmidt, Rodney Cannon; Hooper, Russell Warren

2011-11-01

LIME is a small software package for creating multiphysics simulation codes. The name was formed as an acronym denoting 'Lightweight Integrating Multiphysics Environment for coupling codes.' LIME is intended to be especially useful when separate computer codes (which may be written in any standard computer language) already exist to solve different parts of a multiphysics problem. LIME provides the key high-level software (written in C++), a well defined approach (with example templates), and interface requirements to enable the assembly of multiple physics codes into a single coupled-multiphysics simulation code. In this report we introduce important software design characteristics of LIME, describe key components of a typical multiphysics application that might be created using LIME, and provide basic examples of its use - including the customized software that must be written by a user. We also describe the types of modifications that may be needed to individual physics codes in order for them to be incorporated into a LIME-based multiphysics application.

Experimental investigation of the long term dissolution properties of a cement-based vault backfill

International Nuclear Information System (INIS)

Butcher, E.J.; Borwick, J.; Thorburn, A.A.; Williams, S.J.

2012-01-01

One concept for the long-term management of packages of intermediate-level radioactive waste (ILW) is to place them in underground vaults in a Geological Disposal Facility (GDF). After the packaged waste is placed in the vault it is planned to fill the space around the waste packages with a cement-based backfill prior to closure of the facility. The currently specified backfill is the NRVB (Nirex Reference Vault Backfill), composed of a blend of Portland cement, limestone flour and hydrated lime. Leaching trials are ongoing at the UK National Nuclear Laboratory (NNL) to investigate the dissolution of NRVB until pH values typical of calcium carbonate are achieved. The objective of this work is to determine the buffering capacity of samples of the NRVB, and to allow the sequential release of the alkalinity from the intact samples to be monitored. Leaching is being performed utilising three leachants: deionised water and two saline solutions. Trials have been performed in duplicate for each leachant to allow an initial assessment to be made of the reproducibility of the data produced. In order to simulate the conditions expected in the GDF the approach being used in the trials is a flow through experiment utilising a flexible wall permeameter, within a 35 deg temperature-controlled cell

Glass-Forming Ability of Soda Lime Borate Liquids

DEFF Research Database (Denmark)

Zheng, Qiuju; Mauro, J.C.; Smedskjær, Morten Mattrup

2012-01-01

We investigate the composition dependence of glass-forming ability (GFA) of a series of iron-containing soda lime borate liquids by substituting Na2O for B2O3. We have characterized GFA by measuring the glass stability against crystallization using a differential scanning calorimeter (DSC......). The results show that the GFA decreases when substituting Na2O for B2O3. Moreover, we find that there is no direct link between the kinetic fragility and GFA for the soda lime borate series studied herein. We have also discovered and clarified a striking thermal history dependence of the glass stability...

Cementing a wellbore using cementing material encapsulated in a shell

Energy Technology Data Exchange (ETDEWEB)

Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Spadaccini, Christopher M.; Cowan, Kenneth Michael

2016-08-16

A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

Cementing a wellbore using cementing material encapsulated in a shell

Energy Technology Data Exchange (ETDEWEB)

Aines, Roger D.; Bourcier, William L.; Duoss, Eric B.; Floyd, III, William C.; Spadaccini, Christopher M.; Vericella, John J.; Cowan, Kenneth Michael

2017-03-14

A system for cementing a wellbore penetrating an earth formation into which a pipe extends. A cement material is positioned in the space between the wellbore and the pipe by circulated capsules containing the cement material through the pipe into the space between the wellbore and the pipe. The capsules contain the cementing material encapsulated in a shell. The capsules are added to a fluid and the fluid with capsules is circulated through the pipe into the space between the wellbore and the pipe. The shell is breached once the capsules contain the cementing material are in position in the space between the wellbore and the pipe.

Physical-Chemical and Mechanical characterization of some cement products in Madagascar by using Technical Analysis X-ray Fluorescence and tests receptions

International Nuclear Information System (INIS)

Rasolondraibe, I.P.

2014-01-01

The present work is completely realized at the 'Institut National des Sciences et Techniques Nucleaires (INSTN - Madagascar)' and 'Laboratoire National des Travaux Publics et du Batiment (LNTPB)'. Its purpose is to carry out the physico - chemical and mechanical analysis of the cements products present in Madagascar in order to ensure their qualities in case of Building and Publics Works construction safety. The necessary chemical elements in cements are the loss in ignition (LOI), the insoluble residues (RI), the silica (SiO 2 ), the lime (CaO), the alumina (Al 2 O 3 ), the iron oxide (Fe 2 O 3 ), the magnesia (MgO) and the sulfate (SO 3 ). In this work, analytical laboratory in X - Ray fluorescence department of INSTN - Madagascar using the direct excitation X - Ray fluorescence technique outline their research on lime and iron oxide while L.N.T.P.B materials laboratory can make all using test method by gravimetry and titrimetry according to EN 196 - 2. The results of INSTN - Madagascar show that the concentrations of calcium oxide and iron oxide are consistent with the concentration range provided by the laboratory materials L.N.T.P.B respectively equal to 50.00 % - 65.00 % and 1.00 % - 5.00 %. The results between the two laboratories have a - 4.76 % iron oxide maximum relative deviation and 4,77 % calcium oxide maximum relative deviation. Complementary physical and mechanical tests were performed at L.N.T.P.B materials laboratory respectively in accordance with EN 196 - 3 and EN 196 - 1. The used conventional X - ray fluorescence method fulfill the scope of application needed with good correlation less than ± 5 %. [fr

Lime Kiln Modeling. CFD and One-dimensional simulations

Energy Technology Data Exchange (ETDEWEB)

Svedin, Kristoffer; Ivarsson, Christofer; Lundborg, Rickard

2009-03-15

The incentives for burning alternative fuels in lime kilns are growing. An increasing demand on thorough investigations of alternative fuel impact on lime kiln performance have been recognized, and the purpose of this project has been to develop a lime kiln CFD model with the possibility to fire fuel oil and lignin. The second part of the project consists of three technical studies. Simulated data from a one-dimensional steady state program has been used to support theories on the impact of biofuels and lime mud dryness. The CFD simulations was carried out in the commercial code FLUENT. Due to difficulties with the convergence of the model the calcination reaction is not included. The model shows essential differences between the two fuels. Lignin gives a different flame shape and a longer flame length compared to fuel oil. Mainly this depends on how the fuel is fed into the combustion chamber and how much combustion air that is added as primary and secondary air. In the case of lignin combustion the required amount of air is more than in the fuel oil case. This generates more combustion gas and a different flow pattern is created. Based on the values from turbulent reaction rate for the different fuels an estimated flame length can be obtained. For fuel oil the combustion is very intense with a sharp peak in the beginning and a rapid decrease. For lignin the combustion starts not as intense as for the fuel oil case and has a smoother shape. The flame length appears to be approximately 2-3 meter longer for lignin than for fuel oil based on turbulent reaction rate in the computational simulations. The first technical study showed that there are many benefits of increasing dry solids content in the lime mud going into a kiln such as increased energy efficiency, reduced TRS, and reduced sodium in the kiln. However, data from operating kilns indicates that these benefits can be offset by increasing exit gas temperature that can limit kiln production capacity. Simulated

77 FR 45715 - Application of Key Lime Air Corporation for Commuter Authority

Science.gov (United States)

2012-08-01

... DEPARTMENT OF TRANSPORTATION Office of the Secretary [Docket DOT-OST-2009-0116] Application of Key Lime Air Corporation for Commuter Authority AGENCY: Department of Transportation. ACTION: Notice of... Lime Air Corporation fit, willing, and able, and awarding it a Commuter Air Carrier Authorization...

Belowground ectomycorrhizal fungal communities respond to liming in three southern Swedish coniferous forest stands

DEFF Research Database (Denmark)

Kjøller, Rasmus; Clemmensen, Karina

2009-01-01

In this study we report on changes in the belowground ectomycorrhizal fungal communities in southern Swedish coniferous forests as a consequence of liming with 3-7 ton limestone per hectare 16 years prior to the study. A total of 107 ectomycorrhizal fungi were identified from 969 independently...... sampled root tips by sequencing the internal transcribed spacer region of the ribosomal DNA. Forty, 59 and 51 species were identified in three pine and spruce forests. Within all sites only about 25% of the species overlapped between the limed and the reference areas. However, the most abundant species...... were often found in both limed and reference plots and 60-70% of the root tips at each site were colonised by species occurring in both limed and reference plots. Across all three sites, fungal species belonging to the genus Tylospora and the order Pezizales became significantly more frequent in limed...

California Bearing Ratio (CBR) test on stabilization of clay with lime addition

Science.gov (United States)

Hastuty, I. P.; Roesyanto; Limbong, M. N.; Oberlyn, S. J.

2018-02-01

Clay is a type of soil with particles of certain minerals giving plastic properties when mixed with water. Soil has an important role in a construction, besides as a building material in a wide variety of civil engineering works, soil is also used as supporting foundation of the building. Basic properties of clay are rock-solid in dry and plastic with medium water content. In high water content, clay becomes sticky like (cohesive) and soften. Therefore, clay stabilization is necessary to repair soil’s mechanical properties. In this research, lime is use as a stabilizer that contains the Ca+ element to bond bigger particles. Lime used is slaked lime Ca(OH)2. Clay used has liquid limitation (LL) value of 47.33%, plasticity index of 29.88% and CBR value 6.29. The results explain about 10% lime mixture variation gives the optimum stabilized clay with CBR value of 8.75%.

Effects of watershed and in-stream liming on macroinvertebrate communities in acidified tributaries to an Adirondack lake

Science.gov (United States)

George, Scott D.; Baldigo, Barry P.; Lawrence, Gregory B.; Fuller, Randall L.

2018-01-01

Liming techniques are being explored as a means to accelerate the recovery of aquatic biota from decades of acid deposition in many regions. The preservation or restoration of native sportfish populations has typically been the impetus for liming programs, and as such, less attention has been given to its effects on other biological assemblages such as macroinvertebrates. Furthermore, the differing effects of various lime application strategies such as in-stream and watershed applications are not well understood. In 2012, a program was initiated using in-stream and aerial (whole-watershed) liming to improve water quality and Brook Trout (Salvelinus fontinalis) recruitment in three acidified tributaries of a high-elevation Adirondack lake in New York State. Concurrently, macroinvertebrates were sampled annually between 2013 and 2016 at 3 treated sites and 3 untreated reference sites to assess the effects of each liming technique on this community. Despite improvements in water chemistry in all three limed streams, our results generally suggest that neither liming technique succeeded in improving the condition of macroinvertebrate communities. The watershed application caused an immediate and unsustained decrease in the density of macroinvertebrates and increase in the proportion of sensitive taxa. These changes were driven primarily by a one-year 71 percent reduction of the acid-tolerant Leuctra stoneflies and likely represent an initial chemistry shock from the lime application rather than a recovery response. The in-stream applications appeared to reduce the density of macroinvertebrates, particularly in one stream where undissolved lime covered the natural substrate. The close proximity of our study sites to the in-stream application points (50 and 1230 m) may partly explain these negative effects. Our results are consistent with prior studies of in-stream liming which indicate that this technique often fails to restore macroinvertebrate communities to a pre

Feasibility of producing nano cement in a traditional cement factory in Iraq

Directory of Open Access Journals (Sweden)

Sada Abdalkhaliq Hasan Alyasri

2017-12-01

Full Text Available This study investigates the economic feasibility of producing nano cement through the establishment of a production line within an existing cement factory. Creating a nano cement production line within the Alkufa Cement factory in Iraq is selected as a case study. Evaluation measures including internal rate of return (IRR, net present value (NPV and breakeven point (BEP are used to evaluate the possible gain that can be achieved from this option. The results demonstrated a positive NPV. The IRR is found to be 26.8% and BEP is reached within 3 years after the establishment of the line. This indicates that producing nano cement in the existing cement factory is economically feasible and can be more advantageous than the ordinary cement.

The mechanical effect of the existing cement mantle on the in-cement femoral revision.

Science.gov (United States)

Keeling, Parnell; Lennon, Alexander B; Kenny, Patrick J; O'Reilly, Peter; Prendergast, Patrick J

2012-08-01

Cement-in-cement revision hip arthroplasty is an increasingly popular technique to replace a loose femoral stem which retains much of the original cement mantle. However, some concern exists regarding the retention of the existing fatigued and aged cement in such cement-in-cement revisions. This study investigates whether leaving an existing fatigued and aged cement mantle degrades the mechanical performance of a cement-in-cement revision construct. Primary cement mantles were formed by cementing a polished stem into sections of tubular steel. If in the test group, the mantle underwent conditioning in saline to simulate ageing and was subject to a fatigue of 1 million cycles. If in the control group no such conditioning or fatigue was carried out. The cement-in-cement procedure was then undertaken. Both groups underwent a fatigue of 1 million cycles subsequent to the revision procedure. Application of a Mann-Whitney test on the recorded subsidence (means: 0.51, 0.46, n=10+10, P=0.496) and inducible displacement (means: 0.38, 0.36, P=0.96) revealed that there was no statistical difference between the groups. This study represents further biomechanical investigation of the mechanical behaviour of cement-in-cement revision constructs. Results suggest that pre-revision fatigue and ageing of the cement may not be deleterious to the mechanical performance of the revision construct. Thus, this study provides biomechanical evidence to back-up recent successes with this useful revision technique. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effect of liquid liming on sorghum growth in an Ultisol.

Directory of Open Access Journals (Sweden)

Manuel E. Camacho

2015-06-01

Full Text Available   The aim of this study was to evaluate the effects of the application of liquid lime on sorghum growth in an Ultisol. This research was conducted between August and November, 2011 at the Agricultural Research Center, San José, Costa Rica. In an Ultisol planted with sorghum, in pots of 800 ml, the following treatments where applied: control without lime, calcium carbonate at doses of 10 and 20 l/ha, magnesium oxide at doses of 10 and 20 l/ha, calcium carbonate + magnesium oxide at doses of 5 + 5 and 10 + 10 l/ha, respectively. Six weeks after planting, sorghum was harvested, measuring leaf area, dry and fresh weight of the aerial and root biomass, nutrient absorption and the soil chemical characteristics. Treatments using calcium carbonate and calcium carbonate + magnesium oxide obtained the best values of leaf area and the higher weight of the aerial and root biomass of sorghum. Even though there were no significant differences between liquid lime treatments, there were regarding control without lime and weight biomass variables. Liquid calcium carbonate significantly increased Ca absorption, and the calcium carbonate + magnesium oxide treatment at doses of 10 l/h showed the highest Mg absorption. All amendment treatments caused an improvement of the soil fertility, the most notable being the application of 20 l/ha of magnesium oxide that dropped the exchangeable acidity from 9.02 to 0.36 cmol(+/l, acidity saturation dropped from 95 to 3.3%, and pH increased from 5 to 5.7. It was concluded that the liquid liming amendments had a positive effect over the crop and the soil fertility.

The relationships among lemons, limes and citron: a chromosomal comparison.

Science.gov (United States)

Carvalho, R; Soares Filho, W S; Brasileiro-Vidal, A C; Guerra, M

2005-01-01

Lemons, limes and citron constitute a group of closely related Citrus species, whose species delimitations and taxonomic relationships are unclear. In order to identify karyotypic similarities and species relationships within this group, the CMA+/DAPI- banding pattern and the distribution of the 5S and 45S rDNA sites of 10 accessions of lime, lemon, and citron were investigated. The four cultivars of C. limon analyzed showed the same pattern of CMA+ bands and rDNA sites, suggesting that they originated from a single germplasm, later differentiated by distinct somatic mutations. The lemons C. jambhiri, C. limonia and C. volkameriana displayed karyotypes very similar to each other, but they differed from C. limon by the absence of a single chromosome with one band in each telomere. The limes, C. aurantifolia and C. limettioides, seemed less related to each other and exhibited different heteromorphic chromosome pairs. In C. aurantifolia, the presence of a chromosome type unknown in all other Citrus species cytologically known so far supports the assumption that this accession may be derived from a hybrid with a species from the subgenus Papeda or from another genus. Citrus medica was the only homozygous accession of this group and all of its chromosome types were clearly represented in limes and lemons, some of them forming heteromorphic pairs. The analysis of the distribution of rDNA sites allowed a further refinement of the comparison among accessions. The lemons and limes were heterozygous for all rDNA sites, whereas C. medica was entirely homozygous. These data support the hypothesis that C. medica is a true species while the other nine accessions are hybrids. Copyright 2005 S. Karger AG, Basel.

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

2018-06-01

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.

Application and properties of pure lime façades - case study

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Violeta Bokan Bosiljkov

2008-01-01

Full Text Available The paper presents experiences obtained during application and testing of different pure lime façades that could be successfully used in restoration of historical buildings in Slovenia. The lime façade consists of a rendering layer (rough mortar, a finishing layer (fine mortar and a protective layer of lime wash. For the design of the mortars different industrially and traditionally produced limes were chosen, based on the results of preliminary studies of the authors and experiences of a small enterprise (SE involved in the study. The façade layers were applied to the most problematic northern wall of the historic chapel made from rubble masonry. The chapel belongs to the castle Crnelo, built at the end of the 17th century in the village Turnše, not far from Ljubljana, the capital of Slovenia. The façade layers were made by skilled workers of SE, with about one year time difference between application of rendering and finishing layers, and with a protective layer of coloured lime wash applied to one to three day old finishing layers. On the rendering layers, visual inspection, water absorption tests and determination of carbonation depth were carried out before subsequent finishing layers were applied. The same on-site tests were carried out also on finished façade layers. So far, parallel to the on-site tests, compressive and water absorption tests on prisms prepared from rough mortars were carried out in laboratory.

Effect of liming on the behaviour of 90Sr and 137Cs in a lake ecosystem

International Nuclear Information System (INIS)

Outola, Iisa; Rask, Martti

2011-01-01

Liming of lakes is considered one possible remedial action to reduce the accumulation of radionuclides into fish in the case of a radiological accident. These responses were tested in field conditions in a small acidified lake that was divided into two parts: one limed with CaCO 3 and the other half left as an unlimed control. The transfer of 90 Sr from water into fish decreased on average by 50% during the first year after liming. However, at the same time the 90 Sr concentration in water increased, reaching a maximum within 6 months after liming. Approximately 50% more 90 Sr was detected in water in the limed part of the lake than on control side during the first year. 90 Sr was most probably released from the sediment as the Ca concentration and pH of the water increased. As a result of these two processes, which counterbalanced each other (increased release of 90 Sr into water from sediment and decreased transfer of 90 Sr from water into fish), the 90 Sr concentration in fish did not notably differ between the limed and control sides of the lake. Liming may only be suitable as a remedial action if carried out immediately after a radiological accident, before significant amounts of radionuclides have been deposited in lake sediments. In the case of 137 Cs, the effect of liming was less pronounced. 137 Cs activity concentration in water increased in the first year by 20% and uptake by fish decreased by 20%. - Highlights: → Acidified lake was divided into two parts: one limed with CaCO 3 and the other half left as an unlimed control. → The transfer of 90 Sr from water into fish decreased by 50% during the first year after liming. → At the same time liming increased the 90 Sr concentration in the water by 50%. → The increased amount of 90 Sr in water is assumed to have originated from the lake sediments. → The 90 Sr concentration in fish remained relatively unchanged.

Genetic variation assessment of acid lime accessions collected from south of Iran using SSR and ISSR molecular markers.

Science.gov (United States)

Sharafi, Ata Allah; Abkenar, Asad Asadi; Sharafi, Ali; Masaeli, Mohammad

2016-01-01

Iran has a long history of acid lime cultivation and propagation. In this study, genetic variation in 28 acid lime accessions from five regions of south of Iran, and their relatedness with other 19 citrus cultivars were analyzed using Simple Sequence Repeat (SSR) and Inter-Simple Sequence Repeat (ISSR) molecular markers. Nine primers for SSR and nine ISSR primers were used for allele scoring. In total, 49 SSR and 131 ISSR polymorphic alleles were detected. Cluster analysis of SSR and ISSR data showed that most of the acid lime accessions (19 genotypes) have hybrid origin and genetically distance with nucellar of Mexican lime (9 genotypes). As nucellar of Mexican lime are susceptible to phytoplasma, these acid lime genotypes can be used to evaluate their tolerance against biotic constricts like lime "witches' broom disease".

