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Sample records for calcium lime mortars

  1. Potential Use Of Carbide Lime Waste As An Alternative Material To Conventional Hydrated Lime Of Cement-Lime Mortars

    OpenAIRE

    Al Khaja, Waheeb A.

    1992-01-01

    The present study aimed at the possibility of using the carbide lime waste as an alternative material to the conventional lime used for cement-lime mortar. The waste is a by-product obtained in the generation of acetylene from calcium carbide. Physical and chemical properties of the wastes were studied. Two cement-lime-sand mix proportions containing carbide lime waste were compared with the same mix proportions containing conventional lime along with a control mix without lime. Specimens wer...

  2. The shrinkage in lime mortars

    Directory of Open Access Journals (Sweden)

    Sánchez, J. A.

    1997-03-01

    Full Text Available Nowadays, the methodology existing to measure the shrinkage in air, developed for paste and cement mortars, has serious problems to be applied to lime mortars, due to its different mechanism of hardening several modifications in Norms UNE 80-113-86 y 80-112-89 make possible the determination of the shrinkage in these traditional mortars.

    La metodología existente en la actualidad para la medida de la retracción de secado, desarrollada para las pastas y los morteros de cemento, presenta serios problemas a la hora de su aplicación a los morteros de cal debido a su distinto mecanismo de endurecimiento. Algunas modificaciones de las normas UNE 80-113-86 y 80-112-89 hacen posible la determinación de la retracción en estos morteros tradicionales.

  3. 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…

  4. Simulation of self-healing of dolomitic lime mortar

    NARCIS (Netherlands)

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

    2011-01-01

    In the present research a test procedure was set up to reproduce self-healing on lime-based (both pure calcium and magnesium-calcium) mortar specimens in laboratory. After few months testing, during which the specimens were subjected to wet-dry cycles, thin sections of the specimens were prepared an

  5. Simulation of the self-healing of dolomitic lime mortar

    NARCIS (Netherlands)

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

    2012-01-01

    A test procedure was set up to reproduce laboratory self-healing on lime-based (both pure calcium and magnesium-calcium) mortar specimens. After a few months of testing, during which time the specimens were submitted to wet-dry cycles, thin sections of the specimens were prepared and observed using

  6. [The Analysis of Traditional Lime Mortars from Zhejiang Province, China].

    Science.gov (United States)

    Liu, Xiao-bin; Cui, Biao; Zhang, Bing-jian

    2016-01-01

    The components of ancient mortars have always been an important research field in historic building conservation. It has been well known that using traditional mortars in conservation projects have many advantages, such as compatibility and stability. So, developing new binding materials based on traditional mortar has become an international study hotspot. With China's economic development, the protection of ancient buildings also began to put on the agenda, but the understanding on Chinese traditional mortar is limited, and rare literatures are reported. In the present work, the authors investigate seven ancient city wall sites in Zhejiang Province in situ, and subsequently laboratory analysis were carried out on collected mortar samples. The characterizations of mortar samples were made by multi-density gauge, XRD, FTIR, TG-DSC and wet chemical analysis. The experimental results showed that: the main component of masonry mortars is calcium carbonate, the content between 75% - 90%, and they should be made from relatively pure lime mortar. The raw materials of mortar samples were mainly calcareous quick lime, and sample from Taizhou city also contained magnesium quick lime. There are four city walls were built by sticky-rice mortars. It suggests that the technology of adding the sticky rice soup into mortar was universal in the Ming Dynasties. These mortars have lower density between 1.2 and 1.9 g x cm(-3); this outcome should be the result of long-term natural erosion. We have also analyzed other chemical and physical characteristics of these masonry mortars. The results can afford the basic data for the future repairmen programs, development of new protective materials, and comparative study of mortars.

  7. Evaluation of Lime for Use in Mortar

    Directory of Open Access Journals (Sweden)

    Naktode P.L.

    2014-02-01

    Full Text Available Lime has been used in India as material of construction from very ancient days. The manner in which lime structures about 2000 years old have withstood the ravages of time bear irrefutable evidence to the durability of lime mortars. Lime mortars were the mortars of very recent years – used until the twentieth century. Although they are almost forgotten today, they still remain a viable and important construction method [1]. There is something about this material that remains just as valuable today as it was 150 years ago [2]. The lime belt of Vidarbha area is not of industrial grade. To use for construction purpose it needs some improvement and alteration in the ingredients. This calls the development of an alternative approach to make it suitable for construction in large extent. Keywords:

  8. 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.

  9. 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

  10. 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

  11. 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...

  12. 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

    mortar is a special organic-inorganic composite material. The inorganic component is calcium carbonate, and the organic component is amylopectin, which is presumably derived from the sticky rice soup added to the mortar. A systematic study of sticky rice-lime mortar technology was conducted to help determine the proper courses of action in restoring ancient buildings. Lime mortars with varying sticky rice content were prepared and tested. The physical properties, mechanical strength, and compatibility of lime mortar were found to be significantly improved by the introduction of sticky rice, suggesting that sticky rice-lime mortar is a suitable material for repairing mortar in ancient masonry. Moreover, the amylopectin in the lime mortar was found to act as an inhibitor; the growth of the calcium carbonate crystals is controlled by its presence, and a compact structure results, which may explain the enhanced performance of this organic-inorganic composite compared to single-component lime mortar.

  13. Effect of water-repellent admixtures on the behaviour of aerial lime-based mortars

    OpenAIRE

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

    2009-01-01

    Two different anionic surfactants, sodium oleate and calcium stearate, commercialized as water repellents for cement-based mortars, were added to lime-based mortars in order to check whether they were improved by these admixtures. Different properties of lime-based mortars were evaluated: fresh state behaviour through water retention, air content and setting time, hardened state properties such as density, water absorption through capillarity, water vapour permeability, long-term compressive ...

  14. Role of different superplasticizers on hydrated lime pastes and mortars

    OpenAIRE

    Alvarez, J. I.; Fernandez, J M; Sirera, R. (Rafael); Perez-Nicolas, M. (María); Navarro-Blasco, I. (Íñigo); Duran, A

    2015-01-01

    The behaviour of different superplasticizers admixtures was assessed for hydrated lime pastes and mortars. Sometimes, air lime pastes and mortars were modified with two supplementary cementing materials (SCMs), namely nanosilica (NS) and metakaolin (MK). Two different polycarboxylate ethers, a lignosulfonate and a naphthalene condensed sulfonate superplasticizer were added to lime pastes and mortars and their effects on fresh-state properties as well as on the mechanical strengths were evalua...

  15. Traditional methods of mortar preparation: the hot lime mix

    OpenAIRE

    Margalha, Goreti; Veiga, Rosário; Santos Silva, António; Brito, Jorge

    2011-01-01

    This paper studies the effect of maturation on mortars prepared according to a traditional method of slaking quicklime mixed with sand and kept wet until used (hot lime mix). Two lime/aggregate weight proportions were considered, a rich one (1:5) and a normal one (1:13). The quicklime was used as pieces of crushed calcined limestone and as micronized quicklime, both from industrial production. The mortars prepared with hot lime were kept wet for periods of 1, 7, 45 and 90 days, before mouldin...

  16. [Study on the mechanism of liesegang pattern development during carbonating of traditional sticky rice-lime mortar].

    Science.gov (United States)

    Wei, Guo-feng; Fang, Shi-qiang; Zhang, Bing-jian; Wang, Xiao-qi; Li, Zu-guang

    2012-08-01

    Liesegang patterns in traditional sticky rice-lime mortar undergoing carbonation were investigated by means of FTIR, XRD and SEM. Results indicate that well-developed Liesegang patterns only occur in the mortar prepared with aged lime and sticky rice. The smaller Ca(OH)2 particle size in aged lime and the control of the sticky rice for the crystallization of calcium carbonate lead to the small pores in this mortar. These small pores can make Ca2+ and CO3(2-) highly supersaturated, which explains the reason why Liesegang pattern developed in the sticky rice-aged lime mortar. The formed metastable aragonite proves that Liesegang pattern could be explained based on the post-nucleation theory.

  17. Influence of curing conditions on lime and lime-metakaolin mortars

    OpenAIRE

    Faria, Paulina; Martins, A

    2011-01-01

    Comunicação apresentada ao XII DBMC - International Conference on Durability of Building Materials and Components, Porto, April 12th-15th, 2011 Air-lime mortars with or without pozzolanic components were largely used in historic buildings. Due to natural or accidental degradation it is often necessary the application of repair mortars, durable and compatible with the masonries of historic buildings. Within this context and associating the improvement of mortars characteristics to the ne...

  18. Repair mortars based on lime. Accelerated aging tests

    Directory of Open Access Journals (Sweden)

    Martínez-Ramírez, S.

    1995-06-01

    Full Text Available The behaviour under different accelerated aging tests (freeze/thaw and crystallization cycles of a new lime mortar with biocide properties destinated to monumental repair has been studied. New mortars (which have the biocide impregnated in a clay called sepiolite have a similar behaviour to lime mortars used as a reference. After the aging tests, the biocide properties of the mortars have been tried.

    Se ha estudiado el comportamiento frente a distintos ensayos de envejecimiento acelerado (ciclos de hielo/deshielo y cristalización de sales de un nuevo mortero de cal con propiedades biocidas, destinado a la reparación monumental. Se ha comprobado que los nuevos morteros (que llevan incorporado el biocida impregnado en una arcilla denominada sepiolita tienen un comportamiento muy similar a los morteros de cal utilizados como referencia. Tras los ensayos de envejecimiento se ha visto que las propiedades biocidas de los morteros se mantienen.

  19. Luminescence quartz dating of lime mortars. A first research approach.

    Science.gov (United States)

    Zacharias, N; Mauz, B; Michael, C T

    2002-01-01

    Lime mortars mixed with sand are well suited for connecting structural materials, like stones and bricks, due to the mechanical properties this material exhibits. Their extensive use in architectural and decorative works during the last 4000 years motivated the introduction of the 'Luminescence clock' for age determination of mortars. The same principles as for quartz optically stimulated luminescence (OSL) dating of sediments were applied for age estimation of a mortar fragment removed from a Byzantine church monument dated by archaeological means to 1050-1100 years ago (the first half of the 10th century). The OSL from the quartz was monitored under blue light stimulation and UV detection, using a single-aliquot-regenerative-dose protocol. The quartz-OSL dating of the mortar resulted in 870 +/- 230 a. TL polymineral fine grain dating was also performed on a brick fragment which was connected to the mortar, resulting in a TL age of 1095 +/- 190 a.

  20. Traditional mortar represented by sticky rice lime mortar——One of the great inventions in ancient China

    Institute of Scientific and Technical Information of China (English)

    YANG FuWei; ZHANG BingJian; PAN ChangChu; ZENG YuYao

    2009-01-01

    The development of traditional lime-based bond in ancient times was reviewed in this paper. It was proved by a lot of historical data that the application of organic materials in inorganic mortar was a sharp-cut characteristic during the developing process of construction gelled materials in ancient China. The important role sticky rice mortar ever played and the historical significance were revealed. Due to the excellent performance, such as high adhesive strength, good toughness, water-proof and so on, traditional mortar represented by sticky rice mortar should be one of the greatest technological contributions of the day in the world. Modern technology was employed in the study of the sticky rice lime mortar and the researching results of our laboratory and some researchers, including the compo-sition and the mechanism of solidification, were also presented. It was found that the sticky rice acted as a matrix of bio-mineralization which affected the microstructure of the calcium carbonate crystal and there was cooperation between sticky rice and calcite produced during the solidifying of the sticky rice mortar, which maybe lead to the excellent performance of the mortar. Because of excellent performance and importance in science, sticky rice mortar can be regarded as one of the greatest inventions in construction history of China. Relative research of sticky mortar will be of importance for the exploring of ancient momentous invention and the repairing of ancient construction.

  1. Traditional mortar represented by sticky rice lime mortar——One of the great inventions in ancient China

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The development of traditional lime-based bond in ancient times was reviewed in this paper.It was proved by a lot of historical data that the application of organic materials in inorganic mortar was a sharp-cut characteristic during the developing process of construction gelled materials in ancient China.The important role sticky rice mortar ever played and the historical significance were revealed.Due to the excellent performance,such as high adhesive strength,good toughness,water-proof and so on,traditional mortar represented by sticky rice mortar should be one of the greatest technological contributions of the day in the world.Modern technology was employed in the study of the sticky rice lime mortar and the researching results of our laboratory and some researchers,including the compo-sition and the mechanism of solidification,were also presented.It was found that the sticky rice acted as a matrix of bio-mineralization which affected the microstructure of the calcium carbonate crystal and there was cooperation between sticky rice and calcite produced during the solidifying of the sticky rice mortar,which maybe lead to the excellent performance of the mortar.Because of excellent performance and importance in science,sticky rice mortar can be regarded as one of the greatest inventions in construction history of China.Relative research of sticky mortar will be of importance for the exploring of ancient momentous invention and the repairing of ancient construction.

  2. Accelerator mass spectrometry {sup 14}C dating of lime mortars: Methodological aspects and field study applications at CIRCE (Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Marzaioli, Fabio, E-mail: fabio.marzaioli@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Nonni, Sara, E-mail: sara.nonni@uniroma1.it [Dipartimento di Scienze della Terra, ' Sapienza' Universita di Roma (Italy); Passariello, Isabella, E-mail: isabella.passariello@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Capano, Manuela, E-mail: manuela.capano@unina2.it [CIRCE, INNOVA and Dipartimento di Studio delle Componenti Culturali del Territorio, Seconda Universita degli Studi di Napoli, Santa Maria Capua Vetere, Caserta (Italy); Ricci, Paola, E-mail: paola.ricci@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); Lubritto, Carmine, E-mail: carmine.lubritto@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze Ambientali, Caserta (Italy); De Cesare, Nicola, E-mail: nicola.decesare@unina2.it [CIRCE, INNOVA and Seconda Universita degli Studi di Napoli, Dipartimento di Scienze della Vita, Caserta (Italy); Eramo, Giacomo, E-mail: giacomo.eramo@uniba.it [Dipartimento di Scienze della Terra e Geoambientali, Universita degli Studi di Bari ' Aldo Moro' , Bari (Italy); Quiros Castillo, Juan Antonio, E-mail: quiros.castillo@ehu.es [Universidad del Pais Vasco-Euskal Herriko Unibertsitatea, Dipartimento di Geografia, Prehistoria y Arqueologia, Vitoria-Gasteiz (Spain); and others

    2013-01-15

    Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) has, recently, obtained some promising results in testing the feasibility of mortar radiocarbon dating by means of an ad hoc developed purification procedure (CryoSoniC: Cryobraking, Sonication, Centrifugation) applied to a series of laboratory mortars. Observed results encouraged CryoSoniC accuracy evaluation on genuine mortars sampled from archeological sites of known or independently constrained age (i.e., other {sup 14}C dates on different materials). In this study, some {sup 14}C measurements performed on genuine mortars will be discussed and compared with independently estimated (i.e., radiocarbon/archaeometrical dating) absolute chronologies of two Spanish sites. Observed results confirm the agreement of the CryoSoniC mortar dates with the archaeological expectations for both examined cases. Several authors reported the possibility of obtaining accurate radiocarbon dates of mortar matrices by analyzing lime lumps: binder-related particles of different sizes exclusively composed of calcium carbonate. In this paper, preliminary data for the absolute chronology reconstruction of the Basilica of the cemetery complex of Ponte della Lama (Canosa di Puglia, Italy) based on lime lumps will also be discussed. Dating accuracy will be quantified by comparing {sup 14}C data on mortar lime lumps from a funerary inscription of known age found near the Basilica, in the same study site. For this site, a comparison between absolute chronologies performed by bulk and CryoSoniC purified lime lumps, and charcoal incased in mortars (when found) will also be discussed. Observed results for this site provide evidence of how bulk lime lump dating may introduce systematic overestimations of the analyzed sample while CryoSoniC purification allows accurate dating.

  3. ESR investigation of structure and dynamics of paramagnetic centres in lime mortars from Budinjak, Croatia

    International Nuclear Information System (INIS)

    This study presents the preliminary results of investigation of the types and dynamics of paramagnetic centres in lime mortars from Sveta Petka church in Budinjak, Croatia, using Electron Spin Resonance (ESR) spectroscopy. The excavation in Budinjak discovered a very unique four lobed plan object Sveta Petka, with no additional finds or reliable historical records about the time of its construction. The lime mortars from the church were chosen for analysis in order to characterize the building material and to verify the site chronology by dating them. Lime mortar is valuable but problematic material for luminescence and radiocarbon dating. This type of material has not been dated before using ESR; therefore, careful studies are required to identify the useful paramagnetic centres. The ESR approach suggested in this work concentrates on a calcium carbonate signal. All samples were γ-irradiated in 60C bomb with the doses of 1, 10, 20, 50, 80 and 100 kGy. In all spectra signals from Fe3+ and Mn2+ ions have been observed. Paramagnetic centres which give the ESR signals may be interpreted as CO2−, CO3−, CO33−, HCO32−, SO2−, SO3−, PO2− and PO32− species. However, all spectra are complex and signals are interfering; therefore, computer resolution enhancement method will be needed in further research. The changes in ESR signals amplitude measured at magnetic field range about 3440–3450 G were analysed versus the dose of irradiation, using Mn2+ signals as a reference. Exponential growth of the curve and saturation for doses above 20 kGy were observed; therefore, irradiation with smaller doses is required. These preliminary studies will be helpful in future attempts of dating lime mortars by ESR method.

  4. [Study on the traditional lime mortar from the memorial archway in the southern Anhui province].

    Science.gov (United States)

    Wei, Guo-Feng; Sun, Sheng; Wang, Cheng-Xing; Zhang, Bing-Jian; Chen, Xi-Min

    2013-07-01

    The traditional lime mortar was investigated by means of scanning electron microscope (SEM), X-ray diffractometry and Fourier transform infrared spectrometry (FTIR). The results show that the mortar from the memorial archway in the southern Anhui province was the organic-inorganic composite materials composed of lime with tung oil or sticky rice. It was found that the excellent performance of the tung oil-lime mortar can be explained by the compact lamellar organic-inorganic composite structure that was produced by carbonization reaction of lime, cross-linking reactions of tung oil and oxygen and complexing reaction of Ca2+ and -COO-. The compact micro-structure of sticky rice-lime mortar, which was produced due to carbonation process of lime controlled by amylopectin, should be the cause of the good performance of this kind of organic-inorganic mortar.

  5. Influence of water-repellent treatment on the properties lime and lime pozzolan mortars

    Directory of Open Access Journals (Sweden)

    Fortes Revilla, C.

    2001-06-01

    Full Text Available The influence that water-repellent products can have on physical and micro-structural properties of lime mortars, and lime plus pozzolan mortars has been studied. Three water repellent products have been used. Mixes of the previously mentioned three water repellents plus a biocide product were also applied. Treatments make the total porosity and saturation coefficient of both mortars to decrease, while colorimetric coordinates bear little alteration. All treatments with water repellent products provided mortars with a hydrophobic property index close to 100%. Durability of such mortars has been also studied: salt crystallization test, frost-thaw and dry-wet cycles, as well as ultraviolet radiation test were carried out. Relationship between mortars behavior and their porosity and saturation coefficient were found.

    En el presente trabajo se ha estudiado la influencia de la aplicación de productos hidrofugantes a morteros de cal y morteros de cal y puzolana sobre sus propiedades físicas y microestructurales. Se han estudiado tres productos hidrofugantes. También han sido estudiados dichos productos junto con un biocida. La porosidad total y el coeficiente de saturación de ambos tipos de morteros se ve reducido por el efecto de los tratamientos mientras que las coordenadas colorimétricas se ven poco alteradas. Todos los tratamientos confieren un índice de hidrofobicidad a los morteros próximo al 100%. Asimismo, también se ha estudiado la durabilidad de dichos morteros frente a la cristalización de sales, hielo-deshielo, los ciclos de humedad-sequedad y radiaciones ultravioleta. Se relaciona el comportamiento de los morteros con su porosidad y el coeficiente de saturación.

  6. Considerations about the use of lime-cement mortars for render conservation purposes

    OpenAIRE

    Torgal, Fernando Pacheco; Faria, Joana; Shasavandi, Arman; Jalali, Said

    2011-01-01

    Some investigations about conservation renders points out that Portland cement based mortars should be avoided and should be replaced by lime-pozzolan mortars. However, this type of mortar is still under investigation and the majority of Portuguese construction enterprises operating in the field of building conservation do not possess enough know-how about them. Besides the absolute rejection of the use of Portland cement based mortars even with just a minimum amount appears to be a dogmat...

  7. Lime-based mortars with linseed oil: sodium chloride resistance assessment and characterization of the degraded material

    OpenAIRE

    Nunes, C.; Slížková, Z. (Zuzana); Janotová, D. (Dana)

    2013-01-01

    Lime mortar is often used to repair historic buildings but is prone to salt crystallization with deleterious consequences. Lime mortar is a very susceptible material due to its high porosity and low mechanical resistance. Recent findings concerning mortar additives that impart hydrophobic properties to mortar show that by limiting water penetration, damage from frost and salt can be decreased. Linseed oil was commonly used in former times as an additive for mortar in order to grant hydrophobi...

  8. Limiting salt crystallization damage in lime mortar by using crystallization modifiers

    NARCIS (Netherlands)

    Granneman, S.J.C.; Shahidzadeh, N.; Lubelli, B.A.; Hees, R.P.J. van

    2014-01-01

    Salt crystallization is a recurrent cause of damage in porous building materials. Lime-based mortars, which were widely used in construction of ancient masonry, are especially prone to salt damage, due to their low mechanical strength. Existing solutions to tackle salt damage in mortars have been ma

  9. Carbonation kinetics in roman-like lime mortar

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    Sánchez-Moral, S.

    2004-09-01

    Full Text Available The kinetic parameterisation of lime mortar carbonation is a useful technique for understanding ancient building methods and the long-lived physical-chemical stability of roman monuments. Portlandite (Ca(OH2 binders harden in the air on contact with atmospheric CO2, producing CaCO3. Water evaporation and the presence of silicate aggregates have a three-fold effect: prompting the development of a pore system that permits CO2, self-diffusion, reducing shrinkage and cracking during drying and (possibly giving rise to subsequent pozzolanic reactions. The present survey involved air-hardening a series of roman-like lime mortars which differed in terms of: (i type of aggregate, volcanic tephra and arkose; (ii aggregate/binder ratio, 1:2 as used in the catacombs and 1:4 as found in standard roman construction and (iii temperature, the 17 ºC prevailing in underground environments and the 30 ºC typical of warm Mediterranean areas. The analyses that provided the most useful information were performed in a classic X-ray diffractometer adapted to accommodate an author-designed chamber in which temperature control was achieved by an internal refrigerant and a PID-governed electrical heater Additional data were obtained with DTA and environmental scanning electron microscopy (ESEM. The tests conducted on the Roman-like lime mortars manufactured for the experiment showed that the hardening temperature is a critical factor in the initial phases of carbonation. Calcite precipitation rates and total mineral precipitation increased with temperature, but fell very quickly as calcite precipitated. In theoretical calculations assuming an open reactor with continuous CO2, input, total calcitisation time was found to be 156 m in. at 30 ºC and 175 min. at 17 ºC, whilst in the mortars actually hardened in the experimental part of the study, calcitisation gradually blocked the flow or CO2, gas into the

  10. Lime-based repair mortars with water-repellent admixtures: laboratory durability assessment

    OpenAIRE

    Nunes, C.; Slížková, Z. (Zuzana)

    2015-01-01

    Conservation of architectural structures using lime binders is currently an important research topic aiming compatibility, durability and sustainability. In this study, lime (L) and lime-metakaolin (LM) mortars were prepared with the addition of water-repellent admixtures: linseed oil, stand oil and a silane based water-repellent. Experimental results demonstrate that oil imparts higher hydrophobicity to both L and LM mixtures. Durability was assessed through freeze-thaw and NaCl crystal...

  11. HEAT INSULATING LIME DRY MORTARS FOR FINISHING OF WALLS MADE OF FOAM CONCRETE

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    Loganina Valentina Ivanovna

    2016-05-01

    Full Text Available Different aerated mortars are used for pargeting of walls made of aerated concrete. Though the regulatory documents don’t specify the dependence of plaster density from the density grade of gas-concrete blocks. In case of facing of gas-concrete blocks with the grade D500 using plaster mortars with the density 1400…1600 km/m3 there occurs a dismatch in the values of thermal insulation and vapor permeability of the plaster and base. The authors suggest using dry mortars for finishing of gas-concrete block of the grades D500 и D600, which allow obtaining facing thermal insulating coatings. The efficiency of using four different high-porous additives in the lime dry mortar was compared. They were: hollow glass microspheres, aluminosilicate ash microspheres, expanded vermiculite sand, expanded pearlitic sand. The high efficiency of hollow glass microspheres in heat insulating finishing mortars compared to other fillers is proved.

  12. Influence of nanosilica and a polycarboxylate ether superplasticizer on the performance of lime mortars

    OpenAIRE

    Fernandez, J M; Duran, A; Navarro-Blasco, I. (Íñigo); Lanas, J. (Javier); Sirera, R. (Rafael); Alvarez, J. I.

    2013-01-01

    The effect of individual and combined addition of both nanosilica (NS) and polycarboxylate-ether plasticizer (PCE) admixtures on aerial lime mortars was studied. The sole incorporation of NS increased the water demand, as proved by the mini-spread flow test. An interaction between NS and hydrated lime particles was observed in fresh mixtures by means of particle size distribution studies, zeta potential measurements and optical microscopy, giving rise to agglomerates. On the other hand, the a...

  13. Water transfer properties and shrinkage in lime-based rendering mortars

    Science.gov (United States)

    Arizzi, A.; Cultrone, G.

    2012-04-01

    Rendering is the practice of covering a wall or a building façade with one or more layers of mortar, with the main aim to protect the masonry structure against weathering. The render applied must show high flexibility, good adhesion and compatibility with the support (i.e. stone, brick) and, overall, it should be characterised by low water absorption and high water vapour permeability. Water (in the solid, liquid and vapour state) is one of the main factors that drive construction materials to deterioration. Therefore, to evaluate the quality and durability of a rendering mortar, thus ensuring its protective function in the masonry structure, it is fundamental to assess the behaviour of this mortar towards water. Mortars were elaborated with a calcitic dry hydrated lime, a calcareous aggregate, a pozzolan, a lightweight aggregate, a water-retaining agent and a plasticiser. Four types of lime mortars were prepared, in which the binder-to-aggregate ratios were 1:3, 1:4, 1:6 and 1:9 by weight, whilst the pozzolan was kept at 10% of the lime (by mass) and the total admixtures proportion was less than 2% of the total mass. The influence of the characteristics of mortars pore system on the amount of water absorbed and the kinetics of absorption was investigated by means of: free water absorption and drying; capillary uptake; water permeability; water vapour permeability. Interesting deductions can be made from the values of water and water vapour permeability found for mortars: the former increases exponentially with the sand volume of the mortar, whilst the latter increases almost exponentially with the initial water content added to the mortar mixes during their elaboration. However, the relationship obtained between porosity of mortars and permeability values is not really clear. This finding suggests that the permeability of a material cannot be estimated on the basis of its porosity as it can be made for the capillary uptake and free water absorption. Another

  14. Mortar and concrete based on calcium sulphate binders

    NARCIS (Netherlands)

    Bakker, J.J.F.; Brouwers, H.J.H.

    2006-01-01

    In this study both hemi-hydrate and anhydrite are tested as calcium sulphate binders for structural mortar and concrete. The advantage of using calcium sulphates instead of cement as a binder is the fact that the production of calcium sulphate is more environmental friendly than that of cement. For

  15. Mortar and concrete based on calcium sulphate binders

    OpenAIRE

    Bakker, J.J.F.; Brouwers, H. J. H.

    2006-01-01

    In this study both hemi-hydrate and anhydrite are tested as calcium sulphate binders for structural mortar and concrete. The advantage of using calcium sulphates instead of cement as a binder is the fact that the production of calcium sulphate is more environmental friendly than that of cement. For the calcinations of Portland cement, temperatures up to 1480 oC are needed, while the calcination of for instance hemihydrate requires a temperature of 170 oC

  16. Physical-mechanical characterization of hydraulic and non-hydraulic lime based mortars for a French porous limestone

    CERN Document Server

    Al-Mukhtar, M

    2006-01-01

    The focus of the study presented in this paper is to provide reliable criteria that can be used to estimate the degree of compatibility between the French limestone tuffeau and mortar. It is suggested through this study to use the same parent material (i.e., tuffeau) as mortar. The mortar used in this study is composed of non-hydraulic (hydrated) lime or hydraulic lime and aggregates obtained from fragments and powder of the tuffeau stone. Water transfer properties and mechanical behaviour of the mortars are evaluated and compared with the original stone Tuffeau. Based on these studies, some key guidelines are provided such that a mortar that is compatible with properties of Tuffeau and can be prepared and used as construction material of monuments and maintenance purposes.

  17. 传统糯米灰浆碳化过程中Liesegang环的形成机理研究%Study on the Mechanism of Liesegang Pattern Development During Carbonating of Traditional Sticky Rice-Lime Mortar

    Institute of Scientific and Technical Information of China (English)

    魏国锋; 方世强; 张秉坚; 王晓琪; 李祖光

    2012-01-01

    采用FTIR,XRD,SEM等技术,对传统糯米灰浆碳化过程中出现的Liesegang环现象进行了初步研究.结果表明,使用陈化石灰和糯米浆制备的糯米灰浆在碳化过程中能形成较明显的Liesegang环;陈化石灰一糯米灰浆固化后的极小孔隙,是传统糯米灰浆中Liesegang环形成的本质原因,其形成机理符合延迟成核理论.%Liescgang patterns in traditional sticky rice-lime mortar undergoing carbonation were investigated by means of FTIR, XRD and SEM. Results indicate that well-developed Liesegang patterns only occur in the mortar prepared with aged lime and sticky rice. The smaller Ca(OH)2 particle size in aged lime and the control of the sticky rice for the crystallization of calcium carbonate lead to the small pores in this mortar. These small pores can make Ca2+ and COl23- highly supersaturated, which explains the reason why Liesegang pattern developed in the sticky rice-aged lime mortar. The formed metastable aragonite proves that Liesegang pattern could be explained based on the post-nucleation theory.

  18. Experimental Investigation of Lime Mortar Used in Historical Buildings in Becin, Turkey

    Directory of Open Access Journals (Sweden)

    Adem SOLAK

    2016-05-01

    Full Text Available It is of great importance that the architectural and engineering disciplines work together in the restoration studies of historical buildings which are our cultural heritages. It is required that the bearing system and the materials of the structures should be investigated in detail prior to any conservation. The determination of the properties and compositions of the mortar material used in the construction of the historical building is one of the most important phases of the conservation studies and it is the main purpose of this study. In the scope of the study, the basic physical and mechanical properties, micro structures, raw material compositions, mineralogical and chemical properties of historical mortars taken from Kizil Khan, Karapasah Madrasah and Yelli Mosque structures in Becin antique city are determined. As a result of the study, it is determined that all mortar samples have hydraulic properties that is a result of hydraulic properties of binder lime.DOI: http://dx.doi.org/10.5755/j01.ms.22.1.9022

  19. Mineralogical, textural and physical-mechanical study of hydraulic lime mortars cured under different moisture conditions

    Directory of Open Access Journals (Sweden)

    Arizzi, A.

    2015-06-01

    Full Text Available This work focuses on the chemical-mineralogical, textural and physical-mechanical properties of hydraulic lime mortars made with siliceous and calcareous aggregate. Mortars were cured at 60% and 90% of relative humidity, so as to assess the variability of mortar petrophysical properties in the hardened state due to the moisture conditions. The final aim was to determine the most adequate moisture conditions to be maintained during application and hardening of hydraulic mortars intended for repair interventions. We found out that using a calcareous aggregate and curing mortar at 90% of relative humidity give place to better textural and mechanical properties. However, these characteristics mostly depend on the maximum size of the aggregate grains, which should be smaller than 6 mm, in order to avoid the occurrence of mechanical discontinuities in the mortar.En este trabajo se han estudiado las propiedades químico-mineralógicas, texturales y físico-mecánicas de morteros de cal hidráulica elaborados con áridos silíceo y calcítico. Estos morteros se han curado al 60% y 90% de humedad relativa, con el fin de evaluar las eventuales diferencias en las propiedades petrofísicas de los morteros una vez endurecidos y así establecer cuál de los dos ambientes es recomendable durante la aplicación y fraguado de morteros de cal hidráulica destinados a obras de restauración. Se ha encontrado que el uso de un árido de composición calcítica y el curado al 90% de humedad relativa dan lugar a morteros hidráulicos con mejores características texturales y propiedades mecánicas. De todas formas, estas características dependen principalmente del tamaño máximo del árido empleado, que debería ser inferior a 6 mm para evitar discontinuidades mecánicas en el mortero.

  20. Stable carbon and oxygen isotope investigation in historical lime mortar and plaster - Results from field and experimental study

    Energy Technology Data Exchange (ETDEWEB)

    Kosednar-Legenstein, B. [Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz (Austria); Dietzel, M. [Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz (Austria)], E-mail: martin.dietzel@tugraz.at; Leis, A. [Institute of Water Resources Management, Hydrogeology and Geophysics, Joanneum Research, Elisabethstrasse 16/II, A-8010 Graz (Austria); Stingl, K. [Institute of Applied Geosciences, Graz University of Technology, Rechbauerstrasse 12, A-8010 Graz (Austria)

    2008-08-15

    Lime mortar and plaster were sampled from Roman, medieval and early modern buildings in Styria. The historical lime mortar and plaster consist of calcite formed in the matrix during setting and various aggregates. The stable C and O isotopic composition of the calcite matrix was analyzed to get knowledge about the environmental conditions during calcite formation. The {delta}{sup 13}C{sub matrix} and {delta}{sup 18}O{sub matrix} values range from -31 to 0 per mille and -26 to -3 per mille (VPDB), respectively. Obviously, such a range of isotope values does not represent the local natural limestone assumed to be used for producing the mortar and plaster. In an ideal case, the calcite matrix in lime mortar and plaster is isotopically lighter in the exterior vs. the interior mortar layer according to the relationship {delta}{sup 18}O{sub matrix} = 0.61 . {delta}{sup 13}C{sub matrix} - 3.3 (VPDB). Calcite precipitation by uptake of gaseous CO{sub 2} into alkaline Ca(OH){sub 2} solutions shows a similar relationship, {delta}{sup 18}O{sub calcite} = 0.67 . {delta}{sup 13}C{sub calcite} - 6.4 (VPDB). Both relationships indicate that the {sup 13}C/{sup 12}C and {sup 18}O/{sup 16}O values of the calcite reflect the setting behaviour of the lime mortar and plaster. Initially, CO{sub 2} from the atmosphere is fixed as calcite, which is accompanied by kinetic isotope fractionation mostly due to the hydroxylation of CO{sub 2} ({delta}{sup 13}C{sub matrix} {approx} -25 per mille and {delta}{sup 18}O{sub matrix} {approx} -20 per mille ). As calcite formation continued the remaining gaseous CO{sub 2} is subsequently enriched in {sup 13}C and {sup 18}O causing later formed calcite to be isotopically heavier along the setting path in the matrix. Deviations from such an ideal isotopic behaviour may be due to the evolution of H{sub 2}O, e.g. evaporation, the source of CO{sub 2}, e.g. from biogenic origin, relicts of the natural limestone, and secondary effects, such as

  1. Lime mud from cellulose industry as raw material in cement mortars

    Directory of Open Access Journals (Sweden)

    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.

  2. Properties, characterization, and decay of sticky rice–lime mortars from the Wugang Ming dynasty city wall (China)

    International Nuclear Information System (INIS)

    Urgent restoration of the Wugang Ming dynasty city wall brings about the need for a study of the formulation and properties of mortars. In the present paper, mortar samples from the Wugang Ming dynasty city wall were characterized in a combination of sheet polarized light optical microscopy, scanning electron microscopy with X-ray energy dispersive spectrometer, thermogravimetric/differential scanning calorimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma emission spectroscopy. Results show that mortars are mainly built up from inorganic calcium carbonate based organic–inorganic hybrid material with a small amount of sticky rice, which plays a crucial role in forming dense and compact microstructure of mortars and effectively hindering penetration of water and air into mortars. Analysis of decayed products shows that the detrimental soluble salts originates from ambient environment. - Highlights: • Mortars used in the Wugang city wall are a calcium carbonate-sticky rice hybrid bonding material. • Carbonation processing is extremely slow due to dense and compact microstructure of mortars. • Decying of mortars results from the appearance of soluble salt from ambient environment

  3. Properties, characterization, and decay of sticky rice–lime mortars from the Wugang Ming dynasty city wall (China)

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Ya [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083 (China); Cultural Relics and Archaeology Institute of Hunan, Changsha 410083 (China); Fu, Xuan; Gu, Haibing [Cultural Relics and Archaeology Institute of Hunan, Changsha 410083 (China); Gao, Feng [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083 (China); Liu, Shaojun, E-mail: liumatthew@csu.edu.cn [State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083 (China)

    2014-04-01

    Urgent restoration of the Wugang Ming dynasty city wall brings about the need for a study of the formulation and properties of mortars. In the present paper, mortar samples from the Wugang Ming dynasty city wall were characterized in a combination of sheet polarized light optical microscopy, scanning electron microscopy with X-ray energy dispersive spectrometer, thermogravimetric/differential scanning calorimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy, and inductively coupled plasma emission spectroscopy. Results show that mortars are mainly built up from inorganic calcium carbonate based organic–inorganic hybrid material with a small amount of sticky rice, which plays a crucial role in forming dense and compact microstructure of mortars and effectively hindering penetration of water and air into mortars. Analysis of decayed products shows that the detrimental soluble salts originates from ambient environment. - Highlights: • Mortars used in the Wugang city wall are a calcium carbonate-sticky rice hybrid bonding material. • Carbonation processing is extremely slow due to dense and compact microstructure of mortars. • Decying of mortars results from the appearance of soluble salt from ambient environment.

  4. 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.

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

    Directory of Open Access Journals (Sweden)

    Izaguirre, A.

    2011-06-01

    Full Text Available 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.

    Como alternativa a los materiales con base cemento y a plastificantes obtenidos por vía química, se estudió el efecto de un almidón comercial incorporado a morteros de cal aérea. Se ensayaron dosificaciones diferentes para analizar su influencia sobre las propiedades del material. En los morteros se determinaron densidad, retracción, absorción de agua por capilaridad, permeabilidad, resistencias mecánicas, porosidad, distribución de tamaños de poro y durabilidad frente a ciclos de hielo-deshielo. El almidón actuó como espesante hasta la dosis de 0,30%, pero cambió al añadirlo en la dosis más alta (0,50%: en este caso, se comportó como un plastificante, dispersando la cal a través de la mezcla en fresco, dando lugar a un material más trabajable. Como resultado, en la dosis 0,50%, la matriz del mortero endurecido presentó gran coherencia, por su mayor densidad y menor porosidad, lo que implicó una

  6. 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

  7. 浙江古城墙传统灰浆材料的分析研究%The Analysis of Traditional Lime Mortars from Zhejiang Province,China

    Institute of Scientific and Technical Information of China (English)

    刘效彬; 崔彪; 张秉坚

    2016-01-01

    The components of ancient mortars have always been an important research field in historic building conservation .It has been well known that using traditional mortars in conservation projects have many advantages ,such as compatibility and sta‐bility .So ,developing new binding materials based on traditional mortar has become an international study hotspot .With China’ s economic development ,the protection of ancient buildings also began to put on the agenda ,but the understanding on Chinese traditional mortar is limited ,and rare literatures are reported .In the present work ,the authors investigate seven ancient city wall sites in Zhejiang Province in situ ,and subsequently laboratory analysis were carried out on collected mortar samples .The characterizations of mortar samples were made by multi‐density gauge ,XRD ,FTIR ,TG‐DSC and wet chemical analysis .The experimental results showed that :the main component of masonry mortars is calcium carbonate ,the content between 75% ~90% ,and they should be made from relatively pure lime mortar .The raw materials of mortar samples were mainly calcareous quick lime ,and sample from Taizhou city also contained magnesium quick lime .There are four city walls were built by sticky‐rice mortars .It suggests that the technology of adding the sticky rice soup into mortar was universal in the Ming Dynasties . These mortars have lower density between 1 .2 and 1 .9 g・cm‐3 ;this outcome should be the result of long‐term natural erosion . We have also analyzed other chemical and physical characteristics of these masonry mortars .The results can afford the basic data for the future repairmen programs ,development of new protective materials ,and comparative study of mortars .%灰浆材料一直是古代建筑类文化遗产研究的重要对象,文保工程中使用传统灰浆的诸多优点已广为人知,在认识传统灰浆的基础上开发新的石灰基粘结保护材料已然成为国

  8. 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.

  9. 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.

  10. Raw materials and structure of ancient glutinous rice-lime mortar in China%中国传统糯米-石灰砂浆的原材料和结构

    Institute of Scientific and Technical Information of China (English)

    杨华山; 车玉君; 马小满

    2015-01-01

    Raw materials observed in ancient glutinous rice-lime mortar in China,such as glutinous rice,lime,brown sugar,fine aggre-gate,and clay etc. were investigated in this work. A model was proposed to simulate nonlinear structure in ancient glutinous rice-lime mortar. It was found that the key parameters involved in the model are bifurcation and deflection of fracture energy. The microstructure of glutinous rice-lime mortar were tested by scanning electron microscopic and X-ray diffraction analysis. It was observed that the morphology and size of calcium carbonate were modified by glutinous rice and brown sugar.%研究了中国传统糯米-石灰砂浆的原材料(糯米浆、石灰、红糖浆、河砂和黏土等),并提出了糯米-石灰砂浆的结构模型,该模型刻画了材料的非线性结构。该模型表明,糯米-石灰砂浆的的性能与其结构直接相关,断裂能在其中的分叉和偏转是其强韧化的两个最为关键的要素。糯米-石灰砂浆的微观结构采用SEM和XRD进行分析,测试结果表明:糯米浆和红糖浆对CH碳化反应有一定的影响,CaCO3的晶粒形貌改变和粒度的减小优化了糯米-石灰砂浆的微观结构。

  11. 中国传统灰土灰浆强度增强方法研究%Research on the intensity strengthening of Chinese traditional lime-clay mortar

    Institute of Scientific and Technical Information of China (English)

    李博; 宋燕; 马清林; 梅建军

    2012-01-01

    The formation of hydraulic gel materials in the Chinese traditional lime-clay mortar, namely hydrated calcium silicate and hydrated alu- minum silicate, can significantly increase the strength of mortar. However, it will take an extremely long period to generate these kinds of water rigid compounds under natural conditions. Inspired by the idea of improving the pozzolanie activity by roasting the clay material, a basic principle modern cement technology, this paper explores a method to reduce the formation time of hard water compounds, and then, to improve the intensity of the mortar in a short time. The result of this research is expected to improve the physical properties of traditional lime-clay mortar for a better application in the conservation of traditional brickwork.%中国传统灰土灰浆中水硬性凝胶材料-水合硅酸钙和水合硅酸铝的形成可以大幅度提高其强度,但在自然条件下生成此类水硬性化合物需要很长时间。本文借鉴现代水泥工艺中利用焙烧黏土材料可提高火山灰活性的原理,从而有效缩短形成水硬性化合物的反应时间,在短时间内大大提高灰浆的强度。以此为出发点,加工制备性能优良的灰浆材料,为传统砌体建筑的保护提供适宜的保护修复材料。

  12. Effect of Water-repellent Admixtures on Repair Mortars Made of Lime and Metakaolin%防水剂对石灰偏高岭土修补砂浆性能的影响

    Institute of Scientific and Technical Information of China (English)

    彭小芹; 曹春鹏; 季晓丽; 曾路

    2016-01-01

    以石灰和偏高岭土为主要材料,制备一种适用于岩土类建筑的修补砂浆.用桐油和硬脂酸钙两种防水剂来改善砂浆的耐水性,研究桐油和硬脂酸钙对砂浆强度、反应过程、吸水率和软化系数、干燥收缩的影响,并通过XRD和SEM 对砂浆进行物相分析和微观形貌观测.结果表明:桐油和硬脂酸钙可以显著提高石灰偏高岭土砂浆的耐水性,可使吸水率下降至2.5%以下;桐油和硬脂酸都会阻碍偏高岭土的火山灰反应,在一定程度上降低砂浆的强度,但28 d的抗压强度仍在5 M Pa以上,达到天然水硬性石灰N HL5的强度等级;桐油和硬脂酸钙会影响石灰偏高岭土砂浆的微观形态和结构,桐油使产物的颗粒更细小、更致密,硬脂酸钙则会使产物结构比较疏松.综合考虑砂浆强度、耐水性等因素,得出桐油和硬脂酸钙的最佳掺量分别为5%和1.5%.%A kind of repair mortar for geotechnical building was prepared with lime and metakaolin as major materials .Two kinds of water‐repellent admixtures (tung oil and calcium stearate) were used to im‐prove the water resistance of the mortars .Different properties of the mortars were evaluated ,such as strength ,the process of reaction ,water absorption ,softening coefficient and shrinkage .Phase and micro‐structure analysis of the mortars were carried out through XRD and SEM .The results show that tung oil and calcium stearate can improve water resistance of the mortars significantly .Water absorption of the mortars with tung oil or calcium stearate can be below 2 .5% .Tung oil and calcium stearate hinder the poz‐zolanic reaction of metakaolin ,which as a result decrease the mortars’ strength .But 28 d compressive strength of the mortars are all above 5 MPa .Also ,tung oil and calcium stearate can regulate the growth of products and affect the micromorphology and structure of mortars .Tung oil make the

  13. {sup 14}C chronology of the oldest Scandinavian church in use. An AMS/PIXE study of lime lump carbonate in the mortar

    Energy Technology Data Exchange (ETDEWEB)

    Lindroos, Alf, E-mail: alf.lindroos@abo.fi [Geology and Mineralogy, Department of Natural Sciences, Åbo Akademi University (Finland); Art History, Faculty of Art, Åbo Akademi University (Finland); Ranta, Heikki [Diocese of Lund, Church of Sweden (Sweden); Heinemeier, Jan [AMS " 1" 4C Dating Laboratory, Department of Physics and Astronomy, University of Aarhus (Denmark); Lill, Jan-Olof [Accelerator Laboratory, Turku PET Centre, Åbo Akademi University (Finland)

    2014-07-15

    Mortar dating was applied to newly revealed, original mortar in the church of Dalby in Scania, southern Sweden which is considered to be the oldest still standing church in Scandinavia. Small white lime lumps were sampled by chipping from the supporting pillars in the interior of the church. Special emphasis was in sampling lime lumps because the church is situated in the Scania limestone area and aggregate limestone contamination was anticipated in the bulk mortars. Earlier studies have, however, shown that lime lumps do not contain aggregate material but only possible limestone rests from incomplete calcination. The sampled material was prepared for radiocarbon AMS dating. The carbonate in the lime lumps was hydrolyzed according to the sequential leaching technique developed for the Århus {sup 14}C laboratory in Denmark. Prior to the hydrolysis the lime lumps were examined for dead-carbon contamination using a stereo microscope and cathodoluminescence. The lime lumps displayed heterogeneous carbonate luminescence. This is, however, common and it was not considered a problem because carbonate growth in changing pH/Eh conditions often leads to changing luminescence colors. Two lumps had little dead carbon contamination and an early second millennium {sup 14}C signature. One lump, however, seemed to be heavily contaminated with dead carbon. Since the sample passed the microscopic screening, the leftovers of the lump was subjected to PIXE analysis and compared with the other two lumps. The well-defined, early 2nd millennium {sup 14}C age of the lime lumps of this particular church is an important contribution to the discussion on stone church chronology in Scandinavia.

  14. Historic trass - lime mortars with expansive reactions: Characterization and repair strategies

    NARCIS (Netherlands)

    Hees, R.P.J. van; Nijland, T.G.; Larbi, J.A.; Wijffels, T.J.; Brocken, H.J.P.

    2005-01-01

    The characterisation of two ancient mortars in historic bridges, suffering damage due to thaumasite and other swelling compounds is described. Characterisation was part of the analysis of damage occurring to the brick masonry structure. Expansive reactions were found to have taken place, being the c

  15. Strength and shrinkage properties of mortar containing a nonstandard high-calcium fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Cengiz Duran Atis; Alaettin Kilic; Umur Korkut Sevim [Cukurova University, Balcali-Adana (Turkey). Engineering and Architecture Faculty

    2004-01-01

    A laboratory study was undertaken to assess the compressive and flexural tensile strength and drying shrinkage properties of mortar mixtures containing high-calcium nonstandard Afsin-Elbistan fly ash (FA). Possibility of using Afsin-Elbistan FA in cement-based materials as shrinkage-reducing or compensation agent was also discussed. Five mortar mixtures including control Portland cement (PC) and FA mortar mixtures were prepared. FA replaced the cement on mass basis at the replacement ratios of 10%, 20%, 30% and 40%. Water-cementitious materials ratio was 0.4 for all mixtures. The mixtures were cured at 65% relative humidity and 20{+-}2{sup o}C. The compressive and flexural tensile strength and drying shrinkage values of the mortar mixtures were measured. The results show that Afsin-Elbistan FA reduced drying shrinkage of the mortar by 40%. Therefore, it was concluded that Afsin-Elbistan FA can be used as a shrinkage-reducing agent. The mortar containing 40% FA expanded. This indicates that Afsin-Elbistan FA may be utilized to compensate drying shrinkage of cement-based materials.

  16. Chromatic reintegration of historical mortars with lime-based pozzolanic consolidant products

    NARCIS (Netherlands)

    Borsoi, G.; Pascoal, P.; Pinto, J.P.; Veiga, R.; Faria, P.; Santos Silva, A.

    2013-01-01

    The consolidation process of old renders with loss of cohesion is nowadays performed usually with inorganic compatible products, such as calcium or barium hydroxide or ethyl silicate. The use of organic consolidants as acrylic or vinilic resins is discouraged due to its physico-chemical incompatibil

  17. Influence of Inorganic Admixture on Performance of Sticky Rice-Lime Mortar and Its Mechanism%无机添加剂对糯米灰浆性能影响及机理研究

    Institute of Scientific and Technical Information of China (English)

    李祖光; 方世强; 魏国锋; 张秉坚

    2013-01-01

    采用扫描电镜(SEM)和X射线衍射(XRD)等分析技术,探讨了硫酸铝、明矾和工业石膏对糯米灰浆性能的影响及作用机理.结果显示:硫酸铝对于改善糯米灰浆的力学性能、耐冻融性和耐水性均有较大帮助;明矾对糯米灰浆的改善主要表现在力学性能方面;工业石膏对糯米灰浆在力学性能和耐候性方面均未有明显改善;3种添加剂对减缓和减少糯米灰浆收缩均表现出良好的效果.在实际应用中,建议采用一定比例的硫酸铝作为糯米灰浆的添加剂.%The influence of admixtures(aluminum sulfate,alum,gypsum) on properties of traditional sticky rice-lime mortar and its scientific mechanism was studied by means of SEM and XRD.Results indicate that addition of aluminum sulfate improves the mechanical property,freeze-thaw resistance and water resistance of sticky rice-lime mortar significantly.Whereas the addition of alum mostly improves the mechanical property of sticky rice-lime mortar.Gypsum has few contribution to improvement of mechanical property and weather resistance of sticky rice-lime mortar.All of these three admixtures have favorable effect on slowing down and reducing the shrink of sticky rice-lime mortar.Aluminum sulfate should be used as admixtures for sticky rice-lime mortar in conservation of cultural relics.

  18. Reactive Crystallization of Calcium Sulfate Dihydrate from Acidic Wastewater and Lime

    Institute of Scientific and Technical Information of China (English)

    邓立聪; 张亦飞; 陈芳芳; 曹绍涛; 游韶玮; 刘艳; 张懿

    2013-01-01

    The present work focused on the recycle of the sulfate and the metal ions from acidic wastewater dis-charged by nonferrous metallurgical industry. The effects of the temperature, the reactant concentration, the stirring speed and the metal ions on the reactive crystallization process of calcium sulfate between sulfuric acid and lime were systematically investigated. The morphology of the precipitated crystals evolved from platelet-like and nee-dle-like shape to rod-like shape when the temperature was increased from 25 to 70 °C. An increase in the agglom-eration of calcium sulfate was found with increasing lime concentration. Metal ions markedly retard the rate of crystallization of calcium sulfate dihydrate. The crystallization of gypsum was slowed with the existence of Mg2+in the solution, and the morphology of gypsum was transformed from platelet-like shape to rod-like shape when Mg2+concentration reached 0.08 mol·L-1. The amorphous ferric hydroxide was coated on the calcium sulfate after the co-precipitation process while Zn2+and Al3+ions in the solution enhanced the agglomeration of the calcium sulfate by absorbing on the surface of the crystals. Comprehensive acidic wastewater containing heavy metals was effi-ciently purified by the two stage lime neutralization technology, and highly agglomerated gypsum precipitates with needle-like shape were obtained. The precipitates could be purified by sulfuric acid washing, and the metal ions were effectively separated from the calcium sulfate by-products.

  19. Study on the Traditional Lime Mortar from the Memorial Archway in the Southern Anhui Province%皖南牌坊传统灰浆的科技研究

    Institute of Scientific and Technical Information of China (English)

    魏国锋; 孙升; 王成兴; 张秉坚; 陈希敏

    2013-01-01

    采用FTIR,XRD,SEM等技术,对皖南牌坊上的传统灰浆材料配方进行了初步研究.结果表明,牌坊灰浆样品为石灰掺桐油或糯米而形成的有机-无机复合材料.桐油灰浆强度的形成主要源于灰浆中石灰的碳化反应、桐油与氧气的交联反应和Ca2+与-COO-的配位反应以及由此面形成的致密片层状有机-无机复合结构.糯米淀粉对灰浆碳化过程的调控作用而形成的细密的微观结构是糯米灰浆具有良好性能的微观解释.%The traditional lime mortar was investigated by means of scanning electron microscope (SEM),X-ray diffractometry and Fourier transform infrared spectrometry (FTIR).The results show that the mortar from the memorial archway in the southern Anhui province was the organic-inorganic composite materials composed of lime with tung oil or sticky rice.It was found that the excellent performance of the tung oil-lime mortar can be explained by the compact lamellar organic-inorganic composite structure that was produced by carbonization reaction of lime,cross-linking reactions of tung oil and oxygen and complexing reaction of Ca2+ and-COO-.The compact micro-structure of sticky rice-lime mortar,which was produced due to carbonation process of lime controlled by amylopectin,should be the cause of the good performance of this kind of organic-inorganic mortar.

  20. Influence of Curing on the Strength Development of Calcium-Containing Geopolymer Mortar

    Directory of Open Access Journals (Sweden)

    Zhenzhen Jiao

    2013-11-01

    Full Text Available This paper investigated the curing effects on the mechanical properties of calcium-containing geopolymer mortar. Three precursors are used: Class C fly ash, Class F fly ash plus calcium hydroxide and Class F fly ash plus slag. Curing conditions included: (1 standard curing at 20 ± 3 °C and RH 95% (C; (2 steam curing at 60 °C for 24 h (S; (3 steam curing at 60 °C for 6 h (S6; and (4 oven curing at 60 °C for 24 h (O, then the latter three followed by the standard curing. Under the standard conditions, the flexural strength and compressive strength of Class C fly ash geopolymer mortars developed quickly until the age of 7 days, followed by a gradual increase. Specimens with Class F fly ash plus Ca(OH2 showed slow increase till the age of 28 days. Under these non-standard conditions (2–4, all specimens showed higher 3-day strength, while later strengths were either higher or lower than those in standard conditions, depending on the type of the precursor.

  1. Influence of Admixtures on Properties of Traditional Sticky Rice-lime Mortar and Their Mechanisms%添加剂对传统糯米灰浆性能的影响及其机理

    Institute of Scientific and Technical Information of China (English)

    魏国锋; 张秉坚; 方世强

    2011-01-01

    糯米灰浆是中国古代建筑史上的一项重要科技发明,为了使该传统工艺科学化地为现代文化遗产保护服务,采用SEM和XRD等技术手段,探讨了纸筋、硫酸铝和二水石膏3种添加剂对糯米灰浆性能的影响及其机理.结果表明:纸筋对糯米灰浆抗压强度和耐冻融性的改进最为明显;硫酸铝对改善糯米灰浆的干燥收缩性效果最佳;二水石膏的加入,对样品的耐冻融性并无改进,而且,随着其含量的增加,样品的抗压强度和表面硬度增幅降低.在文化遗产保护实践中,建议采用6%的硫酸铝或3%的纸筋作为糯米灰浆的添加剂.%On the basis of characterization of property of traditional sticky rice-lime mortar, influence of admixtures (aluminum sulfate, gypsum, paper fiber) on properties of traditional sticky rice-lime mortar and their scientific mechanisms are discussed by means of SEM and XRD. It is indicated that paper fiber is the most effective admixture to endure freezing-thawing cycles and increase compressive strength of sticky rice-lime mortar due to disorderly distribution and water-retaining of paper fiber, and the use of aluminum sulfate reduces dry shrinkage values and improves compressive strength because of formation of ettringite in sticky rice-lime mortar. Gypsum is proved to be ineffective to modify freezing-thawing cycles of sticky rice-lime mortar. Meanwhile, compressive strength and surface hardness of sticky rice-lime mortar with gypsum decline as gypsum amounts. It is suggested that 6% aluminum sulfate or 3% paper fiber can be used as admixtures of sticky rice-lime mortar in conservation of cultural relics.

  2. Self-diffusion of calcium ions in soda-lime and slag glasses

    International Nuclear Information System (INIS)

    The self-diffusion coefficients of calcium ions in 16Na2O.12CaO.72SiO2(wt%) glass and 40CaO.20Al2O3.40SiO2(wt%) slag glass at temperatures near and below transition point have been measured employing radio-isotope 45Ca. The concentration gradient of radio-activity in surface layer of glass samples after diffusion annealing was determined by counting the residual activity with a GM-tube counter on the surface by progressively chemical etching away the material in steps of about 1 micron meter. It was found that the self-diffusion coefficients of calcium ions in both glasses below the transition point were of the order of 10-14 -- 10-16 cm2/s, suggesting that the mobility of calcium ions was extremely small in the solid glasses. The activation energy for diffusion of calcium ions in solid glasses was about 60 kcal/mol, which seemed to be reasonable in comparison with the electrostatic binding energy between cation and oxygen ion. The self-diffusion coefficients of calcium ions in the slag glass agrees closely with those of oxygen ions below the transition point, while the self-diffusion coefficients of calcium ions in the soda-lime glass are greater by one order of magnitude than those of oxygen ions in the same glass. The difference of diffusion behavior of calcium ions in the slag and the soda-lime glasses may be attributed to action of alkali ions on the mobility of calcium ions. (auth.)