The Effect of Kaffir Lime Leaves Distillation Residue Oleoresin Concentration on Active Paper Packaging Characteristics

Science.gov (United States)

Kawiji; Utami, R.; Ulum, S.; Khasanah, L. U.; Manuhara, G. J.; Atmaka, W.

2018-03-01

Oleoresin of kaffir lime leaves distillation residue still contains some active compounds such as Citronellal, β-Citronellol, and Linalool which potential to incorporated on the active paper packaging. The purposes of this study were to determine the effect of kaffir lime leaves distillation residue oleoresin concentration on the physical characteristics, sensory characteristics, and antimicrobial activity of the active paper packaging incorporated with kaffir lime leaves distillation residue oleoresin and to determine the functional groups of active paper packaging. The concentration of kaffir lime leaves distillation residue oleoresin were varied at 0%, 2%, 4% and 6%. The result showed that the addition of kaffir lime leaves distillation residue oleoresin increased the thickness and moisture content of the paper and decreased the tensile strengths and folding endurances of active paper packaging. The microbial inhibition tends to increase along with the higher oleoresin concentration addition. Aromatic CH group were found at a wavelength of 897.90 cm-1 of on paper packaging with 2% oleoresin indicated as functional aromatic functional group allegedly obtained from the kaffir lime leaves oleoresin.

Assessment of radiological hazards of naturally occurring radioactive materials in cement industry

International Nuclear Information System (INIS)

Aslam, M.; Gul, R.; Ara, T.; Hussain, M.

2012-01-01

A study on the radiological hazard in Portland cement due to the presence of naturally occurring radioactive materials is being carried out. The Portland cement manufactured in the Islamabad/Rawalpindi region of Pakistan, intermediate products (clinker) and the various raw materials which compose the product have been analysed for 226 Ra, 232 Th and 40 K using a gamma spectrometry system with a N-type high-purity germanium detector of 80 % relative efficiency. From the measured gamma ray spectra, specific activities were determined. The mean values of the total specific activity of 226 Ra, 232 Th and 40 K are 34.2±11.9, 29.1±3.6 and 295.1±66.9 Bq kg -1 , respectively in Portland cement, 28.4±8.7, 11.3±1.7 and 63.1±17.3 Bq kg -1 , respectively in lime stone, 8.2±1.9, 16.2±3.9 and 187.7±53.2 Bq kg -1 , respectively in gypsum, 34.7±13.1, 41.2±6.7 and 187.6±17.2 Bq kg -1 , respectively in clay, 41.1±11.8, 39.3±6.9 and 195.1±29.2 Bq kg -1 , respectively in laterite and 51.1±18.2, 23.2±1.2 and 258.4±15.3 Bq kg -1 , respectively in clinker. The radium equivalent activities (Ra eq ), external hazard index (H ex ), internal hazard index (H in ), absorbed dose rate in air (D) and annual effective dose rate (E eff ) were also determined. The measured activity concentrations for these radio nuclides and radiological indices were compared with the reported national and international data. All these measured values are comparable with the worldwide data reported in UNSCEAR publications. (authors)

Expansive soil stabilization with coir waste and lime for flexible pavement subgrade

Science.gov (United States)

Narendra Goud, G.; Hyma, A.; Shiva Chandra, V.; Sandhya Rani, R.

2018-03-01

Expansive soil properties can be improved by various methods to make it suitable for construction of flexible pavement. The coir pith is the by-product (bio-waste) generated from coir industry during extraction of coir fiber from coconut husk. Openly disposed coir pith can make the surrounding areas unhygienic. This bio-waste can be one of the potential materials to stabilize the expansive soils. In the present study coir pith and lime are used as stabilizers. Different combinations of coir pith contents (1%, 2% and 3%) and lime contents (2%, 3% and 4%)are used to study the behavior of expansive soil. Unconfined compressive strength (UCS) of unstabilized and stabilized soils was determined. Optimum content of coir pith and lime are determined based on UCS of the soil. California bearing ratio of soil determined at optimum contents of coir pith and lime. Flexible pavement layer compositions for two levels of traffic using stabilized soil subgrade.

Nutritional value of organic acid lime juice (Citrus latifolia T., cv. Tahiti

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Carolina Netto Rangel

2011-12-01

Full Text Available Acid lime can be used as fresh fruit or as juice to increase the flavor of drinks. Therefore, it is necessary to analyze organic acid lime nutritional composition in order to evaluate if there are important differences among those conventionally produced. No significant differences in total titrable acidity, pH, ascorbic acid, sucrose, calcium, and zinc were found between the acid lime juice from organic biodynamic crops and conventional crops. However, the organic biodynamic fruits presented higher peel percentage than the conventional ones leading to lower juice yield. On the other hand, fructose, glucose, total soluble solids contents, potassium, manganese, iron, and copper were higher in the conventional samples. These results indicated few nutritional differences between organic and conventional acid lime juices in some constituents. Nevertheless, fruit juice from biodynamic crops could be a good choice since it is free from pesticides and other agents that cause problems to human health maintaining the levels similar to those of important nutritional compounds.

Dissolved organic carbon and nitrogen mineralization strongly affect co2 emissions following lime application to acidic soil

International Nuclear Information System (INIS)

Shaaban, M.; Peng, Q.; Lin, S.; Wu, Y.

2014-01-01

Emission of greenhouse gases from agricultural soils has main contribution to the climatic change and global warming. Dynamics of dissolved organic carbon (DOC) and nitrogen mineralization can affect CO/sub 2/ emission from soils. Influence of DOC and nitrogen mineralization on CO/sub 2/ emissions following lime application to acidic soil was investigated in current study. Laboratory experiment was conducted under aerobic conditions with 25% moisture contents (66% water-filled pore space) at 25 degree C in the dark conditions. Different treatments of lime were applied to acidic soil as follows: CK (control), L (low rate of lime: 0.2g lime / 100 g soil) and H (high rate of lime: 0.5g lime /100g soil). CO/sub 2/ emissions were measured by gas chromatography and dissolved organic carbon, NH4 +-N, NO/sub 3/ --N and soil pH were measured during incubation study. Addition of lime to acidic soil significantly increased the concentration of DOC and N mineralization rate. Higher concentrations of DOC and N mineralization, consequently, increased the CO/sub 2/ emissions from lime treated soils. Cumulative CO/sub 2/ emission was 75% and 71% higher from L and H treatments as compared to CK. The results of current study suggest that DOC and N mineralization are critical in controlling gaseous emissions of CO/sub 2/ from acidic soils following lime application. (author)

Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

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Konstantin Sobolev

2003-01-01

Full Text Available The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA cement helps to improve its ecological compatibility. HVMA cement technology is based on the intergrinding of portland cement clinker, gypsum, mineral additives, and a special complex admixture. This new method increases the compressive strength of ordinary cement, improves durability of the cement-based materials, and - at the same time - uses inexpensive natural mineral additives or industrial by-products. This improvement leads to a reduction of energy consumption per unit of the cement produced. Higher strength, better durability, reduction of pollution at the clinker production stage, and decrease of landfill area occupied by industrial by-products, all provide ecological advantages for HVMA cement.

Cement for Oil Well Cementing Operations in Ghana

African Journals Online (AJOL)

Michael

For Portland cement to qualify as oil well cement, the chemical and physical properties must meet ..... Reservoir Engineering, Stanford University,. Stanford, California, pp. ... Construction”, PhD Thesis, Kwame Nkrumah. University of Science ...

Cytotoxic and antibacterial activity of the mixture of olive oil and lime cream in vitro conditions.

Science.gov (United States)

Sumer, Zeynep; Yildirim, Gulay; Sumer, Haldun; Yildirim, Sahin

2013-01-01

The mixture of olive oil and lime cream has been traditionally used to treat external burns in the region of Hatay/Antakya and middle Anatolia. Olive oil and lime cream have been employed by many physicians to treat many ailments in the past. A limited number of studies have shown the antibacterial effect of olive oil and that it does not have any toxic effect on the skin. But we did not find any reported studies on the mixture of olive oil and lime cream. The aim of this paper is to investigate the cytotoxic and antibacterial activity of olive oil and lime cream individually or/and in combination in vitro conditions, by using disk-diffusion method and in cell culture. The main purpose in using this mixture is usually to clear burns without a trace. Agar overlay, MTT (Cytotoxicity assay) and antibacterial susceptibility tests were used to investigate the cytotoxic and antibacterial activity of olive oil and lime cream. We found that lime cream has an antibacterial activity but also cytotoxic on the fibroblasts. On the other hand olive oil has limited or no antibacterial effect and it has little or no cytotoxic on the fibroblasts. When we combined lime cream and olive oil, olive oil reduced its cytotoxic impact. These results suggest that mixture of olive oil and lime cream is not cytotoxic and has antimicrobial activity.

Evaluation of red mud as pozzolanic material in replacement of cement for production of mortars; Avaliacao da lama vermelha como material pozolanico em substituicao ao cimento para producao de argamassas

Energy Technology Data Exchange (ETDEWEB)

Manfroi, E.P.; Cheriaf, M.; Rocha, J.C., E-mail: elizmanfroi@yahoo.com.b, E-mail: malik@valores.ufsc.b [Universidade Federal de Santa Catarina (UFSC), Florianopolis, SC (Brazil). Dept. de Engenharia Civil

2010-07-01

Red mud is a by-product of the alkaline extraction of aluminum from the bauxite and represents a renewed environmental problem due the significant annual throughput by the plants. In the present work, the pozzolanic properties of Brazilian red mud fired at 600, 700, 800 and 900 deg C were investigated by monitoring lime consumption using DTA analysis and Brazilian standard methodology NBR 5772 (1992). Products and kinetics of hydration were determined in cement pastes produced with 5 and 15% red mud using x-ray diffraction and DTA analysis. Compressive strength and capillary absorption tests were realized on mortars constituted by 5, 10 and 15% red mud in replacement of cement. When calcined at 600 deg C, the red mud develops good pozzolanic properties, and the compressive strength of mortars produced with this waste meet values in accordance with regulatory standard. These results shown than red mud can be used, in partial replacement of cement, as new construction material to produce sustainable mortars with low environmental impact. (author)

Low force cementation.

Science.gov (United States)

Wilson, P R

1996-07-01

The marginal adaptation of full coverage restorations is adversely affected by the introduction of luting agents of various minimum film thicknesses during the cementation process. The increase in the marginal opening may have long-term detrimental effects on the health of both pulpal and periodontal tissues. The purpose of this study was to determine the effects of varying seating forces (2.5, 12.5, 25 N), venting, and cement types on post-cementation marginal elevation in cast crowns. A standardized cement space of 40 microns was provided between a machined gold crown and a stainless steel die. An occlusal vent was placed that could be opened or closed. The post-cementation crown elevation was measured, following the use of two commercially available capsulated dental cements (Phosphacap, and Ketac-cem Applicap). The results indicate that only the combination of Ketac-Cem Applicap and crown venting produced post-cementation crown elevation of less than 20 microns when 12.5 N seating force was used. Higher forces (25 N) and venting were required for comparable seating when using Phosphacap (19 microns). The amount of force required to allow maximum seating of cast crowns appears to be cement specific, and is reduced by effective venting procedures.

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

Ultrafine portland cement performance

Directory of Open Access Journals (Sweden)

C. Argiz

2018-04-01

Full Text Available By mixing several binder materials and additions with different degrees of fineness, the packing density of the final product may be improved. In this work, ultrafine cement and silica fume mixes were studied to optimize the properties of cement-based materials. This research was performed in mortars made of two types of cement (ultrafine Portland cement and common Portland cement and two types of silica fume with different particle-size distributions. Two Portland cement replacement ratios of 4% and 10% of silica fume were selected and added by means of a mechanical blending method. The results revealed that the effect of the finer silica fume mixed with the coarse cement enhances the mechanical properties and pore structure refinement at a later age. This improvement is somewhat lower in the case of ultrafine cement with silica fume.

Application of lime and urea and its effect on development of Phythophthora palmivora.

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Sakti Widyanta Pratama

2015-03-01

Full Text Available Black pod rot disease (BPRD which is caused by Phytophthora palmivora is one of the main diseases of cocoa cultivations particularly in plantations with wet climate. Black pod rot can develop rapidly under high humidity environments, particularly during rainy seasons. This disease can cause loss of harvest of up to 46.63% in East Java. The various control efforts attempted so far have not resulted in significant improvements. Urea, in addition to functioning as fertilizer, can also produce the ammonia gas which is believed to be able to suppress black pod rot. This research aims to determine the effectiveness of black pod rot control using the combination of lime and urea. This research was conducted from June to September 2013. The materials used in test included sterile soil, black pod rot infected cocoa, urea, and agricultural lime. Observation results showed that ammonia could form from urea. Lime can increase the speed of the formation. The ammonia gas forming from 0.06% urea and 0.3% lime can control the P. palmivora fungus inside the soil. Key words: Pod rot, P. palmivora, urea, lime, ammonia

A systematic review of the effectiveness of liming to mitigate impacts of river acidification on fish and macro-invertebrates

International Nuclear Information System (INIS)

Mant, Rebecca C.; Jones, David L.; Reynolds, Brian; Ormerod, Steve J.; Pullin, Andrew S.

2013-01-01

The addition of calcium carbonate to catchments or watercourses – liming – has been used widely to mitigate freshwater acidification but the abatement of acidifying emissions has led to questions about its effectiveness and necessity. We conducted a systematic review and meta-analysis of the impact of liming streams and rivers on two key groups of river organisms: fish and invertebrates. On average, liming increased the abundance and richness of acid-sensitive invertebrates and increased overall fish abundance, but benefits were variable and not guaranteed in all rivers. Where B-A-C-I designs (before-after-control-impact) were used to reduce bias, there was evidence that liming decreased overall invertebrate abundance. This systematic review indicates that liming has the potential to mitigate the symptoms of acidification in some instances, but effects are mixed. Future studies should use robust designs to isolate recovery due to liming from decreasing acid deposition, and assess factors affecting liming outcomes. -- Highlights: •In a systematic review and meta-analysis, we asked how river liming affected fish and invertebrates. •On average, liming increased fish abundance. •Liming also increased average abundance and richness of acid-sensitive invertebrates. •However, benefits were variable and not guaranteed in all acidified rivers. -- A systematic review showed lime application to acidified rivers increased average fish abundance, and abundance and richness in acid-sensitive invertebrates, but not always

Influence of lime on struvite formation and nitrogen conservation during food waste composting.

Science.gov (United States)

Wang, Xuan; Selvam, Ammaiyappan; Wong, Jonathan W C

2016-10-01

This study aimed at investigating the feasibility of supplementing lime with struvite salts to reduce ammonia emission and salinity consequently to accelerate the compost maturity. Composting was performed in 20-L bench-scale reactors for 35days using artificial food waste mixed with sawdust at 1.2:1 (w/w dry basis), and Mg and P salts (MgO and K2HPO4, respectively). Nitrogen loss was significantly reduced from 44.3% to 27.4% during composting through struvite formation even with the addition of lime. Lime addition significantly reduced the salinity to less than 4mS/cm with a positive effect on improving compost maturity. Thus addition of both lime and struvite salts synergistically provide advantages to buffer the pH, reduce ammonia emission and salinity, and accelerate food waste composting. Copyright © 2016 Elsevier Ltd. All rights reserved.

Radioactive waste cementation

International Nuclear Information System (INIS)

Soriano B, A.

1996-01-01

This research was carried out to develop the most adequate technique to immobilize low and medium-activity radioactive waste. different brands of national cement were used, portland and pozzolanic cement. Prismatic and cylindrical test tubes were prepared with different water/cement (W/C) relationship. Additives such a as clay and bentonite were added in some other cases. Later, the properties of these test tubes were evaluated. Properties such as: mechanical resistance, immersion resistance, lixiviation and porosity resistance. Cement with the highest mechanical resistance values, 62,29 MPa was pozzolanic cement for a W/C relationship of 0,35. It must be mentioned that the other types of cements reached a mechanical resistance over 10 MPa, a value indicated by the international standards for transportation and storage of low and medium-activity radioactive waste at a superficial level. However, in the case of immersion resistance, Sol cement (portland type I) with a W/C relationship of 0,35 reached a compression resistance over 61,92 MPa; as in the previous cases, the other cements reached a mechanical resistance > 10 MPa. Regarding porosity, working with W/C relationships = 0,35 0,40 and 0,45, without additives and with additives, the percentage of porosity found for all cements is lower than 40% percentage indicated by international standards. With regard to the lixiviation test, pozzolanic cement best retained Cesium-137 and Cobalt-60, and increased its advantages when bentonite was added, obtaining a lixiviation rate of 2,02 x E-6 cm/day. Sol cement also improved its properties when bentonite was added and obtained a lixiviation rate of 2,84 x E-6 cm/day for Cesium-137. However, Cobalt-60 is almost completely retained with the 3 types of cement with or without additives, reaching the limits indicated by the international standards for the lixiviation rate of beta-gamma emitter < 5,00E-4 cm/day. Characterizing the final product involves the knowledge of its

Shear strength and compressibility behaviour of lime-treated organic clay

OpenAIRE

Yunus, NZM; Wanatowski, D; Hassan, NA; Marto, A

2016-01-01

Apart from strength characteristics, a review of studies on the compressibility of lime-treated soils is equally important that influenced the stability of soil structures. Due to the fact that no study has been carried out, an investigation on the effects of humic acid on strength and compressibility behaviour of lime-stabilised organic clay is presented in this paper. Unconfined Compressive Strength (UCS) and oedometer tests were carried out at different curing periods of 7, 28 and 90 days....

Parameters of Alumina Cement and Portland Cement with Addition of Chalcedonite Meal

Science.gov (United States)

Kotwa, Anna

2017-10-01

Aluminous cement is a quick binder with special properties. It is used primarily to make non-standard monolithic components exposed to high temperatures, + 1300°C. It is also a component of adhesives and mortars. It has a very short setting time. It is characterized by rapid increase in mechanical strength and resistance to aggressive sulphates. It can be used in reinforced concrete structures. Laying of concrete, construction mortar made of alumina cement can be carried out even at temperatures of -10°C. This article discusses a comparison of the parameters of hardened mortar made of alumina cement GÓRKAL 40 and Portland cement CEM I 42.5R. The mortars contain an addition of chalcedonite meal with pozzolanic properties, with particle size of less than 0.063μm. The meal was added in amounts of 5% and 20% of cement weight. Chalcedonite meal used in the laboratory research is waste material, resulting from chalcedonite aggregate mining. It has the same properties as the rock from which it originates. We have compared the parameters of hardened mortar i.e. compressive strength, water absorption and capillarity. The addition of 20% chalcedonite meal to mortars made from aluminous cement will decrease durability by 6.1% relative to aluminous cement mortar without addition of meal. Considering the results obtained during the absorbency tests, it can be stated that the addition of chalcedonite meal reduces weight gains in mortars made with cement CEM I 42.5 R and alumina cement. Use of alumina cement without addition of meal in mortars causes an increase of mass by 248% compared to Portland cement mortars without additions, in the absorption tests. The addition of chalcedonite meal did not cause increased weight gain in the capillary action tests. For the alumina cement mortars, a lesser weight gains of 24.7% was reported, compared to the Portland cement mortar after 28 days of maturing.

Effectiveness of lime and peat applications on cadmium availability in a paddy soil under various moisture regimes.