  3. Bactericidal and virucidal mechanisms in the alkaline disinfection of compost using calcium lime and ash.

    Science.gov (United States)

    Hijikata, Nowaki; Tezuka, Rui; Kazama, Shinobu; Otaki, Masahiro; Ushijima, Ken; Ito, Ryusei; Okabe, Satoshi; Sano, Daisuke; Funamizu, Naoyuki

    2016-10-01

    In the present study, the bactericidal and virucidal mechanisms in the alkaline disinfection of compost with calcium lime and ash were investigated. Two indicator microorganisms, Escherichia coli and MS2 coliphage, were used as surrogates for enteric pathogens. The alkaline-treated compost with calcium oxide (CaO) or ash resulted primarily in damage to the outer membrane and enzyme activities of E. coli. The alkaline treatment of compost also led to the infectivity loss of the coliphage because of the partial capsid damage and RNA exteriorization due to a raised pH, which is proportional to the amount of alkaline agents added. These results indicate that the alkaline treatment of compost using calcium oxide and ash is effective and can contribute to the safe usage of compost from a mixing type dry toilet. PMID:27562698

  4. Hardening of calcium hydroxide and calcium silicate binders due to carbonation and hydration

    OpenAIRE

    Cizer, Özlem; Campforts, J; Balen, Koenraad Van; Elsen, Jan; Gemert, Dionys van

    2006-01-01

    Hardening of calcium hydroxide and calcium silicate binders composed of cement, rice husk ash (RHA) and lime in different compositions were studied with mechanical strength, mercury intrusion porosimetry, thermal analysis and SEM. When cement is partially replaced with RHA and lime, hardening occurs as a result of combined hydration, pozzolanic reaction and carbonation reaction. While hydration of cement contributes to the early strength development of the mortars, carbonation is much more pr...

  5. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics.

    Science.gov (United States)

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-07-01

    Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl(2) accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores.

  6. Properties of Cement Mortar Produced from Mixed Waste Materials with Pozzolanic Characteristics

    Science.gov (United States)

    Yen, Chi-Liang; Tseng, Dyi-Hwa; Wu, Yue-Ze

    2012-01-01

    Abstract Waste materials with pozzolanic characteristics, such as sewage sludge ash (SSA), coal combustion fly ash (FA), and granulated blast furnace slag (GBS), were reused as partial cement replacements for making cement mortar in this study. Experimental results revealed that with dual replacement of cement by SSA and GBS and triple replacement by SSA, FA, and GBS at 50% of total cement replacement, the compressive strength (Sc) of the blended cement mortars at 56 days was 93.7% and 92.9% of the control cement mortar, respectively. GBS had the highest strength activity index value and could produce large amounts of CaO to enhance the pozzolanic activity of SSA/FA and form calcium silicate hydrate gels to fill the capillary pores of the cement mortar. Consequently, the Sc development of cement mortar with GBS replacement was better than that without GBS, and the total pore volume of blended cement mortars with GBS/SSA replacement was less than that with FA/SSA replacement. In the cement mortar with modified SSA and GBS at 70% of total cement replacement, the Sc at 56 days was 92.4% of the control mortar. Modifying the content of calcium in SSA also increased its pozzolanic reaction. CaCl2 accelerated the pozzolanic activity of SSA better than lime did. Moreover, blending cement mortars with GBS/SSA replacement could generate more monosulfoaluminate to fill capillary pores. PMID:22783062

  7. 桐油-石灰传统灰浆的性能与作用机理%Properties and Mechanism of Tung Oil-Lime Traditional Mortar

    Institute of Scientific and Technical Information of China (English)

    赵鹏; 李广燕; 张云升

    2013-01-01

    Continuous observation of the early stage of microstructure formation of mortar bonding materials at room temperature was conducted using an ultrasonic monitoring apparatus. Mechanism of interaction between the key components of ancient mortar bonding materials was analyzed via X-ray diffraction and scanning electron microscopy. The results show that Tung oil can accelerate the formation of microstructure at early stage, and plays a role of biological templates, which regulates the growth of calcium carbon-ate crystal and leads to the smaller particle size and the more compact structure.%  利用超声测试装置连续追踪桐油–石灰传统灰浆的早期结构形成过程,并通过 X 射线衍射仪和扫描电子显微镜分析了桐油–石灰传统灰浆碳化过程中反应产物的种类、数量与组织形貌。结果表明:有机物桐油的掺入加快了石灰浆体的早期结构形成;桐油对碳化反应生成碳酸钙晶体的生长有明显调控作用,桐油限制了碳酸钙的结晶度,晶体尺度小,结构更加致密。

  8. A case study and mechanism investigation of typical mortars used on ancient architecture in China

    Energy Technology Data Exchange (ETDEWEB)

    Zeng Yuyao [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang (China); Zhang Bingjian [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang (China)], E-mail: zbj@mail.hz.zj.cn; Liang Xiaolin [Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang (China)

    2008-07-10

    Mortars sampled from Dutifulness Monument, where typical ancient China mortar formulas and manufacturing processes were used, were analyzed by starch-iodine test, FTIR, DSC-TG, SEM and XRD methods. Several modeling samples were then made according to historical records of Chinese ancient mortar formulas and analyzed with the same techniques. The modeling formulas also were used to consolidate loose specimens. The results show that sticky rice plays a crucial role in the microstructure and the consolidation properties of lime mortars. A possible mechanism was suggested that biomineralization may occur during the carbonation of calcium hydroxide, where the sticky rice functions as a template and controls the growth of calcium carbonate crystal. The organic-inorganic materials formed based on this mechanism will be more favorable for consolidating the loose samples both in strength improvement and durability.

  9. 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.

  10. Some considerations about the use of lime-cement mortars for building conservation purposes in Portugal : a reprehensible option or a lesser evil?

    OpenAIRE

    Torgal, Fernando Pacheco; Faria, Joana; Jalali, Said

    2012-01-01

    Some investigations about conservation actions in historical buildings points out that lime–cement mortars should be avoided and lime–pozzolan mortars should be use instead. Nevertheless this type of mortar is still under investigation and the absolute rejection of the use of Portland cement even with just a minimum amount appears to be a dogmatic position that is not fully grounded in scientific terms. Besides the use of lime–pozzolan mortars requires skilled craftsmanship and at least...

  11. Valorization of Drinking Water Treatment Sludges as Raw Materials to Produce Concrete and Mortar

    Directory of Open Access Journals (Sweden)

    R. M.R. Zamora

    2008-01-01

    Full Text Available The purpose of this work was to assess the technical feasibility to valorize sludges, generated and stored at the Los Berros drinking water facility (PPLB, as raw material to produce building products (mortar and concrete for the construction industry. The experimental study was divided into three stages: 1 sampling and characterization of PPLB sludges to determine their potential as raw material (sand substitute and supplementary cementing materials to produce mortar and concrete; 2 production and characterization of specimens, using sludge in different weight ratios of mixtures with cement, lime, commercial mortar and plaster to prepare mortars and concretes and 3 comparison of compressive strength and drying contraction values between each specimen and the Mexican criteria to build mortars and concretes. The characterization results of the PPLB sludges showed that these residues could be used as a sand substitute in mortar and concrete formulations, since they were mainly comprised of this material (46.83%. The specimens prepared with a the binary formulations, sludge-cement and sludge-mortar (90-10% and b the ternary formulation, sludge-lime-cement (90-5-5%, gave the best results (ranging from 130 to 150 kg cm-2 of the compressive strength test. The compressive strength values of these formulations were higher than those of equivalent mortar (types I, II and III and cement mixtures (125 kg cm-2 prepared according to the Mexican complementary technical criteria to design and build masonry. These cementing properties exhibited by the PPLB sludges might be associated to their high content of aluminum and silicon oxides, 31.98 and 33.23%, respectively. Thus, calcium silicate (the main carrier strength in hardened cement can be produced from lime hydration of cement with the active silica present in the sludge. Considering all these results, the PPLB sludges present a high feasibility for being valorized as raw materials (supplementary cementing

  12. 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.

  13. Some masonary mortar from Hellenistic and Roman period Greece

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, H.H.G.

    1985-01-01

    The Mineral Resources Research Center at the University of Minnesota has been engaged for the past six years in projects to synthesize various hydraulic cements by plasma fusion. An analytical scheme was developed to examine the plasma products. The techniques used to examine these cements were applied to five masonary mortar samples of Hellenistic and Roman periods from three sites in Greece (Olympia, Larissa, and Trikkala). These were examined by chemical, microscopical (polarized light and scanning electron), x-ray diffraction, and differential thermal analysis methods. These samples are typical sand-lime mortars: The aggregates consist of quartz with small amounts of microcline or orthoclase and, in several of the samples, rock and chert fragments. The matrix is largely fine grained calcite and a small amount of calcium silicate hydrate, a typical phase found in hydraulic cements. The sample from the Altis in Olympia (160 to 170 A.D.) is a pink, dense mortar with medium to fine grained aggregate and shows excellent workmanship. This specimen contains reddish fragments which are probably pieces of ceramics which either are used as fill or are poorly crushed material added as a pozzolana. The samples were probably emplaced as a sand and slaked-lime mixture. The limes are impure and thus have feebly hydraulic properties.

  14. Characterization and Degradation of Masonry Mortar in Historic Brick Structures

    Directory of Open Access Journals (Sweden)

    Denis A. Brosnan

    2014-01-01

    Full Text Available This study characterized mortars from a masonry fortification in Charleston, South Carolina (USA, harbor where construction was during the period 1839–1860. This location for analysis was interesting because of the sea water impingement on the structure. The study was included as part of an overall structural assessment with restoration as an objective. The mortars were found to be cement, lime, and sand mixtures in proportions similar to ones expected from the historic literature, that is, one part binder to two parts of sand. The binder was found to be American natural cement, a substance analogous to the European Roman cement. The results suggest that the thermal history of the cement during manufacturing affected setting rate explaining why the cements were considered as variable during the mid-to-late 1800s. Fine pores were found in mortars exposed to sea water resulting from corrosion. Contemporary natural cement was shown to release calcium in aqueous solution. While this release of calcium is necessary for setting in natural and Portland cements, excessive calcium solution, as exacerbated by sea water contact and repointing with Portland cement mortars, was shown to result in brick scaling or decay through cryptoflorescence.

  15. Rendering mortars in Medina Azahara, Part I: Material characterization and alteration process

    OpenAIRE

    Blanco-Varela, M. T.; Puertas, F.; Palomo, A.

    1997-01-01

    Rendering mortars, which are still exposed to the open air on some of the walls of Medina Azahara, are studied and characterized in this work. Some repairing mortars used in different previous restorations are also characterized. Those rendering mortars are of different make considering the composition of their binder: lime, gypsum and mixed lime/ gypsum. Repairing mortars used in previous interventions are made of lime, excepting for a portland cement used by Félix Hernández in the rest...

  16. Physico-chemical characterization of mortars as a tool in studying specific hydraulic components: application to the study of ancient Naxos aqueduct

    Science.gov (United States)

    Maravelaki-Kalaitzaki, P.; Galanos, A.; Doganis, I.; Kallithrakas-Kontos, N.

    2011-07-01

    Mortars and plasters from the ancient aqueduct on the island of Naxos, Greece, were studied with regard to mineralogical and chemical composition, grain size distribution, raw materials and hydraulic properties, in order to assess their characteristics and design compatible repair mortars. The authentic materials contained lime, crushed-brick, siliceous and calcitic aggregates, in different proportions according to mortar type. Crushed-bricks fired at low temperatures and lightweight volcanic aggregates contained amorphous phases, which upon reaction with lime yielded hydraulic components capable of protecting the construction from the continuous presence of water. Hydraulic calcium silicate/aluminate hydrates, the proportions and the perfect packing of the raw materials, along with the diligent application justify the longevity and durability of the studied samples. The hydraulic properties of samples were pointed out through (a) the well-established CO2/H2O ratio derived from the thermogravimetric analysis and (b) by introducing two powerful indices issued from the chemical analysis, namely CaOhydr and soluble SiO2 hydr. These indices improved the clustering of hydraulic mortars and provided better correlation between mortars, plasters and their binders. By comparing grain size distribution and hydraulicity indices it was possible to distinguish among the construction phases. Based on this study, repair mortars were formulated by hydraulic lime, siliceous sand, calcareous and crushed-brick aggregates, with the optimal water content, ensuring optimum workability and compatible appearance with the authentic ones.

  17. Self healing phenomena in concretes and masonry mortars: A microscopic study

    NARCIS (Netherlands)

    Nijland, T.G.; Larbi, J.A.; Hees, R.P.J. van; Lubelli, B.A.; Rooij, M.R. de

    2007-01-01

    A microscopic survey of over 1000 of samples of concrete and masonry mortars from structures in the Netherlands shows that, in practice, self healing occurs in historic lime and lime – puzzolana mortars, in contrast to modern cement bound concretes and mortars. Self healing may be effected by the fo

  18. 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

  19. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar.

    Science.gov (United States)

    Jackson, Marie D; Landis, Eric N; Brune, Philip F; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J M; Ingraffea, Anthony R

    2014-12-30

    The pyroclastic aggregate concrete of Trajan's Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime-volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium-aluminum-silicate-hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8-0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥ 90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45-0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale.

  20. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar.

    Science.gov (United States)

    Jackson, Marie D; Landis, Eric N; Brune, Philip F; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J M; Ingraffea, Anthony R

    2014-12-30

    The pyroclastic aggregate concrete of Trajan's Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime-volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium-aluminum-silicate-hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8-0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥ 90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45-0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale. PMID:25512521

  1. Compressive strength of brick masonry made with weak mortars

    DEFF Research Database (Denmark)

    Pedersen, Erik Steen; Hansen, Klavs Feilberg

    2013-01-01

    The use of weak mortar has a number of advantages (e.g. prevention of expansion joints, environmental issues). However, according to EC6, the strength of masonry vanishes when the compressive strength of the mortar approaches zero. In reality the presence of even unhardened mortar kept in place...... in the joint will ensure a certain level of load-carrying capacity. This is due to the interaction between compression in the weak mortar and tension in the adjacent bricks. This paper proposes an expression for the compressive strength of masonry made with weak lime mortars (fm... of masonry depends only on the strength of the bricks. A compression failure in masonry made with weak mortars occurs as a tension failure in the bricks, as they seek to prevent the mortar from being pressed out of the joints. The expression is derived by assuming hydrostatic pressure in the mortar joints...

  2. Newly-designed Traditional Glutinous Rice-lime Mortar with Micron-nano-particles%微纳米复合掺和料对传统糯米-石灰砂浆强度的影响

    Institute of Scientific and Technical Information of China (English)

    杨华山; 车玉君; 江华利; 林戈; 魏东

    2015-01-01

    Portland cement and polymers have low chemical and physical affinity for traditional building materials .This hinders the restoration of historical buildings .Glutinous rice-lime mortars (GLM ) used in construction since ancient times in China were recov‐ered ,and attempts were made to enhance their performances .Micron particles ,such as limestone ,fly ash and slag ,with silicon fume contained nano-particles were selected on the basis of their properties .Flexural strength and compressive strength of GLM with micron-nano-particles were measured .Test results show that the mechanical performances of newly-designed traditional GLM were improved .And they are compatible with ancient building materials in China ,so it can be used in the restoration of architectural heritage .%水泥基修补材料和高分子修补材料与古迹本体材料存在相容性问题,不利于古迹的修复工作。糯米-石灰砂浆是中国古代传统的一种建筑材料,拟挖掘并提升其性能用于古迹的修补。分别采用石灰石粉、粉煤灰和矿粉等微米级掺和料与硅灰复合,研究微纳米掺和料对糯米-石灰砂浆强度的影响。试验研究的结果表明,微纳米复合掺和料提高了糯米石灰砂浆的力学性能。这种材料与中国古代建筑材料相容,可用于古迹的修复工作。

  3. 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 ...

  4. Salt resistant mortars: present knowledge and future perspectives

    NARCIS (Netherlands)

    Lubelli, B.

    2013-01-01

    Salt crystallization damage is one of the most common causes of decay for bedding, pointing and plastering mortar. Attempts to tackle the problem have been mainly focused on increasing the mechanical strength of the mortar, by the replacement of lime with (PTL) cement, or on reducing the moisture tr

  5. Mørtelegenskaber og billedbehandling (Mortar properties and image processing)

    DEFF Research Database (Denmark)

    Nielsen, Anders

    1998-01-01

    The properties of lime mortars can be essentially improved by adding fillers to the mortars in an intelligent way. This is shown in the thesis of Thorborg von Konow (1997).The changes in the pore structure and the following changes in properties can be treated by means of the rules in materials...

  6. Salt resistant mortars: present knowledge and future perspectives

    NARCIS (Netherlands)

    Lubelli, B.A.

    2013-01-01

    Salt crystallization damage is one of the most common causes of decay for bedding, pointing and plastering mortar. Attempts to tackle the problem have been mainly focused on increasing the mechanical strength of the mortar by the replacement of lime with (PTL) cement, or on reducing the moisture tra

  7. Trichloroethylene decomposition and in-situ dry sorption of Cl-products by calcium oxides prepared from hydrated limes.

    Science.gov (United States)

    Gotoh, Yoshimi; Iwata, Goichi; Choh, Kyaw; Kubota, Mitsuhiro; Matsuda, Hitoki

    2011-10-01

    A comparison of CaOs produced by calcining two types of hydrated lime and calcium carbonate was made for decomposition of trichloroethylene and in-situ dry sorption of the decomposed Cl-products using a lab-scale gas flow type tubular packed bed reactor. About 20 mg of CaO sample was mixed with about 2 g of Al2O3 particles and packed in the reactor and allowed to react with a flowing standard gas containing 500 ppm of C2HCl3 (N2 balance) at 673 and 873 K, under the condition that the reaction of CaO with C2HCl3 might be completed within a few hours. It was found that no thermal decomposition of C2HCl3 at or below 673 K was observed in a reactor packed only with Al2O3 particles. However, a considerable amount of decomposition of C2HCl3 was obtained in a reactor packed with CaO and Al2O3, even at 673 K. For 1 mol of CaO prepared by calcining highly reactive Ca(OH)2 at 673 K, decomposition of 0.42 mol of C2HCl3 and in-situ absorption product of 0.53 mol of CaCl2 were obtained. At 873 K, about 46% of C2HCl3 was thermally decomposed. The total amount of C2HCl3 decomposed in CaO-Al2O3 particle bed at 873 K became nearly twice larger than that at 673 K. For 1 mol of CaO prepared by calcining highly reactive Ca(OH)2 at 873 K, decomposition of 0.59 mol of C2HCl3 and in-situ absorption product of 0.67 mol of CaCl2 were obtained. Small amounts of C2Cl2, C2Cl4, CCl4, etc. were detected during decomposition of C2HCl3 at 673 and 873 K. It was recognized that the data on decomposition of C2HCl3 as well as in-situ dry sorption of Cl-products in CaO particle bed were correlated with specific surface area of the CaO employed. PMID:21821273

  8. Effect of Binder’s Type on Physico-Mechanical and Thermal Properties of Mortars with a Basis of Coir

    Directory of Open Access Journals (Sweden)

    Athanas Konin

    2012-05-01

    Full Text Available This study aims to study the effect of type of binder on properties of mortars with coir. Two types of binders were used for the manufacturing of mortars containing coir: lime is used as binder for mortar nº1 (Mortar 1 and cement is used for mortar nº2 (Mortar 2. The measurements of the physical, mechanical and thermal properties of the specimens show that Mortar 1 has higher water absorption values than those of Mortar 2 and consequently has the lowest values of thermal conductivity. The results also indicate that dry density of the specimens has more important role than the type of binder on mechanical properties. Relationships were established between mechanical properties and dry density of these mortars. These relationships are independent to the type of binder. The mortars also satisfied most recommended thermal insulation standards.

  9. MORTAR WITH UNSERVICEABLE TIRE RESIDUES

    Directory of Open Access Journals (Sweden)

    José Aparecido Canova

    2009-12-01

    Full Text Available This study analyzes the effects of unserviceable tire residues on rendering mortar using lime and washed sand at a volumetric proportion of 1:6. The ripened composite was dried in an oven and combined with both cement at a volumetric proportion of 1:1.5:9 and rubber powder in proportional aggregate volumes of 6, 8, 10, and 12%. Water exudation was evaluated in the plastic state. Water absorption by capillarity, fresh shrinkage and mass loss, restrained shrinkage and mass loss, void content, flexural strength, and deformation energy under compression were evaluated in the hardened state. There was an improvement in the water exudation and water absorption by capillarity and drying shrinkage, as well as a reduction of the void content and flexural strength. The product studied significantly aided the water exudation from mortar and, capillary elevation in rendering.

  10. MORTAR WITH UNSERVICEABLE TIRE RESIDUES

    Directory of Open Access Journals (Sweden)

    J. A. Canova

    2009-01-01

    Full Text Available This study analyzes the effects of unserviceable tire residues on rendering mortar using lime and washed sand at a volumetric proportion of 1:6. The ripened composite was dried in an oven and combined with both cement at a volumetric proportion of 1:1.5:9 and rubber powder in proportional aggregate volumes of 6, 8, 10, and 12%. Water exudation was evaluated in the plastic state. Water absorption by capillarity, fresh shrinkage and mass loss, restrained shrinkage and mass loss, void content, flexural strength, and deformation energy under compression were evaluated in the hardened state. There was an improvement in the water exudation and water absorption by capillarity and drying shrinkage, as well as a reduction of the void content and flexural strength. The product studied significantly aided the water exudation from mortar and, capillary elevation in rendering.

  11. 电位滴定法测定石灰中有效氧化钙含量%Potentiotitrimetric Determination of Available Calcium Oxide in Lime

    Institute of Scientific and Technical Information of China (English)

    马兵兵

    2013-01-01

    Content of available calcium oxide in lime was determined by potentiometric titration using HC1 standard solution as titrant. Conditions of titration were optimized and given as follow: ① acidity at endpoint of titration: pH 7. 00; ② maximum rate of titration: 10 mL · min-1 ; ③ minimum rate of titration: 100 μL · min-1; (4) delay time: 5 s. The proposed method was applied to the analysis of lime sample, and the results obtained were checked quite well with those obtained by manual titration. Values of RSD's (n=5) were found in the range of 0. 10%-0. 19%.%采用电位滴定法,用盐酸标准溶液作为滴定剂,测定石灰中有效氧化钙含量.优化的滴定条件为:①滴定终点pH为7.00;②最大馈液速率10 mL·min-1;③最小馈液速率100 μL·min-1;④滞后时间5s;⑤搅拌时间1 min.方法用于石灰样品分析,测定值与手工滴定法测定值相符,相对标准偏差(n=5)在0.10%~0.19%之间.

  12. 石灰-水泥系外墙防水装饰砂浆与外墙外保温系统适应性研究%The adaptive research of lime-cement waterproof decorative mortar for exterior wall and exterior insulation system

    Institute of Scientific and Technical Information of China (English)

    韩方晖; 王栋民; 许晨阳; 刘晓斌; 刘天德

    2012-01-01

    To make lime-cement waterproof decorative mortar for exterior wall which successes through chemical modification technology to be widely applied in exterior insulation system, it must have good adaptability with exterior insulation system. This paper through establishing force diagram of facing external wall thermal insulation and adopting ESP external wall thermal insulation to be used in high-rise building)analyzing and calculating the earthquake effect by level, wind load and both combination effect and vertical stress gravity and bond force: meanwhile,on the basis of the calculation method to calculate the force of the 100 m-high high-rise building top exterior insulation system in the Beijing center: furthermore, calculating the force of facing external wall thermal insulation when the exterior wall facing is ceramic tile, coating and carrying on the comparison. Results indicate: it is safe when the exterior wall facing is lime-cement waterproof decorative mortar for exterior wall in high-rise exterior insulation system; by the size of the load is for ceramic tile > lime-cement waterproof decorative mortar for exterior wall > coating, in comprehensive comparison, lime-cement waterproof decorative mortar for exterior wall has superiority.%要使通过化学改性技术研制成功的石灰-水泥系外墙防水装饰砂浆在外墙外保温系统中得到广泛应用,其必须与外墙外保温系统有很好的适应性.通过建立饰面外墙外保温系统受力图,对采用膨胀聚苯板作为高层建筑外墙外保温时,所受水平地震作用、风荷载和两者组合效应及竖直方向受力重力和压剪粘结力分析计算;同时,依据这些计算方法计算了北京市中心高为100m的高层建筑顶部外墙外保温系统受力情况;计算了外墙饰面为瓷砖、涂料时外墙外保温系统的受力情况,并对其进行比较.结果表明:外墙饰面为石灰-水泥系外墙防水装饰砂浆时应用于高层外

  13. PREPARATION OF MORTARS FOR RESTORATION OF ARCHITECTURAL MONUMENTS

    Directory of Open Access Journals (Sweden)

    TEREZA TRIBULOVÁ

    2012-09-01

    Full Text Available Mortar mixtures were prepared considering the microscopic observation, granulometric analysis, mercury porosimetry, XRD analysis, thermogravimetric and differential thermal analysis of the original plaster. Two series of lime mortar samples containing identical mixture of aggregates and admixtures but varying in the kind of a lime binder were prepared. In addition, the sample series varied in the ratio between mixing aggregate and binder. Prepared test bodies were subjected to accelerated carbonation process. Carbonated samples were characterized by the measurement of compressive strength, open porosity, water absorption and resistance to salt crystallization. The samples were also again compared with the original plaster by optical microscopy and XRD analysis. Based on the results of analyses of the original plasters and prepared samples of repair mortar the sample containing lime slurry with the mixture of aggregates in the mixing ratio of 1 : 2 was recommended for the restoration procedure.

  14. Characterization of historical mortars in Jordan

    Science.gov (United States)

    Gomez-Heras, M.; Arce, I.; Lopez-Arce, P.; Alvarez de Buergo, M.; Fort, R.

    2012-04-01

    This paper presents the petrographic and mineralogical characterization of mortars from different archaeological sites in Jordan which encompass Nabatean, Late-Antique and Early Islamic (Umayyad) sites, in some cases offering a sequence of different period mortars from the same building. These sites include the Nabataean city of Petra, the Late Antique town of Umm al Jimal and the castle of Qasr Al Hallabat. These mortars were produced with different raw materials and manufacturing technologies, which are reflected on distinctive variations of mineralogy, texture and crystal size and aggregates composition (including volcanic ashes, ceramic fragments, burnt organic material) size and their puzzolanic properties. As a consequence these mortars present different physical properties and reveal nowadays very different states of conservation. There is a dramatic change in mortar properties between those manufactured in pre-Islamic period and those from early Islamic - Ummayad times with a general trend in which these last ones present coarser crystal and aggregate sizes with less puzzolanic aggregates that result in less durable mortars. All of this reflects changes in the different stages of production of the mortar, from the use of either hydraulic, lime putty or slaked lime and the selection of aggregates to the application techniques (polishing). This reflects the evolution of building technology that took place in this area during early Islamic period and how petrological information can shed light on historical interpretation of building technologies. Research funded by AECID (PCI A/032184/10), GEOMATERIALES (S2009/MAT-16) and MCU (Analisis y Documentación de tipología arquitectónica y técnicas constructivas en el periodo de transición Bizantino-Omeya en Jordania)

  15. Water extraction out of mortar during brick laying: A NMR study

    NARCIS (Netherlands)

    Brocken, H.J.P.; Spiekman, M.E.; Pel, L.; Kopinga, K.; Larbi, J.A.

    1998-01-01

    The water extraction out of mortar during brick laying was studied using nuclear magnetic resonance. The experiments show that using a fired-clay brick, the water is extracted out of the mortar within 3 minutes, whereas in the case of a sand-lime brick this takes about 10 minutes. Prewetting a fired

  16. Ancient gypsum mortars from Cyprus: characterization and reinvention

    Science.gov (United States)

    Theodoridou, M.; Ioannou, I.

    2012-04-01

    Mortars with various binding materials have been used across different pre-historic and historic periods to meet several construction applications, such as jointing masonry blocks, finishing walls and isolating water bearing structures. In the framework of an ongoing research programme (NEA ΥΠOΔOMH/NEKΥΠ/0308/17) funded by the Cyprus Research Promotion Foundation, the Republic of Cyprus and the European Union Regional Development Fund, 25 samples of gypsum mortars from different archaeological sites in Cyprus were collected and characterized following a systematic analytical approach. Petrographic observations of thin sections were carried out using polarizing optical microscope. Scanning electron microscopy equipped with energy dispersive X-ray microanalyser (SEM-EDX) was used to examine the microstructure and texture of the mortar samples and to determine semi-quantitatively the chemical composition and interface of their binders. X-ray diffraction (XRD) was performed to identify the main mineral crystalline phases of the specimens' binder and aggregates. Thermal analyses (TG/DTA) were used as a further confirmation of the material composition. The pore structure and volume of the ancient mortars were also determined by mercury intrusion porosimetry (MIP) analysis. Last but not least, a portable drilling resistance measurement system (DRMS) was used for micro-destructive assessment of the mechanical state of the samples. The results confirmed the predominant presence of hydrous calcium sulphate in all samples. Calcite was also found both in the binder and aggregates. Small proportions of SiO2 were also detected. The common ratio of binder to aggregates was 1:2.5. MIP showed porosity values between 14-48% and real densities between 1-1.7 g/cm3. The average pore diameters were smaller in the case of mortars with lower porosity. The use of DRMS indicated lower resistance to drilling for the case of joint mortars (as opposed to analysed gypsum plasters). This

  17. Properties of Calcium Acetate Manufactured with Etching Waste Solution and Limestone Sludge as a Cementitious High-Early-Strength Admixture

    Directory of Open Access Journals (Sweden)

    Deuck-Mo Kim

    2016-01-01

    Full Text Available Concrete is one of the most widely used construction materials. There are several methods available to improve its performance, with one of them being the use of high-early-strength admixtures (HESAs. Typical HESAs include calcium nitrate, calcium chloride, and calcium formate (CF. Industrial by-products, such as acetic acid and lime stone sludge (LSS, can be used together to produce calcium acetate (CA, which can subsequently be used as a cementitious HESA. In this study, calcium carbonate and LSS were mixed with cement in weight ratios of 1 : 1, 1 : 1.5, and 1 : 2, and the properties of the as-produced CA were evaluated. CA and CF were mixed with cement in different weight ratios (0, 1, 2, and 3 wt% to obtain CA- and CF-mortars, respectively. The flow behavior, setting time, pH, and compressive strength of these mortars were evaluated, and their X-ray diffraction patterns were also analyzed. It was found that as the CF content in the CF-mortar increased, the initial strength of the mortar also increased. However, it impaired its long-term strength. On the other hand, when 1% CA was mixed with cement, satisfactory early and long-term strengths were achieved. Thus, CA, which is obtained from industrial by-products, can be an effective HESA.

  18. Comparative investigation of mortars from Roman Colosseum and cistern

    Energy Technology Data Exchange (ETDEWEB)

    Silva, D.A. [Department of Civil and Environmental Engineering, 725 Davis Hall 94720-1710, University of California at Berkeley, Berkeley, CA (United States)]. E-mail: denise@ecv.ufsc.br; Wenk, H.R. [Department of Earth and Planetary Science, 497 McCone 94720-4767, University of California at Berkeley, Berkeley, CA (United States); Monteiro, P.J.M. [Department of Civil and Environmental Engineering, 725 Davis Hall 94720-1710, University of California at Berkeley, Berkeley, CA (United States)

    2005-11-01

    Mortar from the Roman Colosseum and a Roman cistern from Albano Laziale were characterized with optical microscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), and thermal analysis (differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA)). The different techniques provided consistent results that the mortar of the Colosseum is mainly calcareous lime, while the mortar of the cistern is pozzolanic siliceous material. The study highlights the capabilities of the different methods for the analysis of cement. For routine analysis XRD is adequate but for characterization of poorly crystalline phases FT-IR and TGA have definite advantages.

  19. Effect of gypsum content on sulfoaluminate mortars stability

    OpenAIRE

    DESBOIS, Tiffany; Le Roy, Robert; PAVOINE, Alexandre; PLATRET, Gérard; FERAILLE-FRESNET, Adélaïde; ALAOUI, Amina

    2010-01-01

    Calcium sulfoaluminate clinker is one of the most promising cements that would lower the greenhouse gas effect accompanying cement production. This article examines the effect of gypsum content on the dimensional stability of sulfoaluminate mortars. Mechanical properties as chemical evolution are studied. Our results show that the mortar with the greatest gypsum content expands without a decrease of its mechanical properties when it is cured in water. Two hypotheses about the mortars hydratio...

  20. 玻化微珠保温砂浆的碳化试验研究%Research on Carbonization Test of Vitrified Microsphere Thermal Insulation Mortar

    Institute of Scientific and Technical Information of China (English)

    薛若璞; 余以明; 袁新顺; 徐建雄

    2016-01-01

    By accelerated carbonation test,mixing 18%~20% of lime to the special effects and functions of vitrified microsphere thermal insulation mortar were analyzed.The use of calcium hydroxide producing calcium carbonate crys-tals to increase the density and intensity of vitrified microsphere thermal insulation mortar,the concentration of carbon dioxide must be controlled.Low carbon dioxide concentration was conductive to the growth of calcium carbonate crystal which could be packed by cement hydration product to densify the structure of vitrified microsphere thermal mortar,ul-timately the favorable carbon dioxide concentrations were determined to be 2%.%通过加速碳化试验,分析掺入18%~20%的石灰对玻化微珠保温砂浆的特殊影响与作用。要利用氢氧化钙的碳化生成碳酸钙晶体来提高玻化微珠保温砂浆的致密度和强度,必须控制二氧化碳的浓度,低二氧化碳浓度有利于生长的碳酸钙晶体被水泥水化产物包裹从而促使玻化微珠保温砂浆结构致密化,最终确定有利的二氧化碳浓度为2%。

  1. A new surface-modified technology of cement mortar using calcium carbonate biodeposition%一种基于微生物沉积的水泥砂浆表面改性技术

    Institute of Scientific and Technical Information of China (English)

    朱飞龙; 李庚英; 杜虹; 崔鹏飞; 吴亚庆; 刘海峰

    2013-01-01

    The paper presents a new surface modification of cement mortar using biodeposition involving a method employing sporosarcina pasteurii (bacillus pasteurii) bacteria and using cement mortar power as covering layer. It was possible to obtain reduction in water absorption of cement mortars. The effect was more visible in case of using nutrient medium containing urea, and the coefficient of capillary suction of the treated cement mortar was reduced by 58%. Presence of spherical and columnar vaterite and calcite calcium carbonate crystals filling-voids in cement mortar was confirmed by observations under SEM and XRD. The total porosity reduced by 40% was demonstrated by using mercury intrusion porosimetry (MIP).%某些微生物能诱导沉积出具有胶凝和矿化作用的碳酸钙,可以用来修复和密实水泥基材料.但是目前微生物沉积技术工艺复杂,成本高,不利于推广和工程应用.尝试采用水泥砂浆粉作为覆膜载体,利用巴斯德芽孢杆菌对水泥砂浆进行表面处理.研究结果表明,采用该方法能使巴斯德芽孢杆菌在水泥试块表面诱导沉积出碳酸钙,有效减少水泥砂浆的吸水性能.当微生物采用含有尿素的培养基培养时,表面改性后的水泥砂浆吸水系数降低了58%.采用压汞测试仪(MIP)分析了处理前后水泥试块表层的孔隙率以及孔结构特征.发现采用巴斯德芽孢杆菌处理后,样品孔隙率显著降低,大孔的含量显著减少,当微生物采用含有尿素的培养基培养时,总孔隙率降低了40%.X射线衍射仪(XRD)和场发射扫描电镜(SEM)分析表明,经微生物技术处理后水泥试块内部的孔洞和裂缝被球霰石和方解石填充.

  2. AMS radiocarbon dating of mortar: The case study of the medieval UNESCO site of Modena

    Science.gov (United States)

    Carmine, Lubritto; Caroselli, Marta; Lugli, Stefano; Marzaioli, Fabio; Nonni, Sara; Marchetti Dori, S.; Terrasi, Filippo

    2015-10-01

    The carbon dioxide contributing to binder formation during the set of a lime mortar reflects the atmospheric 14C content at the time of construction of a building. For this reason, the 14C dating of mortars is used with increasing frequencies in archaeological and architectural research. Mortars, however, may also contain carbonaceous contaminants potentially affecting radiocarbon dating. The Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE) of the Second University of Naples (SUN) has recently obtained some promising results in mortar radiocarbon dating thanks to the development of a procedure (i.e. CryoSoniC/Cryo2SoniC) aiming to eliminate exogenous C contamination that may occur in a mortar. The construction history of the UNESCO World Heritage Site of Modena (Italy) is still controversial and represents a challenging case study for the application of absolute dating methodologies for different reasons. From the point of view of 14C dating, for example, given the high percentage of carbonate aggregates composing these samples, Modena mortars represent an experimental test particularly indicative of exogenous carbon sources suppression ensuring methodology accuracy. In this paper several AMS Radiocarbon dates were carried out on lime lumps with the aim to: (i) verify procedure accuracy by a comparison of the results obtainable from lime lumps dated after different treatments (i.e. bulk lime lumps vs. CryoSoniC purified lime lumps); (ii) compare different building phases absolute chronology for the medieval UNESCO site of Modena, with that assumed by historical sources in order to assess preliminary the 14C dating feasibility for of the site. Historical temporal constraints and mortar clustering, based on petrography, have been applied to define a temporal framework of the analyzed structure. Moreover, a detailed petrographic characterization of mortars was used both as a preliminary tool for the choice of samples and to infer about the

  3. Alcohol dispersions of calcium hydroxide nanoparticles for stone conservation.

    Science.gov (United States)

    Rodriguez-Navarro, Carlos; Suzuki, Amelia; Ruiz-Agudo, Encarnacion

    2013-09-10

    Alcohol dispersions of Ca(OH)2 nanoparticles, the so-called nanolimes, are emerging as an effective conservation material for the consolidation of stone, mortars, and plasters present in old masonry and/or mural paintings. To better understand how this treatment operates, to optimize its performance and broaden its applications, here we study the nano and microstructural characteristics, carbonation behavior, and consolidation efficacy of colloidal alcohol dispersions of Ca(OH)2 nanoparticles produced by both homogeneous (commercial nanolime) and heterogeneous phase synthesis (aged slaked lime and carbide lime putties). We observe that the alcohol not only provides a high colloidal stability to Ca(OH)2 particles, but also affects the kinetics of carbonation and CaCO3 polymorph selection. This is due to the pseudomorphic replacement of Ca(OH)2 particles by calcium alkoxides upon reaction with ethanol or 2-propanol. The extent of this replacement reaction depends on Ca(OH)2 size and time. Hydrolysis of alkoxides speeds up the carbonation process and increases the CaCO3 yield. The higher degree of transformation into calcium alkoxide of both the commercial nanolime and the carbide lime fosters metastable vaterite formation, while calcite precipitation is promoted upon carbonation of the aged slaked lime due its lower reactivity, which limits calcium alkoxide formation. A higher consolidation efficacy in terms of strength gain of treated porous stone is achieved in the latter case, despite the fact that the carbonation is much faster and reaches a higher yield in the former ones. Formation of alkoxides, which has been neglected in previous studies, needs to be considered when applying nanolime treatments. These results show that the use Ca(OH)2 nanoparticle dispersions prepared with either aged slaked lime or carbide lime putties is an economical and effective conservation alternative to commercial nanolimes produced by homogeneous phase synthesis. Ultimately, this

  4. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    OpenAIRE

    Gai-Fei Peng; Nai-Qian Feng; Qi-Ming Song

    2014-01-01

    The influence of a chloride-ion adsorption agent (Cl agent in short), composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage...

  5. Uso do residuo de beneficiamento de rochas ornamentais na producao de argamassa de multiplo uso; Use of the ornamental rock waste in mortar multiple-use

    Energy Technology Data Exchange (ETDEWEB)

    Faial, Alline Silveira Ribeiro; Xavier, Gustavo de Castro; Alexandre, Jonas; Maia, Paulo Cesar de Almeida; Albuquerque Junior, Fernando Saboya, E-mail: gxavier@uenf.br [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF/LECIV), Campos dos Goytacazes, RJ (Brazil). Lab. de Engenharia Civil

    2012-07-01

    The municipal district of Itapemirim-ES is the largest producer of ornamental stones in Brazil. The processing of these rocks for the manufacture of floor and produces a large amount of waste approximately 15,000 tons/month, which still are responsible for damage to the environment. Aiming at the use of this waste, this paper studies experimentally the production of mortars of multiple use, making the replacement of the use of hydrated lime, widely used in the manufacture of mortars in construction, by the waste of the processing of a marble industry Itapemirim -ES. The mortar waste was characterized and evaluated by comparing performance with mortar with the addition of hydrated lime. We used a slurry with lime as a reference, ie the mixture was made of 1:1:8 (cement: waste / lime sand), where the workability and the properties of the hardened condition were evaluated and compared with the mortars made with the waste of marble. The compressive strength results showed that the waste with lime mortars were 1.6 ± 0.5 MPa and 1.4 MPa respectively ± 0.6 after 28 days of curing, two were classified as P1 (ABNT 13279, 2005), can replace the waste lime, thereby reducing the cost of manufacture of the mortar. (author)

  6. Divisions S-4 - soil fertility and plant nutrition: residual value of lime and leaching of calcium in a kaolinitic ultisol in the high rainfall tropics

    Energy Technology Data Exchange (ETDEWEB)

    Friesen, D.K.; Juo, A.S.R.; Miller, M.H.

    1982-01-01

    A long-term experiment was conducted on a highly acidic (pH 4.6), coarse-textured Ultisol in the high rainfall region of southeastern Nigeria in order to evaluate the requirement for and residual value of lime (Ca(OH)/sub 2/) to a continuous crop rotation, and to determine the fate of applied Ca in the soil profile. The initial lime rates used were 0, 0.5, 1, 2, and 4 t of Ca(OH)/sub 2/ per hectare. Maize (Zea mays) was planted in the first season and cowpea (Vigna unguiculata) in the second season under a no-tillage, stubble conservation system. Relatively low rates of lime are adequate to sustain yields in a continuous maize-cowpea rotation system. Liming at a rate of 0.5 t/ha maintained maize yield near maximum for 2 years after application. Sustained maize yields for 5 years or more were possible with a lime rate of 2 t/ha. Cowpeas performed well and showed strong tolerance to soil acidity when planted as a late second-season crop after maize without additional fertilizer application. The critical level of exchangeable Al ranged from 25 to 55% depending upon rate of chemical fertilizer as well as cowpea variety used. Leaching losses of Ca from the surface soil during the first 3 years were <0.5 t/ha of Ca(OH)/sub 2/-equivalents in the 0- to 2-t/ha treatments. Exchangeable-Al saturation in all subsoil layers of all treatments 3 years after liming exceeded 40% and soil pH (H/sub 2/O) was <4.3 indicating that lime was leached as neutral Ca salts and had little effect in ameliorating subsoil acidity. 17 references, 5 figures, 5 tables.

  7. Influences of Carboxyl Methyl Cellulose on Performances of Mortar

    Institute of Scientific and Technical Information of China (English)

    WANG Yuli; ZHOU Mingkai; SHAN Junhong; XU Fang; YANG Yuhui

    2007-01-01

    Carboxyl methyl cellulose (CMC) was mixed into mortar to improve the waterretention performance of mortar, the quality of floated coat of aerated concrete became better. The consistency and compression strength of mortar with CMC were studied. The water absorption was studied with the method of filter paper. The micro mechanism was researched with X-ray diffraction and scanning electron microscopy(SEM). The experimental results show the water-holding performance of mortar with CMC is largely improved and it is better when the mixed amount is about 1.5%; the compression strength had a descending trend with the increase of CMC; CMC reacted with calcium hydroxide(CH) into the deposition of calcium carboxyl methyl cellulose.

  8. Studies on termite hill and lime as partial replacement for cement in plastering

    Energy Technology Data Exchange (ETDEWEB)

    Olusola, K.O.; Olanipekun, E.A.; Ata, O.; Olateju, O.T. [Obafemi Awolowo University, Ile-Ife, Osun State (Nigeria). Department of Building

    2006-03-15

    This study investigated the compressive strength and water absorption capacity of 50x50x50mm mortar cubes made from mixes containing lime, termite hill and cement and sand. Two mix ratios (1:4 and 1:6) and varying binder replacements of cement with lime or termite hill amounting to 0%, 10%, 20%, 30%, 40% and 50% were used. Test results showed that the compressive strength of the mortar cubes increases with age and decreases with increasing percentage replacement of cement with lime and termite hill. However, for mix ratio 1:6, up to 20% replacement of cement with either lime or termite hill, all the mortar cubes had the same strength; subsequently, the termite hill exhibited a higher compressive strength. For mix ratio 1:4, mortar cubes made from lime/cement and termite hill/cement mixtures had the same strength at 50% replacement. Generally, water absorption is higher in mixtures containing lime (18.10% and 14.20% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level) than those containing termite hill (16.10% and 13.02% for mix ratios 1:6 and 1:4, respectively, both at 50% replacement level). Termite hills seem to be promising as a suitable, locally available housing material for plastering. (author)

  9. Influence of Chloride-Ion Adsorption Agent on Chloride Ions in Concrete and Mortar

    Directory of Open Access Journals (Sweden)

    Gai-Fei Peng

    2014-04-01

    Full Text Available The influence of a chloride-ion adsorption agent (Cl agent in short, composed of zeolite, calcium aluminate hydrate and calcium nitrite, on the ingress of chloride ions into concrete and mortar has been experimentally studied. The permeability of concrete was measured, and the chloride ion content in mortar was tested. The experimental results reveal that the Cl agent could adsorb chloride ions effectively, which had penetrated into concrete and mortar. When the Cl agent was used at a dosage of 6% by mass of cementitious materials in mortar, the resistance to the penetration of chloride ions could be improved greatly, which was more pronounced when a combination of the Cl agent and fly ash or slag was employed. Such an effect is not the result of the low permeability of the mortar, but might be a result of the interaction between the Cl agent and the chloride ions penetrated into the mortar. There are two possible mechanisms for the interaction between the Cl agent and chloride ion ingress. One is the reaction between calcium aluminate hydrate in the Cl agent and chloride ions to form Friedel’s salt, and the other one is that calcium aluminate hydrate reacts with calcium nitrite to form AFm during the early-age hydration of mortar and later the NO2− in AFm is replaced by chloride ions, which then penetrate into the mortar, also forming Friedel’s salt. More research is needed to confirm the mechanisms.

  10. Lime pretreatment of lignocellulosic biomass

    Science.gov (United States)

    Chang, Shushien

    Lignocellulose is a valuable alternative energy source. The susceptibility of lignocellulosic biomass to enzymatic hydrolysis is constrained due to its structural features, so pretreatment is essential to enhance enzymatic digestibility. Of the chemicals used as pretreatment agents, it has been reported that alkalis improve biomass digestibility significantly. In comparison with other alkalis such as NaOH and ammonia, lime (calcium hydroxide) has many advantages; it is very inexpensive, is safe, and can be recovered by carbonating wash water. The effects of lime pretreatment were explored on switchgrass and poplar wood, representing herbaceous and woody biomass, respectively. The effects of pretreatment conditions (time, temperature, lime loading, water loading, particle size, and oxygen pressure) have been systematically studies. Lime alone enhances the digestibility of switchgrass significantly; under the recommended conditions, the 3-d total sugar (glucose + xylose) yields of lime-treated switchgrass were 7 times that of untreated sample. When treating poplar wood, lime must be combined with oxygen to achieve high digestibility; oxidative lime pretreatment increased the 3-d total sugar yield of poplar wood to 12 times that of untreated sample. In a fundamental study, to determine why lime pretreatment is effective, the effects of three structural features on enzymatic digestibility were studied: lignin content, acetyl content, and crystallinity index (CrI). Poplar wood was treated with peracetic acid, potassium hydroxide, and ball milling to produce model lignocelluloses with a broad spectrum of lignin contents, acetyl contents, and CrI, respectively. Enzymatic hydrolysis was performed on the model lignocelluloses to determine the digestibility. Correlations between lignin/carbohydrate ratio, acetyl/carbohydrate ratio, CrI and digestibility were developed. The 95% prediction intervals show that the correlations predict the 1-h and 3-d total sugar conversions of

  11. Tracing formation and durability of calcite in a Punic-Roman cistern mortar (Pantelleria Island, Italy).

    Science.gov (United States)

    Dietzel, Martin; Schön, Frerich; Heinrichs, Jens; Deditius, Artur P; Leis, Albrecht

    2016-01-01

    Ancient hydraulic lime mortar preserves chemical and isotopic signatures that provide important information about historical processing and its durability. The distribution and isotopic composition of calcite in a mortar of a well-preserved Punic-Roman cistern at Pantelleria Island (Italy) was used to trace the formation conditions, durability, and individual processing periods of the cistern mortar. The analyses of stable carbon and oxygen isotopes of calcite revealed four individual horizons, D, E, B-1 and B-2, of mortar from the top to the bottom of the cistern floor. Volcanic and ceramic aggregates were used for the production of the mortar of horizons E/D and B-1/B-2, respectively. All horizons comprise hydraulic lime mortar characterized by a mean cementation index of 1.5 ± 1, and a constant binder to aggregate ratio of 0.31 ± 0.01. This suggests standardized and highly effective processing of the cistern. The high durability of calcite formed during carbonation of slaked lime within the matrix of the ancient mortar, and thus the excellent resistance of the hydraulic lime mortar against water, was documented by (i) a distinct positive correlation of δ(18)Ocalcite and δ(13)Ccalcite; typical for carbonation through a mortar horizon, (ii) a characteristic evolution of δ(18)Ocalcite and δ(13)Ccalcite through each of the four mortar horizons; lighter follow heavier isotopic values from upper to lower part of the cistern floor, and (iii) δ(18)Ocalcite varying from -10 to -5 ‰ Vienna Pee Dee belemnite (VPDB). The range of δ(18)Ocalcite values rule out recrystallization and/or neoformation of calcite through chemical attack of water stored in cistern. The combined studies of the chemical composition of the binder and the isotopic composition of the calcite in an ancient mortar provide powerful tools for elucidating the ancient techniques and processing periods. This approach helps to evaluate the durability of primary calcite and demonstrates the

  12. Chemical Characterization of Lime-Based Binders in Historic Buildings of Latvia

    Science.gov (United States)

    Kirilovica, I.; Gulbe, L.; Vitina, I.; Igaune-Blumberga, S.

    2015-11-01

    The aim of this research is to investigate the chemical composition of stone materials of several local historic buildings with a purpose of elaboration of restoration strategy, including the choice of restoration materials. Most of the examined mortars are lime- based hydraulic mortars, characteristic of the architecture of 19th/20th century. Pure aerial lime binders show reduced compatibility with historic materials, that is why lime binders with pozzolan additive (cement) are an appropriate choice for restoration. In order to examine the changes of hydraulicity (i.e. the property of binders to harden when exposed to water) of perspective restoration binders, a series of blended lime-cement mixtures were synthesized with growing content of cement (up to 10% by weight). A significant relationship between cement content and hydraulic properties has been shown.

  13. Mortar radiocarbon dating: preliminary accuracy evaluation of a novel methodology.

    Science.gov (United States)

    Marzaioli, Fabio; Lubritto, Carmine; Nonni, Sara; Passariello, Isabella; Capano, Manuela; Terrasi, Filippo

    2011-03-15

    Mortars represent a class of building and art materials that are widespread at archeological sites from the Neolithic period on. After about 50 years of experimentation, the possibility to evaluate their absolute chronology by means of radiocarbon ((14)C) remains still uncertain. With the use of a simplified mortar production process in the laboratory environment, this study shows the overall feasibility of a novel physical pretreatment for the isolation of the atmospheric (14)CO(2) (i.e., binder) signal absorbed by the mortars during their setting. This methodology is based on the assumption that an ultrasonic attack in liquid phase isolates a suspension of binder carbonates from bulk mortars. Isotopic ((13)C and (14)C), % C, X-ray diffractometry (XRD), and scanning electron microscopy (SEM) analyses were performed to characterize the proposed methodology. The applied protocol allows suppression of the fossil carbon (C) contamination originating from the incomplete burning of the limestone during the quick lime production, providing unbiased dating for "laboratory" mortars produced operating at historically adopted burning temperatures.

  14. Tangential adhesion strength of cement mortars in masonry

    Directory of Open Access Journals (Sweden)

    Derkach V.N.

    2012-05-01

    Full Text Available The initial shear strength (tangential adhesion and the angle of internal friction in the horizontal plane of mortar joints are among important characteristics, determining the masonry strength and stiffness qualities in case of share. These characteristics influence largely over the limit state approach of buildings and facilities during seismic activity and over wind, crane and other load, causing the panel frame distortion in frame buildings with masonry infill.In the paper the experimental studies results of tangential adhesion strength of cement mortars with solid and hollow ceramic bricks, porous stones, calcium silicate bricks and cellular concrete blocks are presented. This research gives experimental dependences of mortar adhesive strength with mentioned types of masonry units on compressive strength of cement mortar. There is also the comparison of the obtained results with Russian and foreign standards in this paper.

  15. Mineralogical and microstructural studies of mortars from the bath complex of the Roman villa rustica near Mosnje (Slovenia)

    Energy Technology Data Exchange (ETDEWEB)

    Kramar, Sabina, E-mail: sabina.kramar@rescen.si [Institute for the Protection of the Cultural Heritage of Slovenia, Conservation Centre, Restoration Centre, Poljanska 40, 1000 Ljubljana (Slovenia); Zalar, Vesna [University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Geology, Ljubljana (Slovenia); Urosevic, Maja [University of Granada, Faculty of Science, Department of Mineralogy and Petrology, Avda. Fuentenueva s/n, 18071 Granada (Spain); Koerner, Wilfried [University of Vienna, Department of Environmental Geosciences, Althanstrasse 14, 1090 Vienna (Austria); Mauko, Alenka [Slovenian National Building and Civil Engineering Institute, Dimiceva 12, 1000 Ljubljana (Slovenia); Mirtic, Breda [University of Ljubljana, Faculty of Natural Sciences and Engineering, Department of Geology, Ljubljana (Slovenia); Lux, Judita [Institute for the Protection of the Cultural Heritage of Slovenia, Conservation Centre, Preventive Archaeology Department, Tomsiceva 7, 4000 Kranj (Slovenia); Mladenovic, Ana [Slovenian National Building and Civil Engineering Institute, Dimiceva 12, 1000 Ljubljana (Slovenia)

    2011-11-15

    This study deals with the characterization of mortars collected from bath complex of the Roman villa rustica from an archeological site near Mosnje (Slovenia). The mortar layers of the mosaics, wall paintings and mortar floors were investigated. A special aggregate consisting of brick fragments was present in the mortars studied. The mineralogical and petrographic compositions of the mortars were determined by means of optical microscopy, X-ray powder diffraction and FTIR spectroscopy. Analysis of aggregate-binder interfaces using SEM-EDS revealed various types of reactivity rims. In order to assess the hydraulic characteristics of the mortars, the acid-soluble fractions were determined by ICP-OES. Furthermore, the results of Hg-porosimetry and gas sorption isotherms showed that mortars with a higher content of brick fragments particles exhibited a higher porosity and a greater BET surface area but a lower average pore diameter compared to mortars lacking this special aggregate. - Highlights: {yields} Mineral and microstructural characterizations of brick-lime mortars. {yields} Hydraulic character of mortars in Roman baths complex. {yields} Reaction rims were observed around brick fragments and dolomitic grains. {yields} Higher content of brick particles yielded a higher BET surface area. {yields} Addition of brick particles increased porosity and diminished pore size diameter.

  16. 21 CFR 184.1210 - Calcium oxide.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium oxide. 184.1210 Section 184.1210 Food and... Substances Affirmed as GRAS § 184.1210 Calcium oxide. (a) Calcium oxide (CaO, CAS Reg. No. 1305-78-8) is also known as lime, quick lime, burnt lime, or calx. It is produced from calcium carbonate, limestone,...

  17. Strength, porosity, and chloride resistance of mortar using the combination of two kinds of pozzolanic materials

    Science.gov (United States)

    Rukzon, Sumrerng; Chindaprasirt, Prinya

    2013-08-01

    This article presents a study on the resistance to chloride penetration, corrosion, porosity, and strength of mortar containing fine fly ash (FA), ground rice husk-bark ash (RB), and ground bagasse ash (BA). Ordinary Portland cement (CT) was blended with a single pozzolan and two pozzolans. Strength, porosity, rapid chloride penetration, immersion, and corrosion tests were performed to characterize the mortar. Test results showed that the use of ternary blends of CT, FA, and RB or BA decreased the porosity of the mortar, as compared with binary blended mortar containing CT and RB or BA. The resistance to chloride penetration of the mortar improved substantially with partial replacement of CT with FA, RB, and BA. The use of ternary blends of CT, FA and RB or BA produced the mortar with good strength and resistance to chloride penetration. The resistance to chloride penetration was higher with an increase in the replacement level due to the reduced calcium hydroxide.

  18. Rendering mortars in Medina Azahara, Part I: Material characterization and alteration process

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    1997-03-01

    Full Text Available Rendering mortars, which are still exposed to the open air on some of the walls of Medina Azahara, are studied and characterized in this work. Some repairing mortars used in different previous restorations are also characterized. Those rendering mortars are of different make considering the composition of their binder: lime, gypsum and mixed lime/ gypsum. Repairing mortars used in previous interventions are made of lime, excepting for a portland cement used by Félix Hernández in the restoration of one of the rooms back in the 50's. Biological colonization is the main cause of decay in lime mortars, while in mortars made of gypsum, decay is a result of the solubilizating action of rain water.

    En este trabajo se analizan y caracterizan los revocos que, todavía hoy, permanecen sobre algunos paramentos de los muros de la ciudad de Medina Azahara, expuestos a la intemperie. También se caracterizan algunos de los molleros de reparación aplicados en las distintas restauraciones de los revocos. Los revocos están formados por tres clase de morteros, atendiendo a la composición de su ligante: de cal, de yeso y bastardos de cal y yeso. Los morteros de reparación que se han utilizado son de cal, a excepción del utilizado en la restauración de Félix Hernández (década de 1950, en una de las salas, que es de cemento portland. La colonización biológica es la principal causa de deterioro de los morteros de cal, en tanto que la solubilización por las aguas de lluvia lo es en los morteros que contienen yeso.