Science.gov (United States)

Chen, Yanhui; Xie, Tuanhui; Liang, Qiaofeng; Liu, Mengjiao; Zhao, Mingliu; Wang, Mingkuang; Wang, Guo

2016-04-01

In paddy soils, amendments and moisture play important role in the immobilization of cadmium (Cd). The effects of applying lime, peat, and a combination of both on soil Eh, pH, and Cd availability in contaminated soils were investigated under wetted (80 ± 5 % of water holding capacity) and flooded (completely submerged) conditions. In wetted soils, there was little change in Eh, compared to flooded soils where Eh reduced rapidly. Amendments of lime only or in a mixture with peat increased soil pH to different degrees, depending on the lime application rate. However, peat addition only slightly affected soil pH. The decreased Cd availability in flooded soils was related to submergence duration and was significantly lower than that in wetted soils after 14 days. Liming wetted and flooded soils decreased exchangeable Cd and increased carbonates or Fe-Mn oxides bound fractions, while peat addition transformed Cd from carbonates to organic matter bound fractions. The combined application of peat and lime generally showed better inhibitory effects on the availability of Cd than separately application of lime or peat. Higher application rates of lime, peat, or their mixture were more effective at reducing Cd contamination in flooded soil. This indicates that application of peat and lime mixture under flooded conditions was most effective for in situ remediation of Cd-contaminated soils. Further studies are required to assess the long-term effectiveness of the peat and lime mixture on Cd availability in paddy soils.

Lime application for the efficient production of nutraceutical glucooligosaccharides from Leuconostoc mesenteroides NRRL B-742 (ATCC13146).

Science.gov (United States)

Moon, Young Hwan; Madsen, Lee; Chung, Chang-Ho; Kim, Doman; Day, Donal F

2015-02-01

We have previously demonstrated the production of glucooligosaccharides via a fermentation of sucrose with Leuconostoc mesenteroides NRRL B-742 using sodium hydroxide (NaOH) to control the pH. Because NaOH is expensive, we sought to minimize the cost of our process by substituting hydrated lime and saccharate of lime (lime sucrate) in its place. The yield of glucooligosaccharides using either 5 % lime (41.4 ± 0.5 g/100 g) or 5 % lime sucrate (40.0 ± 1.4 g/100 g) were both similar to the NaOH control (42.4 ± 1.5 g/100 g). Based on this, it appears that the cost associated with pH control in our process can be reduced by a factor of approximately 2.4 using lime instead of NaOH. Because our chromatographic stage is based on a Ca(2+)-form resin to separate glucooligosaccharides, the use of lime not only negates the need for costly de-salting via ion-exchange (elimination of two ion-exchange sections) prior to separation, but also greatly reduces the resin regeneration cost.

Thermophysical properties of enzyme clarified Lime (Citrus aurantifolia L) juice at different moisture contents.

Science.gov (United States)

Manjunatha, S S; Raju, P S; Bawa, A S

2014-11-01

Thermophysical properties of enzyme clarified lime (Citrus aurantifolia L.) juice were evaluated at different moisture contents ranging from 30.37 % to 89.30 % (wet basis) corresponding to a water activity range of 0.835 to 0.979. The thermophysical properties evaluated were density, Newtonian viscosity, thermal conductivity, specific heat and thermal diffusivity. The investigation showed that density and Newtonian viscosity of enzyme clarified lime juice decreased significantly (p lime juice with moisture content/water activity employing regression analysis by the method of least square approximation. Results indicated the existence of strong correlation between thermophysical properties and moisture content/water activity of enzyme clarified lime juice, a significant (p < 0.0001) negative correlation between physical and thermal properties was observed.

Characterization of residues of effluent treatment plant from lapping process of soda-lime glass and its application in the production of concrete

International Nuclear Information System (INIS)

Antonio, Aline Pignaton; Calmon, Joao Luiz; Tristao, Fernando Avancini

2012-01-01

This study enunciates the physical, chemical and mineralogical composition of the residue from the process of ETE cutting of soda-lime glasses and its application in concrete as a replacement to the weight of CPV ARI RS cement, at levels of 0, 5, 10, 15 and 20%. Tests were performed on fresh and hardened (ages 3, 7, 28 and 300 days). The results were compared and statistically analyzed. In the fresh state, reductions in the amount of exuding water and consistency were observed. The results of compressive strength were statistically different, while the results for the tensile strength by diametrical compression and modulus of elasticity results were belonging to homogeneous groups. Beneficial effects the levels of residue on the cementitious matrix and the transition zone of concrete were identified by SEM, particularly concrete in S15

Effects of liming on forage availability and nutrient content in a forest impacted by acid rain.

Directory of Open Access Journals (Sweden)

Sarah E Pabian

Full Text Available Acidic deposition and subsequent forest soil acidification and nutrient depletion can affect negatively the growth, health and nutrient content of vegetation, potentially limiting the availability and nutrient content of forage for white-tailed deer (Odocoileus virginianus and other forest herbivores. Liming is a mitigation technique that can be used to restore forest health in acidified areas, but little is known about how it affects the growth or nutrient content of deer forage. We examined the effects of dolomitic limestone application on the growth and chemical composition of understory plants in an acidified forest in central Pennsylvania, with a focus on vegetative groups included as white-tailed deer forage. We used a Before-After-Control-Impact study design with observations 1 year before liming and up to 5 years post-liming on 2 treated and 2 untreated 100-ha sites. Before liming, forage availability and several nutrients were below levels considered optimal for white-tailed deer, and many vegetative characteristics were related to soil chemistry. We observed a positive effect of liming on forb biomass, with a 2.7 fold increase on limed sites, but no biomass response in other vegetation groups. We observed positive effects of liming on calcium and magnesium content and negative effects on aluminum and manganese content of several plant groups. Responses to liming by forbs and plant nutrients show promise for improving vegetation health and forage quality and quantity for deer.

Influence of the mechanical properties of lime mortar on the strength of brick masonry

OpenAIRE

PAVIA, SARA

2013-01-01

PUBLISHED This paper aims at improving the quality of lime mortar masonry by understanding the mechanics of mortars and masonry and their interaction. It investigates how the mortar?s compressive and flexural strengths impact the compressive and bond strength of clay brick masonry bound with calcium lime (CL) and natural hydraulic lime (NHL) mortars. It concludes that the strength of the bond has a greater impact on the compressive strength of masonry than the mortar?s st...

Estimation of atmospheric fluoride by limed filter papers

International Nuclear Information System (INIS)

Smith, D.R.

1988-09-01

The limed filter paper method of static sampling of atmospheric fluoride is reviewed in this report. Use of the technique, in conjunction with precise measurement of the absorbed fluoride and calibration with dynamic air sampling techniques, to estimate atmospheric fluoride levels, is considered to give only qualitative data (± 50%). The limed filter paper method is site specific due to variations in meteorological conditions. Its main value is to indicate seasonal and annual trends in fluoride exposure of vegetation. Subject to these considerations, the lower and upper limits of atmospheric fluoride exposure and the applicability to atmospheric fluoride estimation under routine or emergency fluoride release conditions are discussed, with special emphasis on the limiting factors

Laboratory evaluation of resistance to moisture damage in asphalt mixtures

Directory of Open Access Journals (Sweden)

Ahmed Ebrahim Abu El-Maaty Behiry

2013-09-01

Full Text Available Moisture damage in asphalt mixtures refers to loss in strength and durability due to the presence of water. Egypt road network is showing severe deterioration such as raveling and stripping because the bond between aggregates and asphalt film is broken due to water intrusion. To minimize moisture damage, asphalt mixes are investigated to evaluate the effect of air voids, degree of saturation, media of attack and the conditioning period. Two medias of attack are considered and two anti-stripping additives are used (hydrated lime and Portland cement. The retained Marshall stability and tensile strength ratio are calculated to determine the resistance to moisture damage. The results showed that both lime and cement could increase Marshall stability, resilient modulus, tensile strength and resistance to moisture damage of mixtures especially at higher condition periods. Use of hydrated lime had better results than Portland cement.

Effects of acid rain and liming on the enchytraeid fauna in forest soils

International Nuclear Information System (INIS)

Graefe, U.

1989-01-01

The development of the enchytraeid community has been observed in a Solling beech forest over a period of 11 years. Eight out of 18 formerly established species have disappeared in one decade. The connection to soil chemical changes due to atmospheric deposition is discussed. A comparison of adjoining beech and spruce stands revealed considerably lower species numbers under spruce. The community under beech is developing in the direction of the species community in the spruce stand. Liming affects changes in the dominance structure. Mesophilic species are favoured, acidophilic are repressed. In an oak-beech stand near Hamburg even the recolonization by previously absent species was observed. Liming experiments with 25, 50 and 100 dt CaCO 3 /ha showed decreasing total abundance of enchytraeids proportional to the amount of lime. Species number, diversity and evenness increased with lime treatments up to 50 dt/ha. (orig.)

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.

Evaluation of lime and hydrothermal pretreatments for efficient enzymatic hydrolysis of raw sugarcane bagasse.

Science.gov (United States)

Grimaldi, Maira Prearo; Marques, Marina Paganini; Laluce, Cecília; Cilli, Eduardo Maffud; Sponchiado, Sandra Regina Pombeiro

2015-01-01

Ethanol production from sugarcane bagasse requires a pretreatment step to disrupt the cellulose-hemicellulose-lignin complex and to increase biomass digestibility, thus allowing the obtaining of high yields of fermentable sugars for the subsequent fermentation. Hydrothermal and lime pretreatments have emerged as effective methods in preparing the lignocellulosic biomass for bioconversion. These pretreatments are advantageous because they can be performed under mild temperature and pressure conditions, resulting in less sugar degradation compared with other pretreatments, and also are cost-effective and environmentally sustainable. In this study, we evaluated the effect of these pretreatments on the efficiency of enzymatic hydrolysis of raw sugarcane bagasse obtained directly from mill without prior screening. In addition, we evaluated the structure and composition modifications of this bagasse after lime and hydrothermal pretreatments. The highest cellulose hydrolysis rate (70 % digestion) was obtained for raw sugarcane bagasse pretreated with lime [0.1 g Ca(OH)2/g raw] for 60 min at 120 °C compared with hydrothermally pretreated bagasse (21 % digestion) under the same time and temperature conditions. Chemical composition analyses showed that the lime pretreatment of bagasse promoted high solubilization of lignin (30 %) and hemicellulose (5 %) accompanied by a cellulose accumulation (11 %). Analysis of pretreated bagasse structure revealed that lime pretreatment caused considerable damage to the bagasse fibers, including rupture of the cell wall, exposing the cellulose-rich areas to enzymatic action. We showed that lime pretreatment is effective in improving enzymatic digestibility of raw sugarcane bagasse, even at low lime loading and over a short pretreatment period. It was also demonstrated that this pretreatment caused alterations in the structure and composition of raw bagasse, which had a pronounced effect on the enzymes accessibility to the

Liming effect on P availability from Maardu phosphate rock

International Nuclear Information System (INIS)

Sidlauskas, G.; Masauskas, S.; Ezerinskas, V.

2002-01-01

Thirty years ago phosphate rock from the Maardu deposit was intensively used for soil fertilization in Lithuania. However, the application of finely ground product caused an undesirable dusty operation. Afterwards, a super-phosphate production plant was built in Kedainiai and the use of phosphate rock was completely abandoned. Field experiments with fodder beets and barley were carried out to evaluate the P availability of granulated superphosphate and Maardu phosphate rock. The comparison was made at three acidity levels: a) unlimed acid soil with a high content of Al (pH kcl 4.3-4.4, hydrolytic acidity was 41-44 meq/kg soil), b) soil limed with 0.5n rate CaCO 3 powder limestone based on hydrolytic acidity, and c) soil limed with 1.0n rate CaCO 3 . Two field experiments were carried out with fodder beets. In 1997 the yield increased significantly due to liming. However, no significant yield increases were found due to the application of phosphorus fertilizers. Differences between the effect of superphosphate and phosphate rock were also not observed. This might have been caused by a severe drought during the vegetative growth of plants. In the following year, 1998, a soil with similar acidity was chosen, however it contained even lower amounts of available phosphorus in the arable soil (about 50 mg/kg soil A-L method). In the unlimed soil the yield was low, the effect of superphosphate was better than that of phosphate rock. A good fodder beet yield of 32 to 35 t/ha was obtained and the effect of phosphate rock was better than that of superphosphate at 0.5n CaCO 3 rate. When liming with at the high rate (1.0n CaCO 3 rate according to hydrolytic acidity) the action of phosphate rock declined, and a better yield was obtained with superphosphate. Barley was grown after fodder beets in the 1997 experimental field and the residual effect of superphosphate and phosphate rock was investigated. Weather conditions were favorable for barley growth. Therefore a normal yield

Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries

KAUST Repository

Nair, Sriramya D.; Patzek, Tadeusz; van Oort, Eric

2017-01-01

There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.

Detecting Poor Cement Bonding and Zonal Isolation Problems Using Magnetic Cement Slurries

KAUST Repository

Nair, Sriramya D.

2017-10-02

There has been growing interest in the use of magnetorheological fluids to improve displacement efficiency of fluids (drilling fluids, spacer fluids, cement slurries) in the eccentric casing annuli. When magnetic particles are mixed with the cement slurry for improved displacement, they provide an excellent opportunity for sensing the presence and quality of cement in the annulus. This work focuses on using sophisticated 3D computational electromagnetics to simulate the use of a magnetic cement slurry for well cement monitoring. The main goal is to develop a new tool, which is capable of locating magnetic cement slurry that is placed behind a stainless steel casing. An electromagnetic coil was used to generate a magnetic field inside the borehole. It was found that when a current was passed through the electric coils, magnetic field lines passed through the stainless steel casing, the cement annulus and the rock formation. Three sensors were placed inside the cased borehole and the magnetic field strength variations were observed at these locations. Various factors that have a significant influence on zonal isolation were considered. These include, effect of debonding between casing and cement annulus, effect of changing annuli thickness, influence of a fracture in the rock formation, effect of changing magnetic permeability of cement and finally influence of annuli eccentricity. Based on the results shown in the paper along with the next generation of supersensitive magnetic sensors that are being developed, the magnetic approach appears to be a viable alternative for evaluating the quality of the cement annulus to ensure good zonal isolation.

Geomechanical properties of lime stabilized clayey sands

International Nuclear Information System (INIS)

Arabani, M.; Karami, M. Veis

2007-01-01

Clayey sands that have low plasticity, low compressibility and high strength under loads, are suitable as a base material for any engineering construction projects as well as for roads and building construction. Decrease of plasticity and compressibility as well as increase in strength of these materials can be obtained by many different methods. Of these methods, lime stabilization is a common, applicable, and easy to use approach that can improve geomechanical and geotechnical properties of clayey sand fills. In this study some important geomechanical properties and geotechnical properties of clayey sands including compressive strength, CBR and elastic plastic behavior are investigated. A range of gradations representative of those gradations found in situ in the north of Iran were selected for testing and samples were artificially rebuilt in the laboratory. The mixes were then stabilized with hydrated lime and cured. Different mechanical tests were performed on mature materials. The stress-strain behavior of lime-stabilized mixes was plotted and a parabolic function was used to estimate the trend of stress-strain behavior. The data show that there is a correlation among the results of uniaxial load test, tensile strength, and CBR of the tested specimens. Also, results of the unconfined compression test and the indirect tensile strength test show that an increase in clay content up to a certain percent, in the clay-sand fills, tends to increase the strength of the materials in compression as well as in tension. (author)

The cement recycling of the earthquake disaster debris by Hachinohe Cement Co., Ltd

International Nuclear Information System (INIS)

Kataoka, Masayuki

2015-01-01

A tremendous quantity of earthquake disaster debris and tsunami sediment was resulted by the Great East Japan Earthquake on March 11, 2011. Hachinohe Cement Co., Ltd., a Sumitomo Osaka Cement subsidiary, was the first cement industry company to receive and process such waste materials outside of their usual prefecture area, while the company is performing their treatment and recycling services locally in Hachinohe City and Aomori Prefecture. This report provides an explanation about the recycling mechanism of waste materials and by-products in cement manufacturing process, and introduces an example of actual achievements for the disaster debris treatment by utilizing the cement recycling technologies at the Hachinohe Cement Plant. (author)

Effect of Cement Type on Autogenous Deformation of Cement-Based Materials

DEFF Research Database (Denmark)

Pietro, Lura; Ye, Guang; van Breugel, Klaas

2004-01-01

In this paper, measurements of non-evaporable water content, chemical shrinkage, autogenous deformation, internal relative humidity (RH), pore solution composition, and early-age elastic modulus are presented and discussed. All experiments were performed on Portland cement and blast-furnace slag...... (BFS) cement pastes. Self-desiccation shrinkage of the BFS cement paste was modeled based on the RH measurements, following the capillary-tension approach. The main findings of this study are: 1) self-desiccation shrinkage can be related to self-desiccation both for Portland and for BFS cement pastes......, taking into account the influence of the dissolved salts in the pore solution, 2) the BFS cement paste studied shows pronounced self-desiccation and self-desiccation shrinkage, mainly caused by its very fine pore structure....

Neutron shielding and constructional characteristics of a new type concrete and from borated clinker

International Nuclear Information System (INIS)

Cakaloz, T.

1979-07-01

A boron containing cement, which can be used as nuclear shielding material, is produced at pilot plant scale applying two different methods. In the first method, the raw mixture of a normal portland cement is mixed with pre-calcined colemanite, a calcium borate mineral, and clinkerized in a rotary kiln (borated-clinker). In the second method, the colemanite is mixed with an admixture, which contains mainly limestone and marl, and burnt in the rotary kiln to obtain a borated-lime composite. The borated-lime composite is then added to the normal portland cement clinker up to 2% B 2 O 3 content for shielding purpose. The results have shown that the borated-clinker contained untolerable amount of free lime resulting in a decrease in compressive strength. The addition of the borated-lime composite to the normal portland cement clinker up to 1% B 2 O 3 content did not alter the setting time and the volume expansion properties. The reduction in the compressive strength was found to be tolerable, however, the decrease in the bending strength was 20% lower than that of permissible value. On the other hand, the increase in B 2 O 3 content of the mixture improved the neutron absorptivity resulting in an increase in total cross-section about 7 times for 1% B 2 O 3 without changing the gamma absorption value

Studies of ancient concrete as analogs of cementitious sealing materials for a repository in tuff

Energy Technology Data Exchange (ETDEWEB)

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

1989-03-01

The durability of ancient cementitious materials has been investigated to provide data applicable to determining the resistance to weathering of concrete materials for sealing a repository for storage of high-level radioactive waste. Because tuff and volcanic ash are used in the concretes in the vicinity of Rome, the results are especially applicable to a waste repository in tuff. Ancient mortars, plasters, and concretes collected from Rome, Ostia, and Cosa dating to the third century BC show remarkable durability. The aggregates used in the mortars, plasters, and concretes included basic volcanic and pyroclastic rocks (including tuff), terra-cotta, carbonates, sands, and volcanic ash. The matrices of ancient cementitious materials have been characterized and classified into four categories: (1) hydraulic hydrated lime and hydrated lime cements, (2) hydraulic aluminous and ferruginous hydrated lime cements ({plus_minus} siliceous components), (3) pozzolana/hydrated lime cements, and (4) gypsum cements. Most of the materials investigated are in category (3). The materials were characterized to elucidate aspects of the technology that produced them and their response to the environmental exposure throughout their centuries of existence. Their remarkable properties are the result of a combination of chemical, mineralogical, and microstructural factors. Their durability was found to be affected by the matrix mineralogy, particle size, and porosity; aggregate type, grading and proportioning; and the methodology of placement. 30 refs.

Foamed cement for squeeze cementing low-pressure, highly permeable reservoirs

International Nuclear Information System (INIS)

Chmllowski, W.; Kondratoff, L.B.

1992-01-01

Four different cement squeezing techniques have been used on wells producing from the Keg River formation in the Rainbow Lake area of Alberta, Canada. This paper evaluates 151 cement squeeze treatments performed at 96 wellsites and compares the use of foam cement vs. conventional squeeze treatments and techniques. Discussion includes key aspects, such as candidate selection, slurry design, treatment design, economic evaluation, and operational considerations

Geotechnical and Physico-Chemical Characterization of Low Lime Fly Ashes

Directory of Open Access Journals (Sweden)

Arif Ali Baig Moghal

2013-01-01

Full Text Available In order to explore the possibility of using low-lime fly ashes, the physical and chemical properties which have a direct bearing on their geotechnical and geoenvironmental behaviors have been investigated. In this paper, two types of low-lime fly ashes, originating from India, have been used. A brief account of various methods adopted in characterizing their physical, chemical, and geotechnical properties is presented. The relative importance of each of these properties in enhancing the bulk applicability of fly ashes has been brought out.