  19. 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. PMID:25176490

  20. The physical, chemical, and microscopic properties of masonry mortars from Alhambra Palace (Spain in reference to their earthquake resistance

    Directory of Open Access Journals (Sweden)

    Hanifi Binici

    2016-03-01

    Full Text Available Al-Andalus mortar is an ancient binding material (lime mortar that was used for centuries in numerous historical buildings in Al-Andalus, Granada (Spain. The physico-chemical and microscopic properties of Al-Andalus mortars in Granada were studied as part of an investigation into the mineral raw materials present in the territory of Spain. Scanning electron microscope and X-ray diffraction analyses of eight main types of mortars were performed to show the presence of calcite, gypsum, quartz, and muscovite minerals with organic fibers. Chemical analyses of the specimens showed that high SiO2+Al2O3+Fe2O3 contents yielded high values of hydraulicity and cementation indices. A significant result of this study was that mortars with high hydraulicity and cementation indices have high mechanical strengths. This characteristic may be the main reason for the earthquake resistance of the historical Alhambra Palace.

  1. Thermal and microchemical investigation of Phoenician-Punic mortars used for lining cisterns at Tharros (western Sardinia, Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Ingo, G.M.; Fragala, I.; Bultrini, G.; De Caro, T.; Riccucci, C.; Chiozzini, G

    2004-08-15

    The microchemical and minero-petrographic characterisation of mortars used at Tharros (western Sardinia, Italy) for lining the walls of Phoenician-Punic cisterns has been carried out by means of the combined use of differential thermal analysis-thermogravimetry (DTA-TG), X-ray diffraction (XRD), scanning electron microscopy+energy dispersive spectrometry (SEM+EDS) and optical microscopy (OM). The microchemical and minero-petrographic results combined with the thermal information are used for identifying the nature of the mortars and for clarifying some technological aspects of the manufacturing technique. The results disclose the complex structure of the mortars and evidence weight changes due to dehydration, dehydroxylation and carbonates decomposition that allow to group the major part of the mortars in the well-distinct area of the hydraulic lime mortars with only a small group of mortars, used for bonding the stones of the cistern walls and also in few cases as first layer, to be grouped as lime mortars without hydraulic properties.

  2. 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.

  3. 2nd Historic Mortars Conference

    CERN Document Server

    Hughes, John; Groot, Caspar; Historic Mortars : Characterisation, Assessment and Repair

    2012-01-01

    This volume focuses on research and practical issues connected with mortars on historic structures. The book is divided into four sections: Characterisation of Historic Mortars, Repair Mortars and Design Issues, Experimental Research into Properties of Repair Mortars, and Assessment and Testing. The papers present the latest work of researchers in their field. The individual contributions were selected from the contributions to the 2nd Historic Mortars Conference, which took place in Prague, September, 22-24, 2010. All papers were reviewed and improved as necessary before publication. This peer review process by the editors resulted in the 34 individual contributions included in here. One extra paper reviewing and summarising State-of-the-Art knowledge covered by this publication was added as a starting and navigational point for the reader. The editors believe that having these papers in print is important and they hope that it will stimulate further research into historic mortars and related subjects. 

  4. Thermal conductivity of foam mortar; Waermeleitfaehigkeit von Porenbeton

    Energy Technology Data Exchange (ETDEWEB)

    Lippe, K.F.; Schwab, H. [Ytong AG, Entwicklungszentrum Schrobenhausen (Germany)

    1999-07-01

    Foam mortar in its present-day form was developed during the 20s in Sweden. It consists of porosified calcium silicate hydrates. Porosification is achieved by adding aluminium powder. Optimization of the micro and macro structure of foam mortar resulted in a construction material of low apparent density, high consistency and dimension stability as well as low thermal conductivity. Foam mortar has the lowest thermal conductivity of all massive wall construction materials. (orig.) [German] Porenbeton in der heutigen Form wurde in den 20iger Jahren in Schweden entwickelt. Er besteht aus porosierten Calciumsilicathydraten. Die Porosierung erfolgt durch Zusatz von Aluminiumpulver. Durch die Optimierung der Mikro- und Makrostruktur des Porenbetons, ist ein Baustoff mit niedriger Rohdichte, hoher Festigkeit und Dimensionsstabilitaet sowie niedriger Waermeleitfaehigkeit entstanden. Porenbeton ist der wandbildende Massivbaustoff mit der niedrigsten Waermeleitfaehigkeit. (orig.)

  5. NMR relaxometry study of plaster mortar with polymer additives

    Energy Technology Data Exchange (ETDEWEB)

    Jumate, E.; Manea, D. [Technical University of Cluj-Napoca, Faculty of Civil Engineering. 15 C Daicoviciu Str., 400020, Cluj-Napoca (Romania); Moldovan, D.; Fechete, R. [Technical University of Cluj-Napoca, Department of Physics and Chemistry, 25 G. Baritiu Str., 400027, Cluj-Napoca (Romania)

    2013-11-13

    The cement mixed with water forms a plastic paste or slurry which stiffness in time and finally hardens into a resistant stone. The addition of sand aggregates, polymers (Walocel) and/or calcium carbonate will modify dramatically the final mortar mechanic and thermal properties. The hydration processes can be observed using the 1D NMR measurements of transverse T{sub 2} relaxation times distributions analysed by a Laplace inversion algorithm. These distributions were obtained for mortar pasta measured at 2 hours after preparation then at 3, 7 and 28 days after preparation. Multiple components are identified in the T{sub 2} distributions. These can be associated with the proton bounded chemical or physical to the mortar minerals characterized by a short T{sub 2} relaxation time and to water protons in pores with three different pore sizes as observed from SEM images. The evaporation process is faster in the first hours after preparation, while the mortar hydration (bonding of water molecules to mortar minerals) can be still observed after days or months from preparation. Finally, the mechanic resistance was correlated with the transverse T{sub 2} relaxation rates corresponding to the bound water.

  6. FORMULATION OF EXPANSIVE MORTAR TO TILL THE STONES USING NON-METALLIC MINERALS OF NORTHEAST OF COUNTRY

    Directory of Open Access Journals (Sweden)

    Danielly Vieira de Lucena

    2015-03-01

    Full Text Available One of the most significant methods of advanced technology for mining, the rock massif is employing expansive mortar for cutting of Rock. Furthermore, the entire expansive mortar commercialized in the Brazilian domestic market are imported, as well as those in industrialized country. Both have components from the external market. The aim of this work is to develop expansive mortar with raw materials that have regional and pressure sufficient to remove the rocks of granite and marble type expansion. For this, expansive grout formulations using calcium oxide, calcium carbonate, carboxymethylcellulose are used - CMC (Portland cement, and from the chemical analysis by means of thermal analysis, X-ray diffraction and laser granulometry compared the results with a commercial mortar. The results indicated that the formulations showed characteristics similar to the commercial mortar.

  7. Mineralogical and textural characterization of mortars and plasters from the archaeological site of Barsinia, northern Jordan

    Directory of Open Access Journals (Sweden)

    Mustafa Mohammad AL-Naddaf

    2014-12-01

    Full Text Available Twelve mortar and plaster samples excavated in the archaeological site of Barsinia were mineralogically and petrographically examined by XRay Diffraction (XRD and Stereo and Polarized Light Microscopy, while the total carbonate content was measured using a DietrichFruhling Calcimeter. The physical properties of the samples, such as water uptake under atmospheric pressure and under vacuum, together with density and porosity, were measured. Only twelve samples were available for the purposes of this study: 8 plaster samples and 4 mortar samples. Eleven samples out of the total number of samples were mortars or plasters with lime binder and silica aggregate; calcite and quartz were identified in all of these samples. In most of the samples one or more pozzolanic components were detected; a hydraulic effect therefore exists in practically most of the studied mortars. Excluding the plasters taken from waterbearing constructions such as cisterns, and the mortar sample from the compact floor, the binder content is high; in general, the overall porosity of the studied samples is high. Porosity and petrographic investigation results suggest that the burning temperature of the limestone was low and/or the duration of the combustion was short; such preparation conditions produce a desirable quicklime. Owing to the significant compositional and textural differences between the samples that were reported, there is consequently no suitable general mortar that can be adopted for the restoration of the whole site.

  8. Aired-time and chamotte hydraulic mortars

    Directory of Open Access Journals (Sweden)

    González Cortina, M.

    2002-06-01

    Full Text Available The aim of this research project has been to obtain aired-li me based hydraulic mortars with the addition of chamotte or burnt clay powder obtained from the ceramic industry waste. By doing this, hydraulic properties have been included into lime and hydraulic mortars with a great improvement in mechanical properties. In order to achieve this, different types of chamotte obtained from clay burnt at different temperatures have been tested, changing, at the same time, the proportions of lime, sand, chamotte and water. All the tests have been performed preparing a double set of test pieces to be kept at room temperature or to be immersed in water, determining the Shore C hardness and the mechanical compressive and tensile strengths. Further on, X-ray diffraction analysis have been developed to determine the qualitative composition of the crystalline structure, as well as micro structural analysis, using stereomicroscope and electric microscope scanning, with X-ray microanalysis have been used. As a conclusion, several types of mortars have been created with different proportions, which can be used, due to its characteristics, as keying mortars in brickwork, for restoration works as well as for new constructions.

    El objetivo de éste trabajo es el conseguir morteros hidráulicos, a partir de la cal aérea, con adición de chamota o polvo de arcilla cocida, obtenida de los residuos-desechos de la industria cerámica. De este modo se pretende infundir propiedades hidráulicas a la cal y obtener morteros hidráulicos, con una mejora sustancial de sus propiedades mecánicas. Para ello, se ha experimentado con diversos tipos de chamotas, obtenidas a partir de arcillas cocidas a diferentes temperaturas, y con diversas granulometrías, y se han realizado morteros con distintas dosificaciones, variando las proporciones de cal, arena, chamota y agua. En todos los casos se ha preparado una doble serie de probetas, para conservarlas al aire o

  9. 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.

  10. Compatibility of repair mortars in restoration projects

    OpenAIRE

    Schueremans, Luc; Van Balen, Koenraad; Cizer, Özlem; Janssens, Elke; Serré, Gerty; Elsen, Jan; Brosens, Kris; Ignoul, Sven

    2010-01-01

    Mortars used for restoration must be highly compatible with historic materials in terms of physical, chemical and mechanical properties in order to assure the durability of masonry on the long term. Compatibility criteria are defined based on the original mortar characteristics but the efficiency and the performance of the repair mortar after application on masonry are not generally evaluated. From this perspective, historic mortars and repair mortars from 3 historic masonry structures were a...

  11. 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.

  12. Isotopic analysis for degradation diagnosis of calcite matrix in mortar.

    Science.gov (United States)

    Dotsika, E; Psomiadis, D; Poutoukis, D; Raco, B; Gamaletsos, P

    2009-12-01

    Mortar that was used in building as well as in conservation and restoration works of wall paintings have been analysed isotopically (delta(13)C and delta(18)O) in order to evaluate the setting environments and secondary processes, to distinguish the structural components used and to determine the exact causes that incurred the degradation phenomena. The material undergoes weathering and decay on a large proportion of its surface and in depth, due to the infiltration of water through the structural blocks. Mineralogical analysis indicated signs of sulphation and dissolution/recrystallisation processes taking place on the material, whereas stable isotopes provided information relative to the origin of the CO(2) and water during calcite formation and degradation processes. Isotopic change of the initial delta(13)C and delta(18)O in carbonate matrix was caused by alteration of the primary source of CO(2) and H(2)O in mortar over time, particularly by recrystallisation of calcite with porewater, evaporated or re-condensed water, and CO(2) from various sources of atmospheric and biogenic origin. Human influence (surface treatment) and biological growth (e.g. fungus) are major exogenic processes which may alter delta(18)O and delta(13)C in lime mortar.

  13. On the role of hydrophobic Si-based protective coatings in limiting mortar deterioration.

    Science.gov (United States)

    Cappelletti, G; Fermo, P; Pino, F; Pargoletti, E; Pecchioni, E; Fratini, F; Ruffolo, S A; La Russa, M F

    2015-11-01

    In order to avoid both natural and artificial stone decay, mainly due to the interaction with atmospheric pollutants (both gases such as NOx and SO2 and particulate matter), polymeric materials have been widely studied as protective coatings enable to limit the penetration of fluids into the bulk material. In the current work, an air hardening calcic lime mortar (ALM) and a natural hydraulic lime mortar (HLM) were used as substrates, and commercially available Si-based resins (Alpha®SI30 and Silres®BS16) were adopted as protective agents to give hydrophobicity features to the artificial stones. Surface properties of coatings and their performance as hydrophobic agents were studied using different techniques such as contact angle measurements, capillary absorption test, mercury intrusion porosimetry, surface free energy, colorimetric measurements and water vapour permeability tests. Finally, some exposure tests to UV radiation and to real polluted atmospheric environments (a city centre and an urban background site) were carried out during a wintertime period (when the concentrations of the main atmospheric pollutants are higher) in order to study the durability of the coating systems applied. The effectiveness of the two commercial resins in reducing salt formation (sulphate and nitrate), induced by the interaction of the mortars with the atmospheric pollutants, was demonstrated in the case of the HLM mortar. Graphical Abstract ᅟ.

  14. 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.

  15. Mechanical resilience and cementitious processes in Imperial Roman architectural mortar

    Science.gov (United States)

    Landis, Eric N.; Brune, Philip F.; Vitti, Massimo; Chen, Heng; Li, Qinfei; Kunz, Martin; Wenk, Hans-Rudolf; Monteiro, Paulo J. M.; Ingraffea, Anthony R.

    2014-01-01

    The pyroclastic aggregate concrete of Trajan’s Markets (110 CE), now Museo Fori Imperiali in Rome, has absorbed energy from seismic ground shaking and long-term foundation settlement for nearly two millenia while remaining largely intact at the structural scale. The scientific basis of this exceptional service record is explored through computed tomography of fracture surfaces and synchroton X-ray microdiffraction analyses of a reproduction of the standardized hydrated lime–volcanic ash mortar that binds decimeter-sized tuff and brick aggregate in the conglomeratic concrete. The mortar reproduction gains fracture toughness over 180 d through progressive coalescence of calcium–aluminum-silicate–hydrate (C-A-S-H) cementing binder with Ca/(Si+Al) ≈ 0.8–0.9 and crystallization of strätlingite and siliceous hydrogarnet (katoite) at ≥90 d, after pozzolanic consumption of hydrated lime was complete. Platey strätlingite crystals toughen interfacial zones along scoria perimeters and impede macroscale propagation of crack segments. In the 1,900-y-old mortar, C-A-S-H has low Ca/(Si+Al) ≈ 0.45–0.75. Dense clusters of 2- to 30-µm strätlingite plates further reinforce interfacial zones, the weakest link of modern cement-based concrete, and the cementitious matrix. These crystals formed during long-term autogeneous reaction of dissolved calcite from lime and the alkali-rich scoriae groundmass, clay mineral (halloysite), and zeolite (phillipsite and chabazite) surface textures from the Pozzolane Rosse pyroclastic flow, erupted from the nearby Alban Hills volcano. The clast-supported conglomeratic fabric of the concrete presents further resistance to fracture propagation at the structural scale. PMID:25512521

  16. Possibility of Lime as a Stabilizer in Compressed Earth Brick (CEB

    Directory of Open Access Journals (Sweden)

    Fetra Venny Riza

    2011-01-01

    Full Text Available This paper highlights the production of lime, chemical reaction during the production process, lime reaction with the soil and the prospective use of lime in the future. The research works that has been carried out showed lime has superior properties than cement in enhancing soil structure and also exhibits less embodied energy than cement. The lime through its chemical composition, calcium hydroxide, able to reacts with the pozzolanic materials that presents in the clay soil. This pozzolanic reaction resulted to the formation C-S-H cementitious gel that will further stabilize the soil. The application of lime will also promote healthier environment since carbonation process that occur during carbonation period absorb carbon dioxide in the air. The production of compressed stabilized earth brick using lime will also contributes to greener environment as compared to normal brick production method which consumed extensive energy.

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

    OpenAIRE

    Carolina Netto Rangel; Lucia Maria Jaeger de Carvalho; Renata Borchetta Fernandes Fonseca; Antonio Gomes Soares; Edgar Oliveira de Jesus

    2011-01-01

    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...

  18. Resilience of acid subalpine grassland to short-term liming and fertilisation

    OpenAIRE

    Spiegelberger, T.; Deléglise, C.; DeDanieli, S.; Bernard-Brunet, C.

    2010-01-01

    A fertilisation experiment was started in the French Alps on an acid grassland at 2000 m in 1989 where lime as calcium carbonate (liming) and Thomas Slag enriched by potassium chloride (fertilisation) was added in a random block design until 1992. Since then, no further amendments were applied. Fifteen years after the last application, we revisited the experiment and observed that soil pH was still significantly higher on limed plots, while nitrogen (N) concentrations were lower. On fertilise...

  19. Altered cement hydration and subsequently modified porosity, permeability and compressive strength of mortar specimens due to the influence of electrical current

    NARCIS (Netherlands)

    Susanto, A.; Koleva, D.A.; Van Breugel, K.

    2014-01-01

    This paper reports on the influence of stray current flow on microstructural prop-erties, i.e. pore connectivity and permeability of mortar specimens, and link these to the observed alterations in mechanical properties and cement hydration. Mortar specimens were partly submerged in water and calcium

  20. 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...

  1. Resistance of biofilm-covered mortars to microbiologically influenced deterioration simulated by sulfuric acid exposure

    Energy Technology Data Exchange (ETDEWEB)

    Soleimani, Sahar, E-mail: ssoleima@connect.carleton.ca; Isgor, O. Burkan, E-mail: burkan_isgor@carleton.ca; Ormeci, Banu, E-mail: banu_ormeci@carleton.ca

    2013-11-15

    Following the reported success of biofilm applications on metal surfaces to inhibit microbiologically influenced corrosion, effectiveness and sustainability of E. coli DH5α biofilm on mortar surface to prevent microbiologically influenced concrete deterioration (MICD) are investigated. Experiments simulating microbial attack were carried out by exposing incrementally biofilm-covered mortar specimens to sulfuric acid solutions with pH ranging from 3 to 6. Results showed that calcium concentration in control reactors without biofilm was 23–47% higher than the reactors with biofilm-covered mortar. Formation of amorphous silica gel as an indication of early stages of acid attack was observed only on the control mortar specimens without biofilm. During acidification, the biofilm continued to grow and its thickness almost doubled from ∼ 30 μm before acidification to ∼ 60 μm after acidification. These results demonstrated that E. coli DH5α biofilm was able to provide a protective and sustainable barrier on mortar surfaces against medium to strong sulfuric acid attack. -- Highlights: •Effectiveness of E.coli DH5α biofilm to prevent MICD was studied. •Conditions that lead to MICD were simulated by chemical acidification. •Biofilm-covered mortar specimens were exposed to sulfuric acid solutions. •The presence of biofilm helped reduce the chemically-induced mortar deterioration. •Biofilm remained alive and continued to grow during the acidification process.

  2. Evaluation of electric properties of cement mortars containing pozzolans

    Directory of Open Access Journals (Sweden)

    Cruz, J. M.

    2011-03-01

    Full Text Available In this paper the evolution of the microstructure of Portland cement mortar is analyzed, by using electrical impedance measurements. Cement mortars are compared without and with two pozzolanic substitutions: spent fluid catalytic cracking catalyst (FCC and metakaolin (MK. The measurement method is described and the model for analyzing the electrical impedance spectra is developed. Three electrical parameters are defined: electrical resistivity, capacitance exponent, and capacitive factor. The results show a significant increase in resistivity of the mortars with pozzolans after 7 days of curing, especially in mortars with MK. This increase is correlated with lime-fixing by the pozzolans. The capacitive properties evolve differently at early age, but reach the same values after 148 days. The electrical and mineralogical data show that the evolution of the microstructure in the mortar with MK starts before it does in the mortars with FCC and that the final microstructure becomes different.

    En este trabajo se analiza la microestructura de morteros de cemento Portland, mediante medidas de impedancia eléctrica. Se comparan morteros de cemento sin y con dos sustituciones puzolánicas: residuo de catalizador de craqueo catalítico (FCC y metacaolín (MK. Se describe el método de medida y se desarrolla el modelo de análisis de los espectros de impedancia eléctrica. Se definen tres parámetros eléctricos: resistividad eléctrica, exponente capacitivo, y factor capacitivo. Se observa un aumento importante de la resistividad de los morteros con puzolana a partir de los 7 días de curado, sobre todo en morteros con MK. Este aumento está correlacionado con la fijación de cal de las puzolanas. Las propiedades capacitivas son diferentes a edad temprana, pero se igualan a los 148 días. Los resultados eléctricos y mineralógicos muestran que la evolución microestructural comienza antes en los morteros con MK que con FCC y que la microestructura

  3. 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.

  4. Crushed and River-Origin Sands Used as Aggregates in Repair Mortars

    Directory of Open Access Journals (Sweden)

    Maria Stefanidou

    2016-04-01

    Full Text Available The systematic analysis of mortars from monuments or historic buildings and the simultaneous study of the construction environment show that it was common practice to use naturally occurring sand from local rivers or streams for the production of the mortars. There are cases though, mainly on islands, where sands of natural origin were limited, and marine or crushed sands were used possibly after elaboration. In all cases the particle size analysis of old mortar confirms the presence of even distribution of the granules. As regards the design of the repair mortars, there are criteria that should be taken into consideration in order to produce materials with compatible properties. The main properties concerning sands are the grain distribution and maximum size, the color, the content of fines, and soluble salts. The objective of this research is the study of the physical characteristics of the sands such as the sand equivalent, the gradation, the apparent density, the morphology of the grains, their mineralogical composition and the influence of these properties on the behavior of lime mortars, notably the mechanical and physical properties acquired.

  5. 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.

  6. 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.

  7. 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

  8. A Study on the Properties of Carbon Black Mortar Using Granulated Blast Furnace Slag and Polymer.

    Science.gov (United States)

    Jang, Hong-Seok; Jeon, Ui-Hyeon; So, Seung-Young

    2015-11-01

    White Portland Cement (WPC) and inorganic pigment have been used in colored concrete, but there are some physical problems such as increases in efflorescence, and poor workability and low economics. The aim of this study was to investigate the effects of GBFS and polymer (methyl cellulose) on the physical properties of carbon black mortar. For this purpose, a flow test, compressive strength test and color evaluation and was carried out on cement mortar mixed with polymer by changing the proportion of cement and ratio of GBFS. The results show that the addition of polymer influences significantly the color value efficiency in colored mortar. This is due to the reduction of overall amount of micro pore. This polymer films prevent the transport of soluble calcium towards the surface, and decreases efflorescence. And the flow of colored mortar was increased in proportion to the addition rate of the GBFS. In addition the strength of colored mortars with GBFS at the long-term aged (after 28 days) was higher than that of the general WPC mortar, although its strength was developed slowly at the early ages. PMID:26726652

  9. A Study on the Properties of Carbon Black Mortar Using Granulated Blast Furnace Slag and Polymer.

    Science.gov (United States)

    Jang, Hong-Seok; Jeon, Ui-Hyeon; So, Seung-Young

    2015-11-01

    White Portland Cement (WPC) and inorganic pigment have been used in colored concrete, but there are some physical problems such as increases in efflorescence, and poor workability and low economics. The aim of this study was to investigate the effects of GBFS and polymer (methyl cellulose) on the physical properties of carbon black mortar. For this purpose, a flow test, compressive strength test and color evaluation and was carried out on cement mortar mixed with polymer by changing the proportion of cement and ratio of GBFS. The results show that the addition of polymer influences significantly the color value efficiency in colored mortar. This is due to the reduction of overall amount of micro pore. This polymer films prevent the transport of soluble calcium towards the surface, and decreases efflorescence. And the flow of colored mortar was increased in proportion to the addition rate of the GBFS. In addition the strength of colored mortars with GBFS at the long-term aged (after 28 days) was higher than that of the general WPC mortar, although its strength was developed slowly at the early ages.

  10. PROPERTIES OF LIGHTWEIGHT MASONRY MORTARS WITH HOLLOW GLASS MICROSPHERES FOR WINTER CONDITIONS

    Directory of Open Access Journals (Sweden)

    Semenov Vyacheslav Sergeevich

    2012-10-01

    reduction fillers (such as inflated pearlite, vermiculite etc. demonstrate low strength properties, as such fillers have a high water content. Hollow glass (or ceramic microspheres are known as efficient fillers for lightweight mortars. Multiple research undertakings contain information on the masonry mortar that has the following properties: average density of dry mortar - 450 kg/m3, thermal conductivity factor - 0.17 W/(m·°C, compressive strength at the age of 28 days - 3.2 MPa, water retention rate - over 90 %. The climatic conditions of Russia determine the need to perform masonry works at negative temperatures. Adding antifreeze admixtures is an easy and cheap method that guarantees hydration of the Portland-cement at negative temperatures. The subject of this research covers masonry mortars that have a 15 % hollow glass microsphere content and antifreeze admixtures. Contemporary antifreeze admixtures are multifunctional. Therefore, traditional antifreeze admixtures such as sodium chloride, calcium chloride, sodium nitrite, sodium nitrate, sodium formate, potash were used in the research. The per-cent content of antifreeze admixtures was calculated. The following properties of masonry mortars with a 15 % content of hollow glass microspheres and antifreeze admixtures were identified: average mortar and mortar mixture density, setting time, water retention, compressive and bending strength, and water absorption. Standard research methods were employed. Every mortar has an 8 cm mobility. The benchmark mixture has an average density of 1.085 kg/ m3, average cement stone density of 980 kg/m3, compressive strength at the age of 28 days - 19.8 MPa, water retention rate - 97 %, setting time - 4.5 hours. The attention was driven to the strength analysis of mortars with hollow glass microspheres and antifreeze admixtures at positive and negative temperatures. The authors proved that antifreeze admixtures demonstrated a negative influence on the strength and setting

  11. Incorporation of titanium dioxide nanoparticles in mortars - Influence of microstructure in the hardened state properties and photocatalytic activity

    Energy Technology Data Exchange (ETDEWEB)

    Lucas, S.S., E-mail: sandra.lucas@ua.pt [University of Aveiro/CICECO, Department of Civil Engineering, 3810-193 Aveiro (Portugal); Ferreira, V.M., E-mail: victorf@ua.pt [University of Aveiro/CICECO, Department of Civil Engineering, 3810-193 Aveiro (Portugal); Barroso de Aguiar, J.L., E-mail: aguiar@civil.uminho.pt [University of Minho, Department of Civil Engineering, Campus de Azurem, 4800-058 Guimaraes (Portugal)

    2013-01-15

    The environmental pollution in urban areas is one of the causes for poor indoor air quality in buildings, particularly in suburban areas. The development of photocatalytic construction materials can contribute to clean the air and improve sustainability levels. Previous studies have focused mainly in cement and concrete materials, disregarding the potential application in historic buildings. In this work, a photocatalytic additive (titanium dioxide) was added to mortars prepared with aerial lime, cement and gypsum binders. The main goal was to study the way that microstructural changes affect the photocatalytic efficiency. The photocatalytic activity was determined using a reactor developed to assess the degradation rate with a common urban pollutant, NO{sub x}. The laboratory results show that all the compositions tested exhibited high photocatalytic efficiency. It was demonstrated that photocatalytic mortars can be applied in new and old buildings, because the nanoadditives do not compromise the mortar hardened state properties.

  12. Cross-contamination in Porcelain Mortars.

    Science.gov (United States)

    Bauer-Brandl, A; Falck, A; Ingebrigtsen, L; Nilson, C

    2001-01-01

    Porcelain mortars and pestles are frequently used to comminute drug substances on a small scale and (in some cases) in the production of liquid and semisolid suspensions. Although it is generally accepted that removal of a drug substance from a rough surface by rinsing may be difficult and may lead to cross-contamination, no hard data support that theory. In this study, the amount of salicylic acid remaining on a porcelain mortar after different washing procedures was quantified and compared with the amount remaining on a plastic mortar. Drug residues in the "mg" range on the porcelain mortars made common rinsing procedures appear inappropriate, but no traces of drug were detected on plastic mortars. In addition, the quality of suspension ointments with respect to particle size and homogeneity produced by the two types of mortars was compared. Porcelain and plastic mortars appeared equally suitable for use in the production of semisolid suspensions.

  13. Binder characterisation of mortars used at different ages in the San Lorenzo church in Milan

    Energy Technology Data Exchange (ETDEWEB)

    Bertolini, Luca, E-mail: luca.bertolini@polimi.it; Carsana, Maddalena, E-mail: maddalena.carsana@polimi.it; Gastaldi, Matteo, E-mail: matteo.gastaldi@polimi.it; Lollini, Federica, E-mail: federica.lollini@polimi.it; Redaelli, Elena, E-mail: elena.redaelli@polimi.it

    2013-06-15

    The paper describes a study on the mortars of the basilica of San Lorenzo in Milan, which was carried out to support an archaeological study aimed at dating and documenting the construction techniques used throughout the centuries. The church, which was founded between the 4th and 5th century, at the end of the period when Milan was the capital of the Roman Empire, was subjected in time to extensions, collapses and reconstructions that lasted until the Renaissance period and even later on. Thanks to the good state of conservation, San Lorenzo church is a collection of materials and construction techniques throughout a period of more than a millennium. Mortars were investigated in order to compare the binders used for structural elements built in different historical ages. From an archaeological study, samples of mortars attributed to the late Roman period, the Middle Ages and the Renaissance were available. The binder of each sample was separated by the aggregates and it was characterised on the basis of X-ray diffraction analysis, thermogravimetric analysis and scanning electron microscopy. Constituents of the binder were identified and their origin is discussed in order to investigate if they could be attributed to the original composition of the binder or to possible alteration in time due to atmospheric pollution. Results show that, even though the binder is mainly based on magnesian lime, there are significant differences in the microstructure of the binding matrix used in mortars ascribed to the different historical periods. In the Roman period, in correspondence of the structural elements that required higher strength, also hydraulic cocciopesto mortars were detected. Gypsum was found in most samples, which was maybe added intentionally. - Highlights: • Binders of mortars of San Lorenzo church in Milan were investigated. • Roman, Middle Ages and Renaissance samples were studied by XRD, TG and SEM. • Magnesian-lime binders containing silico

  14. Calcite-forming bacteria for compressive strength improvement in mortar.

    Science.gov (United States)

    Park, Sung-Jin; Park, Yu-Mi; Chun, Woo-Young; Kim, Wha-Jung; Ghim, Sa-Youl

    2010-04-01

    Microbiological calcium carbonate precipitation (MCP) has been investigated for its ability to improve the compressive strength of concrete mortar. However, very few studies have been conducted on the use of calcite-forming bacteria (CFB) to improve compressive strength. In this study, we discovered new bacterial genera that are capable of improving the compressive strength of concrete mortar. We isolated 4 CFB from 7 environmental concrete structures. Using sequence analysis of the 16S rRNA genes, the CFB could be partially identified as Sporosarcina soli KNUC401, Bacillus massiliensis KNUC402, Arthrobacter crystallopoietes KNUC403, and Lysinibacillus fusiformis KNUC404. Crystal aggregates were apparent in the bacterial colonies grown on an agar medium. Stereomicroscopy, scanning electron microscopy, and x-ray diffraction analyses illustrated both the crystal growth and the crystalline structure of the CaCO3 crystals. We used the isolates to improve the compressive strength of concrete mortar cubes and found that KNUC403 offered the best improvement in compressive strength.

  15. 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.

  16. Chemical composition influence of cement based mortars on algal biofouling

    Science.gov (United States)

    Estelle, Dalod; Alexandre, Govin; Philippe, Grosseau; Christine, Lors; René, Guyonnet; Denis, Damidot

    2013-04-01

    The main cause of building-facade biodegradation is the growth of microorganisms. This phenomenon depends on several parameters such as the geographical situation, the environmental conditions and the surface state of the substrate. Several researches have been devoted to the study of the effect of porosity and roughness on the biofouling of stones and mortars. However, none of them have addressed the influence of the mortar chemistry on the microorganism growth kinetic. The main objective of this study is to highlight the influence of the mortar chemistry in relationship with its physical properties on biological weathering. Earlier work showed a good resistance of Calcium Aluminate Cements to biodeterioration by acidogenic bacteria (Thiobacillus) and fungi (Alternaria alternata, Aspergillus Niger and Coniosporium uncinatum). In order to characterize the influence of the mortar chemistry on biofouling, two Portland cements and two alumina cements are used. Among micro-organisms able to grow, green algae are most involved in the aesthetic deterioration of facades. Indeed, they can colonize any type of media and can be a source of nutrients for other micro-organisms such as fungi. The green algae Klebsormidium flaccidum is chosen because of its representativeness. It is indeed the species the most frequently identified and isolated from samples taken on sites. The biofouling kinetic is followed on samples exposed outdoor and on samples tested in a laboratory bench which consists in spraying an algae culture on mortar specimens. The results obtained by in situ trials are compared with the results obtained on the laboratory bench. The microorganism growth kinetic is measured by image analysis. To improve the detection of algae on the surface of the cementitious samples, the raw image is converted in the YIQ color space. Y, I and Q correspond respectively to luminance, in-phase, and quadrature. On the Q channel, the areas covered by algae and the areas of clean mortar

  17. The effects of different types of nano-silicon dioxide additives on the properties of sludge ash mortar.

    Science.gov (United States)

    Luo, Huan-Lin; Chang, Wei-Che; Lin, Deng-Fong

    2009-04-01

    To improve the drawbacks caused by the sludge ash replacement in mortar, the previous studies have shown that the early strength and durability of sludge ash/cement mortar are improved by adding nano-silicon dioxide (nano-SiO2) to mortar. In this article, three types of nano-SiO2--SS, HS, and SP (manufacturer code names)--were applied to sludge ash/cement mixture to make paste or mortar specimens. The object is to further extend the recycle of the sludge ash by determining the better type of nano-SiO2 additive to improve properties of sludge ash/ cement paste or mortar. The cement was replaced by 0, 10, 20, and 30% of sludge ash, and 0 and 2% of nano-SiO2 additives were added to the sludge ash paste or mortar specimens. Tests such as setting time, compressive strength, scanning electron microscopy, X-ray diffraction, nuclear magnetic resonance, and thermogravimetric analysis/differential thermal analysis were performed in this study. Test results show that nano-SiO2 additives can not only effectively increase the hydration product (calcium silicate hydrate [C-S-H] gel), but also make the crystal structure denser. Among the three types of nano-SiO2 additive, the SS type can best improve the properties of sludge ash/cement paste or mortar, followed by the SP and HS types.

  18. COMPRESSIVE STRENGTH TESTING OF EARTH MORTARS

    Directory of Open Access Journals (Sweden)

    Givanildo Alves Azeredo

    2007-06-01

    Full Text Available This paper discusses the compressive strength of earth mortars. The goal is to use these mortars for masonry construction. Although it is necessary to study the whole masonry behaviour, the scope of this paper refers to the mortar only, without taking into account the blocks. As with other masonry units, compressive strength is a basic measure of quality for masonry mortars. However, there is a great variety of methodology for determining their parameters and properties, such as different samples geometry, the way strains are measured and also the platen restraint effect adopted. The present paper outlines certain experimental devices used to determine compressive strength of earth mortars and tries to show their influence on the properties determined. Proposals for the future development of testing earth mortars are outlined.

  19. COMPARATIVE EXPERIMENTAL RESEARCH ON MORTAR BONDING MATERIALS USED IN SEVERAL ANCIENT CITY WALLS%几处古城墙泥灰类粘结材料的对比试验研究

    Institute of Scientific and Technical Information of China (English)

    李广燕; 张云升; 倪紫威

    2012-01-01

    通过对四处古城墙遗址泥灰类粘结材料取样,利用排水法、X射线衍射仪(XRD)、热重-差热分析(DSC-TG)、X射线荧光光谱分析(XRF)、傅立叶红外(FT-IR)、扫描电镜显微镜(SEM)以及碘-淀粉试验等测试手段,系统分析了代表样的物理性能、化学及物相组成和组分配合比.试验结果表明:泥灰类粘结材料的密度在1.81~2.20g/cm3之间,其抗压强度最大达5.23 MPa;泥灰类粘结材料的无机物主要是方解石晶型的碳酸钙,其含量在87.8%~96.8%之间;其有机物为尚未完全降解的糯米支链淀粉成分.正是糯米浆与石灰这种无机/有机相互协同的效应,使得泥灰类粘结材料具有优良的力学性能.%Mortar bonding materials used in four ancient city wall ruins were firstly sampled in this paper. By using micro and macro testing methods such as drainage method, X-ray diffraction (XRD), thermo gravimetric and differential thermal analysis (DSC-TG), X-ray fluorescence spectral analysis (XRF), Fourier transform infrared (FT-IR), scanning electron microscope (SEM)and so on, and iodine-starch test, their physical property, chemical composition, phase constituents and component ratio were analyzed. The experimental results show that apparent density of mortar bonding materials is between 1.81 g/cm3 and 2.20g/cm3 and their compressive strength is up to 5.23MPa. Inorganic of mortar bonding materials is mainly calcium carbonate of calcite crystal whose content is between 87.8% and 96.8%. Organic component is rice amylopectin that is not yet fully biodegradable. This is the effect of inorganic-organic coordination between sticky-rice and lime makes mortar bonding materials have excellent mechanical properties.

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

    International Nuclear Information System (INIS)

    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

  1. Influence of fly ash and its mean particle size on certain engineering properties of cement composite mortars

    Energy Technology Data Exchange (ETDEWEB)

    Gengying Li; Xiaozhong Wu [Shantou University, Shantou (China). Department of Civil Engineering

    2005-06-01

    An experimental investigation on the effects of incorporating large volumes of fly ash on the early engineering properties and long-term strength of masonry mortars is reported. The effect of fly ash and its mean particle size (PD) on the variation of workability and strength has been studied. It was found that fly ash and its mean particle size play a very significant role on the strength of masonry mortars. It has been observed that the early-term strength, except the mortars incorporating coarse fly ash (CFA), was slightly influenced by the replacement with fly ash. The long-term strength (both the bond strength and the compressive strength) will significantly increase, especially for the bond strength of mortars incorporating coarse fly ash. It was also found that the bond strength significantly increased as the mean particle size of fly ash decreases after 28 days curing. However, the 7-day strength was little influenced by fly ash particle size. The fluidity of composite mortar enhanced due to replace cement and lime with fly ash, and the mean PD of fly ash significantly influenced the workability.

  2. Liming of acid soils in Osijek-Baranja county

    Directory of Open Access Journals (Sweden)

    Dolijanović Željko

    2011-01-01

    Full Text Available The negative trend of soil degradation process increases with intensive agricultural production. Therefore, there is a need for soil conditioning like liming, humification, fertilization, etc. to improve soil quality. One of the major problems that occur on agricultural soils of Croatia is acidification. A downward trend of soil pH is mainly present in soils of poor structure with intensive agricultural production. In agricultural practice liming often needs to rely only on the pH value, without determining the hydrolytic acidity, CEC or soil texture. Due to the above mentioned facts, calculation of liming for Osijek-Baranja County was conducted with the help of ALRxp calculator, which takes CEC, soil pH in KCl, hydrolytic acidity, bulk density of soil, soil textural class and depth of the plow layer to 30 cm into account. Low soil pH values have a great influence on soil suitability for crops as well as on the deficit of calcium and magnesium. All of these lead to the degradation of soil structure, and can even lead to disturbances of plant nutrition in some production areas. On such soils, liming would be imperatively required, but with caution because an excessive intake of lime materials, especially without the necessary analysis, causes a decline in organic matter and reduces accessibility for plant uptake of microelements.

  3. Durability of expanded polystyrene mortars

    OpenAIRE

    Ferrándiz Mas, Verónica; García Alcocel, Eva María

    2013-01-01

    The influence of the addition of various types and various concentrations of expanded polystyrene foam (both commercial and recycled) on the durability of Portland cement mortars is studied. In particular, the microstructure is studied utilizing the following methods: capillary absorption of water, mercury intrusion porosimetry, impedance spectroscopy and open porosity. In addition, the effects of heat cycles and freeze–thaw cycles on compressive strength are examined. Scanning electron micro...

  4. Use of olive biomass fly ash in the preparation of environmentally friendly mortars.

    Science.gov (United States)

    Cruz-Yusta, Manuel; Mármol, Isabel; Morales, Julián; Sánchez, Luis

    2011-08-15

    The incorporation of fly ash from olive biomass (FAOB) combustion in cogeneration plants into cement based mortars was explored by analyzing the chemical composition, mineralogical phases, particle size, morphology, and IR spectra of the resulting material. Pozzolanic activity was detected and found to be related with the presence of calcium aluminum silicates phases. The preparation of new olive biomass fly ash content mortars is effective by replacing either CaCO(3) filler or cement with FAOB. In fact, up to 10% of cement can be replaced without detracting from the mechanical properties of a mortar. This can provide an alternative way to manage the olive biomass fly ash as waste produced in thermal plants and reduce cement consumption in the building industry, and hence an economically and environmentally attractive choice.

  5. Thaumasite formation in hydraulic mortars by atmospheric SO2 deposition

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    2001-12-01

    Full Text Available Sulphation of mortars and concretes is a function of diverse environmental factors (SO2 aerosol, temperature, etc as well as some material characteristics. One of the phases that could be formed as consequence of the sulphation of the hydraulic binder is thaumasite. In this paper different hydraulic mortars have been exposed to laboratory exposure chambers in order to reproduce thaumasite formation due to atmospheric SO2. Under the laboratory exposure conditions, thaumasite was formed in hydraulic lime mortars, and mortars elaborated with ordinary Portland cement as well as mineralized white portland cement. However, thaumasite was not formed in mortars made of lime and pozzolan. The first product formed as a result of the SO2-mortar interaction was gypsum. Gypsum reacted with calcite and C-S-H gel, present in the samples, giving place to thaumasite. Low temperature promotes thaumasite formation.

    La sulfatación de morteros y hormigones depende de las condiciones ambientales (SO2 aerosol, temperatura, etc., así como de las características del material. Una de las fases que se puede formar como consecuencia de la sulfatación de los ligantes hidráulicos es la taumasita. En este trabajo se han expuesto diferentes morteros hidráulicos en cámaras de laboratorio con el fin de reproducir la formación de taumasita por efecto del SO2 atmosférico. Bajo las condiciones de laboratorio se formó taumasita en los morteros de cal hidráulica y en los morteros fabricados con cemento portland y cemento blanco mineralizado. Sin embargo, cuando el ligante utilizado en los morteros fue cal y puzolana, no se formó taumasita. El yeso fue el primer producto formado en la interacción entre los morteros y el SO2. A continuación, este yeso reaccionó con la calcita y el gel C-S-H dando lugar a la formación de taumasita. Las bajas temperaturas favorecieron la formación de taumasita.

  6. Characterization of mudejar mortars from St. Gil Abbot church (Zaragoza, Spain: Investigation of the manufacturing technology of ancient gypsum mortars

    Directory of Open Access Journals (Sweden)

    Igea, J.

    2012-12-01

    Full Text Available This work has been focused on the investigation of the technological procedure of Mudejar mortars applied to the characterization of a group of unaltered samples from an example church of Mudejar architecture of Aragon. The research was carried out using multi-analytical techniques including petrographic study, chemistry and mineralogical analysis. All mortars present a homogeneous composition. The binder is made up of a mixture of gypsum and a very low proportion of lime, while the main components of the aggregate are gypsum and carbonate rock fragments, both in a different thermal state of decomposition. The results have proved that both, binder and aggregates display the same composition in these mortars. These aggregates are the by-product of a grinding process of the previously burnt raw materials which have had a positive influence on the properties of the mortars in improving their quality.

    Este trabajo se ha centrado en la investigación de la tecnología de fabricación de morteros mudéjares mediante la caracterización de un conjunto de muestras inalteradas procedentes de una iglesia representativa de la arquitectura Mudéjar aragonesa. La investigación se llevó a cabo mediante el uso combinado de técnicas analíticas incluyendo el estudio petrográfico y el análisis químico y mineralógico. Todos los morteros presentan una composición constante formada por una mezcla de yeso y cal, en muy baja proporción, como ligante, mientras que el árido está formado por fragmentos de rocas yesíferas y carbonatadas en distinto estado de descomposición térmica. Los resultados confirman que en la fabricación de los morteros, ligante y áridos presentan la misma composición, siendo éstos últimos el subproducto de la misma materia prima calcinada, incorporados para elaborar el mortero, tras un proceso de molienda. Esta característica ha influido positivamente en las propiedades de los morteros, mejorando su calidad.

  7. SEM Analysis of the Interfacial Transition Zone between Cement-Glass Powder Paste and Aggregate of Mortar under Microwave Curing

    Directory of Open Access Journals (Sweden)

    Yaning Kong

    2016-08-01

    Full Text Available In order to investigate the effects of microwave curing on the microstructure of the interfacial transition zone of mortar prepared with a composite binder containing glass powder and to explain the mechanism of microwave curing on the improvement of compressive strength, in this study, the compressive strength of mortar under microwave curing was compared against mortar cured using (a normal curing at 20 ± 1 °C with relative humidity (RH > 90%; (b steam curing at 40 °C for 10 h; and (c steam curing at 80 °C for 4 h. The microstructure of the interfacial transition zone of mortar under the four curing regimes was analyzed by Scanning electron microscopy (SEM. The results showed that the improvement of the compressive strength of mortar under microwave curing can be attributed to the amelioration of the microstructure of the interfacial transition zone. The hydration degree of cement is accelerated by the thermal effect of microwave curing and Na+ partially dissolved from the fine glass powder to form more reticular calcium silicate hydrate, which connects the aggregate, calcium hydroxide, and non-hydrated cement and glass powder into a denser integral structure. In addition, a more stable triangular structure of calcium hydroxide contributes to the improvement of compressive strength.

  8. THE HIGH VOLUME REUSE OF HYBRID BIOMASS ASH AS A PRIMARY BINDER IN CEMENTLESS MORTAR BLOCK

    Directory of Open Access Journals (Sweden)

    Cheah Chee Ban

    2014-01-01

    Full Text Available High Calcium Wood Ash (HCWA and Pulverised Fuel Ash (PFA are by-products from the wood biomass and coal energy production which are produced in large quantity with combined annual production of 500 million tonnes. This poses a serious problem for disposal of the waste material especially at places where land is scarce. The prescribed study was aimed to examine the mineralogical phases and their respective amount present in the industrial wastes which governs the hydration mechanism towards self-sustained solidification of the ashes when used in combination. Besides, the influence of various forming pressure and hydrothermal treatment temperature on mechanical strength performance of HCWA-PFA cementless mortar blocks was also examined. In the study, the mechanical strength of the HCWA-PFA cementless mortar block produced using various forming pressure and hydrothermal treatment temperature was assessed in terms of compressive strength and dynamic modulus. The results of the study are indicative that HCWA is rich in calcium oxide and potassium oxide content. This enables the hybridization of HCWA with the amorphous silica and alumina rich PFA to form a solid geopolymer binder matrix for fabrication of cementless mortar block. Throughout the study, dimensionally and mechanically stable HCWA-PFA geopolymer mortar blocks were successfully produced by press forming and hydrothermal treatment method. Based on statistical analysis, the hydrothermal treatment temperature has a statistically insignificant effect on the mechanical strength of the HCWA-PFA cementless mortar blocks. The dominant factor which governs the mechanical strength of the HCWA-PFA cementless mortar blocks was found to be the hydraulic forming pressure. Moreover, it was found that hybridized HCWA-PFA can be recycled as the sole binder for fabrication of cementless concrete block which is a useful construction material.

  9. 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.

  10. 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.

  11. Analysis of bulk and inorganic degradation products of stones, mortars and wall paintings by portable Raman microprobe spectroscopy.

    Science.gov (United States)

    Pérez-Alonso, M; Castro, K; Martinez-Arkarazo, I; Angulo, M; Olazabal, M A; Madariaga, J M

    2004-05-01

    This work reports the use of a portable Raman microprobe spectrometer for the analysis of bulk and decaying compounds in carbonaceous materials such as stones, mortars and wall paintings. The analysed stones include limestone, dolomite and carbonaceous sandstone, gypsum and calcium oxalate, both mono- and dihydrated, being the main inorganic degradation products detected. Mortars include bulk phases with pure gypsum, calcite and mixtures of both or with sand, soluble salts being the most important degradation products. The pigments detected in several wall paintings include Prussian blue, iron oxide red, iron oxide yellow, vermilion, carbon black and lead white. Three different decaying processes have been characterised in the mortars of the wall paintings: (a) a massive absorption of nitrates that reacted with calcium carbonate and promoted the unbinding of pigment grains, (b) the formation of black crusts in the vault of the presbytery and (c) the thermodecomposition of pigments due to a fire.

  12. Damage diagnosis and compatible repair mortars

    NARCIS (Netherlands)

    Hees, R.P.J. van

    1999-01-01

    Mortars for repair and maintenance of historic masonry have to meet specific requirements. Several authors have made contributions, however many cases of failure show that there still is quite a lack of knowledge on the compatibility of repair mortars for historic masonry. The diagnosis of the cause

  13. A technical and economic evaluation of the lime spray dryer process

    Energy Technology Data Exchange (ETDEWEB)

    Jao, Yung-Wo.

    1986-06-01

    A technical and economic evaluation of the lime spray dryer process for the control of SO{sub 2} emissions from utility boilers is presented. The study evaluated retrofitting two 500 MW boilers burning bituminous coal containing 2-3% sulfur. In the lime spray dryer process, a slurry of slaked lime is finely atomized into the flue gas inside a spray dryer absorber located downstream of the air heaters. Sulfur dioxide is absorbed into the slurry droplets where it reacts with the lime to produce calcium sulfite and sulfate. All of the water in the droplets is evaporated by the hot flue gas, leaving a dry particulate. The dry reaction products are collected with the flyash in an electrostatic precipitator or fabric filter downstream of the spray dryer. Part of the waste is mixed with the fresh lime slurry and recycled to the spray dryer to improve lime utilization. The mixture of SO{sup 2} removal waste and flyash is then landfilled. It was concluded that due to the limited experience with the lime spray dryer process on high sulfur coal and electrostatic precipitators, there is some uncertainty with respect to the lime stoichiometry required, precipitator sizing and maintenance cost. With the benefit of favourable assumptions with respect to lime stoichiometry and maintenance, the lime spray dryer process appears to be competitive in cost with limestone slurry scrubbing on 2.5% sulfur coal. The lime spray dryer process offers the promise of higher reliability and of lower costs, particularly if future regulations require wet scrubbing processes to eliminate process wastewater streams or incorporate expensive wastewater treatment. 21 refs., 27 figs., 21 tabs.

  14. 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.

  15. 21 CFR 184.1185 - Calcium acetate.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Calcium acetate. 184.1185 Section 184.1185 Food and... Substances Affirmed as GRAS § 184.1185 Calcium acetate. (a) Calcium acetate (Ca (C2H3O2)2, CAS Reg. No. 62-54-4), also known as acetate of lime or vinegar salts, is the calcium salt of acetic acid. It may...

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

    International Nuclear Information System (INIS)

    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)

  17. 土壤施钙对芒果果实钾、钙、镁含量及品质的影响%Effects of different lime nitrate application rates on potassium, calcium and magnesium content and quality in mango

    Institute of Scientific and Technical Information of China (English)

    李华东; 白亭玉; 郑妍; 张贺; 林电

    2014-01-01

    以“台农1号”芒果为试材,田间试验研究了花前土施不同用量硝酸钙对芒果果实钾、钙、镁含量及产量、品质的影响。结果表明:(1)与不施钙相比,土施钙肥可明显提高果实糖酸比,其原因主要是降低了可滴定酸含量,提高了可溶性糖含量,同时可显著提高果实Vc含量,降低贮藏期果实发病率,在土施钙150 g/株时产量最高,增产率为14.25%。(2)在一定钙用量范围内,土施钙肥可显著提高果肉钙含量,使果皮、果肉与果核的钾、镁含量下降。(3)果皮、果肉及果核钙含量与钙肥用量呈正相关,钾、镁含量与钙肥用量呈负相关。(4)果实可溶性糖含量、 Vc含量及糖酸比与钙肥用量呈正相关,果实可溶性固形物含量、可滴定酸含量、失重率、发病率与钙肥用量呈负相关。土壤增施钙肥有利于提高芒果果实品质,提高果实耐贮性。%A field trial was undertaken to evaluate the effects of applying Ca( NO3 ) 2 in soil before flower period on the contents of potassium, calcium, magnesium and quality of “tainung No. 1” mango. The results showed that: (1) Compare with the results of the control, applying calcium fertilizer could obviously increase the fruit sugar acid ratio because of the increase of content of soluble sugars and acidity reduced, and improve the vitamin C in the fruit, reduce the rotten fruit rate during stor-age. The highest yield occurred when 150 g/plant calcium was applicated, and the yield increased by 14. 25% compared to the control. (2) By applying calcium fertilizer, the calcium content of pulp in fruit was significantly increased, the magnesi-um and potassium contents of peel, pulp and seed in fruit reduced. (3) The calcium contents of peel, pulp and seed in fruit had positive correlation with the calcium application amounts, and the potassium and magnesium contents of peel, pulp and seed in fruit had negative correlation with

  18. Rendering mortars in Medina Azahara, Part II: Material characterization and alteration causes

    Directory of Open Access Journals (Sweden)

    Blanco-Varela, M. T.

    1997-06-01

    Full Text Available In the present work, the depicted coat that covers some of the mortars exposed to weathering in the Medina Azahara archaeological site is .studied. That coat is characterized from the compositional and physical viewpoint and the main causes for its decay are determined. The depicted coat is formed by cal cite and iron oxides. It is quite compact and homogeneous. It is approximately 0.1 to 1 mm thick. The depicted coats supposed by lime mortars have CaCO3 deposits over polychromy rests. Depicted coats supported by gypsum mortars or mixed lime and gypsum mortars have gypsum deposits over polychromy rests. The processes of rendering mortars dissolution and the later crystallization of salts on their surface, together with biological growth, are the main causes of the decay of the depicted coats.

    En el presente trabajo se estudia la capa de policromía que recubre algunos de los morteros conservados a la intemperie en la ciudad de Medina Azahara. Dicha capa se caracteriza desde el punto de vista composicional y físico, determinándose las principales causas de su deterioro. La capa de policromía está formada por calcita y óxidos de hierro. Dicha capa es bastante homogénea y compacta. Su espesor es de 0,1 a 1 mm aproximadamente. Las capas de pintura sustentadas por morteros de cal tienen un depósito de CaCO sobre los restos de policromía. Las capas de pintura sustentadas por morteros de yeso o bastardos de cal y yeso tienen depósitos de yeso sobre los restos de policromía. Los procesos de disolución de los revocos y la posterior cristalización de las sales en su superficie, junto con la colonización biológica, son las principales causas de deterioro de la capa de policromía de su superficie.

  19. Ranking procedure based on mechanical, durability and thermal behavior of mortars with incorporation of phase change materials

    Directory of Open Access Journals (Sweden)

    Cunha, S.

    2015-12-01

    Full Text Available Nowadays, considering the high variety of construction products, adequate material selection, based on their properties and function, becomes increasingly important. In this research, a ranking procedure developed by Czarnecki and Lukowski is applied in mortars with incorporation of phase change materials (PCM. The ranking procedure transforms experimental results of properties into one numerical value. The products can be classified according to their individual properties or even an optimized combination of different properties. The main purpose of this study was the ranking of mortars with incorporation of different contents of PCM based in different binders. Aerial lime, hydraulic lime, gypsum and cement were the binders studied. For each binder, three different mortars were developed. Reference mortars, mortars with incorporation of 40% of PCM and mortars with incorporation of 40% of PCM and 1% of fibers, were tested. Results show that the incorporation of PCM in mortars changes their global performance.Actualmente, existen varios productos de construcción, siendo importante una adecuada selección, con base en sus principales propiedades y funciones. En esta investigación se aplicó un procedimiento de clasificación desarrollado por Czarnecki y Lukowski, en morteros con incorporación de materiales de cambio de fase (PCM. Este procedimiento transforma los resultados experimentales de las propiedades en un único valor numérico. Los productos se clasifican de acuerdo con sus propiedades individuales o en una combinación optimizada de diferentes propiedades. El principal objetivo de este estudio fue la clasificación de morteros basado en los diferentes aglutinantes con incorporación de diferentes cantidades de PCM. Los aglutinantes utilizados fueran la cal aérea, cal hidráulica, yeso y cemento. Para cada aglutinante se han desarrollado tres morteros, siendo morteros de referencia, con incorporación de 40% de PCM y con incorporaci

  20. Leaky Rayleigh wave investigation on mortar samples.

    Science.gov (United States)

    Neuenschwander, J; Schmidt, Th; Lüthi, Th; Romer, M

    2006-12-01

    Aggressive mineralized ground water may harm the concrete cover of tunnels and other underground constructions. Within a current research project mortar samples are used to study the effects of sulfate interaction in accelerated laboratory experiments. A nondestructive test method based on ultrasonic surface waves was developed to investigate the topmost layer of mortar samples. A pitch and catch arrangement is introduced for the generation and reception of leaky Rayleigh waves in an immersion technique allowing the measurement of their propagation velocity. The technique has been successfully verified for the reference materials aluminium, copper, and stainless steel. First measurements performed on mortar specimens demonstrate the applicability of this new diagnostic tool.

  1. Reliability estimates for flawed mortar projectile bodies

    Energy Technology Data Exchange (ETDEWEB)

    Cordes, J.A. [US Army ARDEC, AMSRD-AAR-MEF-E, Analysis and Evaluation Division, Fuze and Precision Armaments Technology Directorate, US Army Armament Research Development and Engineering Center, Picatinny Arsenal, NJ 07806-5000 (United States)], E-mail: jennifer.cordes@us.army.mil; Thomas, J.; Wong, R.S.; Carlucci, D. [US Army ARDEC, AMSRD-AAR-MEF-E, Analysis and Evaluation Division, Fuze and Precision Armaments Technology Directorate, US Army Armament Research Development and Engineering Center, Picatinny Arsenal, NJ 07806-5000 (United States)

    2009-12-15

    The Army routinely screens mortar projectiles for defects in safety-critical parts. In 2003, several lots of mortar projectiles had a relatively high defect rate, 0.24%. Before releasing the projectiles, the Army reevaluated the chance of a safety-critical failure. Limit state functions and Monte Carlo simulations were used to estimate reliability. Measured distributions of wall thickness, defect rate, material strength, and applied loads were used with calculated stresses to estimate the probability of failure. The results predicted less than one failure in one million firings. As of 2008, the mortar projectiles have been used without any safety-critical incident.