Location of quarries of magnesian lime used as raw material of Roman plasters in western Lombardy (Italy

Directory of Open Access Journals (Sweden)

Roberto Bugini

2017-01-01

Full Text Available Lime as building material was widely diffused in Roman architecture of western Lombardy. The presence of magnesite (magnesium carbonate was detected in painted plasters coming from roman sites of Milano: magnesite indicates the use of dolomite to make the lime. Dolomite rocks widely outcrop in the Lombard Prealps: light grey dolomites and dolomitic limestones (Dolomia del Salvatore, Ladinian-Anisian; grey dolomites, sometimes with cyclothemes (Dolomia Principale, Norian. There is no evidence of Roman lime quarries or kilns in this area; the Romans probably exploited the same dolomite outcrops, located along the eastern shore of lake Maggiore, where lime was produced from the Middle Ages onwards. The glacio-fluvial deposits of the middle course of the river Adda (cobbles, pebbles of siliceous limestone together with limestone and dolomite outcropping in the river basin were another medieval and modern source of raw material, mainly to make a moderately hydraulic lime (called “calce forte”, but this kind of lime is lacking in Roman plasters.

Some material and construction aspects regarding in situ recycling of road pavements in South Africa

CSIR Research Space (South Africa)

Paige-Green, P

2006-07-01

Full Text Available In situ recycling as a pavement rehabilitation option in South Africa is becoming increasingly important. Use has been made of both bitumen (emulsion and foamed) and traditional chemical stabilizers (lime, cement, lime/slagment, etc). Very little...

Surface morphology study in high speed milling of soda lime glass

Science.gov (United States)

Konneh, Mohamed; Bagum, Mst. Nasima; Ali, Mohammad Yeakub; Amin, A. K. M. Nurul

2018-05-01

Soda lime glass has a wide range of applications in optical, bio-medical and semi-conductor industries. It is undeniably a challenging task to produce micro finish surface on an amorphous brittle solid like soda lime glass due to its low fracture toughness. In order to obtain such a finish surface, ductile machining has been exploited, as this usually cause's plastic flow which control crack propagation. At sub-micro scale cutting parameters, researchers achieved nano finish surface in micro milling operation using coated tool. However it is possible to enhance the rate of material removal (RMR) of soda lime glass at flexible cutting condition. High speed cutting at micro meter level, extend of thermal softening might be prominent than the strain gradient strengthening. The purpose of this study was to explore the effects of high cutting speed end milling parameters on the surface texture of soda lime glass using uncoated carbide tool. The spindle speed, depth of cut and feed rate were varied from 20,000 to 40,000 rpm, 10 to 30 mm/min and 30 to 50 µm respectively. Mathematical model of roughness has been developed using Response Surface Methodology (RSM). Experimental verification confirmed that surface roughness (Ra) 0.38 µm is possible to achieve at increased RMR, 4.71 mm3/min.

Effects of Lime and Concrete Waste on Vadose Zone Carbon Cycling

DEFF Research Database (Denmark)

Thaysen, Eike Marie; Jessen, Søren; Postma, D.

2014-01-01

In this work we investigate how lime and crushed concrete waste (CCW) affect carbon cycling in the vadose zone and explore whether these amendments could be employed to mitigate climate change by increasing the transport of CO2 from the atmosphere to the groundwater. We use a combination of exper......In this work we investigate how lime and crushed concrete waste (CCW) affect carbon cycling in the vadose zone and explore whether these amendments could be employed to mitigate climate change by increasing the transport of CO2 from the atmosphere to the groundwater. We use a combination...... of experimental and modeling tools to determine ongoing biogeochemical processes. Our results demonstrate that lime and CCW amendments to acid soil contribute to the climate forcing by largely increasing the soil CO2 efflux to the atmosphere. In a series of mesocosm experiments, with barley (Hordeum vulgare L.......) grown on podzolic soil material, we have investigated inorganic carbon cycling through the gaseous and liquid phases and how it is affected by different soil amendments. The mesocosm amendments comprised the addition of 0, 9.6, or 21.2 kg m−2 of crushed concrete waste (CCW) or 1 kg lime m−2. The CCW...

Environment-Friendly Control of Pear Scab and Rust Using Lime Sulfur

Directory of Open Access Journals (Sweden)

Ju Hoon Cha

2018-03-01

Full Text Available Pear scab and rust are the major diseases causing severe epidemics in organic cultivation of pear trees. Incidences of pear scab and rust were compared in organically managed plots and conventionally managed plots to obtain optimum application schedule of environment-friendly control agents in organically managed plots. Organically cultural practice with 10 time-applications of lime sulfur and Bordeaux mixture showed higher than 40% of control efficacies of pear scab and rust compared to conventionally cultural practice. Organically cultural practice with 8 time-applications of lime sulfur considering weather condition showed higher than 30% of control efficacies of pear scab compared to conventionally cultural practice. The results suggest that proper application of environment-friendly control agents such as lime sulfur considering weather condition will enable effective control of the major diseases for organic cultivation of pear.

Effect of quick lime on physicochemical properties of clay soil

Directory of Open Access Journals (Sweden)

Bessaim Mohammed Mustapha

2018-01-01

Full Text Available Clay soils are known for their water sensitivity, which causes irreparable damage to any structure built on this type of soil. In order to avoid such problem, it is necessary to use various improvement and stabilization methods such as treatment with lime. This process has been used successfully in the field for decades. The addition of lime generates various physicochemical reactions within the soil such as cation exchange and pozzolanic reactions which are largely responsible for the improvement of the soil in question. This paper presents a study concerning the variation of physicochemical properties of clayey soil with the addition of quicklime at different percentages. Experiments were performed on two clayey soils (CL type in order to investigate the influence of quicklime on Atterberg limits and pH. These tests were carried out in an attempt to study and follow the development and progression of various reactions occurred within the soil with various lime percentages. The results show that the addition of quicklime causes a significant improvement in soil properties by reducing plasticity and thereby improves the soil workability. It can also be found that the addition of lime increase pH of soil, which allow activating pozzolanic reactions who tend to stabilize the soil in question by formation of cementitious compounds. Finally, the pH can be considered as a relevant parameter who allows a better understanding of the reactions that occur in the soil matrix.

An historical examination of concrete

International Nuclear Information System (INIS)

Mallinson, L.G.

1986-03-01

The requirement that concrete in nuclear waste repositories be stable physically and chemically for hundreds, if not thousands, of years has initiated studies of ancient and old concretes. The history of cement and concrete is described. The oldest know concrete, from Yugoslavia, is ca. 7,500 years old. Concrete was used in many ancient civilisations, including those of Egypt, Greece and Rome. Ancient concretes were usually based upon lime, but sometimes gypsum was used. Pure lime concretes hardened by atomospheric carbonation but the Ancients, in particular the Romans, also employed hydraulic limes and discovered pozzolanas to make superior concretes which, upon hardening, contained complex cementitious hydrates including calcium-silicate-hydrate (CSH), the principal binding element in Portland cement concrete. Portland cement was not invented until 1824 or later and consists principally of calcium silicates formed by clinkerisation of a mixture of limestone and clay in carefully measured proportions. The cement sets hydraulically to form, principally, calcium hydroxide and CSH, the latter being an amorphous or semi-amorphous substance of variable composition. The published literature relating to the analysis of old and ancient cements and concretes is reviewed. A suite of samples spanning the history of concrete has been obtained. A variety of physical and chemical techniques have been employed to characterise these samples. (author)

Effect of Lime Addition Methods on Performance Related Properties of Asphalt Concrete Mixture

Directory of Open Access Journals (Sweden)

Amjad Hamd Khalil Albayati

2016-09-01

Full Text Available In the recent years, some of the newly constructed asphalt concrete pavements in Baghdad as well as other cities across Iraq showed premature failures with consequential negative impact on both roadway safety and economy. Frequently, load associated mode of failure (rutting and fatigue as well as, occasionally, moisture damage in some poorly drained sections are the main failure types found in those newly constructed road. In this research, hydrated lime was introduced into asphalt concrete mixtures of wearing course in two methods. The first one was the addition of dry lime on dry aggregate and the second one was the addition of dry lime on saturated surface dry aggregate moisturized by 2.0 to 3.0 percent of water. For each type of addition, five different percentages of lime as a partial replacement of ordinary limestone mineral filler were used; these were; 1.0, 1.5, 2.0, 2.5, and 3 percent by weight of aggregate besides a control mixture that did not contain lime. Marshall Mix design method was used and the performance properties of moisture damage, resilient modulus, permanent deformation and fatigue characteristics were evaluated using indirect tensile strength, uniaxial repeated loading and repeated flexural beam tests. Also, VESYS5W software was implemented to evaluate the pavements performance in terms of rut depth and fatigue area for a typical pavement structure. The main conclusion withdrawn from this research revealed that the use of 2.5 percent hydrated lime in dry addition method and wet addition method showed an improved fatigue and permanent deformation characteristics, lower moisture susceptibility and high resilient modulus.

The growth of Scots pine and the availability of nutrients in old Finnish liming experiments on drained peatlands

International Nuclear Information System (INIS)

Nieminen, M.; Paetilae, A.

1994-01-01

Liming (with applications of 1000 to 8000 kg/ha) had no long- term (1929-1985) effect on the growth of Scots pine on drained oligotrophic peatlands. Liming plus NPK fertilization had a variable effect on the growth of stands. The same treatment could result in a very different response in different experimental areas. Both liming alone and liming plus NPK fertilization increased the calcium, magnesium and nitrogen contents of peat and decreased the C/Nratio and acidity. Liming plus fertilization decreased needle boron and manganese and increased calcium and nitrogen concentrations. The results of peat and needle analysis indicated that the changes in nitrogen availability to trees caused by liming have not been sufficient enough to affect tree growth. It was also concluded that boron deficiency was the main reason for the lowered yield. (26 refs., 6 tabs., 8 figs.) (author)

Lime Stabilization of Fine-Grained Greenlandic Sediments in Relation to Construction Projects

DEFF Research Database (Denmark)

Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas; Nielsen, Hans Rasmus

2010-01-01

to the cold climate, and it is therefore of great interest to study possible methods to improve the stability of the fine-grained sediments. This presentation will include results of laboratory studies of lime stabilization on a clay soil from Kangerlussuaq, western Greenland. The result includes tests...... of the optimum lime mixture in relation to both reaction time and temperature influence....

Determination of optimal burning temperature ranges for production of natural hydraulic limes

Czech Academy of Sciences Publication Activity Database

Válek, Jan; van Halem, Eveline; Viani, Alberto; Pérez-Estébanez, Marta; Ševčík, Radek; Šašek, Petr

2014-01-01

Roč. 66, September (2014), s. 771-780 ISSN 0950-0618 R&D Projects: GA MK(CZ) DF11P01OVV010 Keywords : natural hydraulic lime * mechanical properties * calcination * CaO * X-ray diffraction * lime reactivity Subject RIV: AL - Art, Architecture, Cultural Heritage Impact factor: 2.296, year: 2014 http://www.sciencedirect.com/science/article/pii/S095006181400628X

The influence of cement type and temperature on chloride binding in cement paste

DEFF Research Database (Denmark)

Jensen, Ole Mejlhede; Korzen, Migge Sofie Hoffmann; Skibsted, Jørgen

1998-01-01

This paper describes effects of cement type and temperature on chloride binding in cement paste, which is an important subject in relation to life-time modelling of reinforced concrete structures. The influence of cement type on chloride binding is investigated by substituting cement with pure...... cement clinker. Both theoretical considerations and experimental data for chloride binding in cement pastes are presented. A physico-chemically based model to describe the influence of temperature on physical binding of chloride is presented. Solid-state 27Al and 29Si magic-angle spinning (MAS) nuclear...... magnetic resonance (NMR) spectroscopy has been used for quantification of the anhydrous and hydrated aluminate and silicate phases in the chloride exposed cement pastes. The 27Al isotropic chemical shift and nuclear quadrupole coupling is reported for a synthetic sample of Friedel's salt, Ca2Al(OH)6Cl×2H2O....

Characterization and chemical activity of Portland cement and two experimental cements with potential for use in dentistry.

Science.gov (United States)

Camilleri, J

2008-09-01

To evaluate the chemical activity of Portland cement and two other cement types with similar chemical composition to mineral trioxide aggregate with the aim of developing these cements for further applications in dentistry. The chemical composition of the three cement types namely Portland cement, calcium sulpho-aluminate cement and calcium fluoro-aluminate cement was evaluated by elemental analysis using energy dispersive analysis with X-ray under the scanning electron microscope and by X-ray diffraction analysis (XRD) to determine the phases. The constituents of the hydration reaction by-products were evaluated by XRD analysis of the set cements at 1, 7, 28 and 56 days and by analysis of the leachate by ion chromatography. The pH of both cements and leachate was determined at different time intervals. Cements admixed with micro-silica were also tested to determine the effect of micro-silica on the reaction by-products. All three cement types were composed of tricalcium silicate as the main constituent phase. The hydration reaction of Portland cement produced calcium hydroxide. However, this was not present in the other cements tested at all ages. Admixed micro-silica had little or no effect on the cements with regard to reaction by-products. The pH of all cements tested was alkaline. Both the experimental calcium sulpho-aluminate cement and calcium fluoro-aluminate cement had different hydration reactions to that of Portland cement even though calcium silicate was the major constituent element of both cement types. No calcium hydroxide was produced as a by-product to cement hydration. Micro-silica addition to the cement had no effect on the hydration reaction.

Soil acidification and liming in grassland production and grassland soil fertility in Slovenia

Directory of Open Access Journals (Sweden)

Jure ČOP

2015-12-01

Full Text Available This paper reviews the evidences on grassland soil acidity and liming in relation to soil processes and herbage production. There is also an outline of the present state of soil acidity and acidity-related traits – contents of organic matter (OM, phosphorus (P and potassium (K in Slovene grassland. In grassland, soil acidification is an ongoing process under humid climate conditions. It is mainly driven by leaching of nutrients, net loss of cations due to retention in livestock products, use of physiologically acid fertilizers, acid rain and N2 fixation. This process is reduced by strong pH buffering capacity of the soil and by physiologically basic fertilizers. Acid grassland soils in Slovenia are widely distributed in spite of the fact that 44% of the total land has developed from a carbonate parent material. Of the 1713 grassland soil samples analysed during 2005-2007 45% were regarded as acid ones (pH < 5.5; in KCl, 57% as soils with very low P status (˂ 6 mg P2O5/100 g soil and 22% as soils with very low K status (˂ 10 mg K2O/100 soil. Increased content of soil organic matter was identified for alpine pastures (˃ 10 % OM in 44% of samples, mainly as a result of low decomposition rate. Liming of acid grassland soils did not always reflect in a higher herbage yield. The cause for this inefficiency is plant composition of grassland. Thus, many grassland plants with relatively high production potential have adapted to acid soil conditions. To illustrate the inconsistent liming effect three researches are reviewed. In the first two researches liming along with fertilizer application did not increase the yield comparing to the fertilized control while in the third research the increase amounted 26 %. Liming improves considerably botanical composition of the acid grassland (e.g. sward where Common Bent – Agrostis tenuis Sibth. – prevails and thus indirectly affects palatability and nutritive value of herbage. Grassland liming has a weak

Design of Fit-for-Purpose Cement to Restore Cement-Caprock Seal Integrity

Science.gov (United States)

Provost, R.

2015-12-01

This project aims to study critical research needs in the area of rock-cement interfaces, with a special focus on crosscutting applications in the Wellbore Integrity Pillar of the SubTER initiative. This study will focus on design and test fit-for-purpose cement formulations. The goals of this project are as follows: 1) perform preliminary study of dispersing nanomaterial admixtures in Ordinary Portland Cement (OPC) mixes, 2) characterize the cement-rock interface, and 3) identify potential high-performance cement additives that can improve sorption behavior, chemical durability, bond strength, and interfacial fracture toughness, as appropriate to specific subsurface operational needs. The work presented here focuses on a study of cement-shale interfaces to better understand failure mechanisms, with particular attention to measuring bond strength at the cement-shale interface. Both experimental testing and computational modeling were conducted to determine the mechanical behavior at the interface representing the interaction of cement and shale of a typical wellbore environment. Cohesive zone elements are used in the finite element method to computationally simulate the interface of the cement and rock materials with varying properties. Understanding the bond strength and mechanical performance of the cement-formation interface is critical to wellbore applications such as sequestration, oil and gas production and exploration and nuclear waste disposal. Improved shear bond strength is an indication of the capability of the interface to ensure zonal isolation and prevent zonal communication, two crucial goals in preserving wellbore integrity. Understanding shear bond strength development and interface mechanics will provide an idea as to how the cement-formation interface can be altered under environmental changes (temperature, pressure, chemical degradation, etc.) so that the previously described objectives can be achieved. Sandia National Laboratories is a multi

The effect of lime pre-treatments of date palm leaves on delignification and in vitro rumen degradability

NARCIS (Netherlands)

Ghorbani, M.; Ahmadi, F.; Rajaee Rad, A.; Zamiri, M.J.; Cone, J.W.; Polikarpov, I.

2017-01-01

Experiments were conducted to determine the effect of lime pre-treatment on the chemical composition and in vitro rumen degradability of date palm leaves (DPL). Lime pre-treatments, with or without oxygen supply, were applied for 1, 2 and 3 weeks at 25 and 40 °C. Lime was neutralized by the

Archaeomagnetic studies in central Mexico—dating of Mesoamerican lime-plasters

Science.gov (United States)

Hueda-Tanabe, Y.; Soler-Arechalde, A. M.; Urrutia-Fucugauchi, J.; Barba, L.; Manzanilla, L.; Rebolledo-Vieyra, M.; Goguitchaichvili, A.

2004-11-01

For the first time results of an archaeomagnetic study of unburned lime-plasters from Teotihuacan and Tenochtitlan in central Mesoamerica are presented. Plasters made of lime, lithic clasts and water, appear during the Formative Period and were used for a variety of purposes in floors, sculptures, ceramics and supporting media for mural paintings in the Oaxaca and Maya area. In Central Mexico, grinded volcanic scoria rich in iron minerals is incorporated into the lime-plasters mixture. Samples were selected from two archaeological excavation projects in the Teopancazco residential compound of Teotihuacan and the large multi-stage structure of Templo Mayor in Tenochtitlan, where chronological information is available. The intensity of remanent magnetization (natural remanent magnetization (NRM)) and low-field susceptibility are weak reflecting low relative content of magnetic minerals. NRM directions are well grouped and alternating field demagnetization shows single or two-component magnetizations. Rockmagnetic experiments point to fine-grained titanomagnetites with pseudo-single domain behavior. Anisotropy of magnetic susceptibility (AMS) measurements document a depositional fabric, with normal to free-surface minimum AMS axes. Characteristic mean site directions were correlated to the paleosecular variation curve for Mesoamerica. Data from Templo Mayor reflect recent tilting of the structures. Teopancazco mean site declinations show good correspondence with the reference curve, in agreement with the radiocarbon dating. Dates for four stages of Teotihuacan occupancy based on the study of lime-plasters range from AD 350 to 550. A date for a possible Mazapa occupation around AD 850 or 950 is also suggested based on the archaeomagnetic correlation. The archaeomagnetic record of a plaster floor in Teopancazco differed from the other nearby sites pointing to a thermoremanent magnetization; comparison with the reference curve suggests dates around AD 1375 or 1415. The

Study of sticky rice-lime mortar technology for the restoration of historical masonry construction.