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

    Science.gov (United States)

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

    2013-11-01

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

  3. Chemical-physical and mineralogical investigation on ancient mortars from the archaeological site of Monte Sannace (Bari-Southern Italy)

    Energy Technology Data Exchange (ETDEWEB)

    Bruno, P.; Calabrese, D.; Di Pierro, M.; Genga, A.; Laganara, C.; Manigrassi, D.A.P.; Traini, A.; Ubbriaco, P

    2004-08-15

    This study concerns experimental results of a chemical-physical and mineralogical characterisation of some mortars, sampled by different masonries brought to light during excavations of the site of Monte Sannace. The aim of the research is to provide, through the characterisation of the mortar samples and the relative raw materials, useful information in order to define the stages of construction and the workers' technological knowledge during different historical periods. DTA/TG/DTG thermoanalytical investigations and X-ray diffractometry analyses can allow to define the nature of both the binder and aggregate materials. As regards a specific mortar with hydraulic behaviour such a study has allowed to recognise also the residual reactivity towards lime of the 'pozzolanic' sand, rich in volcanic ashes, used as aggregate in the original mortar. The thermoanalytical and X-ray diffractometric results together with the granulometric and chemical determinations allow to get information about the preparation techniques of binding materials of old masonries.

  4. 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...

  5. Drying Shrinkage of Mortar with Manufactured Sand%机制砂砂浆干缩性能的研究

    Institute of Scientific and Technical Information of China (English)

    王雨利; 刘素霞; 王卫东; 赵豫洁

    2011-01-01

    Influence of sand-cement ratio on drying shrinkage of mortar with limestone manufactured sand was researched. And the effects of lithologic characters of manufactured sand and the limestone powder content on drying shrinkage of mortars were also studied. The experimental results show that the drying shrinkage of mortar increases with the decrease of sand-cement ratio. The drying shrinkage of mortar increases tiny before the void of sand is mixed fully, and then its drying shrinkage will increase quickly. Drying shrinkage of mortar with limestone manufactured sand is bigger than mortars with granitic and quartzite manufactured sands at early stage(≤7d), and they are reverse after 7d. And drying shrinkage of mortar with manufactured sands is all bigger than that of mortar with river sand. With the increase of limestone powder content, drying shrinkage of mortar with limestone manufactured sand increases firstly, and then decreases. When the curing age is less than 3 days, the drying shrinkage of mortar with 10% lime-stone powder is the least And the curing age is longer than 7 days, the drying shrinkage of mortar with 15% lime-stone powder is the least.%研究了砂灰比对石灰岩机制砂砂浆干缩率、不同类型砂对砂浆干缩率、不同石粉含量对砂浆干缩率的影响.结果表明,随着砂灰比的减小,即水泥浆量的增加,干缩率呈增大的趋势;但在水泥浆未填充满砂子空隙之前,随着水泥浆的增加,干缩率的增幅很小,当填充满之后继续增加,增幅明显变大.在早期(≤7d),石灰岩机制砂砂浆的干缩率大于花岗岩和石英岩机制砂,在后期(>7d),花岗岩和石英岩机制砂砂浆的干缩率大于石灰岩机制砂;在各个龄期,3种机制砂砂浆的干缩率均大于河砂的.随着石粉含量的增大,机制砂砂浆的收缩率先减小后增大.在早期(1d、3d),石粉含量为10%时砂浆干缩率最小;在后期(≥7d),石粉含量为15%时砂浆干缩率最小.

  6. 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%.

  7. Aging Mechanism of Quicklime and Application Study of Aged Lime in Conservation of Cultural Relics%石灰陈化机理及其在文物保护中的应用研究

    Institute of Scientific and Technical Information of China (English)

    魏国锋; 张秉坚; 方世强

    2012-01-01

    Aging mechanism of quicklime and application of aged lime in conservation of cultural relics were studied by means of scanning electron microscope(SEM)and X-ray diffractometry. Results show that calcium hydroxide crystals undergo both substantial size reduction and clear morphological change to form acicular Ca(OH)2(50 nm in diameter and 200 nm in length)and plate-like Ca(OH)2(100 -200 nm in size)crys-tals in the course of aging. Meanwhile, research results indicate that the nano size and high reactivity of aged lime particles prompt the improvement of the mechanical properties of sticky rice-lime mortar and hydraulic conductivity of Ca(OH)2-alcohol dispersions, which solves the problems of low dissolution and permeability associated with the use of Ca(OH)2 solutions. This study is expected to found the stone for application of aged lime in conservation of cultural relics.%采用SEM和XRD等技术手段,探讨了石灰陈化过程机理及其在文物保护中应用的可行性.结果表明,石灰在陈化过程中,随着陈化时间的增加,氢氧化钙的粒径呈现逐渐减小的趋势,形成了直径约50 nm、长度约200 nm的针状氢氧化钙,以及粒径为100~200 nm的板状氢氧化钙;陈化石灰的纳米粒径和高反应活性较好地改善了陈化石灰糯米灰浆的抗压强度、表面硬度等物理性能,并使陈化石灰-乙醇分散液具有良好的渗透性,可较好地解决传统石灰水加固剂溶解度较小和渗透性较差的问题,为其在砖、石、土质文物保护中的应用奠定科学基础.

  8. ASSESSMENT OF FINE RECYCLED AGGREGATES IN MORTAR

    OpenAIRE

    Feys, Charles; Joseph, Miquel; Boehme, Luc; Zhang, Yunlian

    2016-01-01

    In this study, the influence of fine recycled concrete aggregates as replacement for sand in mortar and the use as cement replacement and filler is investigated. Mortar with fine recycled aggregates is examined on its mechanical and physical properties. The samples are also examined on a microscopic scale. The fine recycled concrete aggregates are made with one-year old concrete made in the laboratory. Fine recycled aggregates (FRCA) are added as a cement replacement (0 %, 10 %...

  9. Modeling of Degradation Processes in Historical Mortars

    OpenAIRE

    Sýkora, J

    2014-01-01

    The aim of presented paper is modeling of degradation processes in historical mortars exposed to moisture impact during freezing. Internal damage caused by ice crystallization in pores is one of the most important factors limiting the service life of historical structures. Coupling the transport processes with the mechanical part will allow us to address the impact of moisture on the durability, strength and stiffness of mortars. This should be accomplished with the help of a complex thermo-h...

  10. FarmLime manual: for small-scale production of agricultural lime

    OpenAIRE

    Mitchell, C. J.; Mwanza, M.

    2005-01-01

    This manual is a concise guide to the small-scale production of agricultural lime. It was developed as part of a research project, ‘Low-cost lime for small-scale farming’ otherwise known as FarmLime (Mitchell, CJ, 2005). The ideal agricultural lime is a ground dolomite or dolomitic limestone with a particle size of 100%

  11. 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

  12. Rilem TC 203-RHM: Repair mortars for historic masonry. Requirements for repointing mortars for historic masonry

    NARCIS (Netherlands)

    Hees, R.P.J. van; Groot, C.; Hughes, J.J.; Balen, K. van; Bicer-Simsir, B.; Binda, L.; Elsen, J.; Konow, T. von; Lindqvist, J.E.; Papayanni, I.; Subercaseaux, M.; Tedeschi, C.; Toumbakari, E.E.; Thompson, B.

    2012-01-01

    This paper gives a summary of functional and performance requirements for repointing mortars for historic masonry (design, execution and maintenance). Successful performance of repair and conservation of mortar in historic masonry requires more care with design and execution than with modern masonry

  13. A STUDY OF THE EFFECTS OF POST-COMBUSTION AMMONIA INJECTION ON FLY ASH QUALITY: CHARACTERIZATION OF AMMONIA RELEASE FROM CONCRETE AND MORTARS CONTAINING FLY ASH AS A POZZOLANIC ADMIXTURE

    Energy Technology Data Exchange (ETDEWEB)

    Robert F. Rathbone; Thomas L. Robl

    2001-10-11

    Work completed in this reporting period focused on the measurement of the rate of ammonia loss from mortar and concrete, and the measurement of ammonia gas in the air above the materials immediately after placement. The majority of mortar experiments have been completed, and testing has begun on concrete. The mortar experiments indicate that the rate of ammonia loss is greater in mortars prepared using a higher water content and water:cement (W:C) ratio, although the higher rate is primarily observed within the first 2 days, after which the loss rates are nearly the same. The source of low-calcium (Class F) fly ash exerted a negligible influence on the loss rate. However, mortar prepared using a higher-calcium fly ash evolved ammonia at a slightly slower rate than the Class F ash mortars. The data also indicate that an increase in ventilation increases the ammonia loss rate from mortar, and suggest that a well-ventilated space could substantially increase the loss of ammonia from mortar and, by inference, a concrete slab. Analysis of ammonia concentrations in the air above freshly-placed mortars in an enclosed space indicate that the fly ash ammonia concentration should not exceed 100 mg N/kg ash in confined space applications. For most other applications with some ventilation the maximum acceptable concentration would be approximately 200 mg/kg. Early results from experiments on concrete suggest that, under similar conditions, ammonia diffusion from concrete occurs at a higher rate than in mortar. In addition, increasing the slump of concrete through the use of chemical admixtures has only a minor effect on the ammonia loss rate.

  14. Quantitative microstructure analysis of polymer-modified mortars.

    Science.gov (United States)

    Jenni, A; Herwegh, M; Zurbriggen, R; Aberle, T; Holzer, L

    2003-11-01

    Digital light, fluorescence and electron microscopy in combination with wavelength-dispersive spectroscopy were used to visualize individual polymers, air voids, cement phases and filler minerals in a polymer-modified cementitious tile adhesive. In order to investigate the evolution and processes involved in formation of the mortar microstructure, quantifications of the phase distribution in the mortar were performed including phase-specific imaging and digital image analysis. The required sample preparation techniques and imaging related topics are discussed. As a form of case study, the different techniques were applied to obtain a quantitative characterization of a specific mortar mixture. The results indicate that the mortar fractionates during different stages ranging from the early fresh mortar until the final hardened mortar stage. This induces process-dependent enrichments of the phases at specific locations in the mortar. The approach presented provides important information for a comprehensive understanding of the functionality of polymer-modified mortars.

  15. Cement Pastes and Mortars Containing Nitrogen-Doped and Oxygen-Functionalized Multiwalled Carbon Nanotubes

    Directory of Open Access Journals (Sweden)

    Mauricio Martínez-Alanis

    2016-01-01

    Full Text Available Cement pastes and mortars based on ordinary Portland cement containing nitrogen-doped multiwalled carbon nanotubes (MWCNT-Nx or oxygen-functionalized multiwalled carbon nanotubes (MWCNT-Ox are investigated. To incorporate MWCNTs into the cementitious matrix, the as-produced carpets are dispersed over periods of 1 and 2 hours in distilled water at pH levels of 1 and 7. The cement pastes are prepared by adding 0.1 wt% of MWCNTs to cement powder, followed by characterization with SEM and X-ray diffraction (XRD at an early age (first hours of hydration. The mortars are mechanically characterized during the hydration process for a period of 28 days. SEM characterization of cement pastes revealed that the carbon nanotubes are well incorporated in the cementitious matrix, with the hydrated cement grains interconnected by long carbon nanotubes. XRD characterizations demonstrated that, during the hydration of cement pastes, different peaks emerged that were associated with ettringite, hydrated calcium silicate, and calcium hydroxide, among other structures. Results of the compressive strength measurements for mortars simultaneously mixed with MWCNT-Nx and MWCNT-Ox reached an increment of approximately 30% in compressive strength. In addition, density functional theory calculations were performed in nitrogen-doped and oxygen-functionalized carbon nanotubes interacting with a cement grain.

  16. High-Performance Grouting Mortar Based on Mineral Admixtures

    OpenAIRE

    2015-01-01

    A study on high-performance grouting mortar is reported. The common mortar was modified by mineral admixtures such as gypsum, bauxite, and alunite. The effects of mineral admixtures on the fluidity, setting time, expansion, strength, and other properties of mortar were evaluated experimentally. The microstructure of the modified mortar was characterized by X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. Moreover, the expansive performance and strength of th...

  17. Pengaruh Perendaman Air Laut Terhadap Kualitas Mortar Semen

    OpenAIRE

    Damayanti, Mentari C.; Rauf, Nurlaela; Juarlin, Eko

    2015-01-01

    This research of fabrication cement with adding sugarcane bagasse ash (SBA) as pozzolan. Then chemical composition of cement sample is measured by XRF, setting time of cement and mortar compressive strength is examined with and without immersion. The result showed sea water gives influence for mortar compressive strength. Mortar compressive strength without immersion increases with 6% persentage composition of SBA. While mortar compressive strength with immersion of sea water decreases along ...

  18. The aggressiveness of pig slurry to cement mortars

    OpenAIRE

    Massana Guitart, Jordi; Guerrero Bustos, Ana; Antón Fuentes, Rebeca; Garcimartin Molina, Miguel Angel; Sanchez Espinosa, Elvira

    2013-01-01

    The aim was to measure the behaviour of various mortars employed in livestock media in central Spain and to analyse the aggressiveness of pig slurry to cement blended with fly ash mortars. To achieve this, mortar specimens were immersed in ponds storing pig slurry. Mortar specimens, of 40 ? 40 ? 160 mm, were made from four types of cement commonly used and recommended for rural areas. The types were a sulphate-resistant Portland cement and three cements blended in different proportions with ...

  19. Behavior of fiber reinforced mortar joints in masonry walls subjected to in-plane shear and out-of-plane bending

    Science.gov (United States)

    Armwood, Catherine K.

    In this project, 26 fiber-reinforced mortar (FRM) mixtures are evaluated for their workability and strength characteristics. The specimens tested include two control mixtures and 24 FRMs. The mixtures were made of two types of binders; Type N Portland cement lime (Type N-PCL) and Natural Hydrated Lime 5 (NHL5); and 6 fiber types (5 synthetic fibers and one organic). When tested in flexure, the results indicate that majority of the synthetic fiber mixtures enhanced the performance of the mortar and the nano-nylon and horse hair fibers were the least effective in improving the mortar's modulus of rupture, ductility, and energy absorption. Four FRMs that improved the mortar's mechanical properties most during the flexural strength test were then used to conduct additional experiments. The FRM's compressive strength, as well as flexural and shear bond strength with clay and concrete masonry units were determined. Those four mixtures included Type N-PCL as the binder and 4 synthetic fibers. They were evaluated at a standard laboratory flow rate of 110% +/- 5% and a practical field flow rate of 130% +/- 5%. Results indicate that the use of fibers decreases the compressive strength of the mortar most of the time. However, the bond strength test results were promising: 81% of the FRM mixtures increased the flexural bond strength of the prism. The mixtures at 110 +/- 5% flow rate bonded better with concrete bricks and those ate 130+/-5% flow rate bonded better with clay bricks. The results of the shear bond strength show 50% of the FRM mixtures improved the shear bond strength. The FRM mixtures at 110+/-5% flow rate bonded with clay units provided the most improvement in shear bond strength compared to control specimen results. Along with detailed discussions and derived conclusions of these experiments, this dissertation includes recommendations for the most feasible FRM for different applications.

  20. Effect of lime, gypsum and potassium chloride on growth and nutrient uptake of longkong (Aglaia dookkoo Griff. seedlings

    Directory of Open Access Journals (Sweden)

    Malee, N.

    2007-05-01

    Full Text Available Application of lime and gypsum for alleviation of aluminum toxicity in acid soil, including potassium (K fertilization, may interfere with the nutrient uptake of longkong (Aglaia dookkoo Griff. trees. Threeexperiments were conducted to explore the possible problem of longkong soil. 1 Effect of lime and gypsum on growth and nutrient uptake of longkong seedling. 2 Effect of lime and potassium chloride on potassiumand magnesium uptake of longkong. 3 Relationship between potassium, calcium and magnesium in longkong leaves. The results showed that exchangeable aluminum in the soil decreased with the increase of Ca(OH2 treatment and the application of lime was more effective than that of the gypsum treatment. Theapplication of lime and gypsum tended to increase nutrient concentration in longkong, but did not affect the growth of longkong seedlings. The lime application on nutrient uptake of longkong seedlings decreased Kuptake; no lime and lime treatments were 863 and 720 mg tree-1, while without K applied the per tree uptakes were 579 and 356 mg tree-1 respectively. Besides the K application treatment reduced Ca and Mg uptake.Negative correlations between K and Ca (r = -0.532** and between K and Mg (r = -0.663** in leaves of 60 longkong trees in a farmer's orchard were found.

  1. MORTAR FINITE VOLUME METHOD WITH ADINI ELEMENT FOR BIHARMONIC PROBLEM

    Institute of Scientific and Technical Information of China (English)

    Chun-jia Bi; Li-kang Li

    2004-01-01

    In this paper, we construct and analyse a mortar finite volume method for the dis-cretization for the biharmonic problem in R2. This method is based on the mortar-type Adini nonconforming finite element spaces. The optimal order H2-seminorm error estimate between the exact solution and the mortar Adini finite volume solution of the biharmonic equation is established.

  2. Raman scattering or fluorescence emission? Raman spectroscopy study on lime-based building and conservation materials.

    Science.gov (United States)

    Kaszowska, Zofia; Malek, Kamilla; Staniszewska-Slezak, Emilia; Niedzielska, Karina

    2016-12-01

    This work presents an in-depth study on Raman spectra excited with 1064 and 532nm lasers of lime binders employed in the past as building materials and revealed today as valuable conservation materials. We focus our interest on the bands of strong intensity, which are present in the spectra of all binders acquired with laser excitation at 1064nm, but absent in the corresponding spectra acquired with laser excitation at 532nm. We suggest, that the first group of spectra represents fluorescence phenomena of unknown origin and the second true Raman scattering. In our studies, we also include two other phases of lime cycle, i.e. calcium carbonate (a few samples of calcite of various origins) and calcium oxide (quicklime) to assess how structural and chemical transformations of lime phases affect the NIR-Raman spectral profile. Furthermore, we analyse a set of carbonated limewashes and lime binders derived from old plasters to give an insight into their spectral characteristics after excitation with the 1064nm laser line. NIR-Raman micro-mapping results are also presented to reveal the spatial distribution of building materials and fluorescent species in the cross-section of plaster samples taken from a 15th century chapel. Our study shows that the Raman analysis can help identify lime-based building and conservation materials, however, a caution is advised in the interpretation of the spectra acquired using 1064nm excitation. PMID:27314909

  3. Effect of metakaolinite on strength and chemical resistance of cement mortars

    Energy Technology Data Exchange (ETDEWEB)

    Malolepszy, J.; Pytel, Z. [Mining and Metallurgy Univ., Faculty of Materials Science and Ceramics, Cracow (Poland)

    2000-07-01

    The effect of the percentage of metakaolinite admixture and calcium aluminate content in portland cement, used as the main cementitious components, on the chemical resistance of a series of prepared standard mortars was investigated. Chemical resistance was evaluated by measuring strength, shrinkage and expansion on the samples stored in water and chemical solutions. Results showed minimal change in the standard properties of mortars by the metakaolinite. However, there was marked improvement in chemical resistance. Interest in the study of this material is related to the urgency of finding a useful application for it, in view of the fact that it is produced in large quantities as a waste-product of power generation. It is widely believed that there is a potential application for this product in improving the durability of concrete. 20 refs., 10 tabs., 9 figs.

  4. Enhancing self-healing of lime mortars by built-in crystallization inhibitors

    NARCIS (Netherlands)

    Granneman, S.J.C.; Lubelli, B.; Van Hees, R.P.J.

    2013-01-01

    The weathering of porous materials due to the presence of salts has been known since antiquity. However, serious studies and investigations were not conducted until the 19th century. One of the fi elds of interest includes historic masonry, where salt damage can affect natural stone, brick and morta

  5. The efficacy assessment of water repellent agent POLYMEMBRAN applied on natural stone and hardened lime mortar

    OpenAIRE

    Hasníková, Hana

    2014-01-01

    The subject of the study was assess the influence of water repellent agent on the properties of four different natural stones that are frequently used building material in the Czech Republic. Besides color change were primarily assessed changes in the microstructure, which significantly influences the transport of water and water vapour through treated material.

  6. 陶寺、殷墟白灰面的红外光谱研究%Study on Archaeological Lime Powders from Taosi and Yinxu Sites by FTIR

    Institute of Scientific and Technical Information of China (English)

    魏国锋; 张晨; 陈国梁; 何毓灵; 高江涛; 张秉坚

    2015-01-01

    采用傅里叶变换红外光谱(FTIR)对天然石灰石、模拟白灰面以及采自陶寺遗址和殷墟遗址的白灰面进行了分析检测,以探明陶寺和殷墟遗址白灰面所用原料。结果显示,人工烧制石灰碳化后所形成的方解石,其ν2/ν4比值高达6.31,明显高于天然石灰石中的方解石,从而表明人工烧制石灰碳化所形成的方解石较之天然石灰石中的方解石具有较高的晶体无序度;随着研磨程度的增加,天然石灰石中的方解石和人工烧制石灰碳化形成的方解石,其ν2和ν4值逐渐减小,人工烧制石灰碳化形成方解石的ν2-ν4特征趋势线斜率较高,从而为考古出土人工烧制石灰的判定提供了一种简便、有效的方法。根据此判别方法,陶寺和殷墟遗址的白灰面很可能是采用人工烧制石灰所制备的,表明中国古代先民在距今4300多年的新石器时代晚期已掌握了石灰烧制技术。%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 pow-ders from Taosi and Yinxu sites.Results show thatν2/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 ofν2 andν4 in natural lime-stone and prepared lime mortar decrease.Meanwhile,the trend lines ofν2 versusν4 for calcite in experimentally prepared lime mortar have a steeper slope when compared to calcite in natural limestone.These imply thatν2/ν4 ratio and the slope of the trend lines ofν2 versusν4 can be used to determine the archaeological man-made lime.Based on the experiment results,it is

  7. Expansive mortar-induced ocular injury.

    Science.gov (United States)

    Balasubramanya, Ramamurthy; Rani, Alka; Sangwan, Virender S

    2006-12-01

    We describe here a case of bilateral chemical injury (with an expansive mortar which is being used in recent times to cut the rocks). On examination limbal ischemia was more in the left eye (9 clock hours) than the right eye (2 clock hours). The case was managed by bilateral removal of foreign bodies, along with conjunctival resection and amniotic membrane transplantation in the left eye. At six-month follow-up, patient had best corrected visual acuity of 20/30 and 20/60 in the right and left eyes respectively. Since this being an occupational hazard, proper eye protection gear should be used by persons using this expansive mortar.

  8. Drug contamination of mortars and pestles.

    Science.gov (United States)

    Swinyard, E A; Woodhead, J H

    1978-12-01

    Evidence is presented suggesting that potent water-insoluble antipentylenetetrazol agents triturated in porcelain mortars and pestles are not removed from this mixing device by the usual laboratory washing procedure. Moreover, amounts sufficient to contaminate the next substance triturated in this vessel can be demonstrated by the subcutaneous pentylenetetrazol seizure threshold test. The data show that a rigorous washing routine must be followed to achieve a "clean" mortar and pestle. Attention is also directed to the importance of using disposable hypodermic syringes, test tubes, etc., whenever possible and of designing an internal control test to determine when implements that must be reused are "clean."

  9. Correlation Between Initial Calcium Oxide Content of Slag Blended Cement and Mortar Leaching Mass Loss%矿渣混合水泥中初始氧化钙含量与砂浆溶蚀质量损失的关系

    Institute of Scientific and Technical Information of China (English)

    王培铭; 庞敏; 刘贤萍

    2016-01-01

    In the accelerated corrosion 142 d, the leaching mass loss behavior of Portland cement and slag blended cement of three different slag contents (50%, 70% and 90%, in mass fraction) mortar with two different pre-cured ages (28 and 180 d) was investigated. The initial CaO content, calcium hydroxide (CH) content and total hydration degree were analyzed. Based on the relation between CH content and initial CaO content in cement as well as mass loss, the correlation between the initial CaO content and mass loss, and the effect of total hydration degree on mass loss were studied. The results show that the mass loss of all the specimens of two different pre-cured age increase with the increase of leaching time (after 84 d increased slowly), decrease with the increase of addition of slag in blended cement. That is slag can improve the corrosion resistance performance, the fundamental cause of above improvement lies in slag reduced the CH content and hydration degree of blended cement paste. The mass loss with leaching time of 84 d and CH content (0 except) in cement paste, as well as the hydration degree (only slag blended cement) has the following linear relationship respectively. The former is y=0.207 5x–0.015 7, the latter is y=0.029 6x–0.125 4. The mass loss with leaching time of 84 d and initial CaO content in cement has a logarithmic relationship. Pre-cured 28 d, the regression equation is y=6.059ln(x)–22.164. Pre-cured 180 d, the regression equation is y=7.612 3ln(x)–27.656. Based on the logarithmic relationship, cement mortar corrosion resistance can be preliminary judged.%研究了2个预养护龄期(28和180 d)的硅酸盐水泥和3个矿渣粉掺量(50%、70%和90%)的混合水泥砂浆在加速溶蚀142 d 内的溶蚀质量损失规律,分析了硅酸盐水泥和混合水泥初始 CaO 含量、浆体中氢氧化钙(CH)含量和水化程度,基于浆体中 CH 含量与水泥初始 CaO 含量,以及溶蚀质量损失之间的

  10. Influence of the activators’ type and content on the properties of no cement mortars%激发剂种类及掺量对无水泥砂浆性能的影响

    Institute of Scientific and Technical Information of China (English)

    张海龙; 裴长春

    2015-01-01

    为了优化工业垃圾粉煤灰、高炉矿渣及生石灰作为胶凝材料的无水泥砂浆配合比设计,提高无水泥砂浆的基础性能,试验通过改变碱性激发剂的种类及掺量,研究了无水泥砂浆的表观密度及力学性能,得出了一些有价值的结论。%In order to optimize the mix design of no cement mortars with fly ash, blast furnace slag and lime as cementitious materials and to im-prove the performance of no cement mortars, the test studied the apparent density and mechanical properties of no cement mortars by changing the type and dosage of alkaline activator, some valuable conclusions are obtained.

  11. Comparison of surface properties between kaolin and metakaolin in concentrated lime solutions.

    Science.gov (United States)

    Konan, K L; Peyratout, C; Smith, A; Bonnet, J-P; Rossignol, S; Oyetola, S

    2009-11-01

    The surface adsorption of calcium hydroxide onto kaolin and metakaolin was investigated by monitoring with atomic emission spectroscopy and pH measurements the amounts of ions left in solution after exposing clays to calcium hydroxide solutions of various concentrations. Both clays adsorb calcium and hydroxyl ions but differently. Kaolin adsorbs calcium hydroxide not only at the edges of the clay particles but also onto the basal faces. The adsorbed hydrated calcium ions form a layer on the clay particle surfaces, preventing further dissolution of the clay mineral platelet. Metakaolin shows high pozzolanic activity, which provides the quick formation of hydrated phases at the interfaces between metakaolin and lime solutions. The nature of the hydration products has been investigated using X-ray diffraction (XRD) and differential thermal analysis (DTA). The most important hydrated phases like CSH (hydrated calcium silicate) and C(2)ASH(8) (gehlenite) have been identified. PMID:19682702

  12. FarmLime Project Summary Report

    OpenAIRE

    Mitchell, C. J.; Simukanga, S.; Shitumbanuma, V.; Banda, D.; Walker, B; Steadman, E. J.; Muibeya, B.; Mwanza, M.; Mtonga, M.; Kapindula, D.

    2003-01-01

    This report summarises work funded by the Department for International Development Knowledge and Research programme, as part of the British Government’s programme of aid to developing countries. The ‘FarmLime: Low-cost lime for small-scale farming’ project (R7410) set out to investigate a way of improving the agricultural performance of small scale farms through the use of low-cost agricultural lime produced within the farming district using locally occurring dolomite. The main technical rese...

  13. Monitoring of self-healing phenomena towards enhanced sustainability of historic mortars

    Science.gov (United States)

    Amenta, M.; Karatasios, I.; Maravelaki, P.; Kilikoglou, V.

    2016-05-01

    Mortars are known for their ability to heal their defects in an autogenic way. This phenomenon is expressed by the filling of microcracks by secondary products, restoring or enhancing the material's performance. Parameterization of self-healing phenomenon could be a key factor for the enhanced sustainability of these materials in terms of reduced repair cost and consumption of natural raw materials and thus reduced environmental fingerprint. The fact that this phenomenon takes place autogenously suggests that the material can self-repair its defects, without external intervention, thus leading to a prolonged life cycle. In the present study, the autogenic self-healing phenomenon was studied in natural hydraulic lime mortars, considering aspects of curing time before initial cracking, duration and conditions of the healing period. Furthermore, strength recovery due to autogenic self-healing was measured under high humidity conditions, and thermo-gravimetric analysis (DTA/TG) was performed in all specimens in order to quantitatively assess the available unreacted components in the binder at all ages. Regarding the microstructure of the healing phases, the main products formed during healing consist of calcite and various C-S-H/C-A-H phases. Depending on the parameters mentioned above, there is a wide diversity in the intensity, typology and topography of the secondary phases inside the cracks. The main differences discussed were observed between specimens cracked at very early age and those damaged after 30 days of curing. Similarly, the mechanical properties of the crack-healed specimens were associated with the above findings and especially with the available each-time amount of lime, determined by thermo-gravimetric analysis.

  14. FarmLime: Low-cost lime for small-scale farming

    OpenAIRE

    Mitchell, C. J.

    2005-01-01

    FarmLime (Low-cost lime for small-scale farming) is a multidisciplinary research project that aims to increase the food security of small-scale farmers by improving their access to agricultural lime which neutralises soil acidity and adds nutrients. This project focused on farming districts in northern Zambia that have highly acidic soils with poor crop yields. The aim was to locate suitable carbonate rocks in these farming districts and produce agricultural lime using a low cost method, elim...

  15. Liming can decrease legume crop yield and leaf gas exchange by enhancing root to shoot ABA signalling.

    Science.gov (United States)

    Rothwell, Shane A; Elphinstone, E David; Dodd, Ian C

    2015-04-01

    To meet future requirements for food production, sustainable intensive agricultural systems need to optimize nutrient availability to maximize yield, traditionally achieved by maintaining soil pH within an optimal range (6-6.5) by applying lime (calcium carbonate). However, a field trial that applied recommended liming rates to a sandy loam soil (increasing soil pH from 5.5 to 6.2) decreased pod yield of field bean (Vicia faba L. cv. Fuego) by ~30%. Subsequent pot trials, with liming that raised soil pH to 6.3-6.7, reduced stomatal conductance (g(s)) by 63, 26, and 59% in V. faba, bean (Phaseolus vulgaris), and pea (Pisum sativum), respectively. Furthermore, liming reduced shoot dry biomass by 16-24% in these species. Ionomic analysis of root xylem sap and leaf tissue revealed a decrease in phosphorus concentration that was correlated with decreased g(s): both reductions were partially reversed by adding superphosphate fertilizer. Further analysis of pea suggests that leaf gas exchange was reduced by a systemic increase (roots, xylem sap, and leaves) in the phytohormone abscisic acid (ABA) in response to lime-induced suboptimal plant phosphorus concentrations. Supplying synthetic ABA via the transpiration stream to detached pea leaves, at the same xylem sap concentrations induced by liming, decreased transpiration. Furthermore, the g(s) of the ABA-deficient mutant pea wilty was unresponsive to liming, apparently confirming that ABA mediates some responses to low phosphorus availability caused by liming. This research provides a detailed mechanistic understanding of the physiological processes by which lime application can limit crop yields, and questions the suitability of current liming recommendations. PMID:25740925

  16. EFFECT OF NANOMATERIALS IN CEMENT MORTAR CHARACTERISTICS

    Directory of Open Access Journals (Sweden)

    WAIL N. AL-RIFAIE

    2016-09-01

    Full Text Available Concrete is considered as brittle materials and widely used due to high compressive strength but unfortunately having and has low tensile strength that has a numerous negative impacts on the lifespan of concrete made structures. Therefore, mechanical properties of cement mortar have been investigated experimentally using different types and ratios of nano material to improve the properties. Since the strength of the concrete is of high importance, different materials have been used to enhance the compressive and the tensile characteristics of the cement mortar compressive and tensile strength. Mainly, this objective has been implemented through using micro cement, micro sand, nano silica, and nano clay in developing a nano-cement mortar which can to improve the concrete for the constructional applications. The samples were prepared and tested under tensile and compressive mode according to ASTM-2011 regulations for concrete. The parameters that are taken consideration during the investigation were micro sand, micro cement, nano silica, developed nano clay, and naphthalene sulphonate as super- plasticizers. In general, it has been observed that the results showed a significant increase in both compressive and tensile strength of the mortar at early stages of hardening, where a maximum increase of 22% in the compressive strength was achieved , whereas 3.7 time increase in the compressive strength was recorded over the tradition levels of the concrete strength.

  17. Chloride ingress in cement paste and mortar

    DEFF Research Database (Denmark)

    Jensen, Ole Mejlhede; Hansen, Per Freiesleben; Coats, Alison M.;

    1999-01-01

    In this paper chloride ingress in cement paste and mortar is followed by electron probe microanalysis. The influence of several paste and exposure parameters on chloride ingress are examined (e.g., water-cement ratio, silica fume addition, exposure time, and temperature), The measurements...

  18. Métodos de determinação de cálcio e magnésio trocáveis e estimativa do calcário residual em um Latossolo submetido à aplicação de calcário e gesso em superfície Methods for determining soil exchangeable calcium and magnesium and residual lime in an oxisol submitted to surface application of lime and phosphogypsum

    Directory of Open Access Journals (Sweden)

    Rogério Peres Soratto

    2008-04-01

    Full Text Available A determinação da fração do calcário remanescente no solo ("calcário residual", em área onde foi realizada aplicação de calcário em superfície, sem incorporação, na implantação do sistema plantio direto, pode ser uma ferramenta importante para auxiliar na definição do momento em que se faz necessária a reaplicação de calcário. Nesse sentido, os objetivos deste trabalho foram avaliar: quais os teores de Ca e Mg trocáveis, extraídos por percolação com solução de KCl e resina trocadora de íons; a quantidade do calcário aplicado que ainda não havia reagido no solo, mediante a determinação dos teores de Ca e Mg não-trocáveis; e qual a influência do gesso nos teores de Ca e Mg trocáveis e na dissolução do calcário, 18 meses após a aplicação em superfície. O experimento foi realizado em um Latossolo Vermelho distroférrico, em Botucatu (SP. O delineamento experimental foi de blocos casualizados com parcelas subdivididas e quatro repetições. Nas parcelas, foram aplicadas quatro doses de calcário dolomítico (0, 1.100, 2.700 e 4.300 kg ha-1, com PRNT = 71,2 %, e nas subparcelas, duas doses de gesso agrícola (0 e 2.100 kg ha-1. O calcário e o gesso foram aplicados em superfície, sem incorporação. Houve alta correlação na determinação de Ca e Mg trocável entre os métodos de percolação com solução de KCl e resina trocadora de íons. A extração pelo método da resina trocadora de íons superestimou os teores de Ca e Mg trocáveis em solo com recente aplicação de calcário em superfície. A aplicação de gesso em superfície reduziu a dissolução do calcário na camada superficial (0-0,10 m. Os teores de Ca e Mg não-trocáveis podem ser utilizados para estimar a quantidade de calcário residual no solo.The determination of the non-reacted lime fraction in the soil ("residual lime" after initial surface application of lime without incorporation in no-tillage systems can be important to

  19. Estudo da durabilidade de argamassas alternativas contendo resíduos Durability study of alternative mortars containing wastes

    Directory of Open Access Journals (Sweden)

    J. Farias Filho

    2011-12-01

    study the durability of the alternative mortar incorporated with residues from civil construction and from granite industry. To quantify the durability of the studied materials, it was made test of natural and accelerated weathering through wetting and drying cycles. The materials were submitted to conditions that simulated their use to evaluate their degradation. In the studies of durability of the mortar elevation, percentages of substitutions of lime by recycling residue were used. The amount changed from 30% to 50%. The natural weathering cause a compromise in the durability of the material after 60 days with a decrease in the mechanical behavior and the best results occur to the sample with 30% and 50% of residue. In the accelerated weathering, the results show indicate the formation of calcium and potassium aluminosilicates that can give an increase in the mechanical behavior, however, it was not observed a compromise in the material durability.

  20. Compressive Strength Development and Microstrueture of Cement.asphalt Mortar

    Institute of Scientific and Technical Information of China (English)

    WANG Qiang; YAN Peiyu; KONG Xiangming; YANG Jinbo

    2011-01-01

    The compressive strength developing process and the microstructure of cement-asphalt mortar (CA mortar) were investigated.The fluidity of CA mortar has a great influence on its strength.The optimum value of spread diameter of slump flow test is in the range of 300 to 400 mm.The compressive strength of CA mortar keeps a relatively high growth rate in 56 days and grows slowly afterwards.The residual water of hydration in CA mortar freezes under minus environmental temperature which can lead to a significant reduction of the strength of CA mortar.Increasing A/C retards asphalt emulsion splitting and thus prolongs the setting process of CA mortar.The hydration products of cement form the major structural framework of hardened CA mortar and asphalt is a weak phase in the framework but improves the viscoelastic behavior of CA mortar.Therefore,asphalt emulsion should be used as much as possible on the condition that essential performance criterions of CA mortar are satisfied.

  1. Application of antifungal CFB to increase the durability of cement mortar.

    Science.gov (United States)

    Park, Jong-Myong; Park, Sung-Jin; Kim, Wha-Jung; Ghim, Sa-Youl

    2012-07-01

    Antifungal cement mortar or microbiological calcium carbonate precipitation on cement surface has been investigated as functional concrete research. However, these research concepts have never been fused with each other. In this study, we introduced the antifungal calciteforming bacteria (CFB) Bacillus aryabhattai KNUC205, isolated from an urban tunnel (Daegu, South Korea). The major fungal deteriogens in urban tunnel, Cladosporium sphaerospermum KNUC253, was used as a sensitive fungal strain. B. aryabhattai KNUC205 showed CaCO3 precipitation on B4 medium. Cracked cement mortar pastes were made and neutralized by modified methods. Subsequently, the mixture of B. aryabhattai KNUC205, conidiospore of C. sphaerospermum KNUC253, and B4 agar was applied to cement cracks and incubated at 18 degrees C for 16 days. B. aryabhattai KNUC205 showed fungal growth inhibition against C. sphaerospermum. Furthermore, B. aryabhattai KNUC205 showed crack remediation ability and water permeability reduction of cement mortar pastes. Taken together, these results suggest that the CaCO3 precipitation and antifungal properties of B. aryabhattai KNUC205 could be used as an effective sealing or coating material that can also prevent deteriorative fungal growth. This study is the first application and evaluation research that incorporates calcite formation with antifungal capabilities of microorganisms for an environment-friendly and more effective protection of cement materials. In this research, the conception of microbial construction materials was expanded.

  2. Monitoring accelerated carbonation on standard Portland cement mortar by nonlinear resonance acoustic test

    Science.gov (United States)

    Eiras, J. N.; Kundu, T.; Popovics, J. S.; Monzó, J.; Borrachero, M. V.; Payá, J.

    2015-03-01

    Carbonation is an important deleterious process for concrete structures. Carbonation begins when carbon dioxide (CO2) present in the atmosphere reacts with portlandite producing calcium carbonate (CaCO3). In severe carbonation conditions, C-S-H gel is decomposed into silica gel (SiO2.nH2O) and CaCO3. As a result, concrete pore water pH decreases (usually below 10) and eventually steel reinforcing bars become unprotected from corrosion agents. Usually, the carbonation of the cementing matrix reduces the porosity, because CaCO3 crystals (calcite and vaterite) occupy more volume than portlandite. In this study, an accelerated carbonation-ageing process is conducted on Portland cement mortar samples with water to cement ratio of 0.5. The evolution of the carbonation process on mortar is monitored at different levels of ageing until the mortar is almost fully carbonated. A nondestructive technique based on nonlinear acoustic resonance is used to monitor the variation of the constitutive properties upon carbonation. At selected levels of ageing, the compressive strength is obtained. From fractured surfaces the depth of carbonation is determined with phenolphthalein solution. An image analysis of the fractured surfaces is used to quantify the depth of carbonation. The results from resonant acoustic tests revealed a progressive increase of stiffness and a decrease of material nonlinearity.

  3. Effect of Anti-freezing Admixtures on Alkali-silica Reaction in Mortars

    Institute of Scientific and Technical Information of China (English)

    LIU Junzhe; LI Yushun; LV Lihua

    2005-01-01

    The influence of anti-freezing admixture on the alkali aggregate reaction in mortar was analyzed with accelerated methods. It is confirmed that the addition of sodium salt ingredients of anti-freezing admixture accelerates the alkali silica reaction to some extent, whereas calcium salt ingredient of anti-freezing admixture reduces the expansion of alkali silica reaction caused by high alkali cement. It is found that the addition of the fly ash considerably suppresses the expansion of alkali silica reaction induced by the anti-freezing admixtures.

  4. 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.

  5. 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

  6. Properties of Rice Husk Ash (RHA and MIRHA Mortars

    Directory of Open Access Journals (Sweden)

    Narayanan Sambu Potty

    2014-05-01

    Full Text Available Rice husk Ash (produced by traditional burning called RHA and by using microwave incinerator called MIRHA has shown promise as a cement replacement material. This study investigated the properties of RHA and MIRHA mortar used for brick manufacture at binder sand proportions of 1:3 and 1:4. RHA and MIRHA were intermediate in particle size to cement and sand particles. Percentages of replacement were 5, 10, 15, 20, 25 and 30%, respectively. Strength at w/c ratios (0.5, 0.55, 0.6 and 0.65, respectively was investigated to identify optimum w/c ratios as well as optimum percent replacement of RHA and MIRHA. Variations of IRS, density and water absorption were investigated. Generally 1:3 RHA and 1:3 MIRHA mortars strength showed decreasing trend with increasing percentage replacement with RHA and MIRHA. Whereas 1:4 RHA and 1:4 MIRHA mortars showed increase in strength at 5% replacement and decrease thereafter. IRS values for RHA mortars are generally within limits (0.25-1.5 kg/m2.min recommended. Water absorption values of RHA mortars are generally higher than control mortar. IRS values for MIRHA mortars with w/c 0.5 and 0.55 ranged between 1.4-2.0 kg/m2 .min; indicating the need for wetting the bricks before use. IRS values for 1:3 MIRHA mortars with w/c 0.6 and 0.65 were below 1.0 kg/m2.min indicating low suction values. For 1:4 MIRHA mortars, IRS values were very low in all cases. Water absorption values of MIRHA mortars are generally higher than the control mortar. MIRHA mortars with w/c 0.6 and 0.65 showed low percentages of water absorption.

  7. Low Carbon Footprint Mortar from Pozzolanic Waste Material

    OpenAIRE

    Taha Mehmannavaz; Salihuddin Radin Sumadi; Muhammad Aamer Rafique Bhutta; Mostafa Samadi; Seyed Mahdi Sajjadi

    2014-01-01

    Nowadays, Portland cement clinker leads to emission of CO2 into the atmosphere and therefore causes greenhouse effect. Incorporating of Palm Oil Fuel Ash (POFA) and Pulverized Fuel Ash (PFA) as partial cement replacement materials into mix of low carbon mortar decreases the amount of cement use and reduces high dependence on cements compared to ordinary mortar. The result of this research supported use of the new concept in preparing low carbon mortar for industrial constructions. Strength of...

  8. Flexural reinforcement of concrete with textile reinforced mortar TRM

    OpenAIRE

    Gil Espert, Lluís; Escrig Pérez, Christian; Bernat Masó, Ernest

    2013-01-01

    This work presents a method of strengthening concrete structures based on textiles of high strength and mortars. The combination of textiles and mortars produces a new composite material of cementitic matrix. This material can be used for the reinforcement of concrete beams under bending loads. We tested several combinations of fibers: glass, PBO, steel and carbon fibers with mortar and we used them to reinforce precast concrete beams. All the specimens were tested with a four-point load test...

  9. Effect of kaolin treatment temperature on mortar chloride permeability

    OpenAIRE

    Puertas, F.; Mejía de Gutiérrez, R.; J. Torres

    2007-01-01

    The present paper discusses the results of chloride resistance tests conducted on ordinary Portland cement (OPC) mortars containing a Colombian kaolin pre-treated at temperatures of from 600 to 800 ºC. The resulting metakaolin (MK) was added to OPC mortar mixes in proportions of 10 and 20% by cement weight. The mortars were compared for physical and chemical properties, including capillary absorption, chloride permeability and pore microstructure as assessed by mercury porosimetry....

  10. Influence of Pore Structure on Compressive Strength of Cement Mortar

    OpenAIRE

    Haitao Zhao; Qi Xiao; Donghui Huang; Shiping Zhang

    2014-01-01

    This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement r...

  11. Alkaline cement mortars. Chemical resistance to sulfate and seawater attack

    OpenAIRE

    Puertas, F.; Gutiérrez, R.; Fernández-Jiménez, A.; Delvasto, S.; Maldonado, J.

    2002-01-01

    The durability and chemical resistance of alkali activated slag and fly ash/slag mortars in contact with sulfates and seawater media have been studied. Two methods were used in the evaluation of such durability: Kock-Steinegger and ASTM C1012. A mineralogical and a microstructural characterization of mortars were done at different ages of their conservation in aggressive media through XRD, SEM/ EDX and mercury porosimetry. Results showed a high durability of activated cement mortars in s...

  12. Estimating compressive strength of concrete by mortar testing

    OpenAIRE

    Camões, Aires; Aguiar, J. L. Barroso de; Jalali, Said

    2005-01-01

    Concrete mix design laboratory tests which time consuming and entails considerable effort. This study presents a method of reducing mix design testing costs by testing mortar instead of concrete specimens. The experimental programme consisted of defining mortar mixes equivalent to concrete mixes, moulding specimens of both mortar and concrete mixes studied and finally evaluating the compressive strength of specimens cured at different curing time. Results obtained indicate that a goo...

  13. Durability of Lightweight Concrete and Mortar Exposed under Some Environment

    OpenAIRE

    Hiroshi, SAKURAI; Koichi, AYUTA; Noboru, SAEKI; Yoshio, Fujita; Seiji, Kaneko; Mikito, IKEDA

    1991-01-01

    In this experiment, identically composed specimens of lightweight concrete and of a mortar material were exposed to a cold (coastal) environment (Monbetsu), warm sea environment (Izu) and used in the roof of a building in a warm-climate city (Yokohama) for 3years. The physical and chemical properties of the lightweight concrete specimens and those of the mortar specimens were examined. The results are as follows : (1) The lightweight concrete specimen contained more salt than the same mortar ...

  14. Sulfate and acid resistant concrete and mortar

    Science.gov (United States)

    Liskowitz, John W.; Wecharatana, Methi; Jaturapitakkul, Chai; Cerkanowicz, deceased, Anthony E.

    1998-01-01

    The present invention relates to concrete, mortar and other hardenable mixtures comprising cement and fly ash for use in construction and other applications, which hardenable mixtures demonstrate significant levels of acid and sulfate resistance while maintaining acceptable compressive strength properties. The acid and sulfate hardenable mixtures of the invention containing fly ash comprise cementitious materials and a fine aggregate. The cementitous materials may comprise fly ash as well as cement. The fine aggregate may comprise fly ash as well as sand. The total amount of fly ash in the hardenable mixture ranges from about 60% to about 120% of the total amount of cement, by weight, whether the fly ash is included as a cementious material, fine aggregate, or an additive, or any combination of the foregoing. In specific examples, mortar containing 50% fly ash and 50% cement in cementitious materials demonstrated superior properties of corrosion resistance.

  15. Mortar constituent of concrete under cyclic compression

    Science.gov (United States)

    Maher, A.; Darwin, D.

    1980-10-01

    The behavior of the mortar constituent of concrete under cyclic compression was studied and a simple analytic model was developed to represent its cyclic behavior. Experimental work consisted of monotonic and cyclic compressive loading of mortar. Two mixes were used, with proportions corresponding to concretes having water cement ratios of 0.5 and 0.6. Forty-four groups of specimens were tested at ages ranging from 5 to 70 days. complete monotonic and cyclic stress strain envelopes were obtained. A number of loading regimes were investigated, including cycles to a constant maximum strain. Major emphasis was placed on tests using relatively high stress cycles. Degradation was shown to be a continuous process and a function of both total strain and load history. No stability or fatigue limit was apparent.

  16. The Aesthetical quality of SSA-containing mortar and concrete

    DEFF Research Database (Denmark)

    Kappel, Annemette; Kirkelund, Gunvor Marie; Ottosen, Lisbeth M.;

    2014-01-01

    that gives a characteristic red colour. The process of grinding SSA has shown to improve the compressive strength of SSA- containing mortar (Donatello et al. 2010). Thus, in this study SSA was grinded in 6 different intervals ranging from 0 – 10 min, and then added to the mortar mix replacing 20% of cement....... The experiment revealed that the colour of the SSA-containing mortar intensified as the time interval of the grinding process increased. Each of the 6 steps within the time interval provided an additional colour tone and generated a colour scale consisting of mortar samples ranging from greyish to a more...

  17. High-Performance Grouting Mortar Based on Mineral Admixtures

    Directory of Open Access Journals (Sweden)

    Cong Ma

    2015-01-01

    Full Text Available A study on high-performance grouting mortar is reported. The common mortar was modified by mineral admixtures such as gypsum, bauxite, and alunite. The effects of mineral admixtures on the fluidity, setting time, expansion, strength, and other properties of mortar were evaluated experimentally. The microstructure of the modified mortar was characterized by X-ray diffraction, scanning electron microscopy, and mercury intrusion porosimetry. Moreover, the expansive performance and strength of the grouting mortar were verified by anchor pullout test. The results show that the best conditions for gypsum-bauxite grouting mortar are as follows: a water-to-binder ratio of 0.3, a mineral admixture content of ~15%, and a molar ratio K of 2. The ultimate bearing capacity of the gypsum-bauxite grouting mortar anchor increased by 39.6% compared to the common mortar anchor. The gypsum-bauxite grouting mortar has good fluidity, quick-setting, microexpansion, early strength, and high strength performances.

  18. Carbonatation Influence on Fly Ash and Portland Cement Mortars

    OpenAIRE

    P.L. Valdez–Tamez; A. Durán–Herrera; G. Fajardo–San Miguel; C.A. Juárez–Alvarado

    2009-01-01

    The influence of carbonation on mortars containing 25% of fly ash instead of the cementitious materials was studied. Mortar cylinder specimens were fabricated for 4 different W/C ratios: 0.35, 0.45, 0.55 and 0.65. Mortars with and without fly ash were subjected to an accelerated carbonation process. Volumetric weight, water absorption, compressive strength, water permeability, pH and mercury intrusion porosimetry of the mortar specimens were determined. Due to the fly ash pozzolanic potential...

  19. Carbonatation Influence on Fly Ash and Portland Cement Mortars

    Directory of Open Access Journals (Sweden)

    P.L. Valdez–Tamez

    2009-01-01

    Full Text Available The influence of carbonation on mortars containing 25% of fly ash instead of the cementitious materials was studied. Mortar cylinder specimens were fabricated for 4 different W/C ratios: 0.35, 0.45, 0.55 and 0.65. Mortars with and without fly ash were subjected to an accelerated carbonation process. Volumetric weight, water absorption, compressive strength, water permeability, pH and mercury intrusion porosimetry of the mortar specimens were determined. Due to the fly ash pozzolanic potential, for all W/C ratios, results of the compressive strength tests at 28 days of the mortars with and without fly ash were similar. Mortars with fly ash presented similar water permeability as mortars without fly ash. PH results showed that alkalinity reduction is lower in mortars with fly ash compared to those containing cement only. In all the mortars, the porosimetric analysis indicated that porosity is reduced due to carbonation. Further more, it is showed the predominance of the macro and mesopores.

  20. Effect of Reactivity of Quick Lime on the Properties of Hydrated Lime Sorbent for SO2 Removal

    Institute of Scientific and Technical Information of China (English)

    H.G.Shin; H.Kim; Y.N.Kim; H.S.Lee

    2009-01-01

    The hydration of quick lime and the sulfation of hydrated lime were carried out for verification of relationship between the reactivity of quick lime and the properties of hydrated lime as a sorbent.The effect of reactivity of quick lime was investigated with the change of calcination temperature and time.Results obtained showed that the temperature rise during the hydration of quick limes varied from 31 to 69℃ with the variation of calcination temperature and time.The specific surface area and the sulfation ability of hydrated lime prepared by hydration of quick lime showed a proportional relationship with the reactivity of quick lime.The hydrated lime which was prepared by hydration of quick lime calcined at 1100℃ had the highest reactivity and showed 41.53 m2/g of the specific surface area, 0.16 cm3/g of the pore volume and 87% of the removal efficiency for SO2 removal.

  1. Domain decomposition methods for mortar finite elements

    Energy Technology Data Exchange (ETDEWEB)

    Widlund, O.

    1996-12-31

    In the last few years, domain decomposition methods, previously developed and tested for standard finite element methods and elliptic problems, have been extended and modified to work for mortar and other nonconforming finite element methods. A survey will be given of work carried out jointly with Yves Achdou, Mario Casarin, Maksymilian Dryja and Yvon Maday. Results on the p- and h-p-version finite elements will also be discussed.

  2. Mortar cohesión. The effect of additives

    Directory of Open Access Journals (Sweden)

    Castro, J. H.

    1975-12-01

    Full Text Available This study was concerned with the hydration of clinker compounds in the presence of different additives; it appeared that accelerating additives, such as calcium chloride and silicic acid, produce longer fibers of tobermorite, whereas inhibitors, such as sugar, produce shorter fibers of tobermorite. This same effect was observed in the hydration of anhydrite, in which large crystals of gypsum were produced in the presence of sodium sulphate. So the cohesion in mortars of cement and anhydrite is explained in terms of the role of fibers.Se estudia la hidratación del clínker en presencia de diferentes aditivos encontrándose que los aceleradores, como el cloruro cálcico y el ácido salicílico, producen tobermorita de fibra larga y los inhibidores, como el azúcar, tobermorita de fibra corta. Este mismo efecto se encuentra en la anhidrita, produciéndose cristales de yeso largo, en presencia del sulfato de sodio, y cristales cortos en ausencia del catalizador. La cohesión de un mortero depende luego del largo de sus fibras. Así la cohesión de los morteros de cemento y anhidrita se explican en función del rol de la fibra.

  3. Assessment of chemical analyses by means of portable XRF in the Roman mortars of Complutum archaeological site (Spain)

    Science.gov (United States)

    Ergenç, Duygu; Freire, David; Fort, Rafael

    2016-04-01

    The chemical characterization of lime mortars used in Roman period has a great significance and plays a key role in the acquisition of knowledge with respect to construction technology, raw materials and, accordingly, in its conservation works. When it comes to cultural heritage studies, sampling is always complicated since the minimum damage is the primary concern. The use of non-destructive techniques and direct measurements with portable devices reduce the amount of samples and time consumed in analyses, consequently it could be stated that such techniques are extremely useful in conservation and restoration works. In this study, the portable XRF device was used to determine the composition of chemical elements which compose the Roman lime mortars in the archaeological site of Complutum, Alcalá de Henares (Madrid, Spain) which is listed as a World Heritage Site by UNESCO since 1998. Portable XRF devices have some detection limits below the ones of the laboratory equipment that are immovable and require sampling. In order to correlate the results, sampling and grinding were initially done to prepare the powders for the laboratory XRF analysis with the following elements: Si, Al, Fe, Ca, Mg, K, Ti, Nb, Zr, Sr, Rb, Pb, Zn and Cr. The analyses of the powdered samples were conducted with the laboratory equipment PHILIPS Magix Pro (PW-2440) from the Centre of Scientific Instrumentation CIC in the University of Granada, and the results were compared to the results gathered with X Ray Florescence (EDTRX) THERMO NITON model XL3T from the Petrophysics Laboratory Geosciences Institute IGEO (CSIC-UCM). Analyses were performed on the surfaces of the samples -without any previous preparation-, and on the powdered samples to compare the variations between both traditional XRF analyses and the portable XRF. A good correlation was found among the results obtained by the laboratory equipment, the portable device as well as the surface measurements. The results of this study

  4. Application of Bacillus subtilis 168 as a multifunctional agent for improvement of the durability of cement mortar.

    Science.gov (United States)

    Park, Sung-Jin; Park, Jong-Myong; Kim, Wha-Jung; Ghim, Sa-Youl

    2012-11-01

    Microbiological calcium carbonate precipitation (MCCP) has been investigated for its ability to improve the durability of cement mortar. However, very few strains have been applied to crack remediation and strengthening of cementitious materials. In this study, we report the biodeposition of Bacillus subtilis 168 and its ability to enhance the durability of cement material. B. subtilis 168 was applied to the surface of cement specimens. The results showed a new layer of deposited organic-inorganic composites on the surface of the cement paste. In addition, the water permeability of the cement paste treated with B. subtilis 168 was lower than that of non-treated specimens. Furthermore, artificial cracks in the cement paste were completely remediated by the biodeposition of B. subtilis 168. The compressive strength of cement mortar treated with B. subtilis 168 increased by about 19.5% when compared with samples completed with only B4 medium. Taken together, these findings suggest that the biodeposition of B. subtilis 168 could be used as a sealing and coating agent to improve the strength and water resistance of concrete. This is the first paper to report the application of Bacillus subtilis 168 for its ability to improve the durability of cement mortar through calcium carbonate precipitation.