Science.gov (United States)

Yang, Fuwei; Zhang, Bingjian; Ma, Qinglin

2010-06-15

Replacing or repairing masonry mortar is usually necessary in the restoration of historical constructions, but the selection of a proper mortar is often problematic. An inappropriate choice can lead to failure of the restoration work, and perhaps even further damage. Thus, a thorough understanding of the original mortar technology and the fabrication of appropriate replacement materials are important research goals. Many kinds of materials have been used over the years in masonry mortars, and the technology has gradually evolved from the single-component mortar of ancient times to hybrid versions containing several ingredients. Beginning in 2450 BCE, lime was used as masonry mortar in Europe. In the Roman era, ground volcanic ash, brick powder, and ceramic chip were added to lime mortar, greatly improving performance. Because of its superior properties, the use of this hydraulic (that is, capable of setting underwater) mortar spread, and it was adopted throughout Europe and western Asia. Perhaps because of the absence of natural materials such as volcanic ash, hydraulic mortar technology was not developed in ancient China. However, a special inorganic-organic composite building material, sticky rice-lime mortar, was developed. This technology was extensively used in important buildings, such as tombs, in urban constructions, and even in water conservancy facilities. It may be the first widespread inorganic-organic composite mortar technology in China, or even in the world. In this Account, we discuss the origins, analysis, performance, and utility in historic preservation of sticky rice-lime mortar. Mortar samples from ancient constructions were analyzed by both chemical methods (including the iodine starch test and the acid attack experiment) and instrumental methods (including thermogravimetric differential scanning calorimetry, X-ray diffraction, Fourier transform infrared, and scanning electron microscopy). These analytical results show that the ancient masonry

Morphological Analysis of White Cement Clinker Minerals: Discussion on the Crystallization-Related Defects

Directory of Open Access Journals (Sweden)

Mohamed Benmohamed

2016-01-01

Full Text Available The paper deals with a formation of artificial rock (clinker. Temperature plays the capital role in the manufacturing process. So, it is useful to analyze a poor clinker to identify the different phases and defects associated with their crystallization. X-ray fluorescence spectroscopy was used to determine the clinker’s chemical composition. The amounts of the mineralogical phases are measured by quantitative XRD analysis (Rietveld. Scanning electron microscopy (SEM was used to characterize the main phases of white Portland cement clinker and the defects associated with the formation of clinker mineral elements. The results of a study which focused on the identification of white clinker minerals and defects detected in these noncomplying clinkers such as fluctuation of the amount of the main phases (alite (C3S and belite (C2S, excess of the free lime, occurrence of C3S polymorphs, and occurrence of moderately-crystallized structures are presented in this paper.

Effects of cement particle size distribution on performance properties of Portland cement-based materials

Energy Technology Data Exchange (ETDEWEB)

Bentz, D.P.; Garboczi, E.J.; Haecker, C.J.; Jensen, O.M.

1999-10-01

The original size, spatial distribution, and composition of Portland cement particles have a large influence on hydration kinetics, microstructure development, and ultimate properties of cement-based materials. In this paper, the effects of cement particle size distribution on a variety of performance properties are explored via computer simulation and a few experimental studies. Properties examined include setting time, heat release, capillary porosity percolation, diffusivity, chemical shrinkage, autogenous shrinkage, internal relative humidity evolution, and interfacial transition zone microstructure. The effects of flocculation and dispersion of the cement particles in the starting microstructures on resultant properties are also briefly evaluated. The computer simulations are conducted using two cement particle size distributions that bound those commonly in use today and three different water-to-cement ratios: 0.5, 0.3, and 0.246. For lower water-to-cement ratio systems, the use of coarser cements may offer equivalent or superior performance, as well as reducing production costs for the manufacturer.

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

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

Effect of liming on the molybdenum content in the root and leaf of ...

African Journals Online (AJOL)

Three liming treatments were employed (1, 3 and 4 t/ha CaCO3). The liming operation used on pseudogley induced a statistically significant increase in molybdenum ion absorption into the root system of tomato. Independently from the aforementioned, the values for the root and leaf molybdenum content of tomato in each ...

Seating load parameters impact on dental ceramic reinforcement conferred by cementation with resin-cements.

LENUS (Irish Health Repository)

Addison, Owen

2010-09-01

Cementation of all-ceramic restorations with resin-cements has been demonstrated to reduce the incidence of fracture in service. The aim was to investigate the influence of loading force and loading duration applied during cementation on the reinforcement conferred by a resin-cement on a leucite reinforced glass-ceramic.

LANDSCAPE ARCHAEOLOGY ALONG LIMES TRANSALUTANUS

Directory of Open Access Journals (Sweden)

Eugen S. Teodor

2014-09-01

Full Text Available The project addresses the historical monuments comprised in the longest Roman ‘linear defence’ structure present on the Romanian territory.Despite it being the longest, this historic structure is the least protected and the least known in its technical details. Was indeed Limes Transalutanus an incomplete limes (lacking civilian settlements, for example, an odd construction (a vallum without fossa, an early-alarm line rather than a proper defensive line? Taking on these historical and archaeological challenges, the team attempts to develop an investigation technology applicable to large scale archaeological landscapes - a full evaluation chain, involving aerial survey, surface survey, geophysical investigation, multispectral images analysis, statistic evaluation and archaeological diggings. This technological chain will be systematically applied on the whole length of the objective, that is, on a 155 km distance. The attempt to find answers to issues related to the earth works’ functionality, layout, structure, chronology and relation with adjacent sites will be grounded on exploring the relations of the monument with the surrounding environment, by focussing on finding methods to reconstruct the features of the ancient landscapes, like systematic drilling, palynological tests and toponymical studies.

Separation of hemicellulose-derived saccharides from wood hydrolysate by lime and ion exchange resin.

Science.gov (United States)

Wang, Xiaojun; Zhuang, Jingshun; Fu, Yingjuan; Tian, Guoyu; Wang, Zhaojiang; Qin, Menghua

2016-04-01

A combined process of lime treatment and mixed bed ion exchange was proposed to separate hemicellulose-derived saccharides (HDS) from prehydrolysis liquor (PHL) of lignocellulose as value added products. The optimization of lime treatment achieved up to 44.2% removal of non-saccharide organic compounds (NSOC), mainly colloidal substances, with negligible HDS degradation at 0.5% lime level and subsequent neutralization by phosphoric acid. The residual NSOC and calcium ions in lime-treated PHL were eliminated by mixed bed ion exchange. The breakthrough curves of HDS and NSOC showed selective retention toward NSOC, leading to 75% HDS recovery with 95% purity at 17 bed volumes of exchange capacity. In addition, macroporous resin showed higher exchange capacity than gel resin as indicated by the triple processing volume. The remarkable selectivity of the combined process suggested the feasibility for HDS separation from PHL. Copyright © 2016 Elsevier Ltd. All rights reserved.

Longevity of metal-ceramic crowns cemented with self-adhesive resin cement: a prospective clinical study

Science.gov (United States)

Brondani, Lucas Pradebon; Pereira-Cenci, Tatiana; Wandsher, Vinicius Felipe; Pereira, Gabriel Kalil; Valandro, Luis Felipe; Bergoli, César Dalmolin

2017-04-10

Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding) and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding), resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation) for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.

Microbial communities associated with the anthropogenic, highly alkaline environment of a saline soda lime, Poland

OpenAIRE

Kalwasi?ska, Agnieszka; Felf?ldi, Tam?s; Szab?, Attila; Deja-Sikora, Edyta; Kosobucki, Przemys?aw; Walczak, Maciej

2017-01-01

Soda lime is a by-product of the Solvay soda process for the production of sodium carbonate from limestone and sodium chloride. Due to a high salt concentration and alkaline pH, the lime is considered as a potential habitat of haloalkaliphilic and haloalkalitolerant microbial communities. This artificial and unique environment is nutrient-poor and devoid of vegetation, due in part to semi-arid, saline and alkaline conditions. Samples taken from the surface layer of the lime and from the depth...

Thermophysical properties of hydrophobised lime plasters - The influence of ageing

Science.gov (United States)

Pavlíková, Milena; Zemanová, Lucie; Pavlík, Zbyšek

2017-07-01

The building envelope is a principal responsible for buildings energy loses. Lime plasters as the most popular finishing materials of historical buildings and culture monuments influence the thermal behaviour as well as construction material of masonry. On this account, the effect of ageing on the thermophysical properties of a newly designed lime plasters containing hydrophobic admixture is analysed in the paper. For the comparative purposes, the reference lime plaster is tested. The ageing is accelerated with controlled carbonation process to simulate the final plasters properties. Basic characterization of the tested materials is done using bulk density, matrix density, and porosity measurements. Thermal conductivity and volumetric heat capacity are experimentally assessed using a transient impulse method. The obtained data revealed the significant changes of the both studied thermal parameters in the dependence on plasters composition and age. The assessed material parameters will be stored in a material database, where will find use as an input data for computational modelling of heat transport in this type of porous building materials and evaluation of energy-savings and sustainability issues.

Determining the water-cement ratio, cement content, water content and degree of hydration of hardened cement paste: Method development and validation on paste samples

International Nuclear Information System (INIS)

Wong, H.S.; Buenfeld, N.R.

2009-01-01

We propose a new method to estimate the initial cement content, water content and free water/cement ratio (w/c) of hardened cement-based materials made with Portland cements that have unknown mixture proportions and degree of hydration. This method first quantifies the composition of the hardened cement paste, i.e. the volumetric fractions of capillary pores, hydration products and unreacted cement, using high-resolution field emission scanning electron microscopy (FE-SEM) in the backscattered electron (BSE) mode and image analysis. From the obtained data and the volumetric increase of solids during cement hydration, we compute the initial free water content and cement content, hence the free w/c ratio. The same method can also be used to calculate the degree of hydration. The proposed method has the advantage that it is quantitative and does not require comparison with calibration graphs or reference samples made with the same materials and cured to the same degree of hydration as the tested sample. This paper reports the development, assumptions and limitations of the proposed method, and preliminary results from Portland cement pastes with a range of w/c ratios (0.25-0.50) and curing ages (3-90 days). We also discuss the extension of the technique to mortars and concretes, and samples made with blended cements.

THE LIME PURIFICATION OF SUGAR –CONTAINING SOLUTION USING HIGH VISCOSITY COLLOIDAL SOLUTIONS

Directory of Open Access Journals (Sweden)

K. V.

2015-12-01

Full Text Available Aim of the work was to determine the efficiency of combined application of lime and high-viscous suspensions, containing the aluminium nanoparticles as a precursor in treatment of sugar-containing solutions. At the first stage the aluminium nanopowder, encapsulated into a salt matrix, was produced by the combined precipitation from a gas phase of metal and halogenide of alkali metal (NaCl. For the long-term stabilization of aluminum nanoparticles the method, developed by the authors, for dispersing these powders in the composition of polyethylene glycols was used, providing the colloidal solution of high viscosity (gel. At the second stage, as an object of investigation a juice of sugar beet, produced in the laboratory conditions by water extracting from the beet chips, was applied. In the produced juice the main characteristics of its quality were determined: the content of solids, sucrose, its purity was calculated (ratio of sucrose to solids content, in%. The content of protein and pectin components was also determined (as the main components of the colloidal fraction of the diffusion juice. Conventionally, as a basic reagent for the process of a lime pretreatment a lime milk of 1.18 g/cm3 density, prepared by liming the burned lime using hot water, was used. During the experiments the effectiveness of reagents, containing aluminum in nanoform, on the degree of removal of the colloidal dispersion substances in the process of juice purification in sugar beet production and improvement of its quality, is shown. However, the obtained results show that, depending on the method of producing, the additional reagents with aluminium nanoparticles have different effect on change of diffusion juice purity in the process of its treatment by the lime milk.

Liming Influences Growth and Nutrient Balances in Sugar Maple (Acer saccharum) Seedlings on an Acidic Forest Soil

Science.gov (United States)

Dudley J. Raynal

1998-01-01

Forests in the northeastern US have been limed to mitigate soil acidification and the acidity of surface waters and to improve soil base cation status. Much of the area considered for liming is within the range of sugar maple (Acer saccharum), but there is a poor understanding of how liming influences growth and nutrient balance of this species on...

40 CFR 141.564 - My system practices lime softening-is there any special provision regarding my individual filter...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false My system practices lime softening-is... People Individual Filter Turbidity Requirements § 141.564 My system practices lime softening—is there any special provision regarding my individual filter turbidity monitoring? If your system utilizes lime...

Stability of reinforced cemented backfills

International Nuclear Information System (INIS)

Mitchell, R.J.; Stone, D.M.

1987-01-01

Mining with backfill has been the subject of several international meetings in recent years and a considerable research effort is being applied to improve both mining economics and ore recovery by using backfill for ground support. Classified mill tailings sands are the most commonly used backfill material but these fine sands must be stabilized before full ore pillar recovery can be achieved. Normal portland cement is generally used for stabilization but the high cost of cement prohibits high cement usage. This paper considers the use of reinforcements in cemented fill to reduce the cement usage. It is concluded that strong cemented layers at typical spacings of about 3 meters in a low cement content bulk fill can reinforce the fill and reduce the overall cement usage. Fibre reinforcements introduced into strong layers or into bulk fills are also known to be effective in reducing cement usage. Some development work is needed to produce the ideal type of anchored fibre in order to realize economic gains from fibre-reinforced fills

Microscale Investigation of Arsenic Distribution and Species in Cement Product from Cement Kiln Coprocessing Wastes

Directory of Open Access Journals (Sweden)

Yufei Yang

2013-01-01

Full Text Available To improve the understanding of the immobilization mechanism and the leaching risk of Arsenic (As in the cement product from coprocessing wastes using cement kiln, distribution and species of As in cement product were determined by microscale investigation methods, including electron probe microanalysis (EPMA and X-ray absorption spectroscopy. In this study, sodium arsenate crystals (Na3AsO412H2O were mixed with cement production raw materials and calcined to produce cement clinker. Then, clinker was mixed water to prepare cement paste. EPMA results showed that As was generally distributed throughout the cement paste. As content in calcium silicate hydrates gel (C-S-H was in low level, but higher than that in other cement mineral phases. This means that most of As is expected to form some compounds that disperse on the surfaces of cement mineral phases. Linear combination fitting (LCF of the X-ray absorption near edge structure spectra revealed that As in the cement paste was predominantly As(V and mainly existed as Mg3(AsO42, Ca3(AsO42, and Na2HAsO4.

Liming and fertilisation in Pinus taeda plantations with severe nutrient deficiency in savanna soils

Directory of Open Access Journals (Sweden)

Araína Hulmann Batista

2014-11-01

Full Text Available Soils with high acidity and low exchangeable bases may be responsible for low yields of Pinus taeda in a forest plantation at Jaguariaíva, Paraná State, Brazil. The aim of this study was to evaluate the effect of liming and fertilisation, applied over litter, on two selected areas with Pinus taeda plantations. Soil, litter and pine needles were evaluated for K, Ca and Mg concentrations and soil acidity parameters. Seven treatments were applied: (i complete (N, P, K, Zn, Cu, B, Mo, and lime; (ii without N, P, and K; (iii without Zn, Cu, B, and Mo; (iv without K; (v without Zn; (vi without lime; and (vii control (without nutrients and lime. Soil samples were collected at five soil depths (0-5, 5-10, 10-20, 20-40 and 40-60 cm simultaneously with litter samples. Needles were also collected from the first and second pine flushes. Liming induced soil pH, Ca2+, and Mg2+ increases, and the opposite was observed for Al3+ and Al saturation. Fertilisation increased soil exchangeable K+ concentrations and needle and litter K concentrations. The low Ca and Mg concentrations found in the plant needles might be attributable to their low mobility.

Cadmium uptake by tobacco as affected by liming, N form, and year of cultivation

International Nuclear Information System (INIS)

Tsadilas, C.D.; Karaivazoglou, N.A.; Tsotsolis, N.C.; Stamatiadis, S.; Samaras, V.

2005-01-01

Tobacco is able to accumulate cadmium and reduction of cadmium content can reduce health hazards to smokers. Soil pH and form of N fertilizers are among the factors affecting Cd uptake by tobacco. This hypothesis was tested in an acid soil in northern Greece by a four year field experiment. The variability of Cd uptake by tobacco was attributed to the variation of soil Cd availability as affected by soil pH. Liming with 3000 kg Ca(OH) 2 ha -1 increased soil pH by 0.8 units and decreased extractable with DTPA soil and leaf Cd by 40% and 35%, respectively. The ammonium fertilizer caused the opposite, but weaker, effects. Liming reduced soil Cd more in the ammonium treatment than in nitrate or combined N treatments. The year of cultivation strongly affected soil and leaf Cd. Four years after tobacco cultivation, soil pH was reduced by 0.5 units, whereas soil and leaf Cd reduction was more than 60% in the limed treatments. Liming affected Cd uptake only in the first three years of cultivation. - Liming and N form affect Cd uptake by Virginia tobacco which contributes significantly to the great reduction of extractable soil Cd after three years of continuous cultivation

Lime and rates and sources of phosphorus as influencing soybean yield and chemical properties of Pelotas soil (alfisol)

International Nuclear Information System (INIS)

Machado, M.O.

1983-01-01

The effect of five phosphates as sources of phosphorus for soybean (Bragg cultivar) was evaluated in two rates (100 and 200 Kg/ha of total P 2 O 5 ), on limed and unlimed soil condtions. The experiment was carried out under field conditions, during the soybean growing season of 1973/74, 1974/75, 1975/76 and 1976/77, at UEPAE Pelotas station. The pH and the exchangeable Ca + Mg content from the soil were increased with Gafsa phosphate, but mainly with lime, Thomas slag and Yoorin thermophosphate application. The exchangeable Al content was eliminated by lime application and decreased annually by application of Gafsa phosphate, Thomas slag and Yoorin thermophosphate, when the lime was not applied. Thomas slag and Yoorin thermophosphate were the best phosphates for grain yield and do without lime: however, under limed soil conditions all phosphates had some efficiency, except for the Gafsa phosphate in the first growing season. (Author) [pt

Evaluation of cement thixotropy for the cement of oil wells in areas ...

African Journals Online (AJOL)

... economical for cementing job operations in wells with loss zones. The results also show that the effect of LHF is positive, since in addition to his contribution to long term performances, especially the durability of hardened concrete, it improves the thixotropy of cement made of plaster. Keywords: cementing; lost circulation; ...

The differences between soil grouting with cement slurry and cement-water glass slurry

Science.gov (United States)

Zhu, Mingting; Sui, Haitong; Yang, Honglu

2018-01-01

Cement slurry and cement-water glass slurry are the most widely applied for soil grouting reinforcement project. The viscosity change of cement slurry is negligible during grouting period and presumed to be time-independent while the viscosity of cement-water glass slurry increases with time quickly and is presumed to be time-dependent. Due to the significantly rheology differences between them, the grouting quality and the increasing characteristics of grouting parameters may be different, such as grouting pressure, grouting surrounding rock pressure, i.e., the change of surrounding rock pressure deduced by grouting pressure. Those are main factors for grouting design. In this paper, a large-scale 3D grouting simulation device was developed to simulate the surrounding curtain grouting for a tunnel. Two series of surrounding curtain grouting experiments under different geo-stress of 100 kPa, 150 kPa and 200 kPa were performed. The overload test on tunnel was performed to evaluate grouting effect of all surrounding curtain grouting experiments. In the present results, before 240 seconds, the grouting pressure increases slowly for both slurries; after 240 seconds the increase rate of grouting pressure for cement-water glass slurry increases quickly while that for cement slurry remains roughly constant. The increasing trend of grouting pressure for cement-water glass is similar to its viscosity. The setting time of cement-water glass slurry obtained from laboratory test is less than that in practical grouting where grout slurry solidifies in soil. The grouting effect of cement-water glass slurry is better than that of cement slurry and the grouting quality decreases with initial pressure.

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.)

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

40 CFR 141.553 - My system practices lime softening-is there any special provision regarding my combined filter...

Science.gov (United States)

2010-07-01

... 40 Protection of Environment 22 2010-07-01 2010-07-01 false My system practices lime softening-is... Filter Effluent Requirements § 141.553 My system practices lime softening—is there any special provision regarding my combined filter effluent? If your system practices lime softening, you may acidify...