  5. The central tower of the cathedral of Schleswig - New investigations to understand the alcali-silica reaction of historical mortars

    Science.gov (United States)

    Wedekind, Wanja; Protz, Andreas

    2016-04-01

    The damaging alcali-silica reaction leads to crack-formation and structural destruction at noumerous, constructed with cement mortar, buildings worldwide. The ASR-reaction causes the expansion of altered aggregates by the formation of a swelling gel. This gel consists of calcium silicate hydrate (C-S-H) that increases in volume with water, which exerts an expansive pressure inside the material. The cathedral of Schleswig is one of the oldest in northern Germany. The first church was built in 985-965. The Romanesque building part was erected around 1180 and the Gothic nave at the end of the 13th century. The central tower was constructed between 1888 and 1894 with brick and cement mortar. With 112 meters, the tower is the second-largest church spire of the country of Schleswig-Holstein in northern Germany. Due to the formation of cracks and damages from 1953 to 1956 first restoration works took place. Further developments of cracks are making restoration necessary again today. For developing a suitable conservation strategy, different investigations were done. The investigation included the determination of the pore space properties, the hygric and thermal dilatation and mercury porosimetry measurements. Furthermore, the application of cathodoluminescence microscopy may give information about the alteration process and microstructures present and reveal the differences between unaltered and altered mortars. An obvious relation between the porosity and the swelling intensity could be detected. Furthermore it becomes apparent, that a clear zonation of the mortar took place. The mortar near the surface is denser with a lower porosity and has a significantly lower swelling or dilatation.

  6. Inactivation of Adenovirus Type 5, Rotavirus WA and Male Specific Coliphage (MS2 in Biosolids by Lime Stabilization

    Directory of Open Access Journals (Sweden)

    Aaron B. Margolin

    2007-03-01

    Full Text Available The use of lime to reduce or eliminate pathogen content is a cost-effective treatment currently employed in many Class B biosolids production plants in the United States. A bench scale model of lime stabilization was designed to evaluate the survival of adenovirus type 5, rotavirus Wa, and the male specific bacteriophage, MS2, in various matrices. Each virus was initially evaluated independently in a reverse osmosis treated water matrix limed with an aqueous solution of calcium hydroxide for 24-hr at 22 ± 5°C. In all R/O water trials, adenovirus type 5, rotavirus Wa and MS2 were below detectable levels (<100.5 TCID50/mL and <1 PFU/mL respectively following 0.1-hr of liming. Adenovirus type 5, rotavirus Wa, and MS2, were inoculated into composted, raw and previously limed matrices, representative of sludge and biosolids, to achieve a final concentration of approximately 104 PFU or TCID50/mL. Each matrix was limed for 24-hr at 22 ± 5°C and 4 ± 2°C. In all trials virus was below detectable levels following a 24-hr incubation. The time required for viral inactivation varied depending on the temperature and sample matrix. This research demonstrates reduction of adenovirus type 5, rotavirus Wa, and male-specific bacteriophage, in water, sludge and biosolids matrices following addition of an 8% calcium hydroxide slurry to achieve a pH of 12 for 2-hr reduced to 11.5 for 22-hr by addition of 0.1 N HCl. In these trials, MS2 was a conservative indicator of the efficacy of lime stabilization of adenovirus Type 5 and rotavirus Wa and therefore is proposed as a useful indicator organism.

  7. Oxyfuel combustion in rotary kiln lime production

    OpenAIRE

    Eriksson, Matias; Hökfors, Bodil; Backman, Rainer

    2014-01-01

    The purpose of this article is to study the impact of oxyfuel combustion applied to a rotary kiln producing lime. Aspects of interest are product quality, energy efficiency, stack gas composition, carbon dioxide emissions, and possible benefits related to carbon dioxide capture. The method used is based on multicomponent chemical equilibrium calculations to predict process conditions. A generic model of a rotary kiln for lime production was validated against operational data and literature. T...

  8. Lime-Crusted Rammed Earth: Materials Study

    OpenAIRE

    Mileto, Camilla; Vegas López-Manzanares, Fernando; Alejandre, Francisco Javier; Martín, Juan Jesús; Garcia Soriano, Lidia

    2013-01-01

    This study analyses the durability of rammed-earth wall construction techniques. The analysis focuses on three medieval masonry types from the Castle of Villavieja (Castellón, Spain) using two variations of lime-reinforced rammed earth in its walls: lime-crusted rammed earth and brick-reinforced rammed earth. Materials analysis reveals the good properties of the materials used in the outer wall facing despite its age. It also clearly shows how deterioration depends more on the construction t...

  9. Corrosion effects on soda lime glass

    OpenAIRE

    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 degrees of damage has resulted in a inore clear picture of the stress-conosion luechanisms involved. The effects of these on long tenn strength are discussed.

  10. Thaumasite swelling in historic mortars: field observations and laboratory research

    NARCIS (Netherlands)

    Hees, R.P.J. van; Wijffels, T.J.; Klugt, L.J.A.R. van der

    2003-01-01

    The formation of thaumasite in historic mortars was found to be a recurrent problem in cases of conservation of historic masonry in the Netherlands. Several case studies in which mortar swelling occurred were performed. In this paper two case studies concerning thaumasite formation are briefly descr

  11. Balancing guava nutrition with liming and fertilization

    Directory of Open Access Journals (Sweden)

    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.

  12. Deterioration of concrete structures by acid deposition — an assessment of the role of rainwater on deterioration by laboratory and field exposure experiments using mortar specimens

    Science.gov (United States)

    Okochi, Hiroshi; Kameda, Hideki; Hasegawa, Shin-ichi; Saito, Nobuhiko; Kubota, Ken; Igawa, Manabu

    Deterioration of concrete structures caused by acid deposition was investigated by laboratory and field exposure of portland cement mortar specimens to acid deposition. Laboratory exposure experiment showed that the dissolved amount of calcium hydrates, which were the major components in mortar, increased with the increase in the acidity of simulated acid rain solution and the decrease in the flow rate. There was little difference in their amount among different temperature treatments after each exposure to the solution with the same acidity, namely left at room temperature, heated at 70°C, and cooled at -2°C. The neutralization progressed more deeply under the heated and cooled condition and was accelerated by even acid rain with pH 4.7 during a long period (90 exposure cycles, which correspond to the rainfall amount of 15 years in Japan). A field exposure experiment for two years indicated that the carbonation of calcium hydrates and the formation of other corrosion products such as chloride, nitrate, and sulfate were limited to the surface of mortar specimens. The neutralization progressed more deeply in mortar specimens sheltered from rainwater than in those washed by rainwater.

  13. Porosity estimation of aged mortar using a micromechanical model.

    Science.gov (United States)

    Hernández, M G; Anaya, J J; Sanchez, T; Segura, I

    2006-12-22

    Degradation of concrete structures located in high humidity atmospheres or under flowing water is a very important problem. In this study, a method for ultrasonic non-destructive characterization in aged mortar is presented. The proposed method makes a prediction of the behaviour of aged mortar accomplished with a three phase micromechanical model using ultrasonic measurements. Aging mortar was accelerated by immersing the probes in ammonium nitrate solution. Both destructive and non-destructive characterization of mortar was performed. Destructive tests of porosity were performed using a vacuum saturation method and non-destructive characterization was carried out using ultrasonic velocities. Aging experiments show that mortar degradation not only involves a porosity increase, but also microstructural changes in the cement matrix. Experimental results show that the estimated porosity using the proposed non-destructive methodology had a comparable performance to classical destructive techniques.

  14. Optimization of Blended Mortars Using Steel Slag Sand

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A new kind of mortar made of ground granulated blast-furnace slag (GGBFS), gypsum,clinker and steel slag sand (<4.75 mm) was developed. The ratio of steel slag sand to GGBFS was 1:1 and the amount of gypsum was 4% by weight while the dosage of clinker ranged from 0% to 24%. The optimization formulation of such mortar was studied. The content of steel slag sand should be less than 50% according to the volume stability of blended mortar, and the dosage of clinker is about 10% based on the strength development.Besides strength, the hydration heat, pore structure and micro pattern of blended mortar were also determined.The experimental results show the application of steel slag sand may reduce the dosage of cement clinker and increase the content of industrial waste product such as GGBFS, and the clinker is also a better admixture for blended mortar using steel slag sand.

  15. The performance of mortar containing added metakaolin regarding sulfate action

    Directory of Open Access Journals (Sweden)

    Janneth Torres Agredo

    2010-04-01

    Full Text Available This paper evaluates the performance of adding Colombian metakaolin (MK to mortar when these are submitted to sulphate action. Four proportions of MK were used as cement replacement in this study: 10%, 20%, 35% and 50% by weight of cement; cement having 11% tricalcium aluminate was used. Mortar specimens were immersed in 5% sodium sulphate solution for a total period of 280 days after the specified initial moist curing period, The degree of sulphate attack was evaluated by measuring the mortar’s cylindrical expansion, mortar cubes’ compressive strength reduction and visual inspection of mortar specimens. An additional study using X-ray diffraction was conducted to determine the products formed in the cement pastes due to the sulphate attack. The results showed that MK mortar sulphate resistance increased when increasing MK replacement level. An MK proportion greater than 20% is re-commended for obtaining better performance against sulphate attack.

  16. EQUIVALENT MODEL OF EXPANSION OF CEMENT MORTAR UNDER SULPHATE EROSION

    Institute of Scientific and Technical Information of China (English)

    Jue Zhu; Minqiang Jiaug; Jiankang Chen

    2008-01-01

    The expansion property of cement mortar under the attack of sulfate ions is studied by experimental and theoretical methods.First,cement mortars are fabricated with the ratio of water to cement of 0.4,0.6,and 0.8.Secondly,the expansion of specimen immerged in sulphate solution is measured at different times.Thirdly,a theoretical model of expansion of cement mortar under sulphate erosion is suggested by virtue of represent volume element method.In this model, the damage evolution due to the interaction between delayed ettringite and cement mortar is taken into account.Finally,the numerical calculation is performed.The numerical and experimental results indicate that the model perfectly describes the expansion of the cement mortar.

  17. 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.

  18. Rilem TC 203-RHM: Repair mortars for historic masonry. Repair mortars for historic masonry: From problem to intervention: a decision

    NARCIS (Netherlands)

    Hees, R.P.J. van; Groot, C.; Hughes, J.J.; Balen, K. van; Bicer-Simsir, B.; Binda, L.; Elsen, J.; Konow, T. von; Lindqvist, J.E.; Maurenbrecher, P.; Papayanni, I.; Subercaseaux, M.; Tedeschi, C.; Toumbakari, E.E.; Thompson, M.

    2012-01-01

    This article focuses on repair or replacement mortars for historical buildings. Both the decision process and questions arising are dealt with, in order to better define and illustrate technical requirements for mortars to be used for the repair or restoration of monuments and historic buildings (ma

  19. Incorporation of limestone residue from marble processing plant in the city of Cachoeiro do Itapemirim, Espirito Santo, Brazil, in the production of mortars; Incorporacao de residuo proveniente de usina de beneficiamento de marmore do municipio de Cachoeiro do Itapemirim, ES, Brasil, na confeccao de argamassas

    Energy Technology Data Exchange (ETDEWEB)

    Goncalves, G.P.; Alexandre, J.; Dias, D.P.; Dias Junior, N.S.; Anderson, R.B., E-mail: gabrielkgbs@gmail.co [Universidade Estadual do Norte Fluminense (LECIV/UENF), Campos dos Goytacazes, RJ (Brazil). Centro de Ciencia e Tecnologia. Lab. de Engenharia Civil

    2010-07-01

    Cachoeiro do Itapemirim city (ES), located 136 km from Vitoria, the state's capital, is the largest ornamental stones producer in Brazil, whose beneficiation produces a large amount of waste that, even today, is responsible for major damages done to the environment. This article aims the experimental study of hydrated lime use (product marketed to be used in mortar) by a residue from marble beneficiation from an industry located in that city. Two mixes were made with cement:sand:hydrated lime and cement:sand:residue. The mortars were evaluated by their properties comparisons in fresh and hardened states, namely: consistency index, mass density and incorporated air content, compressive strength, tensile and bending grip for traction. Chemical and mineralogical analysis by X-ray diffraction were also made. The obtained results met the requirements prescribed by ABNT NBR 13 281 (2005). (author)

  20. Use or rice husk ash an addition in mortar

    Directory of Open Access Journals (Sweden)

    Sánchez de Rojas, M. Isabel

    1986-09-01

    Full Text Available With the aid of a 400-litre capacity pilot furnace, in which 40 Kg of rice husk is submitted to controlled combustion, an ash (RHA is obtained for use as an addition, the physicochemical properties of which form the focal point of this work. Results will also be presented for the combustion power of the husk ≃ 4000 kcal/kg, being greater than half the value for normal bituminous coals. Conglomerates have been obtained by mixing RHA with different proportions of lime and portland cement, and their properties are studied with regard to both mortars and concretes. The ultimate aim of the work is to demonstrate how rice husk (world production of which is estimated at 500.106 m3 per annum may be feasibly applied as an addition, without forgetting its excellent properties as a fuel, which makes it particularly suitable for developing countries with a shortage of cement and energy resources.

    Mediante la utilización de un horno-piloto de unos 400 litros de capacidad, en el que se realiza la combustión controlada de unos 40 kg de cáscara de arroz, se consigue una ceniza (RHA, sobre cuyas propiedades físico-químicas se centra el trabajo, para su empleo como adición. Se presentan igualmente resultados sobre el poder de combustión de la cascara ≃ 4.000 kcal/kg, superior a la mitad del valor de los carbones bituminosos normales. Mediante mezclas de RHA con distintas proporciones de cal o de cemento portland, se han conseguido conglomerantes cuyas propiedades se estudian, tanto sobre morteros, como sobre hormigones. El objetivo último del trabajo es mostrar la factible aplicabilidad de la cascara de arroz (cuya "producción" mundial se estima en 500.106 m3 anuales como adición, sin olvidar sus excelentes cualidades como combustible lo que hace especialmente idónea en países en vías de desarrollo, deficitarios en cemento y recursos energéticos.

  1. Dating mortars: three medieval Spanish architectures

    Directory of Open Access Journals (Sweden)

    Quirós Castillo, Juan Antonio

    2011-12-01

    Full Text Available One of the major issues in building archaeology is finding the age of elements and structures discovered. Mortars represent a class of material basically constituted by a mixture of different phases (i.e. binder, aggregates, water and are widely used for constructive uses and artworks. Current scientific literature regarding the possibility of accurate radiocarbon dating for mortars reports different and still contradictory results. In this study, a new protocol for radiocarbon dating of mortar developed at the Centre for Isotopic Research on Cultural and Environmental heritage (CIRCE is used to perform 14C measurements on archaeological mortars coming from three medieval architectures of northern Spain (two churches and the walls of a castle. Results observed will be discussed and compared with independent age estimations (i.e. radiocarbon dating performed on organic materials found in the same study site, archaeological analyses in order to frame experimental observations in the actual site knowledge by means of a multidisciplinary approach.Una de las principales problemáticas a las que se enfrenta la arqueología de la arquitectura es datar los elementos y las estructuras. Las argamasas son un tipo de material constituido por una mezcla de diferentes elementos (agregados, agua y empleadas en muchos tipos de construcciones. Los estudios realizados hasta la actualidad en torno a la posibilidad de realizar dataciones radiocarbónicas precisas han proporcionado resultados contradictorios. El objetivo de este artículo es el de presentar un nuevo protocolo para datar la arquitectura histórica desarrollado por el Centre for Isotopic Research on Cultural and Enviromental Heritage (CIRCE, basado en la realización de dataciones radiocarbónicas de argamasas a partir del análisis de tres arquitecturas medievales del norte del España, dos iglesias y la muralla de un castillo. Los resultados obtenidos han sido confrontados y comparados con otros

  2. Lime-enhanced hydrogen reduction of molybdenite

    Science.gov (United States)

    Mankhand, T. R.; Prasad, P. M.

    1982-06-01

    Kinetics of the direct hydrogen reduction of a high-grade (59 pct Mo) molybdenite (MoS2) concentrate was investigated in the presence of lime as a function of the quantity of lime in the charge, hydrogen flow rate, temperature, and time of reduction. Lime was found to enhance tremendously the reduction rate of MoS2 and drastically reduce H2S emission into the off gas to negligible levels. Successful application of the lime-hydrogen reduction technique was found to depend on the employment of low hydrogen flow rate and moderate temperatures of reduction. In these laboratory studies, best results were obtained with a lime addition ≥ three times the theoretical requirement and at 1173 K in 3.6 ks employing a hydrogen flow rate of 3.33 cm3s-1. The results were tested for the treatment of a low-grade (41 pct Mo) molybdenite concentrate. In this latter case, the procedure consisted of upgrading the concentrate by acid leaching (with dil HC1+HF) followed by lime-hydrogen reduction. The influence of quantity of acids, temperature, and time of leaching were investigated to optimize the conditions required for upgrading the MoS2 concentrate. The molybdenum powders obtained from the highgrade as well as upgraded molybdenite concentrates had 96 to 97 pct purity and could be further refined to 99.9 pct by electron-beam melting. Based on this lime-enhanced hydrogen reduction concept, a new ‘Leach-Reduction-Melting’ approach has been suggested as an alternative to the traditional methods of molybdenum extraction.

  3. Distribution of arsenic and mercury in lime spray dryer ash

    Energy Technology Data Exchange (ETDEWEB)

    Panuwat Taerakul; Ping Sun; Danold W. Golightly; Harold W. Walker; Linda K. Weavers [Ohio State University, Columbus, OH (United States). Department of Civil and Environmental Engineering and Geodetic Science

    2006-08-15

    The partitioning of As and Hg in various components of lime spray dryer (LSD) ash samples from a coal-fired boiler was characterized to better understand the form and fate of these elements in flue gas desulfurization byproducts. LSD ash samples, collected from the McCracken Power Plant on the Ohio State University campus, were separated by a 140-mesh (106 {mu}m) sieve into two fractions: a fly-ash-/unburned-carbon-enriched fraction (> 106 {mu}m) and a calcium-enriched fraction (< 106 {mu}m). Unburned carbon and fly ash in the material > 106 {mu}m were subsequently separated by density using a lithium heteropolytungstate solution. The concentrations of As and Hg were significant in all fractions. The level of As was consistently greater in the calcium-enriched fraction, while Hg was evenly distributed in all components of LSD ash. Specific surface area was an important factor controlling the distribution of Hg in the different components of LSD ash, but not for As. Comparing the LSD ash data to samples collected from the economizer suggests that As was effectively captured by fly ash at 600{sup o}C, while Hg was not. Leaching tests demonstrated that As and Hg were more stable in the calcium-enriched fraction than in the fly-ash- or carbon-enriched fractions, potentially because of the greater pH of the leachate and subsequently greater stability of small amounts of calcium solids containing trace elements in these fractions. 37 refs., 8 figs., 2 tabs.

  4. Composition of mortar as a function of distance to the brick-mortar interface : A study on the formation of cured mortar structure in masonry using NMR, PFM and XRD

    NARCIS (Netherlands)

    Brocken, H.J.P.; Larbi, J.A.; Pel, L.; Pers, N.M. van der

    1999-01-01

    The formation of cured mortar structure in masonry was studied using multiple experimental techniques. Starting with fresh mortar, nuclear magnetic resonance (NMR) was used to measure the water extraction during brick laying. After curing, the composition of cured mortar was investigated with polari

  5. Composition of mortar as a function of distance to the brick-mortar interface: A study on the formation of cured mortar structure in masonry using NMR, PFM and XRD

    NARCIS (Netherlands)

    Brocken, H.J.P.; Larbi, J.A.; Pel, L.; Van der Pers, N.M.

    1999-01-01

    The formation of cured mortar structure in masonry was studied using multiple experimental techniques. Starting with fresh mortar, nuclear magnetic resonance (NMR) was used to measure the water extraction during brick laying. After curing, the composition of cured mortar was investigated with polari

  6. Solidification/stabilization of toxic metals in calcium aluminate cement matrices.

    Science.gov (United States)

    Navarro-Blasco, I; Duran, A; Sirera, R; Fernández, J M; Alvarez, J I

    2013-09-15

    The ability of calcium aluminate cement (CAC) to encapsulate toxic metals (Pb, Zn and Cu) was assessed under two curing conditions. Changes in the consistency and in the setting time were found upon the addition of the nitrates of the target metals. Both Pb and Cu caused a delay in CAC hydration, while Zn accelerated the stiffening of the mortar. Compressive strengths of the metal-doped mortars, when initially cured at 60 °C/100% RH, were comparable with that of the free-metal mortar. Three different pore size distribution patterns were identified and related to the compounds identified by XRD and SEM. Sorbent capacities of CAC for the toxic metals were excellent: a total uptake was achieved for up to 3 wt.% loading of the three metals. In this way, CAC mortars were perfectly able to encapsulate the toxic metals, allowing the use of CAC for waste management as proved by the leaching tests.

  7. Early age monitoring of cement mortar using embedded piezoelectric sensors

    Science.gov (United States)

    Narayanan, Arun; Subramaniam, Kolluru V. L.

    2016-04-01

    A piezoceramic based sensor consisting of embedded Lead Zirconate Titanate (PZT) patch is developed for assessing the progression of hydration and evolution of properties of cement mortar. A method for continuous assessment of cement mortar with different water to cement ratios after casting is presented. The method relies on monitoring changes in the electromechanical (EM) conductance of a PZT patch embedded in mortar. Changes in conductance are shown to sensitively reflect the changes in the mechanical impedance of the cementitious material as it transforms from fluid to solid state.

  8. A Mortar Condition for Mortar Finite Element Methods%Mortar型有限元方法的一类Mortar条件

    Institute of Scientific and Technical Information of China (English)

    姜亚琴

    2011-01-01

    In this paper,we study the approximation of mortar finite element methods and establish a criterion for the optimal mortar condition. Based on the criterion, two mortar conditions are presented. Using the two mortar condition, we construct mortar rotated Q1 element and mortar P1 nonconforming element. By the mortar condition satisfying the criterion, we obtain optimal error estimates for elliptic problems.%研究了mortar型有限元方法的逼近性,建立了一种mortar条件具备最优误差的标准,在满足该标准的基础上介绍了两个mortar条件.利用这两个mortar条件分别构建mortar型旋转Q1元与mortar型P1非协调元.通过检验mortar条件符合标准,证明了这两种mortar有限元方法对于椭圆问题有最优的误差估计.

  9. 废弃混凝土砂浆组分接触硬化性能研究%Research on the Contact-hardening Property of Mortar Component of Demolished Concrete

    Institute of Scientific and Technical Information of China (English)

    彭小芹; 王淑萍; 黄滔; 胡灿

    2011-01-01

    为考察废弃混凝土砂浆组分的接触硬化性能,将与粗集料分离后的砂浆组分磨细,一组磨细粉体直接压制成型,另一组粉体通过加入磨细生石灰和石英砂调整Ca/Si摩尔比为1,在120℃,水固比为5:1的条件下进行动态水热处理后压制成型,测定成型试块的表现密度、抗压强度、抗折强度、软化系数,以表征粉体的接触硬化性能.结果表明:磨细砂浆组分具有接触硬化性能,一定条件的水热反应可优化这种性能.XRD分析显示,水热反应产物主要为结晶不良的水化硅酸钙;成型试块的抗折强度、抗压强度最高分别为5.7 MPa和16.8 MPa,并具有一定的耐水性,软化系数达到0.7.粗集料种类及水热反应恒温时间对其接触硬化性能有一定影响.%In order to investigate the contact-hardening mechanism of the mortar component of demolished concrete, the mortars were separated and ground. One group of the power was directly molded at a certain compression, and the other group was molded after hydro-thermal synthesis at the temperature of 120 °C with a water solid ration of 5 by adding ground lime and quartz sand to adjust Ca/Si morel ratio. The apparent density, compressive strength, flexural strength and softening coefficient of the molded specimens were measured immediately. The results have shown that the ground mortar has a contact-hardening property to some extent and after hydro-thermal reaction, this property is obviously improved. The reacting production is amorphous silicate calcium hydration by XRD analysis. The maximum flexible strength and compressive strength are up to 5.7 Mpa and 16.8 Mpa respectively, and the specimen has a certain water resistance property, of which the softening coefficient can be 0. 7. The property of contact-hardening is affected by the styles of the coarse aggregates of the demolished concretes and the constant time of temperature.

  10. Boron Speciation in Soda-Lime Borosilicate Glasses Containing Zirconium

    International Nuclear Information System (INIS)

    Boron speciation was investigated in soda-lime borosilicate glass containing zirconium. In such compositions, competition between charge compensators (here, sodium and calcium) can occur for the compensation of tetrahedral boron or octahedral zirconium units. 11B MAS NMR is particularly suitable for obtaining data on preferential compensation behavior that directly affects the boron coordination number. In addition to the classical proportions of tri- and tetrahedral boron, additional data can be obtained on the contributions involved in these two coordination numbers. An approach is described here based on simultaneous MAS spectrum analysis of borosilicate glass with variable Zr/Si and Ca/Na ratios at two magnetic field strengths (11. 7 and 18. 8 T), with constraints arising from MQMAS spectroscopy, detailed analysis of satellite transitions, and spin-echo experiments. New possibilities of 11B NMR were presented for improving the identification and quantification of the different contributions involved in tri- and tetrahedral boron coordination. Both NMR and Raman revealed a trend of decreased tetrahedral boron proportion with the increase of Ca/Na ratio or the Zr/Si ratio. This strongly suggests that zirconium compensation takes preference over boron compensation, and that zirconium and boron are both compensated mainly by sodium rather than calcium. (authors)

  11. The formation and solutions of the lime blowing

    Institute of Scientific and Technical Information of China (English)

    SunGuofeng

    2005-01-01

    This article analyses the origin of the lime blowing and gives Solutions of eliminating the limeblowing, which are picking out lime, controlling the grain size, intensifying firing and Showering water on brick.

  12. Strength and Drying Shrinkage of Alkali-Activated Slag Paste and Mortar

    Directory of Open Access Journals (Sweden)

    Mao-chieh Chi

    2012-01-01

    Full Text Available The aim of this study is to investigate the strengths and drying shrinkage of alkali-activated slag paste and mortar. Compressive strength, tensile strength, and drying shrinkage of alkali-activated slag paste and mortar were measured with various liquid/slag ratios, sand/slag ratios, curing ages, and curing temperatures. Experimental results show that the higher compressive strength and tensile strength have been observed in the higher curing temperature. At the age of 56 days, AAS mortars show higher compressive strength than Portland cement mortars and AAS mortars with liquid/slag ratio of 0.54 have the highest tensile strength in all AAS mortars. In addition, AAS pastes of the drying shrinkage are higher than AAS mortars. Meanwhile, higher drying shrinkage was observed in AAS mortars than that observed comparable Portland cement mortars.

  13. Calcium - urine

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/003603.htm Calcium - urine To use the sharing features on this ... enable JavaScript. This test measures the amount of calcium in urine. All cells need calcium in order ...

  14. Calcium supplements

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/007477.htm Calcium supplements To use the sharing features on this page, please enable JavaScript. WHO SHOULD TAKE CALCIUM SUPPLEMENTS? Calcium is an important mineral for the ...

  15. The colour potentials of SSA-containing mortar

    DEFF Research Database (Denmark)

    Kappel, Annemette; Ottosen, Lisbeth M.; Kirkelund, Gunvor Marie;

    2015-01-01

    is with a few exceptions landfilled and thus, wasted.The purpose of the experiments was to examine the influence of SSA and how it affected the colour of mortar samples. SSA was ground in 6 different intervals and added to mortar mixes by replacing 20% of the cement. An additional focus was to examine......This paper reports an experimental study of aesthetical qualities of mortar containing sewage sludgeash (SSA). SSA is the residue produced at water treatment plants where incineration of the sludge is applied in order to decrease volume and to prevent pathogens from spreading. Today SSA...... the possibilities to accentuate the colours of the hardened mortar by using paper cuttings in the production of the samples. The result of the experiments showed that a colour scale can be developed from ground SSA, and that paper may have the potential of providing divers textural qualities when it is used...

  16. Fireclay Refractory Mortars GB/T 14982-2008

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Chai Junlan

    2009-01-01

    @@ 1 Scope This standard specifies the classification, techni-cal requirements, test methods, quality appraisal pro-cedure, packing, marking, transportation, storage and quality certificate of fireclay refractory mortars.

  17. High Alumina Refractory Mortars GB/T 2994-2008

    Institute of Scientific and Technical Information of China (English)

    Wang Jing; Chai Junlan

    2009-01-01

    @@ 1 Scope This standard specifies the classification, techni-cal requirements, test methods, quality appraisal pro-cedure, packing, marking, transportation, storage and quality certificate of high alumina refractory mortars.

  18. Optimization Problem of Mortar Barrel and Bomb Clearances

    Directory of Open Access Journals (Sweden)

    J. P. Sirpal

    1987-07-01

    Full Text Available Optimum mortar windage to achieve maximum accuracy and required velocity for impacting the firing stud under two conditions of constraint is considered. These control constraints are considered to be bounded and the extremals have been studied.

  19. Reduction of copper phytotoxicity by liming: A study of the root anatomy of young vines (Vitis labrusca L.).

    Science.gov (United States)

    Ambrosini, Vítor Gabriel; Rosa, Daniel José; Corredor Prado, Jenny Paola; Borghezan, Marcelo; Bastos de Melo, George Wellington; Fonsêca de Sousa Soares, Cláudio Roberto; Comin, Jucinei José; Simão, Daniela Guimarães; Brunetto, Gustavo

    2015-11-01

    Frequent applications of copper (Cu)-based fungicides on vines causes the accumulation of this metal in vineyard soils, which can cause toxicity in young vines. However, liming may reduce these toxic effects. The present study aimed to evaluate the effects of Cu toxicity on the root anatomy of young vines and the alleviation of Cu toxicity by lime applications to contaminated sandy soil. The treatments consisted of the addition of lime (0.0, 1.5 and 3.0 Mg ha(-1)) and two Cu concentrations (0 and 50 mg kg(-1)) to Typic Hapludalf soil. Young vines 'Niágara Branca' (Vitis labrusca L.) were obtained by micropropagation and cultivated for 70 days. The young vines grown with Cu and without liming presented a disorganized root structure; reduced root cap size; increased diameter (47%), cortex area (128%), vascular cylinder area (93%), and number of cortical layers and cells containing phenolic compounds (132%); and reduced root (41%), stem (44%) and leaf dry mass (21%) and height increase (55%). Moreover, Cu exposure reduced Ca concentrations (13%) and increased Cu concentrations (371%) in the roots. Liming, primarily with the highest tested dose, increased the soil pH (from 4.4 to 5.4-6.1), decreased the Cu concentration in the soil (extracted by CaCl2), increased the calcium (Ca) and magnesium (Mg) uptake by plants, prevented root anatomical changes and benefited young vine growth in soil with higher Cu concentrations. PMID:26318144

  20. Preparation of calcium silicate absorbent from iron blast furnace slag.

    Science.gov (United States)

    Brodnax, L F; Rochelle, G T

    2000-09-01

    Calcium silicate hydrate (CSH) solids were prepared from hydrated lime and iron blast furnace slag in an aqueous agitated slurry at 92 degrees C. While it was hoped a minimal lime/slag ratio could be used to create near-amorphous CSH, the surface area of the product improved by increasing the lime/slag weight ratio to 2. The addition of gypsum to the lime/slag system dramatically improved the formation of surface area, creating solids with 139 m2/g after 30 hr of reaction when only a minimal amount of lime was present. The SO2 reactivity of solids prepared with gypsum greatly exceeded that of hydrated lime, achieving greater than 70-80% conversion of the alkalinity after 1 hr of reaction with SO2. The use of CaCl2 as an additive to the lime/slag system, in lieu of gypsum, also produced high-surface-area solids, 115 m2/g after 21 hr of reaction. However, the SO2 reactivity of these sorbents was relatively low given the high surface area. This emphasized that the correlation between surface area and SO2 reactivity was highly dependent on the solid phase, which was subsequently dependent on slurry composition. PMID:11055162

  1. Characteristics of Bamboo Leaf Ash Blended Cement Paste and Mortar

    OpenAIRE

    Umoh A.A.; Odesola I.

    2015-01-01

    The use of bamboo leaf ash as cement supplement can contribute to reduction in cost and environmental hazard associated with cement production as well as waste pollution caused by the littered bamboo leaves. Therefore, the characteristics of cement paste and mortar incorporating bamboo leaf ash were investigated. The results of the physical properties of the pastes were within the requirements stipulated by relevant standards while that of the mortar cubes indicated that the compressive stren...

  2. Thaumasite formation in hydraulic mortars by atmospheric SO^ deposition

    OpenAIRE

    Blanco-Varela, María Teresa; Martínez-Ramírez, S.; Sabbioni, C.; Zappia, G.; Toumbakari, E. E.; Aguilera, J.; Palomo, Ángel; Riontino, C.; Van Valen, K.

    2001-01-01

    [EN]Sulphation of mortars and concretes is a function of diverse environmental factors (SO^ aerosol, temperature, etc) as well as some material characteristics. One of the phases that could be formed as consequence of the sulphation of the hydraulic binder is thaumasite. In this paper different hydraulic mortars have been exposed to laboratory exposure chambers in order to reproduce thaumasite formation due to atmospheric SO^. Under the laboratory exposure conditions, ...

  3. Effect of Modified Polymer on Crack Resistance of Mortar

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    At present, the basic technical principle in China is to adopt polymers to modifying the properties of mortar so as to improve the crack-resistance of construction structures and to strengthen their water-resisting and climate-resisting properties as well. However, how polymer acts on anti-crack mortar is short of systematic research. Theoretical exposition of polymer mortar is basically explained by Ohama Model, which is cement slaking and polymer coating are carried on together and mutually-cross web structure interweaved with liquid and polymer coating. But anti-crack mortar has its own special characteristics because of fewer polymers mixed in it and its high viscosity. So this paper is to showing how different polymers affect its crack-resistance cannot be reflected from this theory. Vinyl-acetate ethylene (VAC/E) has been selected as representation of polymerization, whose property is modified by compounding it from some inorganic components, such as talc, CaCO3 and so on. And then the mechanics property and shrinkage of anti-crack polymer mortar is tested when different amount of polymers is added as admixture of mortar. The result indicates that, the working performance and mechanics property of the polymer mortar are worse mixed VAC/E only. It basically meets the demands for mechanics strength and working performance when mixed both VAC/E and CaCO3. While it achieves much better mechanical property and working performance than the two former when mixed VAC/E,talc and CaCO3; the result of corresponding scanning electron microscopy (SEM) of sample indicates that the internal result of the polymer mortar, compared with classical Ohama Model, has a particularity that its structure is formed by polymer coating instead of filling up the intervals among cement grains.

  4. The Mortar Element Method with Lagrange Multipliers for Stokes Problem

    Institute of Scientific and Technical Information of China (English)

    Yaqin Jiang

    2007-01-01

    In this paper, we propose a mortar element method with Lagrange multiplier for incompressible Stokes problem, i.e., the matching constraints of velocity on mortar edges are expressed in terms of Lagrange multipliers. We also present P1 nonconforming element attached to the subdomains. By proving inf-sup condition, we derive optimal error estimates for velocity and pressure. Moreover, we obtain satisfactory approximation for normal derivatives of the velocity across the interfaces.

  5. Neutron radiography of heated high-performance mortar

    OpenAIRE

    Weber B; Wyrzykowski M.; Griffa M.; Carl S.; Lehmann E.; Lura P.

    2013-01-01

    Neutron radiography was applied to investigate the water distribution in mortar samples heated from one side to 600 °C. In mortar, aggregates and anhydrous cement are almost transparent to neutrons, while hydration products and water-filled capillary pores bear the largest attenuation. The evolution of the moisture profile shows a sharp dehydration front and accumulation of water due to condensation of water vapor behind this front.

  6. Neutron radiography of heated high-performance mortar

    Directory of Open Access Journals (Sweden)

    Weber B.

    2013-09-01

    Full Text Available Neutron radiography was applied to investigate the water distribution in mortar samples heated from one side to 600 °C. In mortar, aggregates and anhydrous cement are almost transparent to neutrons, while hydration products and water-filled capillary pores bear the largest attenuation. The evolution of the moisture profile shows a sharp dehydration front and accumulation of water due to condensation of water vapor behind this front.

  7. Applicability of Carbonated Electric Arc Furnace Slag to Mortar

    International Nuclear Information System (INIS)

    Authors have been studying the absorption of CO2 in the steelmaking slag. In this study, an application of the electric arc furnace slag after the carbonation to admixture of mortar was investigated with the JIS (A6206-1997) method for ground granulated blast-furnace slag for concrete. The percent flows for the test mortar were smaller than that for the standard mortar. The percent flow of the carbonated slag whose average particle size of more than approximately 4 μm increased with an increase in the average size of the particles. Because the compressive strengths of the test mortar cured for 91 days were almost the same as those cured 28 days, the slag after the carbonation was thought not to have self-hardening property for a medium and long term. The compressive strength for the test mortar was almost unchanged within a range of approximately 2 to 7 μm of the average particle size, and it in this range was highest. The activity indexes for the test mortar prepared with the slag after the carbonation ranged from approximately 40 to 60%.

  8. Applicability of Carbonated Electric Arc Furnace Slag to Mortar

    Science.gov (United States)

    Yokoyama, S.; Arisawa, R.; Hisyamudin, M. N. N.; Murakami, K.; Maegawa, A.; Izaki, M.

    2012-03-01

    Authors have been studying the absorption of CO2 in the steelmaking slag. In this study, an application of the electric arc furnace slag after the carbonation to admixture of mortar was investigated with the JIS (A6206-1997) method for ground granulated blast-furnace slag for concrete. The percent flows for the test mortar were smaller than that for the standard mortar. The percent flow of the carbonated slag whose average particle size of more than approximately 4 μm increased with an increase in the average size of the particles. Because the compressive strengths of the test mortar cured for 91 days were almost the same as those cured 28 days, the slag after the carbonation was thought not to have self-hardening property for a medium and long term. The compressive strength for the test mortar was almost unchanged within a range of approximately 2 to 7 μm of the average particle size, and it in this range was highest. The activity indexes for the test mortar prepared with the slag after the carbonation ranged from approximately 40 to 60 %.

  9. High performance superplasticized silica fume mortars for ferrocement works

    Directory of Open Access Journals (Sweden)

    Rathish Kumar P.

    2010-01-01

    Full Text Available Ferrocement works demand cement mortars of good workability and high strength. Reduction in water-cement ratio combined with a refined pore structure increases the compressive strength in addition to the enhancement of durability characteristics, but the workability decreases. Workability becomes important, as the mortar has to easily penetrate between the layers of the mesh wires. A reasonably workable high strength cement mortar can be obtained by using a high cement content coupled with the use of superplasticizers. These were also found to retain the cohesiveness and check undesirable bleeding and segregation. An experimental program was conducted to study the functional efficacy of an SNF condensate used as a water reducing superplasticizer. The compressive strength and flow characteristics of the mortars were determined to decide their suitability for ferrocement works. The parameters included the mix proportions, the grade of cement, age of curing and the dosage of superplasticizer. It was concluded from the study that the addition of an optimum dosage of superplasticizer improved the workability and strength characteristics of silica fume mortars. There was a late gain in the compressive strength of silica fume mortars.

  10. Properties of wastepaper sludge in geopolymer mortars for masonry applications.

    Science.gov (United States)

    Yan, Shiqin; Sagoe-Crentsil, Kwesi

    2012-12-15

    This paper presents the results of an investigation into the use of wastepaper sludge in geopolymer mortar systems for manufacturing construction products. The investigation was driven by the increasing demand for reuse options in paper-recycling industry. Both fresh and hardened geopolymer mortar properties are evaluated for samples incorporating dry wastepaper sludge, and the results indicate potential end-use benefits in building product manufacture. Addition of wastepaper sludge to geopolymer mortar reduces flow properties, primarily due to dry sludge absorbing water from the binder mix. The average 91-day compressive strength of mortar samples incorporating 2.5 wt% and 10 wt% wastepaper sludge respectively retained 92% and 52% of the reference mortar strength. However, contrary to the normal trend of increasing drying shrinkage with increasing paper sludge addition to Portland cement matrices, the corresponding geopolymer drying shrinkage decreased by 34% and 64%. Equally important, the water absorption of hardened geopolymer mortar decreased with increasing paper sludge content at ambient temperatures, providing good prospects of overall potential for wastepaper sludge incorporation in the production of building and masonry elements. The results indicate that, despite its high moisture absorbance due to the organic matter and residual cellulose fibre content, wastepaper sludge appears compatible with geopolymer chemistry, and hence serves as a potential supplementary additive to geopolymer cementitious masonry products.

  11. Reuse of ground waste glass as aggregate for mortars.

    Science.gov (United States)

    Corinaldesi, V; Gnappi, G; Moriconi, G; Montenero, A

    2005-01-01

    This work was aimed at studying the possibility of reusing waste glass from crushed containers and building demolition as aggregate for preparing mortars and concrete. At present, this kind of reuse is still not common due to the risk of alkali-silica reaction between the alkalis of cement and silica of the waste glass. This expansive reaction can cause great problems of cracking and, consequently, it can be extremely deleterious for the durability of mortar and concrete. However, data reported in the literature show that if the waste glass is finely ground, under 75mum, this effect does not occur and mortar durability is guaranteed. Therefore, in this work the possible reactivity of waste glass with the cement paste in mortars was verified, by varying the particle size of the finely ground waste glass. No reaction has been detected with particle size up to 100mum thus indicating the feasibility of the waste glass reuse as fine aggregate in mortars and concrete. In addition, waste glass seems to positively contribute to the mortar micro-structural properties resulting in an evident improvement of its mechanical performance.

  12. Innovative method and apparatus for the deep cleaning of soluble salts from mortars and lithic materials

    Science.gov (United States)

    Gaggero, Laura; Ferretti, Maurizio; Torrielli, Giulia; Caratto, Valentina

    2016-04-01

    Porous materials (e.g. plasters, mortars, concrete, and the like) used in the building industry or in artworks fail to develop, after their genesis, salts such as nitrates, carbonates (e.g. potassium carbonate, magnesium carbonate, calcium carbonate), chlorides (e.g. sodium chloride) and/or others, which are a concurrent cause of material deterioration phenomena. In the case of ancient or cultural heritage buildings, severe damage to structures and works of art, such as fresco paintings are possible. In general, in situ alteration pattern in mortars and frescoes by crystallization of soluble salts from solutions is caused by capillar rise or circulation in damp walls. Older buildings can be more subject to capillary rise of ion-rich waters, which, as water evaporates, create salt crystals inside the walls. If this pattern reveals overwhelming upon other environmental decay factors, the extraction of salts is the first restoration to recover the artpiece after the preliminary assessment and mitigation of the causes of soaking. A new method and apparatus, patented by University of Genoa [1] improves the quality and durability of decontamination by soluble salts, compared with conventional application of sepiolite or cellulose wraps. The conventional application of cellulose or sepiolite requires casting a more or less thick layer of wrap on the mortar, soaking with distilled water, and waiting until dry. The soluble salts result trapped within the wrap. A set of artificial samples reproducing the stratigraphy of frescoes was contaminated with saline solution of known concentration. The higher quality of the extraction was demonstrated by trapping the salts within layers of Japanese paper juxtaposed to the mortar; the extraction with the dedicated apparatus was operated in a significantly shorter time than with wraps (some hours vs. several days). Two cycles of about 15 minutes are effective in the deep cleaning from contaminant salts. The decontamination was

  13. Fertilizer and Lime: Why They Are Used.

    Science.gov (United States)

    McCaslin, Judith Strand

    This unit teaching guide is designed to help teachers explain the principles of fertilizer and lime use. The first of four major sections is a teaching outline keyed to transparency masters and student handouts. Thirteen major areas are covered in the teaching outline: (1) plant needs; (2) uses of fertilizer; (3) nutrients for plant growth; (4)…

  14. Microstructure evolution of lime putty upon aging

    Science.gov (United States)

    Mascolo, Giuseppe; Mascolo, Maria Cristina; Vitale, Alessandro; Marino, Ottavio

    2010-08-01

    The microstructure evolution of lime putty upon aging was investigated by slaking quicklime (CaO) with an excess of water for 3, 12, 24, 36, 48 and 66 months. The as-obtained lime putties were characterized in the water retention and in the particle size distribution using the static laser scattering (SLS). The same lime putties, dehydrated by lyophilization, were also investigated in the pore size distribution by mercury intrusion porosimetry, in the surface area by the BET method and, finally, in particle morphology by scanning electron microscopy (SEM). The effect of the extended exposure of quicklime to water confirms a shape change from prismatic crystals of portlandite, Ca(OH) 2, into platelike ones. Simultaneously a growth of larger hexagonal crystals at the expense of the smallest ones (Ostwald ripening) favours a secondary precipitation of submicrometer platelike crystals of portlandite. The shape change and the broader particles size distribution of portlandite crystals upon aging seem to contribute to a better plasticity of lime putty.

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

    DEFF Research Database (Denmark)

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

    2014-01-01

    /or electrodialytic remediation, were used in Portland cement mortar. Mortar bars with 15 % weight replacement of cement by APC residues showed compressive strengths up to 40 MPa after 28/32 days. Heavy metal and salt leaching from both crushed and monolithic mortars with APC residues was generally similar...... and comparable to both the reference mortar and mortar with coal fly ash. These results indicate that electrodialytic remediation could be used a pre-treatment method for MSWI APC residues prior to reuse in mortar....

  16. Mortars and treatments in the restoration of the Altarpiece of the High Altar of the Pilar Basilica

    Directory of Open Access Journals (Sweden)

    Luxán, M. P.

    2000-06-01

    Full Text Available The altarpiece of the Assumption of Mary is located in the High Altar of the Pilar Basilica in Zaragoza and is one of the most important works of the Spanish Artistic Heritage. The work, sculptured in alabaster, was carried out between 1509 and 1518 by Damián Forment. The present paper covers the guidelines for the design of repair mortars used to restore the altarpiece. They are based on compatibility criteria with the existing materials and treatments in the altarpiece, according to research carried out during the recent works of cleaning and restoration. During the previous research, the composition of the original mortars was tested, the aggregate granulometry, and the composition of the organic additives used. The patina of the altarpiece was also analyzed and identified. The original mortars were made up of a mixture of gypsum and lime with the addition of oil or fats. In many cases various types of fibre were detected in the mortar, used to improve its mechanical characteristics. The repair mortars were designed with a composition similar to the originals, with a mixture of gypsum and lime, and their compatibility with the alabaster was studied, while also optimizing the granulometry of the aggregates used.

    El retablo de la Asunción de María está situado en el Altar Mayor de la Basílica del Pilar en Zaragoza y es una de las grandes obras del Patrimonio artístico español. La obra, esculpida en alabastro, fue realizada entre 1509 y ¡518 por Damián Forment. En este trabajo se recogen las directrices para el diseño de los morteros de reparación utilizados en la restauración del retablo. Se basaron en criterios de compatibilidad de los materiales y tratamientos existentes en el retablo, según la investigación realizada durante las obras de la última actuación realizada para la limpieza y restauración. En la investigación realizada se comprobó la composición de los morteros originales, la granulometría de los

  17. Microscopic observations of self-healing products in calcareous fly ash mortars.

    Science.gov (United States)

    Jóźwiak-Niedźwiedzka, Daria

    2015-01-01

    The results of microstructural characterization of mortars containing fly ash class C (High Calcium Fly Ash) from combustion of lignite are presented. The evaluation of the microstructure was performed using scanning electron microscope, optical, and confocal microscope. The tested beams were bent till the crack and microcracks opening, which were healed during the different curing time. The results showed that the replacement of cement with fly ash class C influenced the process of crack healing. The addition of HCFA, at both 30% and 60%, speeds up the self-healing process in cracks and particularly in micro-cracks. In the research, the completely filling up of the cracks by new phases has not been observed, only the beginning of such process has been noticed.

  18. Deep placement of lime nitrogen promotes nitrogen fixation and seed yield of soybean with efficient utilization rates

    OpenAIRE

    Ohyama, Takuji; Takahashi, Yoshihiko; Nagumo, Yoshifumi; Tanaka, Kazuya; Sueyoshi, Kuni; Ohtake, Norikuni; Ishikawa, Shinji; Kamiyama, Satoshi; Saito, Masaki; Tewari, Kaushal

    2010-01-01

    Average soybean yield is low compared with the potential yield. N is derived from three sources; N_2 fixation, soil N, and fertilizer N. A heavy supply of N fertilizer often depresses nodule development and N_2 fixation activity, which sometimes results in the reduction of seed yield. We developed a new fertilization technique for soybean cultivation by deep placement (at 20 cm depth from the soil surface) of slow release N fertilizers, coated urea and lime nitrogen (calcium cyanamide) at the...

  19. Pozzolanic Activity of Burned Coal Gangue and Its Effects on Structure of Cement Mortar

    Institute of Scientific and Technical Information of China (English)

    ZHANG Changsen

    2006-01-01

    The pozzolanic activity of coal gangue burned at different burning temperatures was investigated. The burned coal gangue was mixed with portland cement in different proportions ( 20%-60% ). The pozzolanic activity of coal gangue burned and the hydration products were examined, the compressive strengths of the pastes of the mixtures were tested, and the mechanism of the reaction was discussed. The experimental results show that the coal gangue burned at 750 ℃ has the optimum pozzolanic activity, and the burned coal gangue with SiO2 and Al2O3 is in an active form. When the coal gangue burned at 750 ℃ is mixed into portland cement, the content of calcium hydroxide in paste is significantly reduced, while the contents of hydrated calcium silicate and hydrated calcium aluminate are increased accordingly, hence resulting in the improvement of the microstructure of mortar. The compressive strength of cement paste decreases with increasing the content of burned coal gangue. The decease in strength is small in the range of 20%- 30% coal gangue substitution and significant in 30%- 60% substitution.

  20. Properties of microcement mortar with nano particles

    Science.gov (United States)

    Alimeneti, Narasimha Reddy

    Carbon nanotubes (CNT) and Carbon nanofibers (CNF) are one of the toughest and stiffest materials in the world presently with extreme properties yet to be discovered in terms of elastic modulus and tensile strength. Due to the advanced properties of these materials they are being used in almost all fields of science at nanolevel and are being used in construction industry recently for improvement of material properties. Microcement is fine ground cement which as half the particle size of ordinary Portland cement. In this research the behavior of cement mortar of micro cement with the addition of nanoparticles is studied. Due to high aspect ratio and strong van der Waal forces between the particles of CNT and CNF, they agglomerate and form bundles when mixed with water, sonication method is used to mix nanoparticles with few drops of surfactant and super plasticizer. Mechanical properties such as compressive strength and flexural strength with CNT and CNF composites are examined and compared with control samples. 0.1% and 0.05 % of nanoparticles (both CNT and CNF) by the weight of cement are used in this research and 0.8% of super plasticizer by weight of cement was also used along with 0.4, 0.45 and 0.50 water cement ratios for making specimens for compression test. The compressive strength results are not satisfactory as there was no constant increase in strength with all the composites, however strength of few nanocomposites increased by a good percentage. 0.5 water cement ratio cement mortar had compressive strength of 7.15 ksi (49.3 MPa), whereas sample with 0.1% CNT showed 8.38 ksi (57.8 MPa) with 17% increase in strength after 28 days. Same trend was followed by 0.4 water cement ratio as the compressive strength of control sample was 8.89 ksi (61.3 MPa), with 0.05% of CNT strength increased to 10.90 ksi (75.2 MPa) with 23% increase in strength. 0.4 water cement ratio was used for flexural tests including 0.1%, 0.05% of CNT and 0.1%, 0.05% of CNF with 0

  1. Solidification/stabilization of toxic metals in calcium aluminate cement matrices

    Energy Technology Data Exchange (ETDEWEB)

    Navarro-Blasco, I.; Duran, A.; Sirera, R.; Fernández, J.M.; Alvarez, J.I., E-mail: jalvarez@unav.es

    2013-09-15

    Highlights: • Reliable encapsulation and effective sorption of Pb, Zn and Cu on CAC was proved. • Cu and Pb were fully retained in the CAC mortar, while Zn was retained in 99.99%. •A maximum sorption capacity ca. 60 mg/g CAC was attained for Cu. • Three different PSD patterns were established as a function of XRD phase assemblage. • Some metal-loaded mortars achieved suitable mechanical strengths for landfilling. -- Abstract: The ability of calcium aluminate cement (CAC) to encapsulate toxic metals (Pb, Zn and Cu) was assessed under two curing conditions. Changes in the consistency and in the setting time were found upon the addition of the nitrates of the target metals. Both Pb and Cu caused a delay in CAC hydration, while Zn accelerated the stiffening of the mortar. Compressive strengths of the metal-doped mortars, when initially cured at 60 °C/100% RH, were comparable with that of the free-metal mortar. Three different pore size distribution patterns were identified and related to the compounds identified by XRD and SEM. Sorbent capacities of CAC for the toxic metals were excellent: a total uptake was achieved for up to 3 wt.% loading of the three metals. In this way, CAC mortars were perfectly able to encapsulate the toxic metals, allowing the use of CAC for waste management as proved by the leaching tests.

  2. Application of enzymes for efficient extraction, modification, and development of functional properties of lime pectin

    DEFF Research Database (Denmark)

    Dominiak, Malgorzata Maria; Marie Søndergaard, Karen; Wichmann, Jesper;

    2014-01-01

    The objective of the present study was to transform “Waste to Food” using enzymes to recover value-added food ingredients from biomass. Six commercial cellulases were screened to generate proof of concept that enzymes are selective and efficient catalysts for opening of lime peel biomass to recover......2K improved its calcium sensitivity and ability to stabilize acidified milk drinks. The present study demonstrates that it is possible to substitute classical acid-based extraction by enzymatic catalysis and obtain pectin products with desirable functional properties....

  3. Measurement of lime/silica ratio in concrete using PGNAA technique

    Energy Technology Data Exchange (ETDEWEB)

    Naqvi, A.A. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)]. E-mail: aanaqvi@kfupm.edu.sa; Nagadi, M.M. [Department of Physics, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia); Al-Amoudi, O.S.B. [Department of Civil Engineering, King Fahd University of Petroleum and Minerals, Dhahran 31261 (Saudi Arabia)

    2005-12-01

    Prompt gamma neutron activation analysis (PGNAA) technique has been used to determine lime/silica ratio in concrete samples using an accelerator-based PGNAA facility. The ratio was determined from the measured yield of 6.42 MeV prompt {gamma}-rays of calcium and 4.93 MeV {gamma}-rays of silicon from the six concrete samples. The experimental results were compared with the results of the Monte Carlo simulations. An excellent agreement has been achieved between the two. The study has demonstrated successful use of the accelerator-based PGNAA setup in non-destructive analysis of the concrete samples.

  4. Measurement of lime/silica ratio in concrete using PGNAA technique

    International Nuclear Information System (INIS)

    Prompt gamma neutron activation analysis (PGNAA) technique has been used to determine lime/silica ratio in concrete samples using an accelerator-based PGNAA facility. The ratio was determined from the measured yield of 6.42 MeV prompt γ-rays of calcium and 4.93 MeV γ-rays of silicon from the six concrete samples. The experimental results were compared with the results of the Monte Carlo simulations. An excellent agreement has been achieved between the two. The study has demonstrated successful use of the accelerator-based PGNAA setup in non-destructive analysis of the concrete samples

  5. Measurement of lime/silica ratio in concrete using PGNAA technique

    Science.gov (United States)

    Naqvi, A. A.; Nagadi, M. M.; Al-Amoudi, O. S. B.

    2005-12-01

    Prompt gamma neutron activation analysis (PGNAA) technique has been used to determine lime/silica ratio in concrete samples using an accelerator-based PGNAA facility. The ratio was determined from the measured yield of 6.42 MeV prompt γ-rays of calcium and 4.93 MeV γ-rays of silicon from the six concrete samples. The experimental results were compared with the results of the Monte Carlo simulations. An excellent agreement has been achieved between the two. The study has demonstrated successful use of the accelerator-based PGNAA setup in non-destructive analysis of the concrete samples.

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

    OpenAIRE

    V. W. Francis Thoo; N. Zainuddin; Matori, K. A.; S.A. Abdullah

    2013-01-01

    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 Si...

  7. Detachment analysis of dehumidified repair mortars applied to historical masonry walls

    OpenAIRE

    Bocca, Pietro Giovanni; Valente, Silvio; Grazzini, Alessandro; Alberto, Andrea

    2014-01-01

    An innovative laboratory procedure for the pre-qualification of repair mortars is described. The tested mortars are suitable for use with new dehumidified plasters applied to historical masonry walls. Long-term plaster detachment frequently occurs because of the mechanical incompatibility of mortar. The procedure consists of the application of static loads to mixed stone block-mortar specimens with particular characteristics, in terms of geometry and adhesion at the interface. A numerical sim...

  8. Rilem TC 203-RHM. Repair mortars for historic masonry. The role of mortar in masonry: an introduction to requirements for the design of repair mortars

    NARCIS (Netherlands)

    Hees, R.P.J. van; Groot, C.; Balen, K. van; Bicer-Simsir, B.; Binda, L.; Elsen, J.; Konow, T. von; Lindqvist, J.E.; Maurenbrecher, P.; Papayanni, I.; Subercaseaux, M.; Tedeschi, C.; Toumbakari, E.E.; Thompson, M.

    2012-01-01

    Mortar has been in use for many thousands of years and is integral to most masonry construction. Its use is widespread in every culture where masonry is constructed. It is present in the majority of the global built cultural heritage, and is therefore a major consideration in building conservation.

  9. The newly applied mortars in mosaic restoration

    Directory of Open Access Journals (Sweden)

    Fabiana Moro

    2010-11-01

    Full Text Available L’intervention de restauration sur la mosaïque de Dionysos à Cologne a permis, dans le cadre du travail de fin d’étude, une recherche sur les problématiques liées au choix du lit de pose des mosaïques detachées et replacées sur de nouveaux supports. Elle a contribué à l’étude des facteurs qui influencent la conservation des mosaïques qui ont précédemment fait l’objet d’interventions de détachement du site originel.The restoration of the Dionysos mosaic in Cologne gave us the opportunity for analysing the process involved in the choice of interstitial mortars in mosaics that were detached from their original site and re-layed on new supports, thus losing their original setting bed. This intervention lead us to investigate the relationships between restoration and a philological perspective and the damages following the stripping of mosaics.

  10. Oyster shell as substitute for aggregate in mortar.

    Science.gov (United States)

    Yoon, Hyunsuk; Park, Sangkyu; Lee, Kiho; Park, Junboum

    2004-06-01

    Enormous amounts of oyster shell waste have been illegally disposed of at oyster farm sites along the southern coast of Korea. In this study to evaluate the possibility of recycling this waste for use as a construction material, the mechanical characteristics of pulverized oyster shell were investigated in terms of its potential utilization as a substitute for the aggregates used in mortar. The unconfined compressive strengths of various soil mortar specimens, with varying blending ratios of cement, water and oyster shell, were evaluated by performing unconfined compression tests, and the results were compared with the strengths of normal cement mortar made with sand. In addition, the effect of organic chemicals on the hardening of concrete was evaluated by preparing ethyl-benzene-mixed mortar specimens. The long-term strength improvement resulting from the addition of fly ash was also examined by performing unconfined compression tests on specimens with fly-ash content. There was no significant reduction in the compressive strength of the mortars containing small oyster shell particles instead of sand. From these test data, the possible application of oyster shells in construction materials could be verified, and the change in the strength parameters according to the presence of organic compounds was also evaluated.