Sustainable Development of the Cement Industry and Blended Cements to Meet Ecological Challenges

OpenAIRE

Sobolev, Konstantin

2003-01-01

The world production of cement has greatly increased in the past 10 years. This trend is the most significant factor affecting technological development and the updating of manufacturing facilities in the cement industry. Existing technology for the production of cement clinker is ecologically damaging; it consumes much energy and natural resources and also emits pollutants. A new approach to the production of blended or high-volume mineral additive (HVMA) cement helps to improve its ecologi...

Substrate pH and butterfly bush response to dolomitic lime or steel slag amendment

Science.gov (United States)

Steel slag is a fertilizer amendment with a high concentration of calcium oxide, and thus capable of raising substrate pH similar to dolomitic lime. Steel slag, however, contains higher concentrations of some nutrients, such as iron, manganese, and silicon, compared to dolomitic lime. The objectiv...

A theory manual for multi-physics code coupling in LIME.

Energy Technology Data Exchange (ETDEWEB)

Belcourt, Noel; Bartlett, Roscoe Ainsworth; Pawlowski, Roger Patrick; Schmidt, Rodney Cannon; Hooper, Russell Warren

2011-03-01

The Lightweight Integrating Multi-physics Environment (LIME) is a software package for creating multi-physics simulation codes. Its primary application space is when computer codes are currently available to solve different parts of a multi-physics problem and now need to be coupled with other such codes. In this report we define a common domain language for discussing multi-physics coupling and describe the basic theory associated with multiphysics coupling algorithms that are to be supported in LIME. We provide an assessment of coupling techniques for both steady-state and time dependent coupled systems. Example couplings are also demonstrated.

Longevity of metal-ceramic crowns cemented with self-adhesive resin cement: a prospective clinical study

Directory of Open Access Journals (Sweden)

Lucas Pradebon BRONDANI

2017-04-01

Full Text Available Abstract Resin cements are often used for single crown cementation due to their physical properties. Self-adhesive resin cements gained widespread due to their simplified technique compared to regular resin cement. However, there is lacking clinical evidence about the long-term behavior of this material. The aim of this prospective clinical trial was to assess the survival rates of metal-ceramic crowns cemented with self-adhesive resin cement up to six years. One hundred and twenty-nine subjects received 152 metal-ceramic crowns. The cementation procedures were standardized and performed by previously trained operators. The crowns were assessed as to primary outcome (debonding and FDI criteria. Statistical analysis was performed using Kaplan-Meier statistics and descriptive analysis. Three failures occurred (debonding, resulting in a 97.6% survival rate. FDI criteria assessment resulted in scores 1 and 2 (acceptable clinical evaluation for all surviving crowns. The use of self-adhesive resin cement is a feasible alternative for metal-ceramic crowns cementation, achieving high and adequate survival rates.

Formation of superhydrophobic soda-lime glass surface using femtosecond laser pulses

International Nuclear Information System (INIS)

Ahsan, Md. Shamim; Dewanda, Fadia; Lee, Man Seop; Sekita, Hitoshi; Sumiyoshi, Tetsumi

2013-01-01

Highlights: ► We formed superhydrophobic soda-lime glass surface by femtosecond laser pulses. ► Periodic microstructures are printed on the glass surface for superhydrophobicity. ► The contact angle of water droplet on the microstructured glass surface is 155°. ► The transparency of superhydrophobic glass is higher than 77% in visible spectrum. ► We explain the formation mechanism of superhydrophobic soda-lime glass surface. - Abstract: This paper demonstrates the fabrication of superhydrophobic soda-lime glass surface by engineering periodic microgratings with self-formed periodic micro-ripples inside the microgratings using a single beam femtosecond laser. The wetting property of the microstructured surface is improved from hydrophobic to superhydrophobic, presenting a water droplet contact angle ranges from 152° to 155°. The microstructured glass surface shows excellent transparency, which is higher than 77% in the visible spectrum. We strongly believe that our proposed technology can achieve superhydrophobic glass surfaces over a large area for applications in diverse fields.

Initial growth of Schizolobium parahybae in Brazilian Cerrado soil under liming and mineral fertilization

Directory of Open Access Journals (Sweden)

Ademilson Coneglian

Full Text Available ABSTRACT High prices and the scarcity of hardwoods require the use of alternative wood sources, such as the Guapuruvu (Schizolobium parahybae, an arboreal species native to the Atlantic Forest, which has fast growth and high market potential. However, there is no information on its cultivation in the Brazilian Cerrado. Thus, this study aimed to analyze the contribution of mineral fertilization and liming in a Cerrado soil on the initial growth of Schizolobium parahybae. The experiment was set in a randomized block design, with 4 treatments (Cerrado soil; soil + liming; soil + fertilizer; and soil + fertilizer + liming and 15 replicates. The following variables were analyzed: plant height, stem diameter, number of leaves, total, shoot, leaf, root and stem dry matter, and root/shoot ratio. The obtained data were subjected to the analysis of variance, Tukey test and regression analysis. During the initial growth, Schizolobium parahybae can be cultivated in a Brazilian Cerrado soil only under mineral fertilization, with no need for soil liming.

Experimental Study on Artificial Cemented Sand Prepared with Ordinary Portland Cement with Different Contents

Directory of Open Access Journals (Sweden)

Dongliang Li

2015-07-01

Full Text Available Artificial cemented sand test samples were prepared by using ordinary Portland cement (OPC as the cementing agent. Through uniaxial compression tests and consolidated drained triaxial compression tests, the stress-strain curves of the artificial cemented sand with different cementing agent contents (0.01, 0.03, 0.05 and 0.08 under various confining pressures (0.00 MPa, 0.25 MPa, 0.50 MPa and 1.00 MPa were obtained. Based on the test results, the effect of the cementing agent content (Cv on the physical and mechanical properties of the artificial cemented sand were analyzed and the Mohr-Coulomb strength theory was modified by using Cv. The research reveals that when Cv is high (e.g., Cv = 0.03, 0.05 or 0.08, the stress-strain curves of the samples indicate a strain softening behavior; under the same confining pressure, as Cv increases, both the peak strength and residual strength of the samples show a significant increase. When Cv is low (e.g., Cv = 0.01, the stress-strain curves of the samples indicate strain hardening behavior. From the test data, a function of Cv (the cementing agent content with c′ (the cohesion force of the sample and Δϕ′ (the increment of the angle of shearing resistance is obtained. Furthermore, through modification of the Mohr-Coulomb strength theory, the effect of cementing agent content on the strength of the cemented sand is demonstrated.

Experimental Study on Artificial Cemented Sand Prepared with Ordinary Portland Cement with Different Contents.

Science.gov (United States)

Li, Dongliang; Liu, Xinrong; Liu, Xianshan

2015-07-02

Artificial cemented sand test samples were prepared by using ordinary Portland cement (OPC) as the cementing agent. Through uniaxial compression tests and consolidated drained triaxial compression tests, the stress-strain curves of the artificial cemented sand with different cementing agent contents (0.01, 0.03, 0.05 and 0.08) under various confining pressures (0.00 MPa, 0.25 MPa, 0.50 MPa and 1.00 MPa) were obtained. Based on the test results, the effect of the cementing agent content ( C v ) on the physical and mechanical properties of the artificial cemented sand were analyzed and the Mohr-Coulomb strength theory was modified by using C v . The research reveals that when C v is high (e.g., C v = 0.03, 0.05 or 0.08), the stress-strain curves of the samples indicate a strain softening behavior; under the same confining pressure, as C v increases, both the peak strength and residual strength of the samples show a significant increase. When C v is low (e.g., C v = 0.01), the stress-strain curves of the samples indicate strain hardening behavior. From the test data, a function of C v (the cementing agent content) with c ' (the cohesion force of the sample) and Δϕ' (the increment of the angle of shearing resistance) is obtained. Furthermore, through modification of the Mohr-Coulomb strength theory, the effect of cementing agent content on the strength of the cemented sand is demonstrated.

Influence of Cements Containing Calcareous Fly Ash as a Main Component Properties of Fresh Cement Mixtures

Science.gov (United States)

Gołaszewski, Jacek; Kostrzanowska-Siedlarz, Aleksandra; Ponikiewski, Tomasz; Miera, Patrycja

2017-10-01

The main goal of presented research was to examine usability of cements containing calcareous fly ash (W) from technological point of view. In the paper the results of tests concerning the influence of CEM II and CEM IV cements containing fly ash (W) on rheological properties, air content, setting times and plastic shrinkage of mortars are presented and discussed. Moreover, compatibility of plasticizers with cements containing fly ash (W) was also studied. Additionally, setting time and hydration heat of cements containing calcareous fly ash (W) were determined. In a broader aspect, the research contributes to promulgation of the possibility of using calcareous fly ash (W) in cement and concrete technology, what greatly benefits the environment protection (utilization of waste fly ash). Calcareous fly ash can be used successfully as the main component of cement. Cements produced by blending with processed fly ash or cements produced by interginding are characterized by acceptable technological properties. In respect to CEM I cements, cements containing calcareous fly ash worsen workability, decrease air content, delay setting time of mixtures. Cements with calcareous fly ash show good compatibility with plasticizers.

Vanadium extraction from slimes by the lime-bicarbonate method

International Nuclear Information System (INIS)

Lishchenko, T.V.; Vdovina, L.V.; Slobodchikova, R.I.

1978-01-01

Some main parameters of the lime-bicarbonate method of extracting vanadium from residues obtained in washing waters of mazut boilers on thermal stations have been determined. To study the process of vanadium extraction during caking of the residues with lime and subsequent leaching of water-soluble vanadium, a ''Minsk-22'' computer has been used for computation. Analysis of the equation derived has shown that a change in temperature of vanadium leaching, density of pulp, and a kind of heating of the charge affect the process only slightly. It has also been shown that the calcination temperature is expedient to be kept above 850 deg C and consumption temperature is expedient to be kept above 85O deg C and consumption of lime must not exceed 20% of the residues weight. Bicarbonate consumption exerts a decisive influence on completeness of vanadium extraction and must be increased up to >35%; duration of leaching should be raised up to 30-45 minutes. With increasing calcination temperature the duration of leaching decreases. When temperature and duration of calcination increase, the formation of water-soluble vanadium intensifies. With the aid of optimization program seven variants have been chosen, which ensure vanadium extraction into solution by 95-100%

Sorghum yield after liming and combinations of phosphorus sources

Directory of Open Access Journals (Sweden)

Thiago C. Silveira

Full Text Available ABSTRACT Phosphate fertilization has increased sorghum yield, but few studies are available on sorghum production and efficient fertilizer management related to liming and phosphorus (P sources. This work evaluates production, dry matter partitioning and agronomic efficiency (AEI in successive sorghum cycles after application of limestone and combinations of phosphorus sources. Two cycles were conducted in sequence in the same experimental field, in a 2 x 6 factorial scheme, corresponding to soil with or without liming and six combinations of P2O5 sources: control (0 kg ha-1 P2O5, 100% Itafós natural phosphate (NP, 75% NP + 25% single superphosphate (SS, 50% NP + 50% SS, 25% NP + 75% SS and 100% SS. Pots with capacity for 8 dm3 were used in a randomized block design with four replicates. The first cycle, conducted in the summer/autumn season, reached the highest dry matter production and P accumulation in treatments with higher SS proportions, leading to higher AEI. Subsequently, in the second cycle, conducted considering only the residual phosphate fertilization of the first cycle, highest dry matter production and AEI were obtained in the treatment with 100% or higher proportions of natural phosphate in the presence of liming, most likely due to the gradual release of P.

The influence of lime and nitrogen fertilisers on spore counts of Pithomyces chartarum in pasture.

Science.gov (United States)

Cuttance, E L; Laven, R A; Mason, W A; Stevenson, M

2016-11-01

To determine whether the application of lime or nitrogen to pasture affected the spore counts of Pithomyces chartarum. The lime application studies were undertaken on a spring-calving, pasture-based, commercial dairy farm near Te Awamutu, New Zealand. On 6 November 2012, five randomly selected paddocks were split into three equal sections. In two of the sections, lime was applied at either 1.5 or 2.5 t/ha, and the central section was left as an untreated control. Each section was sampled for spore counting weekly from 16 January to 15 May 2013. Starting in January 2013, five other randomly selected paddocks were monitored for spore counts. On 20 March 2013 the average spore counts in three paddocks were >100,000 spores/g of pasture. These paddocks were then divided into three equal sections and lime was applied as described above. Spore counting in each section continued weekly until 15 May 2013. The nitrogen application study was carried out on three commercial dairy farms near Te Awamutu, New Zealand. Two randomly selected paddocks on each farm were divided into three equal sections and, on 20 December 2012, nitrogen in the form of urea was applied at either 50 or 80 kg urea/ha to two of the sections; the central section remained as an untreated control. Each section was sampled for spore counting weekly from 16 January to 15 May 2013. Following pre-summer lime application, treatment at 1.5 or 2.5 t/ha did not affect spore counts over time compared with the control section (p>0.26). Similarly following autumn lime application, treatment at 1.5 or 2.5 t/ha did not affect spore counts over time compared with the control section (p>0.11). Following nitrogen application median spore counts remained 0.49). This study found that application of lime before the risk period for facial eczema, in November, application of lime after a spore count rise, in March, or urea application in December did not affect changes in number of spores produced by P. chartarum. This

Application of lime (CaCO3) to promote forest recovery from severe acidification increases potential for earthworm invasion

Science.gov (United States)

Homan, Caitlin; Beirer, Colin M; McCay, Timothy S; Lawrence, Gregory B.

2016-01-01

The application of lime (calcium carbonate) may be a cost-effective strategy to promote forest ecosystem recovery from acid impairment, under contemporary low levels of acidic deposition. However, liming acidified soils may create more suitable habitat for invasive earthworms that cause significant damage to forest floor communities and may disrupt ecosystem processes. We investigated the potential effects of liming in acidified soils where earthworms are rare in conjunction with a whole-ecosystem liming experiment in the chronically acidified forests of the western Adirondacks (USA). Using a microcosm experiment that replicated the whole-ecosystem treatment, we evaluated effects of soil liming on Lumbricus terrestris survivorship and biomass growth. We found that a moderate lime application (raising pH from 3.1 to 3.7) dramatically increased survival and biomass of L. terrestris, likely via increases in soil pH and associated reductions in inorganic aluminum, a known toxin. Very few L. terrestris individuals survived in unlimed soils, whereas earthworms in limed soils survived, grew, and rapidly consumed leaf litter. We supplemented this experiment with field surveys of extant earthworm communities along a gradient of soil pH in Adirondack hardwood forests, ranging from severely acidified (pH 5). In the field, no earthworms were observed where soil pH 4.4 and human dispersal vectors, including proximity to roads and public fishing access, were most prevalent. Overall our results suggest that moderate lime additions can be sufficient to increase earthworm invasion risk where dispersal vectors are present.

Development of high-performance blended cements

Science.gov (United States)

Wu, Zichao

2000-10-01

This thesis presents the development of high-performance blended cements from industrial by-products. To overcome the low-early strength of blended cements, several chemicals were studied as the activators for cement hydration. Sodium sulfate was discovered as the best activator. The blending proportions were optimized by Taguchi experimental design. The optimized blended cements containing up to 80% fly ash performed better than Type I cement in strength development and durability. Maintaining a constant cement content, concrete produced from the optimized blended cements had equal or higher strength and higher durability than that produced from Type I cement alone. The key for the activation mechanism was the reaction between added SO4 2- and Ca2+ dissolved from cement hydration products.

Cements in Radioactive Waste Disposal

International Nuclear Information System (INIS)

Glasser, F.P.

2013-01-01

The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

Cements in Radioactive Waste Disposal

Energy Technology Data Exchange (ETDEWEB)

Glasser, F. P. [University of Aberdeen, Scotland (United Kingdom)

2013-09-15

The use of cement and concrete to immobilise radioactive waste is complicated by the wide- ranging nature of inorganic cementing agents available as well as the range of service environments in which cement is used and the different functions expected of cement. For example, Portland cement based concretes are widely used as structural materials for construction of vaults and tunnels. These constructions may experience a long pre-closure performance lifetime during which they are required to protect against collapse and ingress of water: strength and impermeability are key desirable characteristics. On the other hand, cement and concrete may be used to form backfills, ranging in permeability. Permeable formulations allow gas readily to escape, while impermeable barriers retard radionuclide transport and reduce access of ground water to the waste. A key feature of cements is that, while fresh, they pass through a fluid phase and can be formed into any shape desired or used to infiltrate other materials thereby enclosing them into a sealed matrix. Thereafter, setting and hardening is automatic and irreversible. Where concrete is used to form structural elements, it is also natural to use cement in other applications as it minimises potential for materials incompatibility. Thus cement- mainly Portland cement- has been widely used as an encapsulant for storage, transport and as a radiation shield for active wastes. Also, to form and stabilise structures such as vaults and silos. Relative to other potential matrices, cement also has a chemical immobilisation potential, reacting with and binding with many radionuclides. The chemical potential of cements is essentially sacrificial, thus limiting their performance lifetime. However performance may also be required in the civil engineering sense, where strength is important, so many factors, including a geochemical description of service conditions, may require to be assessed in order to predict performance lifetime. The

Dental Cements for Luting and Bonding Restorations: Self-Adhesive Resin Cements.

Science.gov (United States)

Manso, Adriana P; Carvalho, Ricardo M

2017-10-01

Self-adhesive resin cements combine easy application of conventional luting materials with improved mechanical properties and bonding capability of resin cements. The presence of functional acidic monomers, dual cure setting mechanism, and fillers capable of neutralizing the initial low pH of the cement are essential elements of the material and should be understood when selecting the ideal luting material for each clinical situation. This article addresses the most relevant aspects of self-adhesive resin cements and their potential impact on clinical performance. Although few clinical studies are available to establish solid clinical evidence, the information presented provides clinical guidance in the dynamic environment of material development. Copyright © 2017 Elsevier Inc. All rights reserved.

Specification and time required for the application of a lime-based render inside historic buildings

Directory of Open Access Journals (Sweden)

Vasco Peixoto de Freitas

2008-01-01

Full Text Available Intervention in ancient buildings with historical and architectural value requires traditional techniques, such as the use of lime mortars for internal and external wall renderings. In order to ensure the desired performance, these rendering mortars must be rigorously specified and quality controls have to be performed during application. The choice of mortar composition should take account of factors such as compatibility with the substrate, mechanical requirements and water behaviour. The construction schedule, which used to be considered a second order variable, nowadays plays a decisive role in the selection of the rendering technique, given its effects upon costs. How should lime-based mortars be specified? How much time is required for the application and curing of a lime-based render? This paper reflects upon the feasibility of using traditional lime mortars in three-layer renders inside churches and monasteries under adverse hygrothermal conditions and when time is critical. A case study is presented in which internal lime mortar renderings were applied in a church in Northern Portugal, where the very high relative humidity meant that several months were necessary before the drying process was complete.

Simultaneous removal of colour, phosphorus and disinfection from treated wastewater using an agent synthesized from amorphous silica and hydrated lime.

Science.gov (United States)

Yamashita, Takahiro; Aketo, Tsuyoshi; Minowa, Nobutaka; Sugimoto, Kiyomi; Yokoyama, Hiroshi; Ogino, Akifumi; Tanaka, Yasuo

2013-01-01

An agent synthesized from amorphous silica and hydrated lime (CSH-lime) was investigated for its ability to simultaneously remove the colour, phosphorus and disinfection from the effluents from wastewater treatment plants on swine farms. CSH-lime removed the colour and phosphate from the effluents, with the colour-removal effects especially high at pH 12, and phosphorous removal was more effective in strongly alkaline conditions (pH > 10). Colour decreased from 432 +/-111 (mean +/- SD) to 107 +/- 41 colour units and PO4(3-)P was reduced from 45 +/- 39 mg/L to undetectable levels at the CSH-lime dose of 2.0% w/v. Moreover, CSH-lime reduced the total organic carbon from 99.0 to 37.9 mg/L at the dose of 2.0% w/v and was effective at inactivating total heterotrophic and coliform bacteria. However, CSH-lime did not remove nitrogen compounds such as nitrite, nitrate and ammonium. Colour was also removed from dye solutions by CSH-lime, at the same dose.