  11. The colour potentials of SSA-containing mortar

    DEFF Research Database (Denmark)

    Kappel, Annemette; Ottosen, Lisbeth M.; Kirkelund, Gunvor Marie;

    2015-01-01

    This paper reports an experimental study of aesthetical qualities of mortar containing sewage sludgeash (SSA). SSA is the residue produced at water treatment plants where incineration of the sludge is applied in order to decrease volume and to prevent pathogens from spreading. Today SSA is with a......This paper reports an experimental study of aesthetical qualities of mortar containing sewage sludgeash (SSA). SSA is the residue produced at water treatment plants where incineration of the sludge is applied in order to decrease volume and to prevent pathogens from spreading. Today SSA...... is with a few exceptions landfilled and thus, wasted.The purpose of the experiments was to examine the influence of SSA and how it affected the colour of mortar samples. SSA was ground in 6 different intervals and added to mortar mixes by replacing 20% of the cement. An additional focus was to examine...... the possibilities to accentuate the colours of the hardened mortar by using paper cuttings in the production of the samples. The result of the experiments showed that a colour scale can be developed from ground SSA, and that paper may have the potential of providing divers textural qualities when it is used...

  12. Use of rubble from building demolition in mortars.

    Science.gov (United States)

    Corinaldesi, V; Giuggiolini, M; Moriconi, G

    2002-01-01

    Because of increasing waste production and public concerns about the environment, it is desirable to recycle materials from building demolition. If suitably selected, ground, cleaned and sieved in appropriate industrial crushing plants, these materials can be profitably used in concrete. Nevertheless, the presence of masonry instead of concrete rubble is particularly detrimental to the mechanical performance and durability of recycled-aggregate concrete and the same negative effect is detectable when natural sand is replaced by fine recycled aggregate fraction. An alternative use of both masonry rubble and fine recycled material fraction could be in mortars. These could contain either recycled instead of natural sand or powder obtained by bricks crushing as partial cement substitution. In particular, attention is focused on the modification that takes place when either polypropylene or stainless steel fibers are added to these mortars. Polypropylene fibers are added in order to reduce shrinkage of mortars, stainless steel fibers for improving their flexural strength. The combined use of polypropylene fibers and fine recycled material from building demolition could allow the preparation of mortars showing good performance, in particular when coupled with bricks. Furthermore, the combined use of stainless steel fibers and mortars containing brick powder seems to be an effective way to guarantee a high flexural strength.

  13. A multiscale mortar multipoint flux mixed finite element method

    KAUST Repository

    Wheeler, Mary Fanett

    2012-02-03

    In this paper, we develop a multiscale mortar multipoint flux mixed finite element method for second order elliptic problems. The equations in the coarse elements (or subdomains) are discretized on a fine grid scale by a multipoint flux mixed finite element method that reduces to cell-centered finite differences on irregular grids. The subdomain grids do not have to match across the interfaces. Continuity of flux between coarse elements is imposed via a mortar finite element space on a coarse grid scale. With an appropriate choice of polynomial degree of the mortar space, we derive optimal order convergence on the fine scale for both the multiscale pressure and velocity, as well as the coarse scale mortar pressure. Some superconvergence results are also derived. The algebraic system is reduced via a non-overlapping domain decomposition to a coarse scale mortar interface problem that is solved using a multiscale flux basis. Numerical experiments are presented to confirm the theory and illustrate the efficiency and flexibility of the method. © EDP Sciences, SMAI, 2012.

  14. Sulfur-free lignins from alkaline pulping tested in mortar for use as mortar additives.

    Science.gov (United States)

    Nadif, A; Hunkeler, D; Käuper, P

    2002-08-01

    Sulfur-free lignin, obtained through the acid precipitation of black liquor from the soda pulping process, has been tested as water reducer in mortar. It has also been compared to existing commercial additives such as naphthalene sulfonates and lignosulfonates. The ash content and sugar content of these lignins are low in comparison to lignosulfonates, conferring on them higher purity. A procedure for small scale testing derived from the industrial norms SN-EN196 and ASTM (Designation C230-90) is presented. Specifically, all the sulfur-free lignins tested improved the flow of the mortar. Selected flax lignins performed better than lignosulfonates though still less than naphthalene sulfonates. Furthermore, certain hemp lignins gave comparable results to the lignosulfonates. Overall, the straw lignin prepared herein is comparable in performance to commercially available lignins, such as Organocell, Alcell and Curan 100. The plant from which the lignin was isolated, and the process of the pulp mill are the primary influences on the performance of the lignin.

  15. Sulfur-free lignins from alkaline pulping tested in mortar for use as mortar additives

    Energy Technology Data Exchange (ETDEWEB)

    Nadif, A.; Hunkeler, D.; Kauper, P. [Ecole Polytechnique Federale de Lausanne (Switzerland). Dept. de Chimie

    2002-08-01

    Sulfur-free lignin, obtained through the acid precipitation of black liquor from the soda pulping process, has been tested as water reducer in mortar. It has also been compared to existing commercial additives such as naphthalene sulfonates and lignosulfonates. The ash content and sugar content of these lignins are low in comparison to lignosulfonates, conferring on them higher purity. A procedure for small scale testing derived from the industrial norms SN-EN196 and ASTM (Designation C230-90) is presented. Specifically, all the sulfur-free lignins tested improved the flow of the mortar. Selected flax lignins performed better than lignosulfonates though still less than naphthalene sulfonates. Furthermore, certain hemp lignins gave comparable results to the lignosulfonates. Overall, the straw lignin prepared herein is comparable in performance to commercially available lignins, such as Organocells, Aicello and Curan 100. The plant from which the lignin was isolated, and the process of the pulp mill are the primary influences on the performance of the lignin. (author)

  16. Water extraction out of mortar during brick laying. An NMR study

    NARCIS (Netherlands)

    Brocken, H.J.P.

    1996-01-01

    The water extraction out of mortar during brick laying was studied by nuclear magnetic resonance. The water extraction is an important parameter that determines, e.g., the stiffness of the mortar due to compaction of the cement particles and the bond strength of the cured-mortar interfaces but allo

  17. POLYMER AND CEMENT MORTARS FOR THE CONSTRUCTION AND REPAIR OF BUILDINGS AND STRUCTURE

    Directory of Open Access Journals (Sweden)

    O. M. Pshinko

    2009-02-01

    Full Text Available In the article the analysis of polymer-cement mortars for their application in construction and repair of buildings and structures is presented. The main properties of known polymer-cement mortars used for this purpose are described. The advantages of application of polymer-cement mortars as repair materials are shown.

  18. Calcium carbonate crystallizations on hypogean mural paintings: a pilot study of monitoring and diagnostics in Roman catacombs

    Science.gov (United States)

    Tapete, D.; Fratini, F.; Mazzei, B.; Camaiti, M.; Cantisani, E.; Riminesi, C.; Manganelli Del Fà, R.; Cuzman, O.; Tiano, P.

    2012-04-01

    One of the deterioration processes affecting mural paintings and rock surfaces within manmade hypogea consists in the formation of calcium carbonate crystallizations, which can create thick coverage and incrustations, even in some cases speleothems. These chemical reactions necessarily require the availability of calcium sources, which can be also of anthropogenic origin (e.g., lime-based mortars). Microclimate parameters also represent environmental forcing factors, on which the morphology and the degree of crystallinity of the precipitated carbonates depend. Understanding past/recent dynamics of carbonate precipitation implies a deep knowledge of the relationships between the exposed surfaces and the microclimate conditions, the impacts of external factors (e.g., groundwater infiltration and percolation from the overlying soil) and how they change over time. This is particularly fundamental for the preservation of hypogean sites which have not comparison with other typologies of environment due to their uniqueness, such as the ancient catacombs carved underneath the suburbs of Rome (Italy), since the 2nd century AD. In this paper we present the multidisciplinary methodological approach designed for the instrumental monitoring of the microphysical environment of the Catacombs of Saints Mark, Marcellian and Damasus, in the framework of the co-operation between the Institute for the Conservation and Valorization of Cultural Heritage and Pontifical Commission for Sacred Archaeology, Vatican, on the project HYPOGEA. Temperature inside the catacomb and on the surfaces, air relative humidity and CO2 concentration are the main of the parameters continuously measured by means of data loggers installed within the cubicles. Contemporarily, standardized methods of photographic documentation and digital micro-photogrammetry are used for change detection analysis of the painted surfaces and ancient plasters, as well as of the test areas purposely realized by applying fresh

  19. 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.

  20. Design for Composing of Lime-flyash Mortar%二灰砂浆组成设计研究

    Institute of Scientific and Technical Information of China (English)

    王斌; 梁洪国; 赵伟

    2006-01-01

    以材料的组成结构与性能的关系为基础,把二灰碎石理解成三个组成结构层次,并利用这样的观点进行组成配合比设计是正确、可行的,值得施工单位参考借鉴.

  1. Effect of mixed-in crystallization inhibitor on resistance of lime-cement mortar against NaCI

    NARCIS (Netherlands)

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

    2010-01-01

    Salt crystallization is a common cause of damage to porous building materials. Recent research has shown that some chemical compounds may inhibit salt crystallization or alter the mode of crystallization, thus limiting salt damage development, provided that the inhibitor was introduced prior to salt

  2. Corrosion Behaviour of a New Low-Nickel Stainless Steel Reinforcement: A Study in Simulated Pore Solutions and in Fly Ash Mortars

    Directory of Open Access Journals (Sweden)

    M. Criado

    2012-01-01

    Full Text Available The present paper studies the corrosion behaviour of a new lower-cost type of austenitic stainless steel (SS with a low nickel content in alkaline-saturated calcium hydroxide solution (a simulated concrete pore (SCP solution with sodium chloride (0.0%, 0.4%, 1.0%, 2.0%, 3.0%, and 5.0% NaCl and embedded in alkali-activated fly ash (AAFA mortars manufactured using two alkaline solutions, with and without chloride additions (2% and 5%, in an environment of constant 95% relative humidity. Measurements were performed at early age curing up to 180 days of experimentation. The evolution with time of electrochemical impedance spectroscopy was studied. Rct values obtained in SCP solution or in fly ash mortars were so high that low-nickel SS preserved its passivity, exhibiting high corrosion resistance

  3. Zooplankton of Lake Orta after liming: an eleven years study

    Directory of Open Access Journals (Sweden)

    Andrea PASTERIS

    2001-02-01

    Full Text Available Lake Orta (N. Italy was severely polluted from 1927 by an effluent from a rayon factory, which discharged great amounts of ammonium nitrogen and copper into the lake. In the mid nineteen fifties, some plating factories also started dumping chromium and aluminum. As a result of ammonium oxidation, the lake became very acid and the concentration of metals in the waters reached very high values. Phytoplankton, zooplankton and fish disappeared suddenly from the lake which was by 1930 classified as “sterile”. Later on, about the fifties, a small population of Cyclops abyssorum re-colonised the lake together with some rotifers, in particular Hexarthra fennica. In mid eighties following the introduction of anti-pollution legislation, ammonium loads were greatly reduced and Daphnia obtusa was recorded. The lake waters however were still very acid, prompting the proposal of the Istituto Italiano di Idrobiologia to lime the lake with calcium carbonate to neutralise the excess acidity and reconstruct the alkaline reserve. This was done successfully from May 1989 to June 1990. pH values began to rise and in the same time the metal concentrations decreased, so that at present the lake waters are almost “normal”. In the meantime, due to the increased pH values, D. obtusa was replaced by D. longispina and, as toxic metal concentrations became lower, Megacyclops viridis, Bosmina longirostris, Diaphanosoma brachyurum, Keratella quadrata, Asplanchna priodonta. and other Brachionidae species appeared. Diaptomidae are still absent, except for some specimens of Arctodiaptomus wierzejskii.

  4. Influence of pore structure on compressive strength of cement mortar.

    Science.gov (United States)

    Zhao, Haitao; Xiao, Qi; Huang, Donghui; Zhang, Shiping

    2014-01-01

    This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure.

  5. Properties of Cement Mortar with Phosphogpysum under Steam Curing Condition

    Directory of Open Access Journals (Sweden)

    Kyoungju Mun

    2008-01-01

    Full Text Available The purpose of this study is to utilize waste PG as an admixture for concrete products cured by steam. For the study, waste PG was classified into 4 forms (dehydrate, β-hemihydrate, III-anhydrite, and II-anhydrite, which were calcined at various temperatures. Also, various admixtures were prepared with PG, fly-ash (FA, and granulated blast-furnace slag (BFS. The basic properties of cement mortars containing these admixtures were analyzed and examined through X-ray diffraction, scanning electron microscopy, compressive strength, and acid corrosion resistance. According to the results, cement mortars made with III-anhydrite of waste PG and BFS exhibited strength similar to that of cement mortars made with II-anhydrite. Therefore, III-anhydrite PG calcined at lower temperature can be used as a steam curing admixture for concrete second production.

  6. Effects of moisture on ultrasound propagation in cement mortar

    Science.gov (United States)

    Ju, Taeho; Li, Shuaili; Achenbach, Jan; Qu, Jianmin

    2015-03-01

    In concrete structures, moisture is often a major cause of chemically related degradations such as alkaline-silica reaction. To develop ultrasonic nondestructive evaluation techniques for monitoring such chemical degradations, it is necessary to understand how moisture affects the propagation of ultrasound in concrete. To this end, the objective of this paper is to experimentally determine the correlation between the moisture content in cement mortar and ultrasonic wave propagation. Specifically, effects of moisture on the ultrasonic phase velocity and attenuation are examined. It is found that, for the cement mortar samples considered in this study, moisture has negligible effect on the ultrasonic phase velocity. However, moisture can significantly increase the attenuation of ultrasound in cement mortar even in the sub-MHz frequency range.

  7. Concentration Boundary Layer Model of Mortar Corrosion by Sulfuric Acid

    Institute of Scientific and Technical Information of China (English)

    SONG Zhigang; ZHANG Xuesong; MIN Hongguang

    2011-01-01

    A long time immersion experiment of mortar specimens is carried out to investigate their degradation mechanism by sulfuric acid. Water-cement ratios of mortar are ranging from 0.5 to 0.7 and the pH value of sulfuric acid is 3.5 and 4.0 respectively. The pH meter is used to monitor the soak solution and the titration sulfuric acid with given concentration is added to maintain original pH value, through which the acid consumption of mortar is recorded. A theoretical reaction rate model is also proposed based on concentration boundary layer model. The results show that theoretical model fits the experimental results well and the corrosion mechanism can be modeled by a diffusion process accompanied with an irreversible chemical reaction when pH value of soak solution is no less than 3.5.

  8. Estimation of masonry mortars strength during stone buildings investigation (rus

    Directory of Open Access Journals (Sweden)

    Derkach V.N.

    2011-11-01

    Full Text Available In this article the analysis of estimation methods of the masonry mortars strength applied in Russia and other countries during stone buildings and constructions investigation was carried out. Advantages and disadvantages of these methods are considered.The new technique of masonry mortars strength estimation is offered. It is based on trials of bored from a masonry body cylindrical samples. It is pointed, that this method is the most universal and informative from all methods considered in this article. The offered testing procedure allows to gain not only a compression strength, but also a shearing strength along horizontal masonry seams. Results of experimental researches of masonry mortars compression strength executed on various techniques are presented.

  9. Use of red mud as addition for portland cement mortars

    International Nuclear Information System (INIS)

    The aim of the present research work was to investigate the possibility of adding red mud, an alkaline leaching waste that is obtained from bauxite during the Bayer process for alumina production, in the raw meal of Portland cement mortars. The red mud is classified as dangerous, according to NBR 10004/2004, and world while generation reached over 117 million tons/year. This huge production requires high consuming products to be used as incorporation matrix and we studied the influence of red mud addition on the characteristics of cement mortars and concrete. In this paper the properties of Portland cement mortars incorporating high amounts of red mud was evaluated: pH variation, fresh (setting time, workability or normal consistency and water retention), and hardened state (mechanical strength, capillary water absorption, density and apparent porosity). Results seem promising for red mud additions up to 20 wt%. (author)

  10. Influence of pore structure on compressive strength of cement mortar.

    Science.gov (United States)

    Zhao, Haitao; Xiao, Qi; Huang, Donghui; Zhang, Shiping

    2014-01-01

    This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure. PMID:24757414

  11. Influence of Pore Structure on Compressive Strength of Cement Mortar

    Directory of Open Access Journals (Sweden)

    Haitao Zhao

    2014-01-01

    Full Text Available This paper describes an experimental investigation into the pore structure of cement mortar using mercury porosimeter. Ordinary Portland cement, manufactured sand, and natural sand were used. The porosity of the manufactured sand mortar is higher than that of natural sand at the same mix proportion; on the contrary, the probable pore size and threshold radius of manufactured sand mortar are finer. Besides, the probable pore size and threshold radius increased with increasing water to cement ratio and sand to cement ratio. In addition, the existing models of pore size distribution of cement-based materials have been reviewed and compared with test results in this paper. Finally, the extended Bhattacharjee model was built to examine the relationship between compressive strength and pore structure.

  12. Application of micromechanics to the characterization of mortar by ultrasound.

    Science.gov (United States)

    Hernández, M G; Anaya, J J; Izquierdo, M A G; Ullate, L G

    2002-05-01

    Mechanical properties of concrete and mortar structures can be estimated by ultrasonic non-destructive testing. When the ultrasonic velocity is known, there are standardized methods based on considering the concrete a homogeneous material. Cement composites, however, are heterogeneous and porous, and have a negative effect on the mechanical properties of structures. This work studies the impact of porosity on mechanical properties by considering concrete a multiphase material. A micromechanical model is applied in which the material is considered to consist of two phases: a solid matrix and pores. From this method, a set of expressions is obtained that relates the acoustic velocity and Young's modulus of mortar. Experimental work is based on non-destructive and destructive procedures over mortar samples whose porosity is varied. A comparison is drawn between micromechanical and standard methods, showing positive results for the method here proposed.

  13. Characteristics of Bamboo Leaf Ash Blended Cement Paste and Mortar

    Directory of Open Access Journals (Sweden)

    Umoh A.A.

    2015-01-01

    Full Text Available The use of bamboo leaf ash as cement supplement can contribute to reduction in cost and environmental hazard associated with cement production as well as waste pollution caused by the littered bamboo leaves. Therefore, the characteristics of cement paste and mortar incorporating bamboo leaf ash were investigated. The results of the physical properties of the pastes were within the requirements stipulated by relevant standards while that of the mortar cubes indicated that the compressive strength generally increased with curing age, and that the mix containing 15% Bamboo Leaf Ash (BLA by mass competes favorably with that of the reference mix at 28days and above. The water absorption and apparent porosity were observed to increase with increase in BLA content, while the bulk density decreases as the percentage of BLA increases from 5% to 25% by mass. The study concluded that 15% BLA replacing cement is adequate for the production of masonry mortar.

  14. Liming of acidified waters: issues and research - a report of the International Liming Workshop

    Science.gov (United States)

    Schreiber, R. Kent

    1982-01-01

    Acidic deposition is a problem of significant national and international concern. It is strongly suspected that acidic deposition has adversely affected aquatic resources in Scandinavia and North America. While substantial resources are being devoted to understanding the causative factors associated with surface water acidification, much less research is being conducted on mitigative strategies. Mitigative techniques involving liming may be useful for short-term protection of specific component of aquatic communities or for renovation of seriously impacted aquatic ecosystems. The selection of effective liming strategies is based on an integrated understanding of the following key factors: biological systems, water chemistry, sediment chemistry, hydrology, and watershed characteristics, effectiveness of neutralizing materials, and application techniques. Research in Scandinavia, Canada, and the U.S. has led to a partial understanding of some of the key factors for successful neutralization of surface waters (Bengtsson, 1982; Fraser and Britt, 1982). However, conflicting results of liming operations and experiments have been reported. (Fraser et al., 1982; Fraser and Britt, 1982; Sverdrup and Bjerle, 1982). Additional research is required to improve the ability of scientists and resource managers to select effective liming strategies. An International Liming workshop was convened during 19-25 September 1982 at the University of Washington's Friday Harbor Laboratories. The major objective of this workshop were: - To identify the most critical deficiencies in the scientific understanding of liming techniques and their long-term consequences. - To develop and document a research strategy to address information deficiencies that are pertinent to the protection or renovation of acidic surface waters in the United States. The participants who contributed to this workshop are listed in Table 1.

  15. 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.

  16. Quantitative Assessment of Citric Acid in Lemon Juice, Lime Juice, and Commercially-Available Fruit Juice Products

    Science.gov (United States)

    PENNISTON, KRISTINA L.; NAKADA, STEPHEN Y.; HOLMES, ROSS P.; ASSIMOS, DEAN G.

    2009-01-01

    Background and Purpose Knowledge of the citric acid content of beverages may be useful in nutrition therapy for calcium urolithiasis, especially among patients with hypocitraturia. Citrate is a naturally-occurring inhibitor of urinary crystallization; achieving therapeutic urinary citrate concentration is one clinical target in the medical management of calcium urolithiasis. When provided as fluids, beverages containing citric acid add to the total volume of urine, reducing its saturation of calcium and other crystals, and may enhance urinary citrate excretion. Information on the citric acid content of fruit juices and commercially-available formulations is not widely known. We evaluated the citric acid concentration of various fruit juices. Materials and Methods The citric acid content of 21 commercially-available juices and juice concentrates and the juice of three types of fruits was analyzed using ion chromatography. Results Lemon juice and lime juice are rich sources of citric acid, containing 1.44 and 1.38 g/oz, respectively. Lemon and lime juice concentrates contain 1.10 and 1.06 g/oz, respectively. The citric acid content of commercially available lemonade and other juice products varies widely, ranging from 0.03 to 0.22 g/oz. Conclusions Lemon and lime juice, both from the fresh fruit and from juice concentrates, provide more citric acid per liter than ready-to-consume grapefruit juice, ready-to-consume orange juice, and orange juice squeezed from the fruit. Ready-to-consume lemonade formulations and those requiring mixing with water contain ≤6 times the citric acid, on an ounce-for-ounce basis, of lemon and lime juice. PMID:18290732

  17. THE MORTAR ELEMENT METHOD FOR A NONLINEAR BIHARMONIC EQUATION

    Institute of Scientific and Technical Information of China (English)

    Zhong-ci Shi; Xue-jun Xu

    2005-01-01

    The mortar element method is a new domain decomposition method(DDM) with nonoverlapping subdomains. It can handle the situation where the mesh on different subdomains need not align across interfaces, and the matching of discretizations on adjacent subdomains is only enforced weakly. But until now there has been very little work for nonlinear PDEs. In this paper, we will present a mortar-type Morley element method for a nonlinear biharmonic equation which is related to the well-known Navier-Stokes equation. Optimal energy and H1-norm estimates are obtained under a reasonable elliptic regularity assumption.

  18. Various mortars for anti-fouling purposes in marine environments

    Energy Technology Data Exchange (ETDEWEB)

    Kanematsu, Hideyuki; Masuda, Tomoka [Department of Materials Science and Engineering, Suzuka National College of Technology, Shiroko-cho, Suzuka, Mie 510-0294 (Japan); Miura, Yoko; Kuroda, Daisuke [Department of General Education, The Company, Suzuka National College of Technology, Shiroko-cho, Suzuka, Mie 510-0294 (Japan); Hirai, Nobumitsu [Department of Chemistry and Biochemistry, Suzuka National College of Technology, Shiroko-cho, Suzuka, Mie 510-0294 (Japan); Yokoyama, Seiji [Department of Mechanical Engineering, Toyohashi University of Technology, 1-1, Hibarigaoka, Tenpaku, Toyohashi, Aichi, 441-8580 (Japan)

    2014-02-20

    The antifouling properties for some mortars with steel making slags were investigated by real marine immersion tests and a unique laboratory acceleration tests with a specially devised biofilm acceleration reactors. Mortars mixed with steel making slags containing abundant iron elements tended to form biofilm and also bifouling. The two kinds of biofilm formation tests were used in this study. Real immersion in marine environments and laboratory test with a specially devised biofilm acceleration reactor. The former evaluated the biofouling characteristics more properly, while the latter did the biofilm formation characteristics more effectively.

  19. Carbonation process in lime pastes with different water/binder ratio

    Directory of Open Access Journals (Sweden)

    Álvarez, J. I.

    2006-03-01

    Full Text Available Most research on binder carbonation is based on the analysis of depth changes in the carbonation front. Moreover, previous studies have dealt with mortars, where aggregates play a role in the variations in carbonation patterns. In the approach adopted in the present study, carbonation was determined in terms of the variation in weight resulting from CO2 absorption, and a new parameter (independent of the drying process, denominated A, was established. This parameter was assessed in several lime pastes with different W/B (water/binder ratios and its variations were correlated to paste microstructure. Due to the type of porosity prevailing in lime pastes, diffusion took place according to Fick's law; water was retained not by capillarity but by surface adsorption. Drying did not retard carbonation in lime pastesLa mayoría de las investigaciones sobre el proceso de carbonatación en materiales conglomerantes estudia el movimiento del frente de carbonatación. Además, los trabajos previos han sido llevados a cabo en morteros, lo que implica variaciones en el comportamiento de la carbonatación debido a la presencia del agregado. En este trabajo, la carbonatación es discutida teniendo en cuenta la variación del peso como consecuencia de la absorción de CO2, al establecer un nuevo parámetro A (independiente del proceso de secado. Este parámetro ha sido evaluado en varias pastas de cal con distinta relación A/C (agua/conglomerante, y su variación se ha correlacionado con la microestructura de las pastas. Durante el proceso de la carbonatación, y debido al tipo de porosidad de las pastas de cal, tiene lugar la difusión de Fick: el agua no es retenida por capilaridad sino por adsorción sobre la superficie. El proceso de secado no retrasa la carbonatación en las pastas de cal.

  20. Capture of gas-phase arsenic oxide by lime: kinetic and mechanistic studies.

    Science.gov (United States)

    Jadhav, R A; Fan, L S

    2001-02-15

    Trace metal emission from coal combustion is a major concern for coal-burning utilities. Toxic compounds such as arsenic species are difficult to control because of their high volatility. Mineral sorbents such as lime and hydrated lime have been shown to be effective in capturing arsenic from the gas phase over a wide temperature range. In this study, the mechanism of interaction between arsenic oxide (As2O3) and lime (CaO) is studied over the range of 300-1000 degrees C. The interaction between these two components is found to depend on the temperature; tricalcium orthoarsenate (Ca3As2O8) is found to be the product of the reaction below 600 degrees C, whereas dicalcium pyroarsenate (Ca2As2O7) is found to be the reaction product in the range of 700-900 degrees C. Maximum capture of arsenic oxide is found to occur in the range of 500-600 degrees C. At 500 degrees C, a high reactivity calcium carbonate is found to capture arsenic oxide by a combination of physical and chemical adsorption. Intrinsic kinetics of the reaction between calcium oxide and arsenic oxide in the medium-temperature range of 300-500 degrees C is studied in a differential bed flow-through reactor. Using the shrinking core model, the order of reaction with respect to arsenic oxide concentration is found to be about 1, and the activation energy is calculated to be 5.1 kcal/mol. The effect of initial surface area of CaO sorbent is studied over a range of 2.7-45 m2/g using the grain model. The effect of other major acidic flue gas species (SO2 and HCl) on arsenic capture is found to be minimal under the conditions of the experiment. PMID:11349294

  1. Argamassas mistas para alvenaria utilizando resíduo de caulim - Parte I: comportamento mecânico Masonry mortars using kaolin processing waste -Part I: mechanical property

    Directory of Open Access Journals (Sweden)

    Aretuza K. A. da Rocha

    2008-12-01

    Full Text Available O caulim é um material com vasta gama de aplicações nos mais diversos setores industriais, como a indústria de papel e a cerâmica. No entanto, sua extração e beneficiamento provocam a geração de enorme quantidade de resíduos. Assim, esse trabalho tem por objetivo analisar a utilização do resíduo do beneficiamento do caulim como matéria-prima alternativa em argamassas para a construção civil. O resíduo foi caracterizado através da determinação de sua composição química, difração de raios X e determinação da distribuição granulométrica. Foram formuladas argamassas substituindo parcialmente a cal hidratada por resíduo. Em seguida, foram confeccionados corpos-de-prova e determinada sua resistência à compressão simples e à tração indireta. A substituição da cal por adições de até 20% de resíduo de caulim possibilitou o aumento da resistência das argamassas estudadas em até 80%. Com base nos resultados, pode-se concluir que o resíduo de caulim pode ser utilizado para a produção de argamassas para construção civil com propriedades mecânicas de acordo com a normalização e que a adição do resíduo pode melhorar a resistência mecânica das argamassas convencionais.Kaolin is a material used in a wide range of applications in many industrial sectors, as the paper and the ceramic industry. However, the kaolin processing industry generates large amounts of waste. Thus, the aim of this work is to evaluate the kaolin processing waste suitability as an alternative raw material for the production of mortars. The waste was characterized by determining its chemical composition, particle size distribution, and X-ray diffraction. Mortars were prepared by partially substituting kaolin waste for hydrated lime. Test specimens were prepared and their compression and indirect tension strength determined. The substitution of the lime by additions of up to 20% of kaolin waste improved the mechanical strength of masonry

  2. 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)

  3. Experimental study of phosphorous gypsum based insulation mortar powder material%磷石膏基保温砂浆胶粉料试验研究

    Institute of Scientific and Technical Information of China (English)

    王玉麟; 赖振斌; 黄巧玲; 漆贵海

    2012-01-01

    The article studies on preparation of thermal insulation mortar powder materials with phosphorus gypsum which was an industrial waste residue, supplemented with cement and slag powder. Phosphorous gypsum based thermal insulation mortar powder material is prepared by experimental study and analysis on the influence of various factors to the mechanical properties and softening coefficient of phosphorous gypsum based mineral binder. The optimized formulation is verified. Through the comparison of mechanical properties and water absorption of gypsum based reference specimen, it is obtained that in the prepared phosphorus gypsum-based insulation mortar, the phosphorus gypsum amount is 54%, slag content is 30%, lime is 5%, cement is 10% and admixture is 1%, which provides a new approach for comprehensive utilization of phosphorus gypsum.%利用工业废渣磷石膏作为主要胶凝材料,辅以水泥、矿渣粉等研制保温砂浆胶粉料.通过各因素对磷石膏基胶粉料力学性能与软化系数影响的试验研究及分析,配制出了磷石膏基保温砂浆胶粉料.并对优化后的配方进行了验证;石膏基准试件的力学性能与吸水率进行了比较,得出磷石膏基保温砂浆中的磷石膏用量为54%时,矿渣掺量为30%,石灰为5%,水泥为10%,外加剂为1%,以期为磷石膏的有效利用提供新的途径.

  4. Building a Better Clicks-and-Mortar Library

    Science.gov (United States)

    Vesey, Ken

    2004-01-01

    One of the most important roles for school libraries in the digital age is to provide students with a context for processing Internet information. It has been suggested that the school library should strive for a more pronounced clicks-and-mortar identity combining the best of the web and the traditional library collection.

  5. Workability and strength of lignite bottom ash geopolymer mortar.

    Science.gov (United States)

    Sathonsaowaphak, Apha; Chindaprasirt, Prinya; Pimraksa, Kedsarin

    2009-08-30

    In this paper, the waste lignite bottom ash from power station was used as a source material for making geopolymer. Sodium silicate and sodium hydroxide (NaOH) were used as liquid for the mixture and heat curing was used to activate the geopolymerization. The fineness of bottom ash, the liquid alkaline/ash ratio, the sodium silicate/NaOH ratio and the NaOH concentration were studied. The effects of the additions of water, NaOH and napthalene-based superplasticizer on the workability and strength of the geopolymer mortar were also studied. Relatively high strength geopolymer mortars of 24.0-58.0 MPa were obtained with the use of ground bottom ash with 3% retained on sieve no. 325 and mean particle size of 15.7 microm, using liquid alkaline/ash ratios of 0.429-0.709, the sodium silicate/NaOH ratios of 0.67-1.5 and 7.5-12.5M NaOH. The incorporation of water improved the workability of geopolymer mortar more effectively than the use of napthalene-based superplasticizer with similar slight reduction in strengths. The addition of NaOH solution slightly improves the workability of the mix while maintaining the strength of the geopolymer mortars.

  6. Chloride ion transport performance in slag mortar under fatigue loading

    Institute of Scientific and Technical Information of China (English)

    WANG CaiHui; SUN Wei; JIANG JinYang; HAN JianDe; YE BangTu

    2012-01-01

    The transport performance of chloride ion in slag cement mortar was investigated experimentally.In the self-designed experiment,fatigue loading was coupled simultaneously with ion transportation process,the diffusion law of chloride ion was obtained by titration and the AE (acoustic emission) technique was employed to detect the real-time damage distribution in the mortar specimen.The results for fatigue stress levels of 0.3,0.4 and 0.5 and slag contents of 0,10%,30% and 50% showed that fatigue loading accelerated the diffusion of chloride ion in mortar and the acceleration effect increased with the increase in stress levels.Slag addition was found to improve anti-chloride ion erosion performance effectively with the best substitution level at 30%,because the inhibition effect of slag on chloride ion diffusion diminished when the slag content exceeded 30%.The comparative experiments indicated that dynamic load has a significant effect on the transport performance of chloride ion in slag cement mortar.

  7. Moisture Diffusivity of Fiber Reinforced Silica Fume Mortars

    OpenAIRE

    Denarié, E.; Houst, Y. F.

    1995-01-01

    The moisture diffusivity is of considerable importance for quantitative assessments of creep and shrinkage as well as durability of cementitious material. For this reason, the influence of the composition of repair mortars on their effective moisture diffusivity as a function of the relative humidity of the surrounding air has been investigated. Silica fume,

  8. Do Schools Still Need Brick-and-Mortar Libraries?

    Science.gov (United States)

    Johnson, Doug; Mastrion, Keith

    2009-01-01

    Do all schools need brick-and-mortar libraries? In this article, Johnson and Mastrion share their contradictory thoughts to the question. Johnson says some schools don't need library facilities or programs or librarians. These schools' teachers and administrators: (1) feel no need for a collaborative learning space; (2) feel the ability to process…

  9. TECHNOLOGICAL PROPERTIES OF CONCRETES AND MORTARS FOR UNDERWATER CONCRETING

    OpenAIRE

    O. V. Anufrieva; B. H. Klochko

    2009-01-01

    The article is about the results of experimental-and-theoretical research of usefulness of mortar and concrete mixes for underwater repair works. It is shown that the developed compositions of hydraulic engineering concretes are characterized by high effectiveness in the corrosive medium.

  10. TECHNOLOGICAL PROPERTIES OF CONCRETES AND MORTARS FOR UNDERWATER CONCRETING

    Directory of Open Access Journals (Sweden)

    O. V. Anufrieva

    2009-03-01

    Full Text Available The article is about the results of experimental-and-theoretical research of usefulness of mortar and concrete mixes for underwater repair works. It is shown that the developed compositions of hydraulic engineering concretes are characterized by high effectiveness in the corrosive medium.

  11. MULTIGRID FOR THE MORTAR FINITE ELEMENT FOR PARABOLIC PROBLEM

    Institute of Scientific and Technical Information of China (English)

    Xue-jun Xu; Jin-ru Chen

    2003-01-01

    In this paper, a mortar finite element method for parabolic problem is presented. Multigrid method is used for solving the resulting discrete system. It is shown that the multigrid method is optimal, I.e, the convergence rate is independent of the mesh size L and the time step parameter т.

  12. Salt-resistant mortars: present knowledge and future perspectives

    NARCIS (Netherlands)

    Lubelli, B.A.

    2014-01-01

    Salt crystallization damage is one of the most common causes of decay for bedding, pointing and plastering mortar. Attempts to tackle the problem showed to often a limited durability to salt decay and a low compatibility with historical buildings. Recent research has shown new possibilities for impr

  13. Low Carbon Footprint Mortar from Pozzolanic Waste Material

    Directory of Open Access Journals (Sweden)

    Taha Mehmannavaz

    2014-04-01

    Full Text Available Nowadays, Portland cement clinker leads to emission of CO2 into the atmosphere and therefore causes greenhouse effect. Incorporating of Palm Oil Fuel Ash (POFA and Pulverized Fuel Ash (PFA as partial cement replacement materials into mix of low carbon mortar decreases the amount of cement use and reduces high dependence on cements compared to ordinary mortar. The result of this research supported use of the new concept in preparing low carbon mortar for industrial constructions. Strength of low carbon mortar with POFA and PFA replacement in cement was affected and changed by replacing percent finesse, physical and chemical properties and pozzolanic activity of these wastes. Waste material replacement instead of Ordinary Portland Cement (OPC was used in this study. This in turn was useful for promoting better quality of construction and innovative systems in construction industry, especially in Malaysia. This study was surely a step forward to achieving quality products which were affordable, durable and environmentally friendly. Disposing ash contributes to shortage of landfill space in Malaysia. Besides, hazard of ash might be another serious issue for human health. The ash disposal area also might create a new problem, which is the area's sedimentation and erosion.

  14. Modeling the thermal characteristics of masonry mortar containing recycled materials

    Science.gov (United States)

    Laney, Morgan Gretchen

    As the building industry in the United States rapidly expands, the reuse of recycled demolition waste aggregates is becoming increasingly more important. Currently, the building industry is the largest consumer of natural resources. The constant use of raw virgin aggregate is resulting in depleting resources, lack of space for landfills, increasing costs, and heightened levels of pollution. The use of these recycled aggregates in building envelopes and the study of thermal properties are becoming a popular area of research in order to improve building energy usage. The construction of Zero Energy Buildings (ZEB) is encouraged by the United States government as a result of the unresolved finite resources and environmental pollution. The focus of this research is on the impact of using recycled demolition waste aggregates on thermal properties, including specific heat capacity and thermal conductivity, in masonry mortar applications. The new forms of aggregate were analyzed for efficiency and practical utilization in construction in seven locations across the United States by embedding the new material into the building envelope of a strip mall mercantile build model from the National Renewable Energy Laboratory (NREL) in the EnergyPlus Building Energy Simulation Program (BESP). It was determined that the recycled aggregate mortar mixtures performed as well as or better than the traditional mortar mix. Opportunities for future research in recycled aggregate mortar mixtures exist in a regional analysis, a regional recycled aggregate cost analysis, and a life cycled cost analysis (LCCA).

  15. 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...

  16. Bioconversion of lime pretreated wheat straw to fuel ethanol

    Science.gov (United States)

    Lime pretreatment and enzymatic saccharification methods were evaluated for conversion of wheat straw cellulose and hemicellulose to fermentable sugars. The maximum yield of monomeric sugars from wheat straw (8.6%, w/v) by lime pretreatment (100 mg/g straw, 121 deg C, 1 h) and enzymatic hydrolysis ...

  17. Some studies on the reaction between fly ash and lime

    Indian Academy of Sciences (India)

    A Basumajumdar; A K Das; N Bandyopadhyay; S Maitra

    2005-04-01

    The reaction between fly ash (FA) and lime is extensively exploited for the manufacture of building bricks, blocks and aggregates. To get a better idea of this reaction, FA from different sources were mixed in different ratios with lime and compacted. The compacts were treated both by ordinary water and hydrothermal curing to promote lime bearing hydrate bond formation e.g. CaO–SiO2–H2O (C–S–H), CaO–Al2O3–H2O (C–A–H) etc. The decrease in free lime content in these compacts was measured as a function of curing time and curing process. This drop in this content was correlated to the chemical composition of the fly ashes. The mathematical relationships between free lime remaining in the compacts after its maximum decrease in concentration and lime binding modulus (a ratio between the amount of added lime and the total amount of lime binding constituents present in FA) for both types of curing were developed. Further, the rate of decrease in free CaO content under both types of curing conditions was compared from kinetic study. From this study the orders of the reactions and rate constants were found out.

  18. 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.

  19. Liming and forest production. Vad haender med skogdproduktionen

    Energy Technology Data Exchange (ETDEWEB)

    Popovic, Budimir (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research)

    1988-01-01

    The growth reaction to the liming registered in different liming experiments could be defined as very weak and of longterm character. One of the most relevant factors was an initial decline of forest growth during the first 10-15 years after liming, followed by a slight increase in growth for the rest of the experimental period. The length of period varied depending on the tree species and site quality. Results obtained from shorter observation periods cannot give a complete picture of the liming effect on forest growth. The liming effect on growth might, like the soil effect, be of very long duration, perhaps as long as 70 years. The combination of liming with other fertilization might be a good solution, especially on poor sites with nitrogen deficiency as a factor limiting tree growth. The experiences of evaluated experiments indicate a deteriorated availability of nitrogen with liming. The air pollution influences forest soil and trees and in this situation it could be reasonable to discuss forest liming as a measure to counter air pollutants by improving soil conditions in a way which is not only beneficial to forest growth but also to ground and surface water. (author) (10 ills., 14 tabs., 12 refs.).

  20. Adsorption of cesium on cement mortar from aqueous solutions

    Energy Technology Data Exchange (ETDEWEB)

    Volchek, Konstantin, E-mail: konstantin.volchek@ec.gc.ca [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Miah, Muhammed Yusuf [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Department of Applied Chemistry and Chemical Technology, Noakhali Science and Technology University (Bangladesh); Kuang, Wenxing; DeMaleki, Zack [Emergencies Science and Technology Section, Environment Canada, 335 River Road, Ottawa, Ontario, Canada K1A 0H3 (Canada); Tezel, F. Handan [Department of Chemical and Biological Engineering, University of Ottawa, 161 Louis-Pasteur, Ottawa, Ontario, Canada K1N 6N5 (Canada)

    2011-10-30

    Highlights: {yields} The adsorption of cesium on cement mortar was investigated in a range of temperatures and cesium concentrations. {yields} The pseudo-second order kinetic model produced a good fit with the experimental kinetic data. {yields} Equilibrium test results correlated well with the Freundlich isotherm adsorption model. {yields} The interaction between cesium ions and cement mortar was dominated by chemical adsorption. - Abstract: The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L{sup -1} and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive {sup 137}Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L{sup -1} while the respective surface concentration on coupons varied from 0.0395 to 22.34 {mu}g cm{sup -2}. Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol{sup -1} suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar.

  1. The adherence in the union stone-mortar

    Directory of Open Access Journals (Sweden)

    Rodríguez García, María Reyes

    1994-06-01

    Full Text Available Stones placates present a wide of problems that result in the fall of plates. One of the causes is the lack of adherence stone-mortar. We considered a study to determine the adherence between several cement mortars (1:3, 1:5, 1:7, 1:9 and a especial mortar prepared with latex and stones (white granite, pink granites, black granites, white marble and cream limestones. The results obtained suggest that only adequate adherence rates (higher than 3 kgf/cm2 achieved with cement mortar 1:3 and especial mortar. Besides it is observed that in the stones studied there is no relation between adherence and the absorption values.

    Los aplacados de piedra presentan una extensa patología que se traduce en la caída de las placas colocadas. Una de las causas es la falta de adherencia mortero-piedra. El estudio se realiza para determinar la tensión de adherencia entre diversos morteros de cemento (1:3, 1:5, 1:7, 1:9 y otro compuesto por mortero y látex y piedras (granito blanco, granitos rosa, granitos negros, mármol blanco y calizas crema. De los resultados obtenidos se deduce que los únicos morteros que permiten valores de adherencia aceptables (superiores a 3 kp/cm2 son el mortero de cemento 1:3 y el especial. Igualmente se comprueba que, en las piedras estudiadas, no existe relación alguna entre la adherencia y la absorción de agua.

  2. Root distribution of rootstocks for 'Tahiti' lime

    Directory of Open Access Journals (Sweden)

    Neves Carmen Silvia Vieira Janeiro

    2004-01-01

    Full Text Available Field studies on citrus roots are important for genetic selection of cultivars and for management practices such as localized irrigation and fertilization. To characterize root systems of six rootstocks, taking into consideration chemical and physical characteristics of a clayey Typic Hapludox of the Northern State of Paraná, this study was performed having as scion the 'IAC-5 Tahiti' lime [Citrus latifolia (Yu. Tanaka]. The rootstocks 'Rangpur' lime (C. limonia Osbeck, 'Africa Rough' lemon (C. jambhiri Lush., 'Sunki' mandarin [C. sunki (Hayata hort. ex Tan.], Poncirus trifoliata (L. Raf., 'C13' citrange [C. sinensis (L. Osb. x P. trifoliata (L. Raf] and 'Catânia 2' Volkamer lemon (C. volkameriana Ten. & Pasq. were used applying the trench profile method and the SIARCS® 3.0 software to determine root distribution. 'C-13' citrange had the largest root system. 'Volkamer' lemon and 'Africa Rough' lemon presented the smallest amount of roots. The effective depth for 80 % of roots was 31-53 cm in rows and 67-68 cm in inter-rows. The effective distance of 80 % of roots measured from the tree trunk exceeded the tree canopy for P. trifoliata, 'Sunki' mandarin, and 'Volkamer' and 'Africa Rough' lemons.

  3. Mineral phases of green liquor dregs, slaker grits, lime mud and wood ash of a Kraft pulp and paper mill

    International Nuclear Information System (INIS)

    Four residues generated in a Kraft, pulp and paper plant, were characterized by X-ray fluorescence spectroscopy (XFA), powder X-ray diffraction (XRD), thermogravimmetric analysis (TG) and Fourier transform infrared spectroscopy (FTIR). A quantitative phase composition model, that accounts for the observed data and for the physico-chemical conditions of formation, was postulated for each material. Emphasis was given on the identification of the mineral components of each material. The green liquor dregs and the lime mud contain Calcite and Gipsite. The slaker grits contains Calcite, Portlandite, Pirssonite, Larnite and Brucite. The Calcite phase, present in the dregs and in the lime mud, has small amounts of magnesium replacing calcium. The wood ash contains Quartz as the major crystalline mineral phase

  4. Comparing the Environmental Impacts of Alkali Activated Mortar and Traditional Portland Cement Mortar using Life Cycle Assessment

    Science.gov (United States)

    Matheu, P. S.; Ellis, K.; Varela, B.

    2015-11-01

    Since the year 1908 there has been research into the use alkali activated materials (AAM) in order to develop cementitious materials with similar properties to Ordinary Portland Cement. AAMs are considered green materials since their production and synthesis is not energy intensive. Even though AAMs have a high compressive strength, the average cost of production among other issues limits its feasibility. Previous research by the authors yielded a low cost AAM that uses mine tailings, wollastonite and ground granulated blast furnace slag (GGBFS). This mortar has an average compressive strength of 50MPa after 28 days of curing. In this paper the software SimaPro was used to create a product base cradle to gate Life Cycle Assessment (LCA). This compared the environmental impact of the AAM mortar to an Ordinary Portland Cement mortar (PCHM) with similar compressive strength. The main motivation for this research is the environmental impact of producing Ordinary Portland Cement as compared to alkali activated slag materials. The results of this LCA show that the Alkali Activated Material has a lower environmental impact than traditional Portland cement hydraulic mortar, in 10 out of 12 categories including Global Warming Potential, Ecotoxicity, and Smog. Areas of improvement and possible future work were also discovered with this analysis.

  5. Inhibition of Cracks on the Surface of Cement Mortar Using Estabragh Fibers

    Directory of Open Access Journals (Sweden)

    Tahereh Soleimani

    2013-01-01

    Full Text Available The influence of adding Estabragh fibers into the cement composites of mortar on surface cracks and mechanical properties of mortar has been studied at various fiber proportions of 0.25%, 0.5%, and 0.75%. The mortar shrinkage was evaluated by counting the number of cracks and measuring the width of cracks on the surface of mortar specimens. Although the Estabragh fibers loss their strength in an alkali environment of cement composites, the ability of Estabragh fibers to bridge on the microcracks in the mortar matrix causes a decrease in the number of cracks and in their width on the surface of the mortar samples in comparison with the plain mortar. However, considering the mechanical properties of specimens such as bending strength and compressive strength, among all fiber proportions, only the specimens with 0.25% of Estabragh fiber performed better in all respects compared to the physical and mechanical properties of reinforced cement composite of mortar. Consequently, by adding 0.25% of Estabragh fibers to the cement mortar, a remarkable inhibition in crack generation on fiber-containing cement composite of mortar is achieved.

  6. Influence of Superplasticizers on Strength and Shrinkage Cracking of Cement Mortar under Drying Conditions

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; WANG Xin'gang; LI Xiangguo; YANG Lei

    2007-01-01

    The effects of polynaphthalene series superplasticizers(PNS) with a low content of sodium sulfate (H-UNF),with a high content of sodium sulfate(C-UNF) and polycarboxylate type superplasticizer (PC) on strength and shrinkage cracking of cement mortar under drying conditions were investigated by means of multi-channel ellipse ring shrinkage cracking test, free shrinkage and strength test. The general effect of PNS and PC is to increase the initial cracking time of mortars, and decrease the cracking sensitivity of mortars. As for decreasing the cracking sensitivity of mortars, PC>H-UNF>C-UNF. To incorporate superplasticizers is apparently to increase the free shrinkage of mortars when keeping the constant w/b ratio and the content of cement pastes. As for the effect of controlling the volume stability of mortars, PC>C-UNF>H-UNF. Maximum crack width of mortars containing PC is lower, but the development rate of maximum crack width of mortars containing H-UNF is faster in comparison with control mortars. The flexural and compressive strengths of mortars at 28-day increase with increasing superplasticizer dosages under drying conditions. PC was superior to PNS in the aspect of increasing strength.

  7. Influence Of Volcanic Scoria On Mechanical Strength, Chemical Resistance And Drying Shrinkage Of Mortars

    Directory of Open Access Journals (Sweden)

    Al-Swaidani A.

    2014-09-01

    Full Text Available In the study, three types of cement have been prepared; one CEM I type (the control sample and two blended cements: CEM II/A-P and CEM II/B-P (EN 197-1, each of them with three replacement levels of volcanic scoria: (10 %, 15 %, 20 % wt. and (25 %, 30 %, 35 % wt., respectively. Strength development of mortars has been investigated at 2, 7, 28 and 90 days curing. Evaluation of chemical resistance of mortars containing scoria-based cements has been investigated through exposure to 5 % sulphate and 5 % sulphuric acid solutions in accordance with ASTM C1012 & ASTM 267, respectively. Drying shrinkage has been evaluated in accordance with ASTM C596. Test results showed that at early ages, the mortars containing CEM II/B-P binders had strengths much lower than that of the control mortar. However, at 90 days curing, the strengths were comparable to the control mortar. In addition, the increase of scoria significantly improved the sulphate resistance of mortars. Further, an increase in scoria addition improved the sulphuric acid resistance of mortar, especially at the early days of exposure. The results of drying shrinkage revealed that the CEM II/B-P mortar bars exhibited a greater contraction when compared to the control mortar, especially at early ages. However, drying shrinkage of mortars was not influenced much at longer times.

  8. Drainage, liming and fertilization of organic soils. 1. Long-term effects on acid/base relations

    Energy Technology Data Exchange (ETDEWEB)

    Braekke, F.H. [Norges Landbrukshoegskole, Aas (Norway). Dept. of Forest Sciences

    1999-06-01

    Long-term changes of the acid/base relations of organic soils after drainage, fertilization and/or liming at three experimental sites - two ombrogenous and one soligenous - in south-central Norway are discussed. These sites were drained, fertilized and/or limed in 1953-1956 and sampled in 1991-1992. Drainage at the ombrogenous sites caused: insignificant shifts of pH, higher bulk densities to 40 cm depth, higher ash percentage, higher contents of N and P to 20 cm depth and reduced concentrations of total Ca, K, Mg, Na, Al and Fe in soil layers deeper than 20 cm. The soligenous site was not effectively drained; despite this, pH dropped about 0.5 unit in the surface and subsurface soil layers of the control plots, while small changes were measured for most other soil variables. The suggested reason for the pH drop is limited sulphide oxidation in the upper 20 cm drained layer. Base saturation at actual soil pH, when all treatments were included, was estimated with good precision by four regressors: pH, extractable Al, extractable Fe and extractable Ca (R{sup 2} = 0.90-0.95). Similar models explained 97-99% of the variation in base saturation at soil pH = 7.0. The lime effects at the properly drained oligotrophic sites were proportional to applied doses; for pH to 40 cm, base saturation to 60 cm, and Ca concentration to 60 cm depth. At the less well-drained soligenous site, effects were limited to the upper 30 cm layer. Both drainage and liming caused higher cation exchange capacities and proper drainage seems to be a prerequisite for the liming effect. Estimated recovery of calcium to 60 cm depth was 64-79% at the ombrogenous sites and 42-46% at the soligenous site 28 refs, 3 figs, 8 tabs

  9. 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.

  10. Stabilization of phosphogypsum using class C fly ash and lime: assessment of the potential for marine applications.

    Science.gov (United States)

    Rusch, Kelly A; Guo, Tingzong; Seals, Roger K

    2002-07-22

    Phosphogypsum (PG, CaSO(4).H(2)O), a solid byproduct of phosphoric acid manufacturing, contains low levels of radium ((266)Ra), resulting in stackpiling as the only currently allowable disposal/storage method. PG can be stabilized with class C fly ash and lime for potential use in marine environments. An augmented simplex centroid design with pseudo-components was used to select 10 PG:class C fly ash:lime compositions. The 43cm(3) blocks were fabricated and subjected to a field submergence test and 28 days saltwater dynamic leaching study. The dynamic leaching study yielded effective calcium diffusion coefficients (D(e)) ranging from 1.15 x 10(-13) to 3.14 x 10(-13)m(2)s(-1) and effective diffusion depths (X(c)) ranging from 14.7 to 4.3mm for 30 years life. The control composites exhibited diametrical expansions ranging from 2.3 to 17.1%, providing evidence of the extent of the rupture development due to ettringite formation. Scanning electron microscopy (SEM), microprobe analysis showed that the formation of a CaCO(3) on the composite surface could not protect the composites from saltwater intrusion because the ruptures developed throughout the composites were too great. When the PG:class C fly ash:lime composites were submerged, saltwater was able to intrude throughout the entire composite and dissolve the PG. The dissolution of the PG increased the concentration of sulfate ions that could react with calcium aluminum oxides in class C fly ash forming additional ettringite that accelerated rupture development. Effective diffusion coefficients and effective diffusion depths alone are not necessarily good indicators of the long-term survivability of PG:class C fly ash:lime composites. Development of the ruptures in the composites must be considered when the composites are used for aquatic applications.

  11. 低强度砂浆灌孔砌块砌体抗压性能试验研究%EXPERIMENTAL RESEARCH ON COMPRESSIVE BEHAVIORS OF GROUTED BLOCK MASONRY WITH LOW-STRENGTH MORTAR

    Institute of Scientific and Technical Information of China (English)

    黄靓; 王辉; 陈胜云

    2012-01-01

    In order to study the effect of mortar strength on compressive behaviors of grouted concrete masonry,nine specimens using lime mortar were analyzed.According to failure pattern,cracking load,ultimate capacity and deformation capacity,a formula was provided to calculate the compressive capacity of grouted concrete masonry when the mortar strength is very low.The ratio of cracking load to ultimate load is very small,which affects the durability of masonry building.Therefore,this paper states that the mortar strength should be higher than a critical value when designing and constructing grouted concrete masonry.%为了研究低强度砂浆对灌孔砌块砌体抗压性能的影响,该文通过9个采用石灰砂浆砌筑的灌孔砌块砌体的抗压试验,对其抗压破坏形态、开裂荷载、极限荷载及变形能力进行了分析,提出了适用于砂浆强度很低的灌孔砌块砌体的抗压强度计算公式。分析表明:低强度砂浆砌块砌体的初裂荷载与极限荷载之比较小,而开裂荷载过低将会对砌体房屋的耐久性产生不利影响,因此,该文认为在进行灌孔砌块砌体的设计和施工时,砂浆的强度应得到保证,不能过低。

  12. Hidrólise da cana-de-açúcar com cal virgem ou cal hidratada Hydrolysis of cane sugar with lime or hydrated lime

    Directory of Open Access Journals (Sweden)

    Diego Azevedo Mota

    2010-06-01

    , mineral matter, total carbohydrates, and hemicellulose as well as the contents of neutral detergent fiber and total digestible nutrients. Times of storage changed contents of crude protein, organic matter, total carbohydrates and hemicellulose. Among the minerals, only content of calcium showed an increase for the sugarcane processing forms. Coeficients of digestibility of dry matter and neutral detergent fiber increased with hydrolises of sugar cane when compared to in natura sugarcane. Hydrolisis with hydrated lime or with virgin lime keeps the nutrional value of sugarcane making its use possible up to 60 hours after storage.

  13. Homogeneity and Strength of Mortar Joints in Pearl-Chain Bridges

    DEFF Research Database (Denmark)

    Lund, Mia Schou Møller; Arvidsson, Michael; Hansen, Kurt Kielsgaard

    2015-01-01

    The load carrying mortar joints in Pearl-Chain Bridges are cast vertically which means that they have a placing depth of up to 2.40 m. In the present paper, the feasibility of casting 2.40 m high homogeneous vertical mortar joints is examined. Three high-strength, expansive, self-compacting, ready......-to-mix mortar products are tested. To the authors’ knowledge, no previous published work has documented the homogeneity and properties of mortar joints of such a height. Hence, the present study documents a practical test procedure where the homogeneity of three mortar joints measuring 20 x 220 x 2400 mm has...... been tested and compared by measuring compressive strength, variation in rebound value, variation in density, and separation. In addition, the appearance of the surface texture has been visually assessed. The measurements indicate that, for all three mortars tested, it is possible to cast homogeneous 2...