Hemp-Lime Performance in Danish Climatic Context. Thermal Conductivity as a Function of Moisture Content

DEFF Research Database (Denmark)

Antonov, Yovko Ivanov; Jensen, Rasmus Lund; Pomianowski, Michal Zbigniew

2016-01-01

concrete is a bio-based building material composed of the woody core of industrial hemp and lime based binder. It is a non-load-bearing material, which can be used as floor and around structural frames for walls and roof. The material is characterized by relatively low environmental impact, moderate...... thermal properties and, high air and moisture permeability. The properties vary with binder composition, mixing and casting techniques, as well as intended application. This research presents preliminary heat and moisture building simulations of single family house made out of hemp-lime composite....... To evaluate the performance of hemp-lime, it is compared to models with common external walls, upon defined parameters. The article also determines the variation of thermal conductivity for hemp-lime commercial plaster and wall mix, as a function of moisture content. The most promising binder composition...

Obtaining a sulfoaluminate belite cement by industrial waste

Directory of Open Access Journals (Sweden)

Elkhadiri, L.

2003-06-01

Full Text Available Sulfoaluminate belite clinkers by burning raw at moderate temperatures near 1250 °C were synthesized. The used mixtures were made by calcium carbonate blended to two industrial wastes: low calcium fly ash and phosphogypsum. The clinkers were characterised by X-Ray Diffraction (XRD, Infrared Spectroscopy (FTIR and free lime. The hydraulic behaviour of the obtained cements, by adequate clinkers with 7% of added gypsum, was followed by XRD, scaning electronic microscopy (SEM, FTIR and NMR.

Los clínkeres belíticos de sulfoaluminatos se obtienen por cocción de crudos a temperaturas moderadas, hacia 1.250 ºC. Esos crudos se componen de carbonato de calcio mezclados con dos subproductos industriales: cenizas volantes pobres en óxido de calcio y fosfoyeso. Los clínkeres obtenidos se caracterizaron a través de Difracción de Rayos X (DRX, Espectroscopia Infrarroja por Transformada de Fourier (FTIR y por la determinación de CaO libre. El comportamiento hidráulico de los cementos elaborados de los clínkeres con el 7% de yeso se estudió por DRX, Microscopía Electrónica de Barrido (SEM, FTIR y Resonancia Magnética Nuclear (RMN

The effect of sand/cement ratio on radon exhalation from cement specimens containing 226Ra

International Nuclear Information System (INIS)

Takriti, S.; Shweikani, R.; Ali, A. F.; Rajaa, G.

2002-09-01

Portland cement was mixed with different kind of sand (calcite and silica) in different ratio to produce radioactive specimens with radium chloride. The release of radon from these samples was studied. The results showed that radon release from the calcite-cement samples increased with the increases of the sand mixed ratio until fixed value (about 20%) then decreased to less than its release from the beginning, and the release changed with the sand size also. Radon release from silica-cement samples had the same observations of calcite-cement samples. It was found that calcite-cement reduced the radon exhalation quantity rather than the silica-cement samples. The decreases of the radon exhalation from the cement-sand may be due to the creation of free spaces in the samples, which gave the possibility to radon to decay into these free spaces rather than radon exhalation. The daughters of the radon decay 214 Bi and 214 Pb reported by gamma measurements of the cement-sand samples. (author)

Cement for oil well developed from ordinary cement: characterization physical, chemical and mineralogical

International Nuclear Information System (INIS)

Oliveira, D.N.S.; Neves, G. de A.; Chaves, A.C.; Mendonca, A.M.G.D.; Lima, M.S. de; Bezerra, U.T.

2012-01-01

This work aims to characterize a new type of cement produced from the mixture of ordinary Portland cement, which can be used as an option in the cementing of oil wells. To enable this work we used the method of lineal programming for the new cement composition, then conducted tests to characterize through particle size analysis by laser diffraction, chemical analysis by EDX, TGA, X-ray diffraction, time grip, resistance to compression. The overall result showed that the new cement had made low-C3A, takes more time to the CPP, thermal stability up to 500 ° C, the kinetics of hydration and low levels of major components consistent with the specifications of ABNT. (author)

Valorisation of sugarcane bagasse ash (SCBA with high quartz content as pozzolanic material in Portland cement mixtures

Directory of Open Access Journals (Sweden)

A. M. Pereira

2018-04-01

Full Text Available Portland cement (OPC production is one of the most contaminating greenhouse gas producing activities. In order to reduce OPC consumption, several alternatives are being assessed, and the use of pozzolanic material is one of them. This paper presents study on the reactivity of sugarcane bagasse ash (SCBA, a residue from sugarcane industry, as a pozzolanic material. In order to evaluate SCBA reactivity, it was mixed in pastes with hydrated lime and OPC, which were microstructurally characterised. These studies showed that SCBA presents some pozzolanic characteristics. Studies on mortars in which OPC was replaced by SCBA in the range 10–30% were also carried out. Replacement in the range 15–20% yielded the best behaviour in terms of compressive strength. Finally, it can be concluded this ash could be valorised despite its relative low pozzolanic reactivity.

Molecular characterization and pathogenicity assays of Colletotrichum acutatum, causal agent for lime anthracnose in Texas

Science.gov (United States)

Several distorted Mexican lime [Citrus aurantiifolia (Christm). Swingle] fruit, leaf, and twig samples with lime anthracnose symptoms were collected from three trees in residential areas of Brownsville, Texas. The causal fungal organism, Colletotrichum acutatum J. H. Simmonds was isolated from leave...

Evaluation of stainless steel crowns cemented with glass-ionomer and resin-modified glass-ionomer luting cements.

Science.gov (United States)

Yilmaz, Yucel; Simsek, Sera; Dalmis, Anya; Gurbuz, Taskin; Kocogullari, M Elcin

2006-04-01

To evaluate in vitro and in vivo conditions of stainless steel crowns (SSC) cemented using one luting glass-ionomer cement (Aqua Meron) and one luting resin-modified glass-ionomer cement (Vitremer). In the in vitro part of this study, retentive properties of SSCs cemented using Aqua Meron and Vitremer on extracted primary first molars were tested. In addition, two specimens of each group were used to evaluate the tooth hard tissue-cement, within the cement itself, cement-SSC, and tooth hard tissue-cement-SSC under scanning electron microscope (SEM). In the in vivo part of this study, 152 SSCs were placed on the first or second primary molars of 86 children, and cemented using either Aqua Meron or Vitremer. The crowns were examined for retention. In addition, the clinical views of the crowns were recorded with an intraoral camera. No significant difference was found between the mean retentive forces of Aqua Meron and Vitremer (P> 0.05). SSCs cemented with Aqua Meron and Vitremer had an average lifespan of 26.44 and 24.07 months respectively. Only one (0.66%) of 152 SSCs was lost from the Aqua Meron group during post-cementation periods. Nineteen of the 152 SSCs (12.5%) had dents or perforations.

Basic Deformation Parameters of Solid Clay Bricks and Small Masonry Walls

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P. Bouška

2000-01-01

Full Text Available The basic mechanical properties of clay brick masonry and its components were experimentally investigated in the laboratories of the Klokner Institute. The test specimens of masonry materials and the relevant mechanical properties have been identified in solid clay bricks and cement-lime mortar. The aim of the research activity was to study both the deformability of the prevailing type of clay masonry in the existing buildings, i.e. the masonry made from the solid clay units and the lime-cement mortar, and the most important mechanical properties of masonry components.

Investigations on generation and use of a sludge-lime fertilizer. Untersuchungen zur Erzeugung und Anwendung eines Klaerschlamm-Kalkduengers

Energy Technology Data Exchange (ETDEWEB)

Boehnke, B; Weiling, R

1980-06-01

Sludge is an important energy and raw material source, which if possible should be utilized in agriculture. Through the addition of unslaked lime a hygienically safe product can be prepared with the help of a suitable treatment process and can be offered in granulated form as a valuable sludge-lime fertilizer. Sludges of different consistencies and origins were investigated. Varying amounts and types of lime were used and the products were tested for easy handling, storage capability and temperature influence on the hygienic conditions. In order to obtain a disseminable substance, a solid matter content of over 60% is necessary. This is achieved through variation of the lime content depending on the solid content of the respective sludge. According to the existing regulations, which fix the minimum CaO content in a lime fertilizer at 30%, a predewatering of the sludge up to 25%-30% of the solid matter content is sufficient. Economic viability is assured, specially in areas where intensive agricultural use of lime fertilizer is necessary. (orig.) With 32 refs., 15 tabs., 27 figs.

Use of kaolin waste for production os soil-lime blocks

International Nuclear Information System (INIS)

Anjos, C.M. dos; Neves, G.A.

2011-01-01

There is an evident growth in waste generation over the last decades, especially in developing countries. The mining industry produces large quantities and different kinds and levels of dangerousness, such as the kaolin processing industry, which produces waste based on silica, mica and kaolinite. Disposal of this material in an inappropriate location causes significant environmental impacts, which could be minimized with the use of waste as raw material for use in construction. This paper has as main objective to study the incorporation of the kaolin processing waste into soil-lime. The residues of kaolin were calcined at a temperature of 800 ° C for evaluation of pozzolanic activity. Raw materials and conventional alternatives were characterized by means of test particle size analysis by laser diffraction, chemical analysis, X-ray diffraction. Then, blocks conventional soil-lime and soil-lime with the introduction of residual kaolin in proportions of 10%, 20%, 30% and 40% were cast and cured in a moist chamber for periods of 28, 60 and 90 days. The technological tests of compressive strength results obtained within the specifications of the ABNT. The best results were for 90 days of healing and 20% residue. (author)

Study on properties and testing methods of thermo-responsive cementing system for well cementing in heavy oil thermal recovery

Science.gov (United States)

Li, Lianjiang

2017-08-01

In this paper, thermo-responsive cement slurry system were being developed, the properties of conventional cement slurry, compressive strength high temperature of cement sheath, mechanical properties of cement sheath and thermal properties of cement sheath were being tested. Results were being used and simulated by Well-Life Software, Thermo-responsive cement slurry system can meet the requirements of heavy oil thermal recovery production. Mechanical and thermal properties of thermo-responsive cement sheath were being tested. Tensile fracture energy of the thermo-responsive cement sheath is larger than conventional cement. The heat absorption capacity of conventional cement sheath is larger than that of thermo-responsive cement sheath, this means more heat is needed for the unit mass once increasing 1.0 °C, which also indicates that thermo-responsive cement own good heat insulating and preservation effects. The heat conductivity coefficient and thermal expansion coefficient of thermo-responsive cement is less than and conventional cement, this means that thermo-responsive cement have good heat preservation and insulation effects with good thermal expansion stabilities.

Wood ash as a soil additive and liming agent

International Nuclear Information System (INIS)

Campbell, A.; Etiegni, L.; Mahler, R.L.

1991-01-01

This study evaluated wood ash as an agricultural soil supplement and liming material. Winter wheat (Triticum aestivum) and poplar (Populus sp.) were grown in a greenhouse on six different Idaho soils amended with different ash concentrations. At ash levels equal to or lower than 2%, no detrimental effects were observed. In fact, the biomass of the wheat and the caliper and height of the poplar cuttings increased more at 2% ash 940 metric tons/ha than with the control soil. These results suggest that wood ash could be used in agricultural applications as a low analysis fertilizer containing potassium and as a liming agent. Land application of wood ash could be less expensive and more environmentally sound than present landfilling practices

Effect of temporary cements on the microtensile bond strength of self-etching and self-adhesive resin cement.

Science.gov (United States)

Carvalho, Edilausson Moreno; Carvalho, Ceci Nunes; Loguercio, Alessandro Dourado; Lima, Darlon Martins; Bauer, José

2014-11-01

The aim of this study was to evaluate the microtensile bond strength (µTBS) of self-etching and self-adhesive resin cement systems to dentin affected by the presence of remnants of either eugenol-containing or eugenol-free temporary cements. Thirty extracted teeth were obtained and a flat dentin surface was exposed on each tooth. Acrylic blocks were fabricated and cemented either with one of two temporary cements, one zinc oxide eugenol (ZOE) and one eugenol free (ZOE-free), or without cement (control). After cementation, specimens were stored in water at 37°C for 1 week. The restorations and remnants of temporary cements were removed and dentin surfaces were cleaned with pumice. Resin composite blocks were cemented to the bonded dentin surfaces with one of two resin cements, either self-etching (Panavia F 2.0) or self-adhesive (RelyX U-100). After 24 h, the specimens were sectioned to obtain beams for submission to µTBS. The fracture mode was evaluated under a stereoscopic loupe and a scanning electron microscope (SEM). Data from µTBS were submitted to two-way repeated-measure ANOVA and the Tukey test (alpha = 0.05). The cross-product interaction was statistically significant (p cements reduced the bond strength to Panavia self-etching resin cements only (p cements did not interfere in the bond strength to dentin of self-adhesive resin cements.

An Experimental Study of Portland Cement and Superfine Cement Slurry Grouting in Loose Sand and Sandy Soil

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Weijing Yao

2018-04-01

Full Text Available Grouting technology is widely applied in the fields of geotechnical engineering in infrastructure. Loose sand and sandy soil are common poor soils in tunnel and foundation treatments. It is necessary to use superfine cement slurry grouting in the micro-cracks of soil. The different effectiveness of Portland cement slurry and superfine cement slurry in sandy soil by the laboratory grouting experiment method were presented in this paper. The grouting situations of superfine cement slurry injected into sand and sandy soil were explored. The investigated parameters were the dry density, wet density, moisture content, internal friction angle, and cohesion force. The results show that the consolidation effect of superfine cement is better than that of Portland cement due to the small size of superfine cement particles. The superfine cement can diffuse into the sand by infiltration, extrusion, and splitting. When the water–cement ratio of superfine cement slurry is less than 2:1 grouting into loose sand, the dry and wet density decrease with the increase in the water–cement ratio, while the moisture content and cohesive force gradually increase. When the water–cement ratio of superfine cement slurry is 1:1 grouting into loose sand and sandy soil, the dry density, wet density, and cohesive force of loose sand are larger than those of sandy soil. The results of the experiment may be relevant for engineering applications.

The influence of chemical composition and fineness on the performance of alkali activated cements obtained from blast furnace slags

International Nuclear Information System (INIS)

Langaro, Eloise Aparecida; Matoski, Adalberto; Luz, Caroline Angulski da; Buth, Islas Stein; Moraes, Maryah Costa de; Pereira Filho, Jose Ilo

2017-01-01

New binders are being developed for concrete in order to reduce the environmental impact mainly related to CO_2 emissions. Alkali -activated cements (CATs) are obtained from lime-aluminosilicate materials and an alkali activator and can reduce by 80% the emission of CO_2 compared to Portland Cement (PC). Papers have also shown physical and mechanical properties similar or higher than those presented by the PC, however, the activation of raw material is complex. Recent papers have also have showed a strong influence of the characteristics of raw material on the performance of CAT, however, little mentioned in the literature.. Therefore, this paper aimed to analyze the influence of characteristics of blast furnace slag (fineness and chemical composition) on the behavior of activated alkali cements. For this purpose, two slags were used, A and B, which were submitted to different milling times; and activated using 5% of NaOH. Mortars and pastes were prepared for compressive strength testing (7 and 28 days), measurements of heat of hydration and investigation of microstructure (XRD and DSC) were made. The results showed that the mortar made with slag A reached a very good mechanical performance, close to 48MPa at 28 days, and higher formation of CSH, in opposite of slag B. The probable hypothesis of this study is that the system formed in CAT made with slag A (containing more Al_2O_3) could provide CSH with a greater incorporation of Al and a lower crystallinity, increasing the mechanical strength. (author)

Asphalt cement poisoning

Science.gov (United States)

... petroleum material that hardens when it cools. Asphalt cement poisoning occurs when someone swallows asphalt. If hot ... found in: Road paving materials Roofing materials Tile cements Asphalt may also be used for other purposes.

An investigation into the Traditional Method of Production of Omani Sarooj

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A. W. Hago

1999-12-01

Full Text Available In the past, sarooj had been used as the basic cementing material with which the A flaj system (the irrigation system used in Oman was built. Worldwide, materials like sarooj existed and were known for their good impermeability and long durability. For this reason it was extensively used in hydraulic structures. Even in this century and with the ready availability of Portland cements, special plants were erected to produce materials like sarooj for major dams in the world. In the process of hydration In sarooj-lime mixes or in sarooj-cement mixes free lime is released which causes distress through the expansion of the mortar if allowed to accumulate. If free lime is stabilized within the structure of the mortar. it imparts additional strength and durability to it. The mortar becomes less permeable to water, which increases its resistance to wearhering. The stabilization is possible through the presence of a reactive silica/alumina in the mix so that it reacts with the free lime to form calcium silicates/aluminates. The properties of sarooj depend largely on the type of the raw material and the calcination parameters. This paper describes this material, its method of production and uses, and highlights research currently conducted to improve its properties.

Sustainable Blended Cements-Influences of Packing Density on Cement Paste Chemical Efficiency.

Science.gov (United States)

Knop, Yaniv; Peled, Alva

2018-04-18

This paper addresses the development of blended cements with reduced clinker amount by partial replacement of the clinker with more environmentally-friendly material (e.g., limestone powders). This development can lead to more sustainable cements with reduced greenhouse gas emission and energy consumption during their production. The reduced clicker content was based on improved particle packing density and surface area of the cement powder by using three different limestone particle diameters: smaller (7 µm, 3 µm) or larger (70 µm, 53 µm) than the clinker particles, or having a similar size (23 µm). The effects of the different limestone particle sizes on the chemical reactivity of the blended cement were studied by X-ray diffraction (XRD), thermogravimetry and differential thermogravimetry (TG/DTG), loss on ignition (LOI), isothermal calorimetry, and the water demand for reaching normal consistency. It was found that by blending the original cement with limestone, the hydration process and the reactivity of the limestone itself were increased by the increased surface area of the limestone particles. However, the carbonation reaction was decreased with the increased packing density of the blended cement with limestone, having various sizes.

Crown and bridge cements: clinical applications.

Science.gov (United States)

Bunek, Sabiha S; Powers, John M

2012-12-01

Cement selection can be confusing because factors such as substrate, the type of restoration, and patient needs must be considered. Some substrates require additional treatment before cementation. This article describes the most commonly used traditional crown and bridge cements (GI and RMGI) used for metal and metal-ceramic restorations, and resin cements used for all-ceramic restorations. Advantages, disadvantages, indications, and contraindications of cements have been reviewed. Recommended uses of cements for metal, ceramic, and laboratory composite restorations have been presented. General guidelines for surface treatment ot silica- and zirconia-based restorations when using resin cements have been discussed.

Development of New Lemon-Lime Flavored Beverage for OGTT: Acceptability and Reproducibility.