  14. Plastic shrinkage of mortars with shrinkage reducing admixture and lightweight aggregates studied by neutron tomography

    Energy Technology Data Exchange (ETDEWEB)

    Wyrzykowski, Mateusz, E-mail: mateusz.wyrzykowski@empa.ch [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Lodz University of Technology, Department of Building Physics and Building Materials, Lodz (Poland); Trtik, Pavel [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Münch, Beat [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); Weiss, Jason [Purdue University, School of Civil Engineering, West Lafayette (United States); Vontobel, Peter [Paul Scherrer Institute, Laboratory for Neutron Scattering and Imaging, Villigen (Switzerland); Lura, Pietro [Empa, Swiss Federal Laboratories for Materials Science and Technology, Concrete and Construction Chemistry Laboratory, Dübendorf (Switzerland); ETH Zurich, Institute for Building Materials (IfB), Zurich (Switzerland)

    2015-07-15

    Water transport in fresh, highly permeable concrete and rapid water evaporation from the concrete surface during the first few hours after placement are the key parameters influencing plastic shrinkage cracking. In this work, neutron tomography was used to determine both the water loss from the concrete surface due to evaporation and the redistribution of fluid that occurs in fresh mortars exposed to external drying. In addition to the reference mortar with a water to cement ratio (w/c) of 0.30, a mortar with the addition of pre-wetted lightweight aggregates (LWA) and a mortar with a shrinkage reducing admixture (SRA) were tested. The addition of SRA reduced the evaporation rate from the mortar at the initial stages of drying and reduced the total water loss. The pre-wetted LWA released a large part of the absorbed water as a consequence of capillary pressure developing in the fresh mortar due to evaporation.

  15. Mechanism and Durability of Repair Systems in Polymer-Modified Cement Mortars

    Directory of Open Access Journals (Sweden)

    Ru Wang

    2015-01-01

    Full Text Available This paper investigated the mechanism and durability of repair systems made of ordinary cement-based repair mortar and three kinds of polymer-modified repair mortars with old concrete, SBR dispersion, SAE dispersion, and SAE powder. By comparing the bonding properties of mortars before and after erosion, it was found that polymers could effectively improve the durability of the repair system and SAE powder had the best improvement. Micromorphology study of the repair mortar and the interface of repair mortar with old concrete through SEM showed that the polymer film formed from SAE powder whatever in the mortar or at the interface was dense and tough, the film formed from SAE dispersion was loose and weak, while the film formed from SBR dispersion was in between them, which explained the difference in the tensile bond strength and the durability of the repair systems.

  16. Utilization of ground waste seashells in cement mortars for masonry and plastering.

    Science.gov (United States)

    Lertwattanaruk, Pusit; Makul, Natt; Siripattarapravat, Chalothorn

    2012-11-30

    In this research, four types of waste seashells, including short-necked clam, green mussel, oyster, and cockle, were investigated experimentally to develop a cement product for masonry and plastering. The parameters studied included water demand, setting time, compressive strength, drying shrinkage and thermal conductivity of the mortars. These properties were compared with those of a control mortar that was made of a conventional Portland cement. The main parameter of this study was the proportion of ground seashells used as cement replacement (5%, 10%, 15%, or 20% by weight). Incorporation of ground seashells resulted in reduced water demand and extended setting times of the mortars, which are advantages for rendering and plastering in hot climates. All mortars containing ground seashells yielded adequate strength, less shrinkage with drying and lower thermal conductivity compared to the conventional cement. The results indicate that ground seashells can be applied as a cement replacement in mortar mixes and may improve the workability of rendering and plastering mortar.

  17. Filler effect of fine particle sand on the compressive strength of mortar

    Science.gov (United States)

    Jaturapitakkul, Chai; Tangpagasit, Jatuphon; Songmue, Sawang; Kiattikomol, Kraiwood

    2011-04-01

    The river sand, which is a non-pozzolanic material, was ground into 3 different particle sizes. Portland cement type I was replaced by the ground river sands at 10wt%-40wt% of binder to cast mortar. Compressive strengths of mortar were investigated and the filler effect of different fine particles of sand on the compressive strength of mortar was evaluated. The results show that the compressive strength of mortar contributed from the filler effect of smaller particles is higher than that of the coarser ones. The difference in compressive strength of mortar tends to be greater as the difference in ground river sand fineness increases. The results also suggest that ASTM C618 specification is not practically suitable for specifying pozzolan in concrete since the strength activity index of mortar containing ground river sand (high crystalline phase) with 33.8wt% of particles retained on a 45-μm sieve can pass the strength requirement.

  18. Use of lime cement stabilized pavement construction

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, M.A.; Raju, G.V.R.P. [JNTU College of Engineering, Kakinada (India). Dept. of Civil Engineering

    2009-08-15

    Expansive clay is a major source of heave induced structural distress. Swelling of expansive soils causes serious problems and produce damages to many structures. Many research organizations are doing extensive work on waste materials concerning the feasibility and environmental suitability. Fly ash, a waste by product from coal burning in thermal power stations, is abundant in India causing severe health, environmental and disposal problems. Attempts are made to investigate the stabilization process with model test tracks over expansive subgrade in flexible pavements. Cyclic plate load tests are carried out on the tracks with chemicals like lime and cement introduced in fly ash subbase laid on sand and expansive subgrades. Test results show that maximum load carrying capacity is obtained for stabilized fly ash subbase compared to untreated fly ash subbase.

  19. Stabilization of Expansive Soil by Lime and Fly Ash

    Institute of Scientific and Technical Information of China (English)

    ZHANG Ji-ru; CAO Xing

    2002-01-01

    An experimental program was undertaken to study the individual and admixed effects of lime and fly ash on the geotechnical characteristics of expansive soil. Lime and fly ash were added to the expansive soil at 4% -6% and 40% - 50% by dry weight of soil, respectively. Testing specimens were determined and examined in chemical composition, grain size distribution, consistency limits, compaction, CBR ,free swell and swell capacity. The effect of lime and fly ash addition on reducing the swelling potential of an expansive soil is presented.It is revealed that a change of expansive soil texture takes place when lime and fly ash are mixed with expansive soil. Plastic limit increases by mixing lime and liquid limit decreases by mixing fly ash, which decreases plasticity index. As the amount of lime and fly ash is increased, there are an apparent reduction in maximum dry density,free swell and swelling capacity under 50 kPa pressure, and a corresponding increase in the percentage of coarse particles, optimum moisture content and CBR value. Based on the results, it can be concluded that the expansive soil can be successfully stabilized by lime and fly ash.

  20. 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. PMID:25902974

  1. Effects of different liming agencies in forests. A literature review

    Energy Technology Data Exchange (ETDEWEB)

    Nihlgaard, B.; Budimir, P.

    1984-07-01

    In the introduction of this report the different reasons for acidification of forest soils are summarized. The buffering systems of the soil are reviewed: the carbonate, silicate, aluminium and the iron buffering systems and the cation exchange system. Results of soil acidification are mentioned. Different liming agencies in use are described. Changes in the chemical soil processes due to liming are described. From a soil biology point of view liming means that the turnover of carbon and nitrogen is increased, with lowered C/N-ratio as a consequence. The tree production might be influenced, sometimes strongly positively but more often with slightly lowered volume production. This decrease is mainly interpreted as a result of disturbed mycorrhiza, possibly a negative nitrate-effect, and sometimes as a relative magnesium or bor deficiency. Increased production seems mainly to appear when liming is done in young stands or before reforestation. The conclusions are - that liming has a long term positive effect on the chemical soil status in preventing the resolution of aluminum and other metals, subsequently with positive effects on the soil and ground water in the long run - that one has to be careful with liming in old stands, in order not to get a decreased volume production - that one probably has to compensate for the acidification leaching effects in the soil by adding eg magnesium and bor together with lime in many forest soils.

  2. Dry and wet "deposition" studies of the degradation of cement mortars

    OpenAIRE

    Martínez-Ramírez, S.; Thompson, G.E.

    1998-01-01

    The reaction of portland cement mortars with SO2 gaseous pollutant and artificial 'acid rain' solution has been examined using laboratory exposure chambers, with realistic presentation rates of pollutants. The mortar were previously carbonated to produce superficial carbonation. Two mortars with different w/c ratio and hence specific surface were prepared and exposed into the chambers. For dry deposition of SO2 pollutant gas, the important ro...

  3. The compatibility of earth-based repair mortars with rammed earth substrates

    OpenAIRE

    Gomes, M. Idália; Gonçalves, Teresa D.; Faria, Paulina

    2013-01-01

    Earth constructions are susceptible to degradation due to natural or human causes. The degradation of the exterior surface of earth walls is very common, either due to lack of maintenance or to the use of incompatible materials, and often requires the application of a repair mortar. This work analyses experimentally the performance of earth-based repair mortars applied on rammed earth surfaces. The mortars are based on earth collected from rammed earth buildings in south Portugal or on a c...

  4. Bending performance of concrete beams strengthened with textile reinforced mortar TRM

    OpenAIRE

    Gil Espert, Lluís; Escrig Pérez, Christian; Bernat Masó, Ernest

    2013-01-01

    This work presents a method of strengthening concrete structures based on textiles of high strength and mortars. The combination of textiles and mortars produces a new composite material with cementitious matrix. This material can be used for the reinforcement of concrete beams under bending loads. We tested several combinations of fibers: glass, Poliparafenil Benzobisoxazol (PBO), steel and carbon fibers with mortar and we used them to reinforce precast concrete beams. All the specimens were...

  5. CASCADIC MULTIGRID METHODS FOR MORTAR WILSON FINITE ELEMENT METHODS ON PLANAR LINEAR ELASTICITY

    Institute of Scientific and Technical Information of China (English)

    陈文斌; 汪艳秋

    2003-01-01

    Cascadic multigrid technique for mortar Wilson finite element method ofhomogeneous boundary value planar linear elasticity is described and analyzed. Firstthe mortar Wilson finite element method for planar linear elasticity will be analyzed,and the error estimate under L2 and H1 norm is optimal. Then a cascadic multigridmethod for the mortar finite element discrete problem is described. Suitable grid trans-fer operator and smoother are developed which lead to an optimal cascadic multigridmethod. Finally, the computational results are presented.

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

    OpenAIRE

    López-Zaldívar, O.; Mayor-Lobo, P. L.; Fernández-Martínez, F.; Hernández-Olivares, F.

    2015-01-01

    This article presents the results of a research developing high performance cement mortars with the addition of municipal solid waste incineration fly ash (MSWIFA) stabilized as insoluble carbonates. The encapsulation of hazardous wastes in mortar matrixes has also been achieved. The ashes present high concentrations of chlorides, Zn and Pb. A stabilization process with NaHCO3 has been developed reducing 99% the content of chlorides. Developed mortars replace 10% per weight of the aggregates ...

  7. Repointing Mortars for Conservation of a Historic Stone Building in Trinity College, Dublin

    OpenAIRE

    Duffy, Aidan; Cooper, Tim P.; Perry, Simon H.

    1993-01-01

    With atmospheric pollution causing building stone to decay at accelerated rates, conservation of historic stone monuments is becoming an increasingly important issue. Mortar joints have a marked effect on how moisture moves in a wall and, hence, on how the wall weathers. Not only does mortar bind stones together, but also a good mortar will prevent the ingress of moisture (and pollutants), enable the buildings to dry out, accommodate movement and will not act as a source of harmful chemicals ...

  8. Repointing Mortars for Conservation of a Historic Stone Building in Trinity College, Dublin

    OpenAIRE

    Perry, Simon H.; Duffy, Aidan

    1997-01-01

    With atmospheric pollution causing building stone to decay at accelerated rates, conservation of historic stone monuments is becoming an increasingly important issue. Mortar joints have a marked effect on how moisture moves in a wall and, hence, on how the wall weathers. Not only does mortar bind stones together, but also a good mortar will prevent the ingress of moisture (and pollutants), enable the buildings to dry out, accommodate movement and will not act as a source of harmful chemicals ...

  9. The Kinetics of Calcination of High Calcium Limestone

    Directory of Open Access Journals (Sweden)

    P. C. Okonkwo

    2012-02-01

    Full Text Available The kinetics of calcination of a high calcium type of limestone was studied. Ukpilla limestone found in the central region of Nigeria was studied. The limestone composition shows that the limestone has 51.29% calcium oxide and 41.53% loss on ignition and magnesium oxide content of 2.23%. The following parameters were determined; diffusion coefficient of lime layer, and mass transfer coefficient, conductivity of lime layer and beat transfer coefficient, convective parameter and diffusive parameter for temperatures 9000C, 10000C, 10600C and 10800C. The reaction was found to be limited by mass and heat transfers across the tune layer of the calcining article, theoptimal temperature of calcination was found to be 10600C. Diffusivity and mass transfer coefficient decreases with increase in calcination temperature. The thermal conductivity increases with increase in temperature. The diffusive and convective parameter decreases with increase in temperature. The reactivity of lime calcined at different temperatures were determined. The reactivity of the lime increases with decrease in calcination temperature.

  10. The Influence of Calcium Chloride Salt Solution on the Transport Properties of Cementitious Materials

    Directory of Open Access Journals (Sweden)

    Yaghoob Farnam

    2015-01-01

    Full Text Available The chemical interaction between calcium chloride (CaCl2 and cementitious binder may alter the transport properties of concrete which are important in predicting the service life of infrastructure elements. This paper presents a series of fluid and gas transport measurements made on cementitious mortars before and after exposure to various solutions with concentrations ranging from 0% to 29.8% CaCl2 by mass. Fluid absorption, oxygen diffusivity, and oxygen permeability were measured on mortar samples prepared using Type I and Type V cements. Three primary factors influence the transport properties of mortar exposed to CaCl2: (1 changes in the degree of saturation, (2 calcium hydroxide leaching, and (3 formation of chemical reaction products (i.e., Friedel’s salt, Kuzel’s salt, and calcium oxychloride. It is shown that an increase in the degree of saturation decreases oxygen permeability. At lower concentrations (~12%, the formation of chemical reaction products (mainly calcium oxychloride is a dominant factor decreasing the fluid and gas transport in concrete.

  11. Lime stabilization of fine-grained sediments in western Greenland

    DEFF Research Database (Denmark)

    Jørgensen, Anders Stuhr; Ingeman-Nielsen, Thomas; Skels, Peteris

    2011-01-01

    due to the cold climate, and it is therefore of great interest to study possible methods to improve the stability and strength properties. This project includes laboratory studies of lime stabilization on fine-grained marine sediments from Kangerlussuaq, western Greenland. The results have included...... tests to determine the optimum lime content and the strength development in relation to both reaction time and curing temperature. Hopefully the results from this project will lead to a future use of lime stabilization and make it possible to use/reuse materials of poor quality at construction sites...

  12. Liming and phosphorus fertilization in soils under cerrado

    International Nuclear Information System (INIS)

    The effects of liming and phosphorus fertilizer (300 Kg P2O5/ha) application on dry matter accumulation and P-uptake by sorghum plants were studied under greenhouse conditions. Plants were grown in four Oxisols originally under cerrado vegetation. There was a positive correlation between P-fertilization and liming on dry matter accumulation and P-uptake by plants. The results showed that the main effect of liming in these soils was on the elimination of phytotoxicity, mainly due to exchangeable aluminum. (M.A.C.)

  13. Pore structure and carbonation in blended lime-cement pastes

    OpenAIRE

    Álvarez, J. I.; Arandigoyen, M.

    2006-01-01

    The present study aims to gain a fuller understandingof the curing process in lime pastes (100, 90, 80, 70,60, 50 and 40% lime) blended with cement by analyzingcarbonation in these materials. A hydrated, airslaked lime powder and CEM II A/L 32.5 Portlandcement were used for the blends. These materialswere singled out for research primarily because theymay be used in the restoration of heritage monuments.Variation in weight was used as an indicator for carbonation.A new parameter, A, was found...

  14. Kinetic study of hydrated lime reaction with HCl.

    Science.gov (United States)

    Yan, Rong; Chin, Terence; Liang, David Tee; Laursen, Karin; Ong, Wan Yean; Yao, Kaiwen; Tay, Joo Hwa

    2003-06-01

    Hydrochloride (HCl) is an acidic pollutant present in the flue gas of most municipal or hazardous waste incinerators. Hydrated lime (Ca(OH)2) is often used as a dry sorbent for injection in a spray reactor to remove HCI. However, due to the short residence time encountered, this control method has generally been found to have low conversion efficiencies which results in the high lime usage and generates large amount of fly ash as solid wastes. A fundamental study was carried outto investigate the kinetics of HCl-lime reaction under simulated flue gas conditions in order to better understand the process thereby providing a basis for an optimized lime usage and reduced fly ash production. The initial reaction rate and conversion of three limes were studied using a thermogravimetric analyzer by varying the gas flow rate, temperature (170-400 degrees C), and HCI concentrations (600-1200 mg/m3) as well as the associated particle size and surface area of the limes. The initial lime conversions were found to rely mostly on the residence time, while the ultimate lime conversions were strongly influenced by temperature and the reaction products. CaOHCI was found to be the primary product in most cases, while for one specific lime, CaCl2 was the ultimate conversion product after an extended time period. The true utilization of lime in flue gas cleanup is thus higher when CaOHCl is considered as the final product than those based on CaCl2 as the final product, which has been commonly used in previous studies. The initial reaction was controlled by diffusion of HCl in gas phase and the subsequent reaction by gaseous diffusion through the developing product layer. Increasing the HCI concentration raised the initial rate as well as conversion. However, overloading the lime with excessive HCI caused clogging at its surface and a drop in the ultimate conversion. Limes with smaller particle diameters and higher surface areas were found to be more reactive. The effect of gas

  15. Effects of slag fineness on durability of mortars

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    In recent years, the usages of by-products and wastes in industry have become more important. The importance of the sustainable development is also of increasing. The utilizations of wastes, as mineral admixture or fine aggregate, reduce the consumption of the natural resources and improve the durability of concrete. In this study, the effect of the fineness on the high temperature and sulphate resistances of concrete mortar specimens, produced with ground granulated blast-furnace slag (GBFS)replacing cement, is investigated. The compressive and flexural strength test results for all series related to durability effects,exposing temperature and solutions, exposure times for these durability effects, slag content and fineness are discussed. Consequently, the optimum slag contents are determined for producing the sulphate and high temperature resistant mortars.

  16. Fracture mechanics of polymer mortar made with recycled raw materials

    Directory of Open Access Journals (Sweden)

    Marco Antonio Godoy Jurumenha

    2010-12-01

    Full Text Available The aim of this work is to show that industrial residues could be used in construction applications so that production costs as well as environmental protection can be improved. The fracture properties of polymer mortar manufactured with recycled materials are investigated to evaluate the materials behaviour to crack propagation. The residues used in this work were spent sand from foundry industry as aggregate, unsaturated polyester resin from polyethylene terephthalate (PET as matrix and polyester textile fibres from garment industry, producing an unique composite material fully from recycled components with low cost. The substitution of fresh by used foundry sand and the insertions of textile fibres contribute to a less brittle behaviour of polymer mortar.

  17. Nonconforming mortar element methods: Application to spectral discretizations

    Science.gov (United States)

    Maday, Yvon; Mavriplis, Cathy; Patera, Anthony

    1988-01-01

    Spectral element methods are p-type weighted residual techniques for partial differential equations that combine the generality of finite element methods with the accuracy of spectral methods. Presented here is a new nonconforming discretization which greatly improves the flexibility of the spectral element approach as regards automatic mesh generation and non-propagating local mesh refinement. The method is based on the introduction of an auxiliary mortar trace space, and constitutes a new approach to discretization-driven domain decomposition characterized by a clean decoupling of the local, structure-preserving residual evaluations and the transmission of boundary and continuity conditions. The flexibility of the mortar method is illustrated by several nonconforming adaptive Navier-Stokes calculations in complex geometry.

  18. Interfacial (Fiber-matrix) Properties of High-strength Mortar (150 MPa) from Fiber Pullout

    DEFF Research Database (Denmark)

    Shannag, M.J.; Brincker, Rune; Hansen, Will

    1996-01-01

     The steel fiber-matrix properties of high-strength mortar (150 MPa), such as DSP (densified small particle), are obtained and compared to an ordinary strength mortar (40 MPa) using a specially designed fiber pullout apparatus. A new method for estimating the debonding energy of the interfacial......-strength DSP mortar has significantly improved interfacial properties compared to ordinary strength mortar. These results are important in the understanding of the role of steel fibers in improving the tensile properties of high-strength, brittle, cement-matrix composites....

  19. Analysis of main parameters affecting substrate/mortar contact area through tridimensional laser scanner.

    Science.gov (United States)

    Stolz, Carina M; Masuero, Angela B

    2015-10-01

    This study assesses the influence of the granulometric composition of sand, application energy and the superficial tension of substrates on the contact area of rendering mortars. Three substrates with distinct wetting behaviors were selected and mortars were prepared with different sand compositions. Characterization tests were performed on fresh and hardened mortars, as well as the rheological characterization. Mortars were applied to substrates with two different energies. The interfacial area was then digitized with 3D scanner. Results show that variables are all of influence on the interfacial contact in the development area. Furthermore, 3D laser scanning proved to be a good method to contact area measurement.

  20. Evaluation of Salt Removal from Azulejo Tiles and Mortars using Electrodesalination

    DEFF Research Database (Denmark)

    Ferreira, Célia Maria Dias; Ottosen, Lisbeth M.; Christensen, Iben Vernegren;

    2011-01-01

    loss of historic value. In this work preliminary studies with single tiles presenting an underlying layer of mortar have been conducted to assess the amount of salts that can be removed from the building material using a new technique called “electrodesalination”, in which the salt’s ions...... and underlying mortar are no longer at risk of salt induced decay. The main conclusions are that the technique is successful in extracting salts from mortars (removals efficiencies between 88% and 92%) but not as good for the tile (removals between 10% and 80%). The risk of salt damage to the mortar and tile...

  1. Analysis of main parameters affecting substrate/mortar contact area through tridimensional laser scanner.

    Science.gov (United States)

    Stolz, Carina M; Masuero, Angela B

    2015-10-01

    This study assesses the influence of the granulometric composition of sand, application energy and the superficial tension of substrates on the contact area of rendering mortars. Three substrates with distinct wetting behaviors were selected and mortars were prepared with different sand compositions. Characterization tests were performed on fresh and hardened mortars, as well as the rheological characterization. Mortars were applied to substrates with two different energies. The interfacial area was then digitized with 3D scanner. Results show that variables are all of influence on the interfacial contact in the development area. Furthermore, 3D laser scanning proved to be a good method to contact area measurement. PMID:26046982

  2. Clay content of argillites: Influence on cement based mortars

    OpenAIRE

    Habert, Guillaume; CHOUPAY, Nathalie; Escadeillas, Gilles; MONTEL, Jean Marc; Guillaume, D

    2009-01-01

    The pozzolanic activity of four heated powders containing different clays has been tested. Mineral transformations during calcination from 20 to 900 °C have been followed by X-ray diffraction (XRD) and Differential Scanning Calorimetry (DSC). Compressive strength tests were performed at 1, 7 and 28 days on cement-clay mortars using 30% of pozzolanic material as a replacement by mass for cement. Calcination temperatures corresponded to the stages of potentially high reactivity identified by XR...

  3. Properties of Fiber-Reinforced Mortars Incorporating Nano-Silica

    OpenAIRE

    Ahmed Ghazy; Mohamed T. Bassuoni; Eugene Maguire; Mark O’Loan

    2016-01-01

    Repair and rehabilitation of deteriorating concrete elements are of significant concern in many infrastructural facilities and remain a challenging task. Concerted research efforts are needed to develop repair materials that are sustainable, durable, and cost-effective. Research data show that fiber-reinforced mortars/concretes have superior performance in terms of volume stability and toughness. In addition, it has been recently reported that nano-silica particles can generally improve the m...

  4. Modelling anisotropic damage and permeability of mortar under dynamic loads

    OpenAIRE

    Chen, W.; MAUREL, O.; REESS, T.; MATALLAH, M.; FERRON, A.; C. La Borderie; G. Pijaudier-Cabot

    2011-01-01

    This paper deals with the development of a model for concrete subjected to dynamic loads. Shock waves are generated by Pulsed Arc Electro-hydraulic Discharges (PAED) in water and applied to mortar samples. A diphasic model (liquid water and vapour) is implemented in order to describe the electrical discharge and the propagation of shock waves in water. An anisotropic damage model is devised, which takes account of the strain rate effect and the crack closure effect. Coupling between anisotrop...

  5. Alkaline cement mortars. Chemical resistance to sulfate and seawater attack

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2002-09-01

    Full Text Available The durability and chemical resistance of alkali activated slag and fly ash/slag mortars in contact with sulfates and seawater media have been studied. Two methods were used in the evaluation of such durability: Kock-Steinegger and ASTM C1012. A mineralogical and a microstructural characterization of mortars were done at different ages of their conservation in aggressive media through XRD, SEM/ EDX and mercury porosimetry. Results showed a high durability of activated cement mortars in sulfates and seawater media. NaOH activated mortars are the most sensitive to environment attack with formation of expansive products as gypsum and ettringite, although in very low proportion.

    Se ha estudiado la estabilidad química en medios sulfáticos y de agua de mar de morteros de escorias activadas alcalinamente y morteros de mezclas de escoria y cenizas volantes activadas alcalinamente. Se han empleado dos métodos para evaluar dicha estabilidad: Kock-Steinegger y la norma ASTM C1012. Se ha realizado una caracterización mineralógica y micro estructural de los morteros (a diferentes edades de permanencia en los medios agresivos a través de DRX, SEM/EDX y porosimetría de mercurio. Los resultados obtenidos han demostrado la elevada durabilidad de todos los morteros de cementos activados estudiados frente a la agresividad de los sulfatos y del agua de mar Los morteros de escoria activada con NaOH son los más susceptibles al ataque por esos medios, conformación de productos expansivos como el yeso y la etringita, aunque en proporciones muy bajas.

  6. Recycling of copper tailings as an additive in cement mortars

    OpenAIRE

    Onuaguluchi, Obinna; EREN, Özgür

    2012-01-01

    Increasing demands for copper and copper allied products have made the processing of low grade ores with high volume waste output unavoidable. Presently, billions of tons of copper tailings can be found in major copper producing countries. The impact of copper tailings at 0%, 5% and 10% addition level by mass of cement on the fresh and hardened properties of mortars were determined. Results showed that dry copper tailings affect mixture consistency negatively. However, the use of pre-wetted t...

  7. Adsorption of cesium on cement mortar from aqueous solutions.

    Science.gov (United States)

    Volchek, Konstantin; Miah, Muhammed Yusuf; Kuang, Wenxing; DeMaleki, Zack; Tezel, F Handan

    2011-10-30

    The adsorption of cesium on cement mortar from aqueous solutions was studied in series of bench-scale tests. The effects of cesium concentration, temperature and contact time on process kinetics and equilibrium were evaluated. Experiments were carried out in a range of initial cesium concentrations from 0.0103 to 10.88 mg L(-1) and temperatures from 278 to 313 K using coupons of cement mortar immersed in the solutions. Non-radioactive cesium chloride was used as a surrogate of the radioactive (137)Cs. Solution samples were taken after set periods of time and analyzed by inductively coupled plasma mass spectroscopy. Depending on the initial cesium concentration, its equilibrium concentration in solution ranged from 0.0069 to 8.837 mg L(-1) while the respective surface concentration on coupons varied from 0.0395 to 22.34 μg cm(-2). Equilibrium test results correlated well with the Freundlich isotherm model for the entire test duration. Test results revealed that an increase in temperature resulted in an increase in adsorption rate and a decrease in equilibrium cesium surface concentration. Among several kinetic models considered, the pseudo-second order reaction model was found to be the best to describe the kinetic test results in the studied range of concentrations. The adsorption activation energy determined from Arrhenius equation was found to be approximately 55.9 kJ mol(-1) suggesting that chemisorption was the prevalent mechanism of interaction between cesium ions and cement mortar.

  8. Alkali Aggregate Reaction in Alkali Slag Cement Mortars

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    By means of "Mortar Bar Method",the ratio of cement to aggregate was kept as a constant 1∶2.25,the water-cement ratio of the mixture was 0.40,and six prism specimens were prepared for each batch of mixing proportions with dimensions of 10×10×60mm3 at 38±2℃ and RH≥95%, the influences of content and particle size of active aggregate, sort and content of alkali component and type of slag on the expansion ratios of alkali-activated slag cement(ASC) mortars due to alkali aggregate reaction(AAR) were studied. According to atomic absorption spectrometry,the amount of free alkali was measured in ASC mortars at 90d.The results show above factors affect AAR remarkably,but no dangerous AAR will occur in ASC system when the amount of active aggregate is below 15% and the mass fraction of alkali is not more than 5% (Na2O).Alkali participated in reaction as an independent component, and some hydrates containing alkali cations were produced, free alkalis in ASC system can be reduced enormously.Moreover,slag is an effective inhibitor, the possibility of generating dangerous AAR in ASC system is much lower at same conditions than that in ordinary Portland cement system.

  9. Properties of Fiber-Reinforced Mortars Incorporating Nano-Silica

    Directory of Open Access Journals (Sweden)

    Ahmed Ghazy

    2016-02-01

    Full Text Available Repair and rehabilitation of deteriorating concrete elements are of significant concern in many infrastructural facilities and remain a challenging task. Concerted research efforts are needed to develop repair materials that are sustainable, durable, and cost-effective. Research data show that fiber-reinforced mortars/concretes have superior performance in terms of volume stability and toughness. In addition, it has been recently reported that nano-silica particles can generally improve the mechanical and durability properties of cement-based systems. Thus, there has been a growing interest in the use of nano-modified fiber-reinforced cementitious composites/mortars (NFRM in repair and rehabilitation applications of concrete structures. The current study investigates various mechanical and durability properties of nano-modified mortar containing different types of fibers (steel, basalt, and hybrid (basalt and polypropylene, in terms of compressive and flexural strengths, toughness, drying shrinkage, penetrability, and resistance to salt-frost scaling. The results highlight the overall effectiveness of the NFRM owing to the synergistic effects of nano-silica and fibers.

  10. Link between microstructure and tritiated water diffusivity in mortars

    Directory of Open Access Journals (Sweden)

    Dangla P.

    2013-07-01

    Full Text Available Ions and radionuclide diffusivity in concrete is one of the most important factors that determine service life and safety assessment of cement based structures in nuclear power plants and radioactive-waste repositories. Apart from the influence of cement paste microstructure, the presence of aggregates may have an impact on transport properties of the material. The well-known interfacial transition zone, denoted by ITZ, is created near the aggregates and characterized by a greater porosity. The goal of this study is to investigate the competition between the more diffusing ITZ zone and the less diffusing aggregates. To this end, several series of tritiated water diffusion tests are conducted on mortars characterized by different water-to-cement ratios and sand volume fractions. In parallel, microstructure of these materials is explored by mercury and water porosimetry. It was observed that at low sand content (0% – 50%, diffusion properties of mortars are dominated by aggregates dilution effect. At 60% sand, diffusion increases significantly suggesting that percolation’s pores threshold has been reached. Results indicate also that sand particle size distribution has a great impact on the diffusivity of mortars.

  11. Link between microstructure and tritiated water diffusivity in mortars

    Science.gov (United States)

    Larbi, B.; Dridi, W.; Le Bescop, P.; Dangla, P.; Petit, L.

    2013-07-01

    Ions and radionuclide diffusivity in concrete is one of the most important factors that determine service life and safety assessment of cement based structures in nuclear power plants and radioactive-waste repositories. Apart from the influence of cement paste microstructure, the presence of aggregates may have an impact on transport properties of the material. The well-known interfacial transition zone, denoted by ITZ, is created near the aggregates and characterized by a greater porosity. The goal of this study is to investigate the competition between the more diffusing ITZ zone and the less diffusing aggregates. To this end, several series of tritiated water diffusion tests are conducted on mortars characterized by different water-to-cement ratios and sand volume fractions. In parallel, microstructure of these materials is explored by mercury and water porosimetry. It was observed that at low sand content (0% - 50%), diffusion properties of mortars are dominated by aggregates dilution effect. At 60% sand, diffusion increases significantly suggesting that percolation's pores threshold has been reached. Results indicate also that sand particle size distribution has a great impact on the diffusivity of mortars.

  12. Variability of inorganic and organic constituents in lime spray dryer ash

    Energy Technology Data Exchange (ETDEWEB)

    Panuwat Taerakul; Ping Sun; Harold Walker; Linda Weavers; Danold Golightly; Tarunjit Butalia [Ohio State University, Columbus, OH (US). Department of Civil and Environmental Engineering and Geodetic Science

    2005-10-01

    Flue gas desulfurization (FGD) by-products, including lime spray dryer (LSD) ash, have many demonstrated uses. However, concern about the temporal variability in the chemical properties of this material has limited widespread utilization. To determine the variability in inorganic and representative model organic constituents, this study measured elemental composition, leaching properties, polycyclic aromatic hydrocarbon (PAH) concentrations, available lime index (ALI), calcium carbonate equivalent (CCE), and total neutralization potential (TNP) for a representative LSD ash. All parameters investigated showed little variability over different time periods (e.g., daily to yearly) and little variability between samples collected from different particle collection hoppers. Metal concentrations including As, Se, and Hg in LSD ash and in the leachate did not surpass limits for land application (EPA 503 Rule) or limits for the determination of hazardous waste as specified in the Resource Conservative and Recovery Act (RCRA). While a number of PAHs were detected, including naphthalene and phenanthrene, the levels were low and in the range of natural soils. The low variability in ALI, CCE, TNP, and inorganic and organic composition suggests that LSD ash is a consistent and environmentally benign material for agricultural and other engineering applications. 28 refs., 7 figs., 5 tabs.

  13. Analysis on soil compressibility changes of samples stabilized with lime

    Directory of Open Access Journals (Sweden)

    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.

  14. Calcium Carbonate

    Science.gov (United States)

    ... before being swallowed; do not swallow them whole. Drink a full glass of water after taking either the regular or chewable tablets or capsules. Some liquid forms of calcium carbonate must be shaken well before use.Do not ...

  15. Calcium Calculator

    Science.gov (United States)

    ... Latvia - Lebanon - Libya - Lithuania - Luxembourg - Macedonia, Republic of - Malaysia - Malta - Mexico - Moldova - Morocco - Netherlands - New Zealand - Nigeria - ... and Statistics Popular content Calcium content of common foods What is Osteoporosis? The Board Introduction to Bone ...

  16. Calcium Electroporation

    DEFF Research Database (Denmark)

    Frandsen, Stine Krog; Gibot, Laure; Madi, Moinecha;

    2015-01-01

    BACKGROUND: Calcium electroporation describes the use of high voltage electric pulses to introduce supraphysiological calcium concentrations into cells. This promising method is currently in clinical trial as an anti-cancer treatment. One very important issue is the relation between tumor cell kill...... efficacy-and normal cell sensitivity. METHODS: Using a 3D spheroid cell culture model we have tested the effect of calcium electroporation and electrochemotherapy using bleomycin on three different human cancer cell lines: a colorectal adenocarcinoma (HT29), a bladder transitional cell carcinoma (SW780......), and a breast adenocarcinoma (MDA-MB231), as well as on primary normal human dermal fibroblasts (HDF-n). RESULTS: The results showed a clear reduction in spheroid size in all three cancer cell spheroids three days after treatment with respectively calcium electroporation (p

  17. Liming of acid soils in Osijek-Baranja county

    OpenAIRE

    Dolijanović Željko; Andrijačić Martina; Đurđević Boris; Vukadinović Vladimir; Vukadinović Vesna; Jurišić Mladen; Bertić Blaženka; Jug Irena

    2011-01-01

    The negative trend of soil degradation process increases with intensive agricultural production. Therefore, there is a need for soil conditioning like liming, humification, fertilization, etc. to improve soil quality. One of the major problems that occur on agricultural soils of Croatia is acidification. A downward trend of soil pH is mainly present in soils of poor structure with intensive agricultural production. In agricultural practice liming often need...

  18. Evaluation of Hydrated Lime Filler in Asphalt Mixtures

    OpenAIRE

    Mohammed Abbas Hasan Al-Jumaily

    2008-01-01

    Mineral filler is one of important materials and affecting on properties and quality of asphalt mixtures .There are different types of mineral filler depended on cost and quality , the matter encourages us to achieve this study to evaluate hydrated lime filler effects on properties of asphalt mixes related with strength and durability. Conventional asphaltic concrete mixtures with Portland cement and soft sandstone fillers and mixtures modified with hydrated lime were evaluated for their fund...

  19. Micromachining soda-lime glass by femtosecond laser pulses

    Science.gov (United States)

    Jia, Wei; Yu, Jian; Chai, Lu; Wang, Ching-Yue

    2015-08-01

    The physical process of forming a modified region in soda-lime glass was investigated using 1 kHz intense femtosecond laser pulses from a Ti: sapphire laser at 775 nm. Through the modifications induced by the femtosecond laser radiation using selective chemical etching techniques, we fabricated reproducible and defined microstructures and further studied their morphologies and etching properties. Moreover, a possible physical mechanism for the femtosecond laser modification in soda-lime glass was proposed.

  20. Shock, release, and tension response of soda lime glass

    International Nuclear Information System (INIS)

    This work describes the result of shock wave experiments on soda lime glass in which the shock wave profiles were recorded simultaneously at or near the impact surface and the free surface of the glass specimen by means of multi-beam VISAR. Since earlier work indicated that the glass under shock compression does not follow the Gladstone-Dale model, these profiles provide accurate and self consistent values of transit times for shock, release, and tensile waves propagating in soda lime glass

  1. The chemistry and expansion of limestone - Portland cement mortars exposed to sulphate containing solutions

    International Nuclear Information System (INIS)

    Some concretes in sulphate-bearing groundwaters can deteriorate slowly through chemical reactions which cause expansion and stress. The overall process involves diffusion of sulphate into the concrete, chemical reaction with some cement constituents, internal expansion and, finally, physical disruption of the reacted zone. This work addresses the chemical reactions and the expansion resulting from them so that the overall process of sulphate attack can be modelled eventually. The extent and rate of reaction of calcium sulphate with ordinary and sulphate resisting Portland cements (OPC and SRPC) have been measured under various conditions. Additionally, mortar bars were fabricated from OPC, OPC/BFS (blast furnace slag) and SRPC cements with carboniferous limestone and exposed to various sulphate-containing solutions. The linear expansion of the bars was continuously monitored over a period of about 200 days and, after exposure, the bars were analysed in detail. The results show that the bulk expansion during sulphate attack is proportional to sulphur taken up in insoluble ettringite and magnesium (when present) precipitated as brucite. The results are used to rationalise the behaviour of concretes in sulphate-bearing environments. (author)

  2. The Properties of Cement Mortars Modified by Emulsified Epoxy and Micro-fine Slag

    Institute of Scientific and Technical Information of China (English)

    CHEN You-zhi; WANG Hong-xi; MA Zhi-yong; LI Qing-hua

    2003-01-01

    The epoxy resin polymer cement mortars with excellent performances were made up through modifying ordinary Portland cement with emulsified epoxy and micro-fine slag.The microstructure of the epoxy resin polymer cement materials was studied and their hydration and hardening characteristics were discussed by means of modern analysis measures such as SEM,XRD and Hg-intrusion micromeritics.The experimental results indicate that the series effects of water-reducing,density,pozzolanicity,filling and solidification crosslinking through the action together with epoxy organism and micro-fine slag endowed cement-based materials with perfect performances.The main hydration products in the system are C-S-H gel and hydrated calcium aluminate.At later age,AFt can be in existence,and no Ca(OH)2 is found.When epoxy resin is solidified,the organism is in a network structure.In the micro-pore structure of hydrated cement with modified epoxy and fine slag,big harmful pores were fewer,more harmless abundant micro pores were and the possible pore radius was smaller than that of ordinary Portland cement.

  3. Optimization of Mix Proportion of High Performance Mortar for Structural Applications

    Directory of Open Access Journals (Sweden)

    Cheah C. Ban

    2010-01-01

    Full Text Available Problem statement: Mortar mix is a major construction material in fabrication of ferrocement structural elements. However, there have been scarce amount of technical data available on suitable mix proportion to achieve structural grade mortar with specific strength requirement and adequate level of workability for proper placement into construction formwork. Moreover, current practice in ferrocement construction work which uses mortar mix with cement: sand ratio ranging between 1:1.5 to 1:2 incurs high requirement of cement yet producing mix with suboptimum level of compressive strength. Approach: An experimental investigation was carried out to evaluate workability and compressive strength properties of structural grade mortar mixes with various cement: sand ratios ranging from 1:2.0-1:2.75 and varying water/binder ratio between 0.35 and 0.50. Throughout the laboratory investigation, a total of 28 batches of mortar mixes with various mix proportion were designed, cast and tested in accordance to relevant standards of practice prescribed by British Standard Institute (BSI and American Society of Testing Material (ASTM. Results: At the end of the laboratory investigation program, high performance mortar mix with compressive strength exceeding 55 MPa and slump level within 50-90 mm which is suitable for heavy duty ferrocement construction work was successfully developed. Moreover, data on mix proportion for several other grades of mortar mixes ranging from grade 35 to grade 55 were also derived. Conclusion: It was found that optimum cement: Sand ratio of structural mortar is 1:2.25. With the use of this cement: Sand ratio in the production of structural grade mortar mix in fabrication of ferrocement structural elements, consumption of cement binder will be economized hence resulting in potential savings in term of material and production cost of mortar mix in the construction industry. Besides, it was also observed that strengths

  4. Calcium sulfoaluminate (Ye'elimite) hydration in the presence of gypsum, calcite, and vaterite

    Energy Technology Data Exchange (ETDEWEB)

    Hargis, Craig W. [Department of Civil and Environmental Engineering, University of California, Berkeley, CA (United States); Telesca, Antonio [School of Engineering, University of Basilicata, Potenza (Italy); Monteiro, Paulo J.M., E-mail: monteiro@ce.berkeley.edu [Department of Civil and Environmental Engineering, University of California, Berkeley, CA (United States)

    2014-11-15

    Six calcium sulfoaluminate-based cementitious systems composed of calcium sulfoaluminate, calcite, vaterite, and gypsum were cured as pastes and mortars for 1, 7, 28 and 84 days. Pastes were analyzed with X-ray diffraction, thermogravimetric and differential thermal analyses. Mortars were tested for compressive strength, dimensional stability and setting time. Furthermore, pastes with a water/cementitious material mass ratio of 0.80 were tested for heat evolution during the first 48 h by means of isothermal conduction calorimetry. It has been found that: (1) both calcite and vaterite reacted with monosulfoaluminate to give monocarboaluminate and ettringite, with vaterite being more reactive; (2) gypsum lowered the reactivity of both carbonates; (3) expansion was reduced by calcite and vaterite, irrespective of the presence of gypsum; and (4) both carbonates increased compressive strength in the absence of gypsum and decreased compressive strength less in the presence of gypsum, with vaterite's action more effective than that of calcite.

  5. SIMULTANEOUS CONTROL OF HGO, SO2, AND NOX BY NOVEL OXIDIZED CALCIUM-BASED SORBENTS

    Science.gov (United States)

    The paper gives results of an investigation of two classes of calcium (Ca)-based sorbents (hydrated limes and silicate compounds). (NOTE: Efforts to develop multipollutant control strategies have demonstrated that adding certain oxidants to different classes of Ca-based sorbents...

  6. SIMULTANEOUS CONTROL OF HG(0), SO2, AND NOX BY NOVEL OXIDIZED CALCIUM-BASED SORBENTS

    Science.gov (United States)

    The paper gives results of an investigation of two classes of calcium (Ca)-based sorbents (hydrated limes and silicate compounds). {NOTE: Efforts to develop multipollutant control strategies have demonstrated that adding certain oxidants to different classes of Ca-based sorbents ...

  7. [Severe ocular burns by calcium carbide in a speleologist: a case report].

    Science.gov (United States)

    Testud, F; Voegtlé, R; Nordmann, J P; Descotes, J

    2002-03-01

    A case of severe ocular burns in an amateur speleologist is reported. The explosion of his acetylene lamp caused the projection of calcium carbide particles, which induced burning of the cornea and conjunctiva in both eyes. He slowly recovered in several months. The pathophysiology of the burns, linked to the in situ production of lime, and their management are discussed.

  8. Interpretation of the lime column penetration test

    Science.gov (United States)

    Liyanapathirana, D. S.; Kelly, R. B.

    2010-06-01

    Dry soil mix (DSM) columns are used to reduce the settlement and to improve the stability of embankments constructed on soft clays. During construction the shear strength of the columns needs to be confirmed for compliance with technical assumptions. A specialized blade shaped penetrometer known as the lime column probe, has been developed for testing DSM columns. This test can be carried out as a pull out resistance test (PORT) or a push in resistance test (PIRT). The test is considered to be more representative of average column shear strength than methods that test only a limited area of the column. Both PORT and PIRT tests require empirical correlations of measured resistance to an absolute measure of shear strength, in a similar manner to the cone penetration test. In this paper, finite element method is used to assess the probe factor, N, for the PORT test. Due to the large soil deformations around the probe, an Arbitrary Lagrangian Eulerian (ALE) based finite element formulation has been used. Variation of N with rigidity index and the friction at the probe-soil interface are investigated to establish a range for the probe factor.

  9. The Evolution of Click-n-Mortar E-tailing in Denmark

    DEFF Research Database (Denmark)

    Bøge Sørensen, Lars; Holst, Lisa L.

    2003-01-01

    The paper at hand presents an extension and application of Kotzab & Madlbergers (Kotzab &Madlberger, 2001) original clicks-and-mortar web-scan framework, which is here used to reexaminethe click-and-mortar activities of the top 100 Danish retailers and compare with resultsfrom the identical study...

  10. Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack.

    Science.gov (United States)

    Lee, Seung-Tae

    2009-08-01

    The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates. PMID:19467853

  11. Steel corrosion resistance in model solutions and reinforced mortar containing wastes

    NARCIS (Netherlands)

    Koleva, D.A.; Van Breugel, K.

    2012-01-01

    This work reports on the corrosion resistance of steel in alkaline model solutions and in cement-based materials (mortar). The model solutions and the mortar specimens were Ordinary Portland Cement (OPC) based. Further, hereby discussed is the implementation of an eco-friendly approach of waste util

  12. Influence of recycled fine aggregates on the resistance of mortars to magnesium sulfate attack.

    Science.gov (United States)

    Lee, Seung-Tae

    2009-08-01

    The influence of recycled fine aggregates, which had been reclaimed from field-demolished concretes, on the resistance of mortar specimens to magnesium sulfate attack was investigated. Mortar specimens were prepared with recycled fine aggregates at different replacement levels (0%, 25%, 50%, 75% and 100% of natural fine aggregate by mass). The mortar specimens were exposed to 4.24% magnesium sulfate solution for about 1 year at ambient temperature, and regularly monitored for visual appearance, compressive strength loss and expansion. Additionally, in order to identify products of magnesium sulfate attack, mortar samples incorporating 0%, 25% and 100% replacement levels of the recycled fine aggregates were examined by X-ray diffraction (XRD) technique. Experimental results confirmed that the use of recycled fine aggregates up to a maximum 50% replacement level is effective under severe magnesium sulfate environment, irrespective of type of recycled fine aggregates. However, the worse performance was observed in mortar specimens incorporating 100% replacement level. It was found that the water absorption of recycled fine aggregates affected deterioration of mortar specimens, especially at a higher replacement level. XRD results indicated that the main cause of deterioration of the mortar specimens was primarily due to the formation of gypsum and thaumasite by magnesium sulfate attack. In addition, it appeared that the conversion of C-S-H into M-S-H by the attack probably influenced mechanical deterioration of mortar specimens with recycled fine aggregates.

  13. Mortar Upwind Finite Volume Element Method with Crouzeix-Raviart Element for Parabolic Convection Diffusion Problems

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    In this paper, we study the semi-discrete mortar upwind finite volume element method with the Crouzeix-Raviart element for the parabolic convection diffusion problems.It is proved that the semi-discrete mortar upwind finite volume element approximations derived are convergent in the H1- and L2-norms.

  14. Chloride Ion Transport in Fly Ash Mortar under Action of Fatigue Loading

    Institute of Scientific and Technical Information of China (English)

    WANG Caihui; SUN Wei; JIANG Jinyang

    2012-01-01

    In order to study the chloride ion transport performance in fly ash addition mortar,a new method,in which the fatigue loading and chloride diffusion are undertaken simultaneously,was developed.This method realizes coupling the fatigue damage process and the process of chloride transporting of fly ash mortar.The transport performance of chloride in fly ash mortar specimens was studied under different stress levels.Moreover,the effect of fly ash content on transport performance of chloride ion in mortar was investigated.AE (Acoustic Emission) and SEM were used to acquire the damage distribution of mortar specimens under action of fatigue load.The results show that the diffusion coefficient of chloride in mortar specimens increases with stress level of fatigue loading.The addition of fly ash can mitigate the penetration of chloride ion.The results of microcrack 3D location acquired by AE,accompanied with crack characterizing from SEM,indicate that the damage degree of mortar specimen increases with stress level of fatigue loading.Furthermore,higher damage degree of mortar leads to more the chloride ion content in the sample.

  15. Rilem TC 203-RHM: repair mortars for historic masonry. Performance requirements for renders and plasters

    NARCIS (Netherlands)

    Hees, R.P.J. van; Hughes, J.J.; Balen, K. van; Bicer-Simsir, B.; Binda, L.; Elsen, J.; Konow, T. von; Lindqvist, J.E.; Maurenbrecher, P.; Papayanni, I.; Subercaseaux, M.; Tedeschi, C.; Toumbakari, E.E.; Thompson, M.

    2012-01-01

    This article focuses on repair or replacement mortars for historical buildings. Both the decision process and questions arising are dealt with, in order to better define and illustrate technical requirements for mortars to be used for the repair or restoration of monuments and historic buildings (ma

  16. Properties of Foamed Mortar Prepared with Granulated Blast-Furnace Slag

    Directory of Open Access Journals (Sweden)

    Xiao Zhao

    2015-01-01

    Full Text Available Foamed mortar with a density of 1300 kg/m3 was prepared. In the initial laboratory trials, water-to-cement (w/c ratios ranging from 0.54 to 0.64 were tested to determine the optimal value for foamed mortar corresponding to the highest compressive strength without compromising its fresh state properties. With the obtained optimal w/c ratio of 0.56, two types of foamed mortar were prepared, namely cement-foamed mortar (CFM and slag-foamed mortar (SFM, 50% cement was replaced by slag weight. Four different curing conditions were adopted for both types of foamed mortar to assess their compressive strength, ultrasonic pulse velocity (UPV and thermal insulation performance. The test results indicated that utilizing 50% of slag as cement replacement in the production of foamed mortar improved the compressive strength, UPV and thermal insulation properties. Additionally, the initial water curing of seven days gained higher compressive strength and increased UPV values as compared to the air cured and natural weather curing samples. However, this positive effect was more pronounced in the case of compressive strength than in the UPV and thermal conductivity of foamed mortar.

  17. The Influence of Calcium Chloride Salt Solution on the Transport Properties of Cementitious Materials

    OpenAIRE

    Yaghoob Farnam; Taylor Washington; Jason Weiss

    2015-01-01

    The chemical interaction between calcium chloride (CaCl2) and cementitious binder may alter the transport properties of concrete which are important in predicting the service life of infrastructure elements. This paper presents a series of fluid and gas transport measurements made on cementitious mortars before and after exposure to various solutions with concentrations ranging from 0% to 29.8% CaCl2 by mass. Fluid absorption, oxygen diffusivity, and oxygen permeability were measured on morta...

  18. Effect of organic matter and liming on the reduction of cadmium uptake from soil by triticale and spring oilseed rape

    Energy Technology Data Exchange (ETDEWEB)

    Ciecko, Zdzislaw; Wyszkowski, Miroslaw; Krajewski, Wladyslaw; Zabielska, Jadwiga [Department of Environmental Chemistry, University of Warmia and Mazury in Olsztyn, Plac Lodzki 4, 10-718 Olsztyn (Poland)

    2001-12-17

    The aim of the study conducted on triticale and spring oilseed rape was to determine the role of liming, brown coal and compost medium in reducing the effect of cadmium contamination (at the rates of 0, 7.5, 15 and 22.5 mg Cd kg{sup -1} of soil) on yield and chemical composition of the crop. In the series of experiments without liming, a considerable decline in the yield of spring triticale grain, straw, root weight and green mass yield of rape was observed in response to the soil contamination with cadmium. Brown coal and especially compost medium added to soil neutralised the negative effect of cadmium on the grain yield and reduced a decrease in the yield of straw and roots of triticale. Soil liming proved to reduce the yield drop in oilseed rape caused by the contamination of soil with cadmium. The content of cadmium in roots and grain of spring triticale far exceeded that determined in triticale straw. The pollution of soil with cadmium caused a 26-fold increase in the content of this metal in grain, a 10-fold increase in roots of triticale and a twofold in oil-seed rape. Application of compost medium, brown coal and, to a smaller extent, liming reduced the level of cadmium in the parts of triticale brought to investigation. The soil contamination with cadmium caused certain modifications in the content of nitrogen, potassium, magnesium, calcium and sodium in spring triticale and in the content of N-total, potassium and magnesium in spring oilseed rape.

  19. Physical Properties and Microscopic Structure of Tung Oil-Lime Putty%桐油灰浆材料的物理性能与显微结构

    Institute of Scientific and Technical Information of China (English)

    魏国锋; 方世强; 李祖光; 张秉坚

    2013-01-01

    采用扫描电镜、X射线衍射、傅里叶变换红外光谱等技术手段,初步探讨了桐油灰浆的材料配方和理化性能,为其在古代建筑、船舶等文化遗产保护中的应用提供理论依据.结果显示,用Ca(OH)2和熟桐油制备的桐油灰浆综合性能最佳,其90 d抗压强度和剪切强度较普通石灰浆分别提高了72%和245%,吸水系数仅为普通石灰浆的1/620,抗氯离子侵蚀能力和耐冻融循环等性能均大大改善;该桐油灰浆的优良性能源于桐油的强固化能力以及桐油与Ca(OH)2反应形成的致密结构.%The recipes and properties of tung oil-lime putty were investigated by means of scanning electron microscope(SEM),X-ray diffractometry(XRD) and Fourier transform infrared spectrometry (FTIR).The results show that the putty prepared with tung oil and Ca(OH)2 has the best properties.Compared with the common lime mortar,the 90 days compressive strength and shear strength of the tung oil-Ca(OH)2 putty increase by 72% and 245% respectively and the water absorption coefficient reduces to 1/620 of that of the common lime mortar.The excellent performance of the tung oil-Ca(OH)2 putty can be explained by the strong ability to cure of tung oil and the dense microstructure of the tung oil-Ca(OH)2 putty.

  20. Effect of Lime on Mechanical and Durability Properties of Blended Cement Based Concrete

    Science.gov (United States)

    Acharya, Prasanna Kumar; Patro, Sanjaya Kumar; Moharana, Narayana C.

    2016-06-01

    This work presents the results of experimental investigations performed to evaluate the effect of lime on mechanical and durability properties of concrete mixtures made with blended cement like Portland Slag Cement (PSC) and Portland Pozzolana Cement (PPC) with lime content of 0, 5, 7 and 10 %. Test result indicated that inclusion of hydraulic lime on replacement of cement up to 7 % increases compressive strength of concrete made with both PSC and PPC. Flexural strength increased with lime content. Highest flexural strength is reported at 7 % lime content for both PSC and PPC. Workability is observed to decrease with lime addition which could be compensated with introduction of super plasticizer. Acid and sulphate resistance increase slightly up to 7 % of lime addition and is found to decrease with further addition of lime. Lime addition up to 10 % does not affect the soundness of blended cements like PSC and PPC.

  1. Composite cement mortars based on marine sediments and oyster shell powder

    Directory of Open Access Journals (Sweden)

    Ez-zaki, H.

    2016-03-01

    Full Text Available Additions of dredged marine sediments and oyster shell powder (OS as cement substitute materials in mortars are examined by several techniques. The sediments have high water and chloride contents and calcite, quartz, illite and kaolinite as principal minerals. The OS powders are entirely composed of calcium carbonate and traces of other impurities. Four mixtures of treated sediments and OS powders at 650 °C and 850 °C are added to Portland cement at 8%, 16% and 33% by weight. The hydration of composite pastes is followed by calorimetric tests, the porosity accessible to water, the bulk density, the permeability to gas, the compressive strength and the accelerated carbonation resistance are measured. In general, the increase of addition amounts reduced the performance of mortars. However, a reduction of gas permeability was observed when the addition was up to 33%. Around 16% of addition, the compressive strength and carbonation resistance were improved.En este trabajo se ha valorado la sustitución de cemento en morteros por sedimentos marinos dragados y polvo de concha de ostra (OS. Los sedimentos tienen altos contenidos de agua, cloruros, calcita, cuarzo, illita y caolinita como minerales principales. Los polvos OS están compuestos de carbonato cálcico y trazas de otras impurezas. Se añadieron a un cemento Portland, cuatro mezclas de los sedimentos y polvos de OS tratados a 650 °C y 850 °C en proporciones del 8%, 16% y 33% en peso. La hidratación de pastas se estudió a través de calorimetría. Se estudió además la porosidad accesible al agua, densidad aparente, permeabilidad al gas, resistencia a compresión y carbonatación acelerada. En general, un aumento en la adición produjo una reducción del rendimiento de los morteros. Se observó, sin embargo, una reducción de la permeabilidad a los gases con porcentajes de adición de hasta el 33%. Con valores del 16% de sustitución, mejoraron las resistencias mecánicas y la

  2. Corrosion sensor for monitoring the service condition of chloride-contaminated cement mortar.

    Science.gov (United States)

    Lu, Shuang; Ba, Heng-Jing

    2010-01-01

    A corrosion sensor for monitoring the corrosion state of cover mortar was developed. The sensor was tested in cement mortar, with and without the addition of chloride to simulate the adverse effects of chloride-contaminated environmental conditions on concrete structures. In brief, a linear polarization resistance method combined with an embeddable reference electrode was utilized to measure the polarization resistance (Rp) using built-in sensor electrodes. Subsequently, electrochemical impedance spectroscopy in the frequency range of 1 kHz to 50 kHz was used to obtain the cement mortar resistance (Rs). The results show that the polarization resistance is related to the chloride content and Rs; ln (Rp) is linearly related to the Rs values in mortar without added chloride. The relationships observed between the Rp of the steel anodes and the resistance of the surrounding cement mortar measured by the corrosion sensor confirms that Rs can indicate the corrosion state of concrete structures.