Science.gov (United States)

Chotwanvirat, Phawinpon; Thewjitcharoen, Yotsapon; Parksook, Wyn; Krittiyawong, Sirinate; Hutaphat, Kritchana; Nakasatien, Soontaree; Kaocharoen, Sming; Himathongkam, Thep

2016-05-01

The oral glucose tolerance test (OGTT) is essential procedure in both screening and diagnosis of impaired glucose tolerance (IGT), impaired fasting glucose (IFG) and diabetes mellitus (DM), but it is not easy to perform because of intense sweetness of the 75-g glucose test beverage causing abdominal discomfort post-testing. Therefore, the new formula of non-carbonated lemon-lime flavored beverage was developed to increase its palatability and better compliance. To develop a new non-carbonated lemon-lime flavored beverage to replace the standard beverage for OGTT Subsequently, the diagnostic value and acceptability between the new formula and the traditional 75-g OGTT formula were compared in healthy subjects. The new lemon-lime flavored formula was developed to replace the standard beverage for OGTT by adding 1,000 milligram of citric acid and 0.03 gram of lime flavor to 75 gram of anhydrous glucose to a final volume of 300 ml. The study was conducted in 30 healthy subjects who underwent the traditional 75-gram OGTT test and the new formula of OGTT beverage one week later, or vice versa, to access acceptability, indices markers of insulin secretion, and insulin sensitivity. Palatability was determined by rating on a 9-point Hedonic Scale. Thirty healthy subjects (15 females) with the age of 33.2 ± 7.5 years and body mass index of 22.9 ± 3.5 kg/m² were enrolled. No significant difference was found between plasma glucose in 0, 30, 60, 90, and 120 minutes, insulin level (0 and 120 minutes) and four insulin surrogate markers in both traditional 75-gram OGTT and new formula of lemon-lime flavored OGTT beverage. The overall satisfaction score of the new formula OGTT was better when compared with the scores of the traditional OGTT (7.1 ± 1.8 vs. 4.7 ± 2.0). Only one subject complained about abdominal discomfort in both episode of OGTT CONCLUSION: The modified lemon-lime flavored beverage for OGTT demonstrated better acceptance in the subjects without difference in

In-Depth Transcriptome Sequencing of Mexican Lime Trees Infected with Candidatus Phytoplasma aurantifolia.

Science.gov (United States)

Mardi, Mohsen; Karimi Farsad, Laleh; Gharechahi, Javad; Salekdeh, Ghasem Hosseini

2015-01-01

Witches' broom disease of acid lime greatly affects the production of Mexican lime in Iran. It is caused by a phytoplasma (Candidatus Phytoplasma aurantifolia). However, the molecular mechanisms that underlie phytoplasma pathogenicity and the mode of interactions with host plants are largely unknown. Here, high-throughput transcriptome sequencing was conducted to explore gene expression signatures associated with phytoplasma infection in Mexican lime trees. We assembled 78,185 unique transcript sequences (unigenes) with an average length of 530 nt. Of these, 41,805 (53.4%) were annotated against the NCBI non-redundant (nr) protein database using a BLASTx search (e-value ≤ 1e-5). When the abundances of unigenes in healthy and infected plants were compared, 2,805 transcripts showed significant differences (false discovery rate ≤ 0.001 and log2 ratio ≥ 1.5). These differentially expressed genes (DEGs) were significantly enriched in 43 KEGG metabolic and regulatory pathways. The up-regulated DEGs were mainly categorized into pathways with possible implication in plant-pathogen interaction, including cell wall biogenesis and degradation, sucrose metabolism, secondary metabolism, hormone biosynthesis and signalling, amino acid and lipid metabolism, while down-regulated DEGs were predominantly enriched in ubiquitin proteolysis and oxidative phosphorylation pathways. Our analysis provides novel insight into the molecular pathways that are deregulated during the host-pathogen interaction in Mexican lime trees infected by phytoplasma. The findings can be valuable for unravelling the molecular mechanisms of plant-phytoplasma interactions and can pave the way for engineering lime trees with resistance to witches' broom disease.

Push-out bond strengths of different dental cements used to cement glass fiber posts.

Science.gov (United States)

Pereira, Jefferson Ricardo; Lins do Valle, Accácio; Ghizoni, Janaina Salomon; Lorenzoni, Fábio César; Ramos, Marcelo Barbosa; Barbosa, Marcelo Ramos; Dos Reis Só, Marcus Vinícius

2013-08-01

Since the introduction of glass fiber posts, irreversible vertical root fractures have become a rare occurrence; however, adhesive failure has become the primary failure mode. The purpose of this study was to evaluate the push-out bond strength of glass fiber posts cemented with different luting agents on 3 segments of the root. Eighty human maxillary canines with similar root lengths were randomly divided into 8 groups (n=10) according to the cement assessed (Rely X luting, Luting and Lining, Ketac Cem, Rely X ARC, Biscem, Duo-link, Rely X U100, and Variolink II). After standardized post space preparation, the root dentin was pretreated for dual-polymerizing resin cements and untreated for the other cements. The mixed luting cement paste was inserted into post spaces with a spiral file and applied to the post surface that was seated into the canal. After 7 days, the teeth were sectioned perpendicular to their long axis into 1-mm-thick sections. The push-out test was performed at a speed of 0.5 mm/min until extrusion of the post occurred. The results were evaluated by 2-way ANOVA and the all pairwise multiple comparison procedures (Tukey test) (α=.05). ANOVA showed that the type of interaction between cement and root location significantly influenced the push-out strength (Pcements and glass ionomer cements showed significantly higher values compared to dual-polymerizing resin cements. In all root segments, dual-polymerizing resin cements provided significantly lower bond strength. Significant differences among root segments were found only for Duo-link cement. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Mineral resource of the month: hydraulic cement

Science.gov (United States)

van Oss, Hendrik G.

2012-01-01

Hydraulic cements are the binders in concrete and most mortars and stuccos. Concrete, particularly the reinforced variety, is the most versatile of all construction materials, and most of the hydraulic cement produced worldwide is portland cement or similar cements that have portland cement as a basis, such as blended cements and masonry cements. Cement typically makes up less than 15 percent of the concrete mix; most of the rest is aggregates. Not counting the weight of reinforcing media, 1 ton of cement will typically yield about 8 tons of concrete.

Hydration of fly ash cement and microstructure of fly ash cement pastes

Energy Technology Data Exchange (ETDEWEB)

Shiyuan, H.

1981-01-01

The strength development and hydration of fly ash cement and the influence of addition of gypsum on those were studied at normal and elevated temperatures. It was found that an addition of a proper amount of gypsum to fly ash cement could accelerate the pozzolanic reaction between CH and fly ash, and as a result, increase the strength of fly ash cement pastes after 28 days.

Sludge hygienization: Helminth eggs destruction by lime treatment Ascaris eggs as model

Energy Technology Data Exchange (ETDEWEB)

Banas, S.; Schwartzbrod, J. [Lab. de Chimie Physique et Microbiologie de l' Environnement, Nancy (France); Remy, M. [Lhoist, on behalf of the European Lime Assoication (EuLA), Bruessel (Germany); Boehm, R. [Univ. Hohenheim, Stuttgart (Germany); Verfuerden, M. [Fels-Werke GmbH, im Namen des Bundesverbandes der Deutschen Kalkindustrie (BVK), Koeln (Germany)

2003-07-01

Most pathogens in the raw sewage are concentrated into the sewage sludge. They can be separated into four categories: viruses, bacteria, protozoa and larger parasites such as human roundworms, tapeworms and liver flukes. Such micro-organisms can cause disease in humans, the transmission occurring in several ways e.g. by inhaling sludge aerosols or dust, by eating vegetables or fruits contaminated by sludge, drinking water contaminated by run-off or by eating meat from livestock infected by grazing pastures fertilised with sludge. The presence of helminth eggs in urban sludge may constitute a sanitary risk when used as agricultural fertiliser. To avoid any contamination, the efficiency of a certain number of sludge hygienization processes must be tested. One of these involves decontamination with quicklime. The Ascaris egg inactivation by liming with lime milk, slaked lime and quicklime is studied in a series of sludges coming from slaughterhouses. (orig.)

Analysis of Chemical Composition of Portland Cement in Ghana: A Key to Understand the Behavior of Cement

OpenAIRE

Bediako, Mark; Amankwah, Eric Opoku

2015-01-01

The performance of Portland cement in concrete or mortar formation is very well influenced by chemical compositions among other factors. Many engineers usually have little information on the chemical compositions of cement in making decisions for the choice of commercially available Portland cement in Ghana. This work analyzed five different brands of Portland cement in Ghana, namely, Ghacem ordinary Portland cement (OPC) and Portland limestone cement (PLC), CSIR-BRRI Pozzomix, Dangote OPC, a...

Desarrollo de hormigones con aglomerante cal-puzolana fina como material cementicio suplementario Development of concrete mixtures with fine lime-pozzolan binder as supplementary cementitious material

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Juan José Dopico

2008-01-01

size between 0.1-lOum, can fill the gaps between cement grains, while the larger pozzolan particles, having size between 10-lOQim, can fill the gaps between fine aggregate grains; this results in a much denser matrix. The addition of lime during concrete mixing also increases the Ca+2 and OH ion concentration, which results in a better and faster hydration of both ordinary portland cement (OPC and pozzolanic reaction products. The use of LPB as an active addition in some ultra-high performance concretes could lowe the cost of the product for equivalent strength and durability performance, through the use of less cement, thus improving the ecologic profile of the material. Results from an initial series of tests are examined in this paper; further testing is required to establish the benefits of the use of LPC in High Performance Concrete. Examples of applications of this work in concretes are also presented.

Characterization of Construction Material Properties through Gamma Spectroscopy, X-ray Fluorescence, and Hyper-spectral Imagery for Background Correction Applications in Nuclear Detection

Science.gov (United States)

2014-03-27

requirements. Admixtures include blast furnace slag , low-lime fly ash, high-lime fly ash, and silica flume. Chemical compositions of these...Portland Cement Blast Furnace Slag Low-lime Fly Ash High-lime Fly Ash Silica Flume CaO 63 40 1 20 0 SiO2 22 35 50 35 90 Al2O3 6 8 25 20 2...vanadium and nickel (Jones, 1993). Waste engine oil is sometimes used to produce asphalt binders and is known to contain chromium and zinc . However

Karakteristik Kimia dan Fisika Semen Pozolan Kapur yang Diperkaya Silika Abu Sekam Padi

OpenAIRE

Assa, Asma; Adinata, Erwin

2013-01-01

Development of infrastructures intensively in the last decades has increased the demand for building materials, such as cement. This also causes the prices of Portland Cement, the most common type of cements has also increased and sometimes it is difficult to find it in the markets. Another type of cement namely Lime Pozolan Cement (SPK) may be used to substitute for Portland Cement for building construction which receives relatively low loads. The SPK is produced from pozolan materials and l...

Influence of temporary cement contamination on the surface free energy and dentine bond strength of self-adhesive cements.

Science.gov (United States)

Takimoto, Masayuki; Ishii, Ryo; Iino, Masayoshi; Shimizu, Yusuke; Tsujimoto, Akimasa; Takamizawa, Toshiki; Ando, Susumu; Miyazaki, Masashi

2012-02-01

The surface free energy and dentine bond strength of self-adhesive cements were examined after the removal of temporary cements. The labial dentine surfaces of bovine mandibular incisors were wet ground with #600-grit SiC paper. Acrylic resin blocks were luted to the prepared dentine surfaces using HY Bond Temporary Cement Hard (HY), IP Temp Cement (IP), Fuji TEMP (FT) or Freegenol Temporary Cement (TC), and stored for 1 week. After removal of the temporary cements with an ultrasonic tip, the contact angle values of five specimens per test group were determined for the three test liquids, and the surface-energy parameters of the dentine surfaces were calculated. The dentine bond strengths of the self-adhesive cements were measured after removal of the temporary cements in a shear mode at a crosshead speed of 1.0mm/min. The data were subjected to one-way analysis of variance (ANOVA) followed by Tukey's HSD test. For all surfaces, the value of the estimated surface tension component γ(S)(d) (dispersion) was relatively constant at 41.7-43.3 mJm(-2). After removal of the temporary cements, the value of the γ(S)(h) (hydrogen-bonding) component decreased, particularly with FT and TC. The dentine bond strength of the self-adhesive cements was significantly higher for those without temporary cement contamination (8.2-10.6 MPa) than for those with temporary cement contamination (4.3-7.1 MPa). The γ(S) values decreased due to the decrease of γ(S)(h) values for the temporary cement-contaminated dentine. Contamination with temporary cements led to lower dentine bond strength. The presence of temporary cement interferes with the bonding performance of self-adhesive cements to dentine. Care should be taken in the methods of removal of temporary cement when using self-adhesive cements. Copyright © 2011 Elsevier Ltd. All rights reserved.

Impacts of fresh lime juice and peel on atherosclerosis progression in an animal model

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Maryam Boshtam

2013-11-01

Full Text Available BACKGROUND: The main protective role of antioxidants in the progression of atherosclerosis has been shown in some studies. Therefore, this project evaluated the effects of Citrus aurantifolia (Christm juice and peel on antioxidant activity and atherosclerosis progression in rabbits receiving a hypercholesterolemic diet. METHODS: Forty white New Zealand male rabbits were randomly allocated to four groups. All groups were on hypercholesterolemic diet for two months. While the first group was considered as the hypercholesterolemic control, groups 2 and 3 (intervention groups received 5 ml/day lime juice and 1 g/day dried lime peel powder, respectively. Group 4 was fed a normal diet (normal control. Before and after the study, weight was measured and a fasting blood specimen was taken from the rabbits. Serum lipids analyses and antioxidant activity evaluations were then performed. The rabbits’ aorta and coronary arteries were separated and the presence of fatty streaks was studied. RESULTS: Comparing to the hypercholesterolemic control group (-25.2 ± 7.0, only the plasma total antioxidant capacity change was significantly more in rabbits supplemented with lime juice (16.3 ± 14.7 and peel (8.6 ± 7.1 (P = 0.008. The presence of fatty streaks in coronary arteries and aorta of the intervention groups [juice (0.2 ± 0.01; peel (0.0 ± 0.00] was significantly decreased compared to the hypercholesterolemic control group (1.2 ± 0.4 (P < 0.001. CONCLUSION: Based on our findings, Citrus aurantifolia peel and juice increase plasma antioxidant capacity in rabbits, and can thus prevent or decelerate the process of atherogenesis. However, lime peel is more effective than lime juice.   Keywords: Animal, Atherosclerosis, Atherogenic Diet, Fatty Streak, Intervention, Lime    Normal 0 false false false EN-US X-NONE AR-SA

Copper, nickel and zinc phytoavailability in an oxisol amended with sewage sludge and liming

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Martins Adão Luiz Castanheiro

2003-01-01

Full Text Available Contents of heavy metal on agricultural soils have been raised by land applications of sewage sludge and may constitute a hazard to plants, animals and humans. A field experiment was carried out from 1983 to 1987, to evaluate the long-term effect of sewage sludge application, with and without liming, on heavy metal accumulation and availability in a Rhodic Hapludox soil grown with maize (HMD 7974 hybrid. Trials were set up in a completely randomized blocks design with four replications. Each block was split in two bands, one with and another without liming. The sludge was applied in each band at rates: 0, 20, 40, 60 and 80 Mg ha-1 (dry basis in a single application; and 40, 60 and 80 Mg ha-1 split in two, three and four equal yearly applications, respectively. The soil was sampled for chemical analysis each year after harvest. Soil samples were analysed for Cu, Ni and Zn in extracts obtained with DTPA and Mehlich-3 solutions, and in extracts obtained by digestion with nitric-perchloric acid (total metal contents, using an inductively coupled plasma (ICP spectrometer. In general, Zn, Cu and Ni concentrations in DTPA and Mehlich-3 extracts increased linearly with sludge application. Total Cu and Zn concentrations increased when sludge was applied, whereas total Ni concentrations were not affected. Both extractants were suitable to evaluate Cu and Zn availability to corn in the soil treated with sewage sludge. Liming reduced the DTPA extractability of Zn. DTPA-extractable Cu concentrations were not significantly affected by liming. Mehlich-3-extractable Cu and Zn concentrations increased with liming. Only DTPA extractant indicated reduction of Ni concentrations in the soil after liming.

Colorectal cancer and non-malignant respiratory disease in asbestos cement and cement workers

International Nuclear Information System (INIS)

Jacobsson, K.

1993-09-01

Radiologically visible parenchymal changes (small opacities >= 1/0;ILO 1980 classification) were present in 20% of a sample of workers (N=174), employed for 20 years (median) in an asbestos cement plant. Exposure-response relationships were found, after controlling for age and smoking habits. In a sample of asbestos cement workers with symptoms and signs suggestive of pulmonary disease (N=33), increased lung density measured by x-ray computed tomography, and reduced static lung volumes and lung compliance was found. In a cohort of asbestos cement workers (N=1.929) with an estimated median exposure of 1.2 fibres/ml, the mortality from non-malignant respiratory disease was increased in comparison to a regional reference cohort (N=1.233). A two-to three-fold increase of non-malignant respiratory mortality was noted among workers employed for more than a decade in the asbestos cement plant, compared to cement workers (N=1.526), who in their turn did not experience and increased risk compared to the general population. In the cohorts of asbestos cement and cement workers, there was a tow-to three-fold increased incidence of cancer in the right part of the colon, compared to the general population as well as to external reference cohorts of other industrial workers (N=3.965) and fishermen (N=8.092). A causal relation with the exposure to mineral dust and fibres was supported by the findings of higher risk estimated in subgroups with high cumulated asbestos doses or longer duration of cement work. The incidence of cancer in the left part of the colon was not increased. Morbidity data, but not mortality data, disclosed the subsite-specific risk pattern. Both asbestos cement workers and cement workers has an increased incidence of rectal cancer, compared with the general population, and with the fishermen. The risk was, however, of the same magnitude among the other industrial workers. 181 refs

Compressive Strength and Physical Properties Behavior of Cement Mortars with addition of Cement Klin Dust

OpenAIRE

Auday A Mehatlaf

2017-01-01

Cement Klin Dust (CKD) was the waste of almost cement industry factories, so that in this paper utilization of CKD as filler in cement and/or concrete was the main objective. CKD from the Karbala cement factory had been used and analysis to know the chemical composition of the oxides was done. In this paper cement mortars with different weight percentages of CKD (0,5,10,20,30,40) had been prepared. Physical properties such as density and porosity were done in different age curing (3, 7, 28) d...

Chromium content in human skin after in vitro application of ordinary cement and ferrous-sulphate-reduced cement

DEFF Research Database (Denmark)

Fullerton, A; Gammelgaard, Bente; Avnstorp, C

1993-01-01

The amount of chromium found in human skin after in vitro application of cement suspensions on full-thickness human skin in diffusion cells was investigated. Cement suspensions made from ordinary Portland cement or Portland cement with the chromate reduced with added ferrous sulphate were used....... The cement suspensions were either applied on the skin surface under occlusion for 48 h or applied repeatedly every 24 h for 96 h. No statistically significant difference in chromium content of skin layers between skin exposed to ordinary Portland cement, skin exposed to cement with added ferrous sulphate...... and unexposed skin was observed, despite a more permeable skin barrier at the alkaline pH of the cement suspensions, i.e., pH 12.5. Increased chromium levels in epidermis and dermis were seen when ordinary Portland cement was applied as a suspension with added sodium sulphate (20%) on the skin surface for 96 h...

Hydration kinetics of cement composites with varying water-cement ratio using terahertz spectroscopy

Science.gov (United States)

Ray, Shaumik; Dash, Jyotirmayee; Devi, Nirmala; Sasmal, Saptarshi; Pesala, Bala

2015-03-01

Cement is mixed with water in an optimum ratio to form concrete with desirable mechanical strength and durability. The ability to track the consumption of major cement constituents, viz., Tri- and Dicalcium Silicates (C3S, C2S) reacting with water along with the formation of key hydration products, viz., Calcium-Silicate-Hydrate (C-S-H) which gives the overall strength to the concrete and Calcium Hydroxide (Ca(OH)2), a hydration product which reduces the strength and durability, using an efficient technique is highly desirable. Optimizing the amount of water to be mixed with cement is one of the main parameters which determine the strength of concrete. In this work, THz spectroscopy has been employed to track the variation in hydration kinetics for concrete samples with different water-cement ratios, viz., 0.3, 0.4, 0.5 and 0.6. Results show that for the sample with water-cement ratio of 0.3, significant amount of the C3S and C2S remain unreacted even after the initial hydration period of 28 days while for the cement with water-cement ratio of 0.6, most of the constituents get consumed during this stage. Analysis of the formation of Ca(OH)2 has been done which shows that the concrete sample with water-cement ratio of 0.6 produces the highest amount of Ca(OH)2 due to higher consumption of C3S/C2S in presence of excess water which is not desirable. Samples with water-cement ratio of 0.4 and 0.5 show more controlled reaction during the hydration which can imply formation of an optimized level of desired hydration products resulting in a more mechanically strong and durable concrete.