  3. Effect of surfactants on pressure-sensitivity of CNT filled cement mortar composites

    Science.gov (United States)

    Han, Baoguo; Yu, Xun

    2014-11-01

    Sodium dodecyl sulfate (SDS) and sodium dodecylbenzene sulfonate (NaDDBS) were used as surfactants to disperse multi-walled carbon nanotubes (MWNT) in cement mortar and fabricate pressure-sensitive carbon nanotubes filled cement mortar composites. The pressure-sensitivity of cement mortar composites with different concentrations of MWNT and different surfactants was explored under repeated loading and impulsive loading, respectively. Experimental results indicate that the response of the electrical resistance of composites with NaDDBS to external force is more stable and sensitive than that of composites with SDS. Therefore, NaDDBS has higher efficiency than SDS for the dispersion of MWNT in cement mortar, and it is an effective surfactant for fabricating MWNT filled cement mortar composites with superior pressure-sensitivity.

  4. Mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions

    Institute of Scientific and Technical Information of China (English)

    熊良宵; 虞利军

    2015-01-01

    To investigate the mechanical properties of cement mortar in sodium sulfate and sodium chloride solutions, uniaxial compression test and ultrasonic test were performed. Test results show that the relative dynamic elastic modulus, the mass variation, and the compressive strength of cement mortar increase first, and then decrease with increasing erosion time in sodium sulfate and sodium chloride solutions. The relative dynamic elastic moduli and the compressive strengths of cement mortars with water/cement ratios of 0.55 and 0.65 in sodium sulfate solution are lower than those in sodium chloride solution with the same concentration at the 420th day of immersion. The compressive strength of cement mortar with water/cement ratio of 0.65 is more sensitive to strain rate than that with water/cement ratio of 0.55. In addition, the strain-rate sensitivity of compressive strength of cement mortar will increase under attacks of sodium sulfate or sodium chloride solution.

  5. A study of the application of residue from burned biomass in mortars

    Directory of Open Access Journals (Sweden)

    Enori Gemelli

    2004-12-01

    Full Text Available The goal of this work was to study the viability of burnt biomass residue from a pulp and paper plant applied as a raw material for mortar used in the construction industry. The waste - bottom ash - was incorporated into the mortar as a mineral addition to the Portland cement. The effect of the waste's grain size on the properties of mortars containing 10% in volume of waste was investigated, as well as the effect of the concentration of waste with grain size under 0.15 mm. The samples were evaluated after 28 days of aging by uniaxial compression, leaching test and scanning electron microscopy. These characterization techniques indicated that the properties of the mortars depend on the concentration, granulation and size distribution of the waste in the mortar's structure. Furthermore, some chemical elements may be present in stabilized and/or encapsulated form in the cement matrix.

  6. An electrochemical and microstructural characterization of steel-mortar admixed with corrosion inhibitors

    Institute of Scientific and Technical Information of China (English)

    Tuan; Anh; Nguyen; Recep; AVCI

    2009-01-01

    The present research brings new insights on the role of admixed corrosion inhibitors in the processes of cement hydration and rebar corrosion. The admixing of NaCl and the corrosion inhibitors in fresh mortar was found to alter the morphology and microstructure of the hardened mortar at the steel-mortar interfacial region. The admixing of the inhibitors increased the risk of carbonation of cement hydrates at the steel-mortar interfacial region, but partially displaced chloride ions. Chloride and the admixed inhibitors facilitated the formation of different cement hydrates and affected chloride binding at the steel-mortar interfacial region. The admixing of all three inhibitors was found to increase the polarization resistance of steel, indicating reduced corrosion rate of the steel over 48-day exposures to salt ponding.

  7. Microstructure and mechanical performance of modified mortar using hemp fibres and carbon nanotubes

    KAUST Repository

    Hamzaoui, Rabah

    2014-04-01

    Mechanical performance of modified mortar using hemp fibres is studied following various processing conditions. Hemp fibres combined with carbon nanotubes (CNT) are introduced in mortar and their effect is studied as function of curing time. The cement phase is replaced by different percentages of dry or wet hemp fibres ranging from 1.1. wt% up to 3.1. wt% whereas carbon nanotubes are dispersed in the aqueous solution. Our experimental results show that compressive and flexural strengths of wet fibres modified mortar are higher than those for dry hemp-mortar material. The achieved optimal percentage of wet hemp fibres is 2.1. wt% allowing a flexural strength higher than that of reference mortar. The addition of an optimal CNT concentration (0.01. wt%) combined with wet hemp has a reinforcing effect which turns to be related to an improvement of compressive and flexural strengths by 10% and 24%, respectively, in comparison with reference condition. © 2013 Elsevier Ltd.

  8. Elastic and Transport Properties of Steam-Cured Pozzolanic-Lime Rock Composites Upon CO2 Injection

    Science.gov (United States)

    Emery, Dan; Vanorio, Tiziana

    2016-04-01

    Understanding the effect of pozzolanic ash-lime reactions on the rock physics properties of the resulting rock microstructure is important for monitoring unrest conditions in volcanic-hydrothermal systems as well as for devising concrete with enhanced performance. By mixing pozzolana ash with lime, the ancient Romans unwittingly incorporated these reactions in the production of their famous concrete. Recently, it has been discovered that a fiber-reinforced, concrete-like rock is forming naturally at depth of 1.5 km within the Campi Flegrei volcanic-hydrothermal systems due to upwelling lime-rich fluids permeating a pozzolana rich layer. This study aims to investigate possible physico-chemical conditions contributing to both enhance and undermine the properties of the subsurface rocks of volcanic-hydrothermal systems and, in turn, build upon those processes that the ancient Romans exploited to create their famous concrete. We prepared samples by mixing the pozzolana volcanic ash, slaked lime, aggregates of Neapolitan Yellow tuff, and seawater from Campi Flegrei in the same ratios as the ancient Romans. To mimic the conditions of the caldera, we used alkaline water from a well in the Campi Flegrei region rich in sulfate, bicarbonate, calcium, potassium, and magnesium ions. Yet, the samples were cured for 28 days in steam-rich environment to favor hydration and hence, enhancing the stability of calcium- alumino-silicate hydrates and setting strength of the rock samples. We measured baseline properties of porosity, permeability, P-wave velocity, and S-wave velocity of the samples as well as imaged the fibrous microstructure. P and S-wave velocities were used to derive bulk, shear, and Young's moduli. Subsequently, samples were injected with an aqueous carbon dioxide, CO2 (aq), solution and the changes in their microstructure and physical properties measured. Exposure of the concrete-like rock samples to CO2 -rich fluid lowers pH below 12.5, thus affecting the stability

  9. Lime and gypsum application on the wheat crop

    Directory of Open Access Journals (Sweden)

    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.

  10. Wood residues as fuel source for lime kilns. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Philip, R.J.; Azarniouch, M.K.

    1982-11-01

    Despite flow problems encountered when feeding wet hog fuel with mill-produced lime mud directly into the cold end of a pilot kiln, a decrease in fossil fuel consumption of approximately 20%, based on long term average product flow rates, was obtained. The flow problems consisted of material adherence onto the kiln wall, increased dusting and feed-end losses. The lime produced with hog fuel showed higher reactivity than lime produced without hog fuel. Upon causticizing a high-sulphidity mill green liquor, the equilibrium causticizing efficiency was not affected by the use of wood residues in calcining. However, there was some deterioration in the settling and filtration characteristics of the lime mud due to the presence of hog fuel contaminants. The normal fuel requirement per ton of lime in mill kilns is only about one third of that in the pilot kiln. Because most of the problems and limitations encountered in the pilot kiln were associated with the very high mass ratio of hog fuel to lime mud required to achieve even 20% replacement, fossil fuel substitution of 30 to 50% might be attainable in commercial-scale lime kilns. The ultimate goal of complete or near-complete substitution of fossil fuel by wood residues can be achieved by additional firing of dried (moisture content 10-15%) fines from the hot end of the kiln. Since this latter type of fuel is substantially more costly than wet, non-comminuted hog fuel, its usage should be minimized. 14 refs., 9 figs., 11 tabs.

  11. Mechanical properties of high performance concrete made with high calcium high sulfate fly ash

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Y.; Sun, W. [Southeast Univ., Nanjing (China). Dept. of Materials Science and Engineering; Shang, L. [Nanjing Ningyuan Science and Technology Development Co., Nanjing (China)

    1997-07-01

    A high calcium fly ash with high SO{sub 3} content was used to produce high performance concrete. In all the mixes, the fly ash contents of 50% and 60% by weight were applied. Although fly ash cement pastes showed severe volume instability and poor pore structure development, mortars and concretes incorporating high mass high calcium fly ash exhibited good performance in both fresh and hardened state as those with low calcium fly ash did. The 3d and 28d compressive strength of mortars reached 25.2--42.2MPa respectively with the water binder ratio varying from 0.30 to 0.24. What is noticeable is that all the mortars and concretes showed good strength developing tendency with the 90d compressive strength up to 67.3--85.5MPa. This investigation reveals once more the fact that some materials which are not up to standard can still play a special role so long as the components are carefully chosen and proportions properly designed.

  12. Carbon fibre-reinforced, alkali-activated slag mortars

    Directory of Open Access Journals (Sweden)

    Garcés, P.

    2007-12-01

    Full Text Available The paper describes the effect of carbon fibre on alkaliactivated slag mortar (AAS mechanical strength, volume stability and reinforcing steel corrosion, compared to its effect on the same properties in Portland cement (PC properties. Mechanical strength and volume stability tests were performed as set out in the respective Spanish UNE standards. The corrosion rate of steel embedded in the specimens studied was determined from polarization resistance analysis. One of the findings of the study performed was that carbon fibre failed to improve AAS or CP mortar strength. As far as volume stability is concerned, the inclusion of carbon fibres in AAS with a liquid/solid ratio of 0.5 reduced drying shrinkage by about 50%. The effect of carbon fibre on PC mortars differed from its effect on AAS mortars. Studies showed that in the presence of carbonation, steel corrosion reached higher levels in carbon-fibre reinforced AAS mortars; the inclusion of 1% carbon fibre improved corrosion resistance perceptibly in these same mortars, however, when exposed to chloride attack.Se ha estudiado el efecto de la incorporación de fibras de carbón en el comportamiento mecánico, estabilidad de volumen y nivel de corrosión de la armadura en morteros de escorias activadas alcalinamente (AAS. Se evalúa la influencia de las fibras de carbón en el comportamiento de morteros alcalinos en comparación con el efecto que producen en morteros de Portland (CP. Los ensayos mecánicos y de estabilidad de volumen se han realizado según lo establecido en la norma UNE que los regula. Se ha utilizado la técnica de la Resistencia a la Polarización para determinar la velocidad de corrosión del acero embebido en las muestras estudiadas. Como consecuencia del estudio realizado, se ha podido concluir que la adición de fibras de carbón a morteros de AAS y CP no mejora las características resistentes de los mismos. En relación con la estabilidad de volumen, la incorporación de

  13. First results about effects of liming on saprophytic fungal communities in the Ah-horizon of a spruce forest soil in France (Vosges)

    International Nuclear Information System (INIS)

    Soil fungi, including mycorrhiza, are strongly affected by zoil chemical parameters such as the ratio of calcium and/or magnesium to aluminium and the pH-value. So, it was very interesting to compare the rhizospheric microfungal flora between a declining spruce stand and a healthy spruce stand. The site chosen for this investigation was situated in the Vosges in the northeast of France. The rhizospheric soil, from the Ah-horizon of a sandy loam podzol, limed (the healthy spruce stand) or unlimed (the declining spruce stand) was sampled in a 65-year-old Norway spruce forest. The study was made 7 years after liming. Fungal isolations were performed using the dilution plate method. Pronounced differences in species abundance and composition were found between the limed and the unlimed stands. Of the 49 isolated species (24 from declining spruce plot and 34 from healthy spruce plot) only nine were found at both plots. The greatest diversity is observed at the healthy spruce stand; it may be due to the liming. This study indicates that soil microfungi could be sensitive to increased acidity of the rain with subsequent effects. (orig.)

  14. Steel passive state stability in activated fly ash mortars

    Directory of Open Access Journals (Sweden)

    Fernández-Jiménez, A.

    2010-12-01

    Full Text Available The present study explores the behaviour of structural steel embedded in Portland cement (OPC mortars and NaOH- and NaOH-waterglass-activated fly ash, in the presence and absence of 2 % Cl- (CaCl2. Variations were determined in the corrosion potential (Ecorr, linear polarization resistance (Rp and corrosion current density (icorr under different environmental conditions (90 days at 95 % relative humidity (RH, 30 days at ≈ 30 % RH, 760 days at ≈ 95 % RH. In the absence of Cl-, fly ash mortars were able to passivate steel reinforcement, although the stability of the passive state in changing environmental conditions was found to depend heavily on the activating solution used. Steel corrosion in the presence of 2 % Cl- was observed to be similar to the corrosion reported for the material in OPC mortars.

    En el presente trabajo se estudia el comportamiento del acero estructural embebido en morteros de cemento Pórtland (OPC y de cenizas volantes activadas con NaOH y una mezcla de NaOH y waterglass, en ausencia y en presencia de un 2% de Cl- (CaCl2. Se determino la evolución del potencial de corrosión (Ecorr, la resistencia de polarización lineal (Rp y la intensidad de corrosión (icorr, variando las condiciones ambientales (90 días al 95% de humedad relativa (HR-30 días a ≈ 30% HR- 760 días a ≈ 95% HR. En ausencia de Cl- los morteros de cenizas volantes activadas pueden pasivar los refuerzos de acero, si bien la estabilidad del estado pasivo ante cambios en las condiciones ambientales parece mostrar una fuerte dependencia de la solución activadora empleada. En presencia de un 2% de Cl- los aceros se corroen mostrando en comportamiento similar al observado en morteros en base OPC.

  15. Effect of kaolin treatment temperature on mortar chloride permeability

    Directory of Open Access Journals (Sweden)

    Puertas, F.

    2007-03-01

    Full Text Available The present paper discusses the results of chloride resistance tests conducted on ordinary Portland cement (OPC mortars containing a Colombian kaolin pre-treated at temperatures of from 600 to 800 ºC. The resulting metakaolin (MK was added to OPC mortar mixes in proportions of 10 and 20% by cement weight. The mortars were compared for physical and chemical properties, including capillary absorption, chloride permeability and pore microstructure as assessed by mercury porosimetry. The best performance was recorded for the samples containing 20% of the material treated at 800 ºC.En el presente trabajo se incluyen los resultados de la resistencia a la penetración de cloruros de morteros de Cemento Portland Ordinario (OPC adicionados con un caolín colombiano sometido a tratamiento térmico en un rango de temperaturas entre 600 y 800 °C. Los productos del tratamiento térmico, metacaolín (MK, son incorporados en mezclas de morteros de OPC en proporciones del 10 y 20% en relación al peso del cemento. Se comparan sus características físico-químicas, entre las cuales se incluye la microestructura de poros evaluada por la técnica de porosimetría de mercurio, con la absorción capilar y la permeabilidad a cloruros. Se concluye que las muestras adicionadas con un 20% del material tratado térmicamente a 800 °C presentan el mejor desempeño en sus propiedades finales.

  16. Study of mortars with industrial residual plastic scales

    Directory of Open Access Journals (Sweden)

    Magariños, O. E.

    1998-06-01

    Full Text Available This work proposes the utilization of industrial residues of PET (Polyethylene Terephtalate as a partial substitute of arids (sand in mortar making for construction components. Therefore, the environmental impact of large volumes of plastic of urban residues could be decreased. When PET scales were added to mortars in partial replacement of sand, lower unitary weight, acceptable absorption and resistances according to international specifications were achieved. Mortars with 66% of sand replacement by scales and without any additive, showed optimal characteristics to be used in concret block manufacturing.

    Este trabajo de investigación se desarrolla a partir de la hipótesis de utilizar los desechos post-industriales de PET (Tereftalato de Polietileno como sustituto de áridos (arena, ingrediente de morteros, en la fabricación de componentes constructivos. En dicho trabajo se estudian las propiedades físico-químicas de distintos morteros en los que se reemplazó el contenido de árido por escamas de plástico en distintas proporciones. Se compararon y evaluaron las propiedades físico-mecánicas de los morteros en estudio con los convencionales mediante ensayos de resistencia a la flexión, compresión, absorción, durabilidad y microfotografías por barrido electrónico. Estos estudios determinaron que el agregado de PET en morteros puede ser usado como un posible sustituto de áridos, ya que se obtuvieron morteros con 66% de reemplazo de arena por escamas que presentaron menor peso unitario, absorción aceptable y resistencias acordes a las exigidas por normas.

  17. Analysis on thermal bridge of building mortar in insulation building block in view of thermal theory%基于热工理论的保温砌块用砌筑砂浆的热桥分析

    Institute of Scientific and Technical Information of China (English)

    卢玫珺; 郑智峰; 王春苑

    2012-01-01

    Aero-concrete insulation building block was extensively used as padding wall of framed building. At present, mixed mortar is mostly adopted as building mortar. But in view of major structure, mixed mortar has relative heat conduction coefficient. Thus, part of lime crack will become thermal bridge problem in heat transmission of aero-concrete insulation building block. Energy efficiency of padding wall will be seriously reduced. In view of thermal theory, mixed and insulation mortar are partly selected, and effect on thermal bridge of aero-concrete insulation building block is analyzed in thermal property. Insulation mortar is used in insulation building block, obvious effect on building energy efficiency will be come into being. This conclusion is of the same view just right with national standard GB 50411-2007 "Code for Acceptance of Energy Efficient Building Construction".%加气混凝土保温砌块被广泛用作框架结构填充墙,目前大多采用混合砂浆作为砌筑砂浆.然而相对于主体结构的加气混凝土而言,混合砂浆导热系数相对较大,因此,灰缝部分就成为加气混凝土保温砌块传热的热桥,这将严重降低填充墙节能效果.基于热工理论,分别选取混合砂浆和保温砂浆,对加气混凝土砌块的热桥影响进行热工性能分析,保温砌块采用保温砂浆砌筑,将取得明显的建筑节能效果,该结论与GB 50411-2007《建筑节能工程施工质量验收规范》具有一致性.

  18. Performance of fly ash-based geopolymer mortar

    OpenAIRE

    Abdollahnejad, Zahra; Félix, T.; Torgal, Fernando Pacheco; Aguiar, J. L. Barroso de

    2015-01-01

    This study has investigated the joint effect of several mix parameters on the properties of foam geopolymers. The mix parameters analysed through a laboratory experiment of 54 different mortar mixes were, sodium silicate/sodium hydroxide mass ratio (2.5, 3.5, 4.5), activator/binder mass ratio (0.6, 0.8, 1.0), chemical foaming agent type (hydrogen peroxide (H2O2) and sodium perborate (NaBO3)) and foaming agent mass ratio content (1%, 2%, 3%). Properties, SEM and FTIR analysis and c...

  19. Measurement of mortar permittivity during setting using a coplanar waveguide

    International Nuclear Information System (INIS)

    A sensor based on a coplanar waveguide structure was designed to perform non-destructive tests for material characterization in which the measurement can be done only on one side of the sample. The measurements were compared with the impedance of a capacitor filled with the same material. The permittivity and insertion loss of the sensor showed valuable information about the setting process of a mortar slab during the first 28 days of the hardening process, and a good correlation between both measurements was obtained, so the proposed setup can be useful for structural surveillance and moisture detection in civil structures

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

    Science.gov (United States)

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

    2003-01-01

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

  1. A study of fly ash-lime granule unfired brick

    Energy Technology Data Exchange (ETDEWEB)

    P. Chindaprasirt; K. Pimraksa [Khon Kaen University (Thailand). Department of Civil Engineering

    2008-02-15

    In this paper, the properties of fly ash-lime granule unfired bricks are studied. Granules were prepared from mixtures of fly ash and lime at fly ash to hydrated lime ratios of 100:0 (Ca/Si = 0.2), 95:5 (Ca/Si = 0.35) and 90:10 (Ca/Si = 0.5). After a period of moist curing, the microstructure and mineralogy of the granules were studied. Microstructure examination reveals that new phases in the form of needle-like particles are formed at the surface of granule. The granules were used to make unfired bricks using hydrothermal treatment at temperature of 130 {+-} 5{sup o}C and pressure of 0.14 MPa. The microstructures, mineralogical compositions, mechanical properties and environmental impact of bricks were determined. The results reveal that the strengths of unfired bricks are dependent on the fineness of fly ash. The strength is higher with an increase in fly ash fineness. The strengths of the fly ash-lime granule unfired brick are excellent at 47.0-62.5 MPa. The high strength is due to the formation of new products consisting mainly of hibschite and Al-substituted 11 {angstrom} tobermorite. The main advantage of utilization of granule is the ability to increase the pozzolanic reaction of fly ash through moisture retained in the granule. In addition, the heavy elements, in particular Cd, Ni, Pb and Zn are efficiently retained in the fly ash-lime granule unfired brick.

  2. Correction of Excessive Soil Acidity with Different Liming Materials

    Directory of Open Access Journals (Sweden)

    Milan Mesić

    2001-06-01

    According to the changes of soil pH, hydrolytic acidity, base saturation level and mobile aluminium content in soil for all investigation years, the differences in rapidity and duration of activity of particular liming material were recorded. Hydrated lime, sugar factory waste lime, ground soft lithothamnium limestone, hard limestone and dolomite influenced the soil chemical properties on the similar way, but not equally. When higher doses of these materials were applied the excessive soil acidity was almost completely neutralised. Compared to the other liming materials the efficacy of not ground lithothamnium limestone was somewhat lower, and that of phosphogypsum and special natural substrata was considerably lower. Winter wheat and corn were used as test crops and they were grown in the crop sequence winter wheat – corn – corn – winter wheat. According to the winter wheat and corn grain yield recorded at different trial treatments, the trial was statistically significant in all 4 years of investigation. At the first investigation year the highest yield of winter wheat was recorded at the treatment with higher dose of sugar factory waste lime. At the second, third and fourth year highest yields of test crops were obtained at trial treatment with higher dose of ground soft lithothamnium limestone.

  3. Calcium and bones

    Science.gov (United States)

    Bone strength and calcium ... calcium (as well as phosphorus) to make healthy bones. Bones are the main storage site of calcium in ... your body does not absorb enough calcium, your bones can get weak or will not grow properly. ...

  4. Calcium carbonate overdose

    Science.gov (United States)

    Tums overdose; Calcium overdose ... Calcium carbonate can be dangerous in large amounts. ... Some products that contain calcium carbonate are certain: ... and mineral supplements Other products may also contain calcium ...

  5. Get Enough Calcium

    Science.gov (United States)

    ... Calcium Print This Topic En español Get Enough Calcium Browse Sections The Basics Overview Foods and Vitamins ... 2 of 4 sections Take Action! Take Action: Calcium Sources Protect your bones – get plenty of calcium ...

  6. Effect of copolymer latexes on physicomechanical properties of mortar containing high volume fly ash as a replacement material of cement.

    Science.gov (United States)

    Negim, El-Sayed; Kozhamzharova, Latipa; Gulzhakhan, Yeligbayeva; Khatib, Jamal; Bekbayeva, Lyazzat; Williams, Craig

    2014-01-01

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

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

    Directory of Open Access Journals (Sweden)

    El-Sayed Negim

    2014-01-01

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

  8. Influence of Bed Ash and Fly Ash Replacement in Mortars

    Directory of Open Access Journals (Sweden)

    S. L. Summoogum-Utchanah

    2015-03-01

    Full Text Available The study evaluates the influence of fly ash and bottom ash as partial cement substitutes in mortars by studying the particle size distribution, consistency, flow, fresh density, air content, compressive strength and flexural strength characteristics. The results revealed that fly ash and cement had relatively the same particle size distribution unlike bottom ash. In the fresh state, as the amount of pozzolans increased in the mixtures, the mortars showed an enhancement in workability, were susceptible to water loss by bleeding, and exhibited a decline in fresh density. The early strength gains of the fly ash samples were low but reached higher than the control after 28 days of curing. The flexural strength increased as the fly ash content rose to reach a maximum at 20 % replacement. However, the 2-day compressive strength of bottom ash samples was higher than the control but decreased after 28 days of curing while the flexural strength declined with addition of bottom ash except at 5 % substitution.

  9. Coupling nonlinear Stokes and Darcy flow using mortar finite elements

    KAUST Repository

    Ervin, Vincent J.

    2011-11-01

    We study a system composed of a nonlinear Stokes flow in one subdomain coupled with a nonlinear porous medium flow in another subdomain. Special attention is paid to the mathematical consequence of the shear-dependent fluid viscosity for the Stokes flow and the velocity-dependent effective viscosity for the Darcy flow. Motivated by the physical setting, we consider the case where only flow rates are specified on the inflow and outflow boundaries in both subdomains. We recast the coupled Stokes-Darcy system as a reduced matching problem on the interface using a mortar space approach. We prove a number of properties of the nonlinear interface operator associated with the reduced problem, which directly yield the existence, uniqueness and regularity of a variational solution to the system. We further propose and analyze a numerical algorithm based on mortar finite elements for the interface problem and conforming finite elements for the subdomain problems. Optimal a priori error estimates are established for the interface and subdomain problems, and a number of compatibility conditions for the finite element spaces used are discussed. Numerical simulations are presented to illustrate the algorithm and to compare two treatments of the defective boundary conditions. © 2010 Published by Elsevier B.V. on behalf of IMACS.

  10. Shock response of soda lime glass at 6 GPA

    Science.gov (United States)

    Dandekar, Dattatraya

    2012-03-01

    This paper describes the results of a variety of shock wave experiments performed on soda lime glass to understand the modifying influence of so called "Failure wave" on its compression, under single shock, release, and tension. These experiments were done to a peak shock induced stress of around 6-7 GPa. Shock induced response was recorded by means of VISAR. The results of these experiments performed on soda lime glass at 6-7 GPa indicate that: (i) The effect of failure wave propagation is to lower the impedances of failed glass under both shocked compressed and released states and the effect is not initiated instantaneously at the impact surface. (ii) Failure wave velocity is determined to be 1.42 km/s. (iii) The spall strength of soda lime glass in the region transversed by failure wave is not negligible i.e., the pull-back velocity is around 50 m/s.

  11. Studies on the reuse of waste printed circuit board as an additive for cement mortar.

    Science.gov (United States)

    Ban, Bong-Chan; Song, Jong-Yoon; Lim, Joong-Yeon; Wang, Soo-Kyoon; An, Kwang-Guk; Kim, Dong-Su

    2005-01-01

    The recent development in electronic industries has generated a drastic increase in production of printed circuit boards (PCB). Accordingly, the amount of waste PCB from electronic productions and waste electronics and its environmental impact such as soil and groundwater contamination have become a great concern. This study aims to propose a method for reuse of waste PCB as an additive for cement mortar. Although the expansibility of waste PCB powder finer than 0.08 mm in water was observed to be greater than 2.0%, the maximum expansion rates in water for 0.08 to approximately 0.15 and 0.15 to approximately 0.30 mm sized PCB powders were less than 2.0%, which satisfied the necessary condition as an alternative additive for cement mortar in place of sand. The difference in the compressive strength of standard mortar and waste PCB added mortar was observed to be less than 10% and their difference was expected to be smaller after prolonged aging. The durability of waste PCB added cement mortar was also examined through dry/wet conditioning cyclic tests and acidic/alkaline conditioning tests. From the tests, both weight and compressive strength of cement mortar were observed to be recovered with aging. The leaching test for heavy metals from waste PCB added mortar showed that no heavy metal ions such as copper, lead, or cadmium were detected in the leachate, which resulted from fixation effect of the cement hydrates.

  12. Improvements of nano-SiO2 on sludge/fly ash mortar.

    Science.gov (United States)

    Lin, D F; Lin, K L; Chang, W C; Luo, H L; Cai, M Q

    2008-01-01

    Sewage sludge ash has been widely applied to cementitious materials. In this study, in order to determine effects of nano-SiO(2) additives on properties of sludge/fly ash mortar, different amounts of nano-SiO(2) were added to sludge/fly ash mortar specimens to investigate their physical properties and micro-structures. A water-binding ratio of 0.7 was assigned to the mix. Substitution amounts of 0%, 10%, 20%, and 30% of sludge/fly ash (1:1 ratio) were proposed. Moreover, 0%, 1%, 2%, and 3% of nano-SiO(2) was added to the mix. Tests, including SEM and compressive strength, were carried out on mortar specimens cured at 3, 7, and 28 days. Results showed that sludge/fly ash can make the crystals of cement hydration product finer. Moreover, crystals increased after nano-SiO(2) was added. Hence, nano-SiO(2) can improve the effects of sludge/fly ash on the hydration of mortar. Further, due to the low pozzolanic reaction active index of sludge ash, early compressive strengths of sludge/fly ash mortar were decreased. Yet, nano-SiO(2) could help produce hydration crystals, which implies that the addition of nano-SiO(2) to mortar can improve the influence of sludge/fly ash on the development of the early strength of the mortar.

  13. Reuse of de-inking sludge from wastepaper recycling in cement mortar products.

    Science.gov (United States)

    Yan, Shiqin; Sagoe-Crentsil, Kwesi; Shapiro, Gretta

    2011-08-01

    This paper presents results of an investigation into the use of de-inking sludge from a paper recycling mill as feedstock material in the manufacture of cement mortar products, including masonry blocks and mortar renders. Both physical and mechanical properties of mortar specimens containing various amounts of de-inking sludge were investigated. It was observed that the addition of de-inking sludge to cement mortar at a fixed water-to-cement ratio significantly reduced flow properties and increased setting time. Water absorption and volume of permeable voids of cement mortar increased with increased dosage of de-inking sludge, with a corresponding reduction of bulk density. The 91-day compressive strength of mortar samples with 2.5 wt% and 20 wt% de-inking sludge loadings retained 83% and 62% respectively of the reference mortar strength. The corresponding drying shrinkage increased by up to 160% compared to reference samples. However, a de-inking sludge loading of up to 2.5 wt% did not significantly alter measured physical and mechanical properties. The results demonstrate that despite the high moisture absorbance of de-inking sludge due to its organic matter and residual cellulose fibre content, it serves as a potential supplementary additive and its cellulosic content proving to be an active set retardant to cementitious masonry products.

  14. Combined Effects of Non-Conforming Fly Ash and Recycled Masonry Aggregates on Mortar Properties

    Directory of Open Access Journals (Sweden)

    Ana Isabel Torres-Gómez

    2016-08-01

    Full Text Available This work evaluates the effects of using non-conforming fly ash (Nc-FA generated in a thermoelectric power plant as filler material for mortars made with natural sand (NA and recycled sand from masonry waste (FRMA. The incorporation of powdered recycled masonry filler (R-MF is also tested as an alternative to siliceous filler (Si-F. Three families of mortars were designed to study: the effect of replacing Si-F with Nc-FA on mortars made with NA; the effect of replacing Si-F with Nc-FA on mortars made with 50% of NA and 50% of FRMA; and the effect of replacing Si-F with R-MF on mortars made with NA and FRMA. Replacing Si-F with Nc-FA is a viable alternative that increases the mechanical strength, the workability and durability properties and decreases the shrinkage. The use of FRMA and Nc-FA improved the mechanical strength of mortars, and it slightly increased the shrinkage. The replacement of Si-F with R-MF on mortars made with FRMA is not a good alternative, because it has a negative impact on all of the properties tested. This work can help both to reduce cement and natural resources’ consumption and to increase the recycling rate of Nc-FA and FRMA.

  15. Influence of Temperature on Sulfate Attack of Limestone Filler Cement Mortar

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Mortar prisms were made with three different cementitious materials (with or without mineral admixture) plus 30% mass of limestone filler. After 28 days of curing in water at room temperature, the mortars were submerged in 2% magnesium sulfate solution at different temperatures (5 ℃, 20 ℃ and alternate temperature between 5 ℃ and 20 ℃) for a year. The appearance and strength development were measured on these immersed prisms at intervals, and samples selected from the surface of prisms were examined by X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). The results show that the influence of temperature on the resistance to sulfate attack of mortar is related to the binder compositions. A higher temperature leads to a quicker strength loss and appearance deterioration of the mortar without mineral admixture. For blended cements, a higher temperature is favorable for the pozzolanic reaction of mineral admixture and the overall deterioration of mortar is reduced with the increasing temperature. When the mineral admixture has a lower reactivity, such influence of temperature on the resistance to sulfate attack of mortar containing admixtures becomes greater. At the three different solution temperatures, two blended cements show significantly improved resistances to sulfate attack. After 1 year of exposure to magnesium sulfate solutions, the formation of thaumasite was checked in the OPC mortars at both 5 ℃ and 20 ℃. It is concluded that the thaumasite formation is not limited to structures at low temperature (less than 15 ℃).

  16. Mechanism of Expansion of Mortars with Limestone Filler due to External Sulfate Attack

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    The mechanism of expansion of mortars and pastes with limestone filler due to external sulfate attack was studied.Mortars and pastes made at water to solid ratios of 0.45, 0.5, 0.6 from Portland Cement (OPC) with 0%, 20% or 30% (w/w) limestone filler (LF) were cured in a 95±1% RH moist room at 20±1 ℃ for 14 or 28 days. They subsequently were immersed in 5% Na2SO4(0.35 M) solution at ambient temperature (1~35 ℃). The expansion of the specimens was measured every month, and selected samples were examined by X-ray diffraction (XRD) and scanning electron microscope (SEM). The results indicate that mortars with 20% LF show larger expansion than that of OPC mortars at up to 9 months of exposure,and the amount of gypsum in both mortars and pastes with LF is much more than that in mortars and pastes without LF. Therefore, it is reasonable to conclude that the formation of massive gypsum leads to the lager expansion of the mortars and pastes containing 20% LF. These behaviors may be explained by the changes in hydration products due to the addition of LF.

  17. Compression Sensibility of Magnetic-concentrated Fly Ash Mortar under Uniaxial Loading

    Institute of Scientific and Technical Information of China (English)

    JIA Xingwen; ZHANG Yajie; QIAN Jueshi

    2012-01-01

    The electrical conductivity,compression sensibility,workability and cost are factors that affect the application of conductive smart materials in civil structures.Consequently,the resistance and compression sensibility of magnetic-concentrated fly ash (MCFA) mortar were investigated using two electrode method,and the difference of compression sensibility between MCFA mortar and carbon fiber reinforced cement (CFRC)under uniaxial loading was studied.Factors affecting the compression sensibility of MCFA mortar,such as MCFA content,loading rate and stress cycles,were analyzed.Results show that fly ash with high content of Fe3O4 can be used to prepare conductive mortar since Fe3O4 is a kind of nonstoichiometric oxide and usually acts as semiconductor.MCFA mortar exhibits the same electrical conductivity to that of CFRC when the content of MCFA is more than 40% by weight of sample.The compression sensibility of mortar is improved with the increase of MCFA content and loading rate.The compression sensibility of MCFA mortar is reversible with the circling of loading.Results show that the application of MCFA in concrete not only provides excellent performances of electrical-functionality and workability,but also reduces the cost of conductive concrete.

  18. ALKALI-ACTIVATED CEMENT MORTARS CONTAINING RECYCLED CLAY-BASED CONSTRUCTION AND DEMOLITION WASTE

    Directory of Open Access Journals (Sweden)

    F. Puertas

    2015-09-01

    Full Text Available The use of clay-based waste as an aggregate for concrete production is an amply studied procedure. Nonetheless, research on the use of this recycled aggregate to prepare alkaline cement mortars and concretes has yet to be forthcoming. The present study aimed to determine: the behaviour of this waste as a pozzolan in OPC systems, the mechanical strength in OPC, alkali-activated slag (AAS and fly ash (AAFA mortars and the effect of partial replacement of the slag and ash themselves with ground fractions of the waste. The pozzolanic behaviour of clay-based waste was confirmed. Replacing up to 20 % of siliceous aggregate with waste aggregate in OPC mortars induced a decline in 7 day strength (around 23 wt. %. The behaviour of waste aggregate in AAMs mortars, in turn, was observed to depend on the nature of the aluminosilicate and the replacement ratio used. When 20 % of siliceous aggregate was replaced by waste aggregate in AAS mortars, the 7 day strength values remained the same (40 MPa. In AAFA mortars, waste was found to effectively replace both the fly ash and the aggregate. The highest strength for AAFA mortars was observed when they were prepared with both a 50 % replacement ratio for the ash and a 20 % ratio for the aggregate.

  19. Properties of Chemically Combusted Calcium Carbide Residue and Its Influence on Cement Properties

    Directory of Open Access Journals (Sweden)

    Hongfang Sun

    2015-02-01

    Full Text Available Calcium carbide residue (CCR is a waste by-product from acetylene gas production. The main component of CCR is Ca(OH2, which can react with siliceous materials through pozzolanic reactions, resulting in a product similar to those obtained from the cement hydration process. Thus, it is possible to use CCR as a substitute for Portland cement in concrete. In this research, we synthesized CCR and silica fume through a chemical combustion technique to produce a new reactive cementitious powder (RCP. The properties of paste and mortar in fresh and hardened states (setting time, shrinkage, and compressive strength with 5% cement replacement by RCP were evaluated. The hydration of RCP and OPC (Ordinary Portland Cement pastes was also examined through SEM (scanning electron microscope. Test results showed that in comparison to control OPC mix, the hydration products for the RCP mix took longer to formulate. The initial and final setting times were prolonged, while the drying shrinkage was significantly reduced. The compressive strength at the age of 45 days for RCP mortar mix was found to be higher than that of OPC mortar and OPC mortar with silica fume mix by 10% and 8%, respectively. Therefore, the synthesized RCP was proved to be a sustainable active cementitious powder for the strength enhanced of building materials, which will result in the diversion of significant quantities of this by-product from landfills.

  20. OPTIMIZATION OF BACTERIOLOGICAL QUALITY OF BIOSOLIDS BY LIME ADDITION

    Directory of Open Access Journals (Sweden)

    M. Farzadkia ، N. Jaafarzadeh ، L. Loveimi Asl

    2009-01-01

    Full Text Available Lack of well-stabilized biosolids is a basic problem for many municipal wastewater treatment plants in Iran. Disposed biosolids from west Ahvaz wastewater treatment plant were generally used for agricultural activities. Initial evidence showed that these biosolids were untreated and had the potential to transmit many pollutants to the environment and create hazards for public health, although anaerobic digester was selected for this wastewater treatment plant. The main objective of this research was to evaluate and optimize the bacteriological quality of biosolids by lime addition in west Ahvaz wastewater treatment plant. The stability and reuse potential of biosolids from existing anaerobic digester and lime added biosolids were investigated. Lime addition to biosolids was performed in the reactor with 30 L capacity. Averge amounts of fecal coliforms and viable helminthes ova in disposal biosolids from anaerobic digester were 1.3×1015 MPN / g of dry solids and 314 ova / 4 g of dry solids, respectively. By lime addition with the ratio about 0.265 g Ca (OH2 per g of dry solids, pH was not dropped under 12 and growth of fecal coliform was not detected after 30 days. In this regard, discharged biosolids from this plant was unstable and very dangerous for reuse or disposal. Lime addition could stabilize the biosolids and reduce fecal coliforms more than 99.99% and had concordance with class B of United State Environmental Protection Agency criteria. Lime-stabilized biosolids could hence be well used for reconditioning the poor soil and for covering of solid waste landfill-sites.

  1. Recycling of ash from mezcal industry: a renewable source of lime.

    Science.gov (United States)

    Chávez-Guerrero, L; Flores, J; Kharissov, B I

    2010-10-01

    Agave bagasse is a byproduct generated in the mezcal industry. Normally it is burned to reduce its volume, then a byproduct is generated in the form of residual ash, which can contaminate the water in rivers and lakes near the production places called "mezcaleras". This report details measurements of the Agave Salmiana fiber transformation after the burning process. The wasted ash was heated at 950°C, and then hydrolyzed. The compounds were indentified using the X-ray diffraction. The images obtained by scanning electron microscope showed all the morphological transformations of the lime through the whole process. Thermal, elemental and morphological characterization of the agave bagasse were done. Experiments showed that 16% of ash was produced in the burning process of agave bagasse (450°C), and 66% of the ash remains after heating (950°C) in the form of calcium oxide. The results show an important renewable source of calcium compounds, due to the high production of agave based beverages in México.

  2. Thermodynamic investigation of lime-enhanced molybdenite reduction using methane-containing gases

    International Nuclear Information System (INIS)

    Lime-enhanced molybdenite reduction (LEMR) with methane-containing gases has been thermodynamically studied. The reaction proceeds through the direct oxidation of MoS2 by CaO to form intermediate molybdenum oxidized species, MoO2 and CaMoO4. The thermodynamics of Mo-O-C-H and Mo-Ca-O-C-H systems has been investigated instead of Mo-Ca-S-O-C-H system, as the sulfur is captured by calcium and forms a neutral compound (i.e. calcium sulfide). The role of reducing agent is the reduction of these oxidized species. Reduction of oxidized species by methane will yield Mo, Mo2C or MoC. The thermodynamic investigation resulted in construction of stability diagrams of molybdenum compounds. These diagrams were constructed for CH4-H2, CH4-H2-Ar and CH4-CO2-H2O gas mixtures. In addition to stability regions of Mo, Mo2C and MoC, the carbon deposition area was also identified. The results showed that by using appropriate gas composition and temperature, different molybdenum-containing phases would be stable thermodynamically while soot formation can be avoided.

  3. Thermodynamic investigation of lime-enhanced molybdenite reduction using methane-containing gases

    Energy Technology Data Exchange (ETDEWEB)

    Najafabadi, Samad Ghasemi, E-mail: samad_ghasemi@yahoo.com [Materials Engineering Department, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Abbasi, Mohammad Hasan; Saidi, Ali [Materials Engineering Department, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of)

    2010-05-20

    Lime-enhanced molybdenite reduction (LEMR) with methane-containing gases has been thermodynamically studied. The reaction proceeds through the direct oxidation of MoS{sub 2} by CaO to form intermediate molybdenum oxidized species, MoO{sub 2} and CaMoO{sub 4}. The thermodynamics of Mo-O-C-H and Mo-Ca-O-C-H systems has been investigated instead of Mo-Ca-S-O-C-H system, as the sulfur is captured by calcium and forms a neutral compound (i.e. calcium sulfide). The role of reducing agent is the reduction of these oxidized species. Reduction of oxidized species by methane will yield Mo, Mo{sub 2}C or MoC. The thermodynamic investigation resulted in construction of stability diagrams of molybdenum compounds. These diagrams were constructed for CH{sub 4}-H{sub 2}, CH{sub 4}-H{sub 2}-Ar and CH{sub 4}-CO{sub 2}-H{sub 2}O gas mixtures. In addition to stability regions of Mo, Mo{sub 2}C and MoC, the carbon deposition area was also identified. The results showed that by using appropriate gas composition and temperature, different molybdenum-containing phases would be stable thermodynamically while soot formation can be avoided.

  4. 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 ...

  5. Soil Stabilization Using Lime: Advantages, Disadvantages and Proposing a Potential Alternative

    Directory of Open Access Journals (Sweden)

    Ibtehaj Taha Jawad

    2014-07-01

    Full Text Available This study is an overview of previous studies on lime (quick and hydrated -treated soil. Lime is the oldest traditional stabilizer used for soil stabilization. The mechanism of soil-lime treatment involves cation exchange, which leads to the flocculation and agglomeration of soil particles. The high pH environment then causes a pozzolanic reaction between the free Ca+2 cations and the dissolved silica and alumina. Lime-treated soil effectively increases the strength, durability and workability of the soil. Such treatment also improves soil compressibility. A fluctuation behavior was observed on the influence of lime on soil permeability. However, the factors affecting the permeability of the soil-lime mixture should be extensively studied. Nonetheless, lime treatment has a number of inherent disadvantages, such as carbonation, sulfate attack and environment impact. Magnesium oxide/hydroxide are thus proposed as a suitable alternative stabilizer to overcome at least some of the disadvantages of using lime in soil stabilization.

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

    Directory of Open Access Journals (Sweden)

    Xiongzhou Yuan

    2015-06-01

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

  7. THE INFLUENCE OF TEMPERATURE AND ADMIX- TURES ON ACTIVATION OF LOW CALCIUM FLY ASH

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to composition and structure properties of low calcium fly ash, the activation and reaction degree of fly ash-lime and fly ash-lime-gypsum system were studied in different alkali surroundings and temperatures by thermal-gravity analysis.The degree of reaction and pore structure analysis test results show that composite alkali play an important role in the activation and degree of reaction of fly ash at room temperature. But when increasing curing temperature, gypsum would play an important role in activation and hydration of fly ash.

  8. Glass forming ability of soda lime borate Liquids

    OpenAIRE

    Zheng, Qiuju; Mauro, J. C.; Smedskjær, Morten Mattrup; Potuzak, M.; Keding, Ralf; Yue, Yuanzheng

    2010-01-01

    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....

  9. INFLUENCE OF FLY ASH REPLACEMENT ON STRENGTH PROPERTIES OF CEMENT MORTAR

    OpenAIRE

    AMARNATH YERRAMALA; BHASKAR DESAI V; RAMA CHANDURDU C

    2012-01-01

    Strength properties of fly ash mortars were evaluated through laboratory investigations. OPC of 53 grade replaced with class F fly ash with 5 - 25 % in the increments of 5 %. The results shown that at early age at all fly ash replacements the strength decreased with respect to normal mortar. However, after 28 days and above themortars made with fly ash replacement up to 15% resulted higher strength than normal OPC mortar. Fly ash replacement of 20 and 25% always had lower strength than normal...

  10. Calcium paradox and calcium entry blockers

    NARCIS (Netherlands)

    Ruigrok, T.J.C.; Slade, A.M.; Nayler, W.G.; Meijler, F.L.

    1984-01-01

    Reperfusion of isolated hearts with calcium-containing solution after a short period of calcium-free perfusion results in irreversible cell damage (calcium paradox). This phenomenon is characterized by an excessive influx of calcium into the cells, the rapid onset of myocardial contracture, exhausti

  11. Biological effects in limed forests; Biologiska effekter i kalkad skog. Aarsrapport 1998. Effektuppfoeljning av Skogsstyrelsens program foer kalkning och vitaliseringsgoedsling av skogsmark

    Energy Technology Data Exchange (ETDEWEB)

    Larsson, Per-Erik; Akselsson, Cecilia; Bengtsson, Roland; Bjelke, Ulf

    1999-10-01

    The Swedish Board of Forestry experimental work with liming and vitalising (nutrient compensation) of forest soil includes an extensive review program of the effects of this work. Results from the experimental work are presented in annual reports. This report gives an account of the review program carried out to indicate the results of the biological effects. The studies are performed within the Swedish Board of Forestry's large-scale experiments with the liming and vitalising fertilisation of forest soil. The report covers the time period, or parts of the period, from 1991 to 1998. The results in short are as follows: (1) Benthic invertebrate: The investigation revealed that a dose of 3 tonnes per hectare was insufficient to have a substantial effect on the fauna in acidified streams during the first seven years after treatment. An increase in the number of species and taxon or larger bio-diversity could not be confirmed. No indications of harmful effects on the fauna, caused by high lime concentrations, were found., (2) Benthic algae: Changes to benthic flora in streams after soil treatment was minimal. The total number of species increased slightly after lime treatment. At the same time the number of acid indicating species diminished. In other words, the decrease in acidity has improved the water quality. No negative effects, as a result of soil treatment were found., (3) Nutritional status in needles: The trees reacted quickly to the treatments. The soil treatment led to an increase in levels of calcium in the needles. Treatment using wood ash and the vitalising agent 'Skogvital' led to an increase in calcium and boron levels. Treatment using a mixture of wood ash and lime resulted in increased magnesium and manganese levels. Samples were taken one and three years respectively after treatment. A longer period of time is required to carry out a detailed evaluation of the nutritional status of the needles., and (4) Tree vitality: It is not

  12. Limitation of sulfur dioxide removal in a FGD spray dryer using once through slaked lime

    Energy Technology Data Exchange (ETDEWEB)

    Dantuluri, S.R.

    1988-01-01

    The present study discusses the importance of slaking operation and its effect on the removal efficiency in a spray dryer operated FGD system using slaked lime slurry. Laboratory scale slaking experiments were run to look into various characteristics of resulting slurry. Pilot plant tests were made to quantify the effects of different parameters on spray removal efficiency. A vertical tower mill was used to grind calcium hydroxide slurry to attain smaller particle size. X-ray diffraction and SEM techniques were used to visualize the crystallinity and surface area measurements were made for different slurries and an attempt was made to relate these parameters with the sorbent's performance in removing SO[sub 2] across the spray dryer. The findings of the present work indicate that increasing the surface area beyond certain values, the spray system can be operated under gas-phase controlled conditions, which should give maximum possible efficiency. The new version of the model SPRAYMOD-N was used to mimic these conditions to arrive at the gas phase controlled efficiency and corresponding particle size to achieve those conditions. It is found that slaked lime slurry particles around 2.3 microns size can give an efficiency of around 75 percent in the spray dryer for an inlet SO[sub 2] concentration of 1000 ppm, operated at a stoichiometric ratio (SR) of one and saturation approach temperature of 20F. Pilot tests conducted in this study with 2.4 micron Ca(OH)[sub 2] slurry achieved this efficiency. Predicted efficiency values (with constant rate period only) fell off at higher SR values, showing the significance of the falling rate period at those conditions.

  13. A crystal-chemical investigation of phases of relevance to lime-chromite roast reactions

    International Nuclear Information System (INIS)

    The aim of this investigation was to elucidate the crystal chemistry of phases in the CaO-chromium oxide-Si-O2 system, by single crystal x-ray diffractometry. The crystal chemistry of calcium and chromium-containing phases, with chromium valencies higher than trivalent, which occur in the chromite-lime roast process has been investigated. The phases include the monocalcium, tricalcium and pentacalcium ortho-chromates and the fluor and oxy-chromium apatites. The crystal structures of Ca5Cr3O12 and Ca5Cr1.8Si1.2O12, the chromium analogues of silico-carnotite, Ca5P2SiO12, have been determined. An alternative model for the structure of Ca3(CrO4)2 has been investigated in which some of the (CrO4) tetrahedra are positionally disordered. It is proposed that the structure determined may represent an average of two different structure types and the transformation from the one polymorph to the other involves the alternate flipping of the disordered tetrahedra. The disordered model implies an alternative stoichiometry Ca10(CrO4)7 in which 6/7 of the chromium is pentavalent and 1/7 is hexavalent. The phase chemistry of mixtures of lime and chromite has been examined at temperatures above 850 0C in air. Ca5Cr3O12' Ca5(CrO4)F and Ca3(CrO4)2 are produced as relatively pure phases. Optimum chromite: lime addition is in the order 1:1, such that the product phases include Ca5Cr3O12, Ca4Fe+32Al2O10 and MgO. Reaction kinetics are however unfavourable. By replacing 7% CaO with CaF2, the kinetics are improved. The product phases are fluor-chromium apatite Ca5Cr3O10F, Ca4Fe+32Al2O12 and MgO. The apatite, like Ca5Cr3O12, may be preferentially leached with dilute acid

  14. Preparation and characterization of calcium aluminate by chemical synthesis

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Saturated Ca(OH)2 and AlCl3 solutions were used to synthesize calcium aluminate hydrate precipitates at room temperature; high purity calcium aluminate powders with stable phases were made by calcination of the precursors at a temperature as low as1100℃. PSD and BET analysis revealed the particles with sizes ranging from submicrometer to several micrometers and with a specific area of 13 m2/g. The measurement of hydraulic exotherm revealed that the exothermal rate is in peak for about 2 h. The exothermal quantities are 449.24 J/g at 12 h and 488.38 J/g at 24 h. Its strength development is quick and the 1 day curing strength is almost equal to 100% of the 3 days curing strength in the mortar test.

  15. DNA markers provide insight about common lime in historicalplantings

    DEFF Research Database (Denmark)

    Hansen, Ole Kim; Thomsen, Pernille; Rasmussen, Christine Waage

    2014-01-01

    As part of the restoration process of an avenue of common lime (Tilia × europaea) from 1760 in the Royal Danish Gardens, all remaining trees were genotyped with DNA markers before they were felled. As such, information about the nature of the plant material (clonal versus non-clonal) and mode...

  16. Evaluation of Hydrated Lime Filler in Asphalt Mixtures

    Directory of Open Access Journals (Sweden)

    Mohammed Abbas Hasan Al-Jumaily

    2008-01-01

    Full Text Available Mineral filler is one of important materials and affecting on properties and quality of asphalt mixtures .There are different types of mineral filler depended on cost and quality , the matter encourages us to achieve this study to evaluate hydrated lime filler effects on properties of asphalt mixes related with strength and durability. Conventional asphaltic concrete mixtures with Portland cement and soft sandstone fillers and mixtures modified with hydrated lime were evaluated for their fundamental engineering properties as defined by Marshall properties , index of retained strength , indirect tensile strength , permanent deformation characteristics , and fatigue resistance .A typical dense graded mixture employed in construction of surface course pavement in Iraq in accordance with SCRB specifications was used .The materials used in this study included mineral aggregate materials (coarse and fine sizes were originally obtained from Najaf Sea quarries and two grades of asphalt cements produced from Daurah refinery which are D47 and D66 . The physical properties , stiffness modulus and chemical composition are evaluated for the recovered asphalt cement from prepared asphalt mixes containing various filler types .The paper results indicated that the addition of hydrated lime as mineral filler improved the permanent deformation characteristics and fatigue life and the use of hydrated lime will decrease the moisture susceptibility of the asphalt mixtures.

  17. LIME SPRAY DRYER FLUE GAS DESULFURIZATION COMPUTER MODEL USERS MANUAL

    Science.gov (United States)

    The report describes a lime spray dryer/baghouse (FORTRAN) computer model that simulates SO2 removal and permits study of related impacts on design and economics as functions of design parameters and operating conditions for coal-fired electric generating units. The model allows ...

  18. Distribution of polycyclic aromatic hydrocarbons in lime spray dryer ash

    Energy Technology Data Exchange (ETDEWEB)

    Ping Sun; Panuwat Taerakul; Linda K. Weavers; Harold W. Walker [Ohio State University, Columbus, OH (United States). Department of Civil and Environmental Engineering and Geodetic Science

    2005-10-01

    Four lime spray dryer (LSD) ash samples were collected from a spreader stoker boiler and measured for their concentrations of 16 U.S. EPA specified polycyclic aromatic hydrocarbons (PAHs). Results showed that the total measured PAH concentration correlated with the organic carbon content of the LSD ash. Each LSD ash sample was then separated using a 140 mesh sieve into two fractions: a carbon-enriched fraction ({gt}140 mesh) and a lime-enriched fraction ({lt}140 mesh). Unburned carbon was further separated from the carbon-enriched fraction with a lithiumheteropolytungstate (LST) solution. PAH measurements on these different fractions showed that unburned carbon had the highest PAH concentrations followed by the carbon-enriched fraction, indicating that PAHs were primarily associated with the carbonaceous material in LSD ash. However, detectable levels of PAHs were also found in the lime-enriched fraction, suggesting that the fine spray of slaked lime may sorb PAH compounds from the flue gas in the LSD process. 37 refs., 5 figs., 4 tabs.

  19. Atividade pozolânica dos resíduos do beneficiamento do caulim para uso em argamassas para alvenaria Pozolanic activity of kaolin processing residues for use in masonry mortars

    Directory of Open Access Journals (Sweden)

    Romualdo R. Menezes

    2009-12-01

    Full Text Available A indústria do beneficiamento do caulim gera enorme quantidade de resíduos, descartados indiscriminadamente no meio ambiente; assim, este trabalho tem por objetivo analisar a viabilidade técnica e a atividade pozolânica dos resíduos do beneficiamento do caulim para a produção de argamassas. Os resíduos foram caracterizados através da determinação de sua distribuição granulométrica e composição química, difração de raios X e análise térmica diferencial e gravimétrica; em seguida, determinou-se o índice de atividade pozolânica dos resíduos de caulim com a cal e o cimento Portland. Argamassas de cimento:cal:areia foram preparadas e o resíduo, na condição natural e após queima a 600 °C por 2 h, substituiu parcialmente o cimento nas proporções de 5, 10, 15 e 20% em massa. Corpos-de-prova foram moldados e determinada sua resistência a compressão simples. Conclui-se, com base nos resultados, que os resíduos são constituídos de caulinita, mica e quartzo e que a utilização do resíduo calcinado aumenta a resistência das argamassas após 28 dias de cura em até 150%.The kaolin processing industry generates large amounts of waste, which is indiscriminately dumped in open-air sites. This work evaluates the technical suitability and pozolanic activity of kaolin processing wastes for the production of mortars. The wastes were characterized by particle size distribution and chemical composition determination, X-ray diffraction and thermal differential and gravimetric analyses. The pozolanic activity index was determined using lime and Portland cement. Cement:lime:sand mortars were formulated and the kaolin wastes replaced cement by 5, 10, 15 and 20% on weight basis. The kaolin wastes were used in their natural condition and after thermal treatment at 600 °C for 2 h. Test specimens were produced and their compression strength determined. The results indicated that the waste consists of quartz, kaolinite and mica, and

  20. A Model for Dissolution of Lime in Steelmaking Slags

    Science.gov (United States)

    Sarkar, Rahul; Roy, Ushasi; Ghosh, Dinabandhu

    2016-08-01

    In a previous study by Sarkar et al. (Metall. Mater. Trans. B 46B:961 2015), a dynamic model of the LD steelmaking was developed. The prediction of the previous model (Sarkar et al. in Metall. Mater. Trans. B 46B:961 2015) for the bath (metal) composition matched well with the plant data (Cicutti et al. in Proceedings of 6th International Conference on Molten Slags, Fluxes and Salts, Stockholm City, 2000). However, with respect to the slag composition, the prediction was not satisfactory. The current study aims to improve upon the previous model Sarkar et al. (Metall. Mater. Trans. B 46B:961 2015) by incorporating a lime dissolution submodel into the earlier one. From the industrial point of view, the understanding of the lime dissolution kinetics is important to meet the ever-increasing demand of producing low-P steel at a low basicity. In the current study, three-step kinetics for the lime dissolution is hypothesized on the assumption that a solid layer of 2CaO·SiO2 should form around the unreacted core of the lime. From the available experimental data, it seems improbable that the observed kinetics should be controlled singly by any one kinetic step. Accordingly, a general, mixed control model has been proposed to calculate the dissolution rate of the lime under varying slag compositions and temperatures. First, the rate equation for each of the three rate-controlling steps has been derived, for three different lime geometries. Next, the rate equation for the mixed control kinetics has been derived and solved to find the dissolution rate. The model predictions have been validated by means of the experimental data available in the literature. In addition, the effects of the process conditions on the dissolution rate have been studied, and compared with the experimental results wherever possible. Incorporation of this submodel into the earlier global model (Sarkar et al. in Metall. Mater. Trans. B 46B:961 2015) enables the prediction of the lime dissolution rate