Página 1 dos resultados de 45 itens digitais encontrados em 0.003 segundos

Lightweight composite concrete produced with water treatment sludge and sawdust: Thermal properties and potential application

Sales, Almir; SOUZA, Francis Rodrigues de; SANTOS, Wilson Nunes dos; ZIMERD, Alexsandro Mendes; ALMEIDA, Fernando do Couto Rosa
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
38.632312%
The main objective of this study was to evaluate the potential application of a lightweight concrete produced with lightweight coarse aggregate made of the water treatment sludge and sawdust (lightweight composite), by determining the thermal properties and possible environmental impact of future residue of this concrete. Two types of concrete were prepared: concrete produced with the lightweight composite dosed with cement/sand/composite/water in a mass ratio of 1:2.5:0.67:0.6 and conventional concrete dosed with cement/sand/crushed stone/water in a mass ratio of 1:4.8:5.8:0.8. The thermal properties were determined by the hot wire parallel technique. The possible environmental impact was measured using the procedures and guidelines of the Brazilian Association of Technical Standards - ABNT. The concrete produced with the lightweight composite presented a 23% lower thermal conductivity than the conventional concrete. The concrete produced with the lightweight composite presented a set of thermal properties suitable for the application of this concrete in non-structural sealing elements. The concentration of aluminum in the solubilized extract of the concrete produced with the lightweight composite was much lower than the concentration of aluminum in the water treatment sludge...

Interfacial interactions in concretes with silica fume and SBR latex

ROSSIGNOLO, Joao Adriano
Fonte: ELSEVIER SCI LTD Publicador: ELSEVIER SCI LTD
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
37.48096%
This paper deals with the effect of silica fume and styrene-butadiene latex (SBR) on the microstructure of the interfacial transition zone (ITZ) between Portland cement paste and aggregates (basalt). Scanning electron microscope (SEM) equipped with energy dispersive X-ray analysis system (EDX) was used to determine the ITZ thickness. In the plain concrete a marked ITZ around the aggregate particles (55 mu m) was observed, while in concretes with silica fume or latex SBR the ITZ was less pronounced (35-40 mu m). However, better results were observed in concretes with silica fume and latex SBR (20-25 mu m). (C) 2008 Elsevier Ltd. All rights reserved.; Research Sponsoring Foundation of Sao Paulo State (Fundacao de Apoio a Pesquisa do Estado de Sao Paulo - FAPESP); Civil Engineering National Laboratory (Laboratorio Nacional de Engenharia Civil - LNEC) in Lisbon, Portugal

"Concreto leve de alto desempenho modificado com SB para pré-fabricados esbeltos - dosagem, produção, propriedades e microestrutura" ; High performance latex-modified lightweight aggregate concrete for thin precast components - dosage, production, properties and microstructure

Rossignolo, João Adriano
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 08/01/2003 PT
Relevância na Pesquisa
58.9196%
Esta tese aborda a aplicação da tecnologia dos concretos leves de alto desempenho (CLAD) para a produção de elementos construtivos esbeltos pré-fabricados, tais como painéis estruturais e de vedação e peças para cobertura, apresentando um concreto com propriedades especiais em função da utilização conjunta de látex de estireno butadieno (SB), sílica ativa, superplastificante acelerador e agregados leves nacionais, denominado concreto leve de alto desempenho modificado com SB. Desenvolveu-se um amplo programa experimental para a análise dos concretos, tendo como objetivos o estudo dos processos de dosagem e produção, caracterização das propriedades dos concretos nos estados fresco e endurecido, análise da ductilidade de elementos construtivos esbeltos pré-fabricados submetidos à flexão, assim como a obtenção de informações microestruturais sobre a matriz de cimento e a zona de transição entre o agregado e a matriz de cimento. Os resultados do programa experimental demonstraram que os concretos leves de alto desempenho modificados com SB são extremamente adequados à produção de elementos pré-fabricados esbeltos, devido essencialmente à redução da massa específica e ao excelente desempenho das propriedades relacionadas à resistência mecânica e durabilidade. Nos estudos microestruturais...

"Utilização da escória de alumínio na fabricação de argila expandida" ; APPLICATION OF ALUMINUM SLAG INCORPORATED IN LIGTHWEIGHT AGGREGATE

Takahashi, Elisa Akiko Nakano
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 14/09/2006 PT
Relevância na Pesquisa
58.47022%
O presente trabalho estuda a viabilidade de utilização da escória de alumínio, que é um rejeito da indústria recicladora de alumínio, atualmente sem valor agregado, como elemento integrante na fabricação de argila expandida. A argila expandida é produzida a partir de argilas que produzam expansão piroplástica, que são utilizadas como agregado leve na fabricação de concreto estrutural e também como artigo decorativo em jardins. Inicialmente foram feitas análises dos materiais de partida, como difração de raios X, microscopia eletrônica de varredura, fluorescência de raios X, análise granulométrica, análise termogravimétrica e análise térmica diferencial da argila. Foram feitas incorporações do rejeito junto à massa de argila, na proporção de 5%, 10%, 15% e 20% em massa. As formulações estudadas foram analisadas quanto à expansão linear, variação de massa, massa específica aparente e absorção de água. Foram feitos também ensaios de lixiviação e solubilização. Os principais resultados obtidos mostraram que é viável o uso da escória de alumínio até aproximadamente 5% em massa, para a produção da argila expandida, com características aceitáveis e dentro das normas vigentes. Palavraschave: reciclagem...

Agregado leve de argila calcinada para uso em concreto estrutural: viabilidade de cerâmica vermelha do Estado de São Paulo; Calcined clay lightweight aggregate for use in structural concrete: viability of the red ceramic from the state of São Paulo

Santis, Bruno Carlos de
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/11/2012 PT
Relevância na Pesquisa
68.845312%
Este trabalho tem por objetivo o estudo da viabilidade da utilização de cerâmica vermelha para a confecção de agregados leves de argila calcinada para utilização em concretos estruturais. Inicialmente, foram coletadas amostras de solo de cinco diferentes empresas produtoras de cerâmica vermelha do estado de São Paulo. As massas cerâmicas foram caracterizadas por meio das técnicas de limites de liquidez (LL) e plasticidade (LP), análise granulométrica, análise química e difração de raios X (DRX). Os corpos de prova confeccionados com essas massas cerâmicas, queimados à temperatura de 900ºC, foram caracterizados por meio da avaliação da retração linear, absorção de água, porosidade aparente, massa específica aparente, expansão por umidade e resistência à compressão. Após a caracterização dos corpos de prova de cerâmica vermelha, foram escolhidas duas amostras para a confecção dos agregados leves de argila calcinada. Em seguida, foram confeccionados corpos de prova de concreto com agregados leves de argila calcinada, argila expandida e brita. Os corpos de prova de concreto leve foram caracterizados pelos ensaios de slump, massa específica fresca, teor de ar incorporado, resistência à compressão...

Comportamento das ligações tipo cavilha em estruturas mistas madeira - betão

Branco, Jorge M.
Fonte: Universidade do Minho Publicador: Universidade do Minho
Tipo: Dissertação de Mestrado
Publicado em /02/2003 POR
Relevância na Pesquisa
47.9397%
Dissertação de mestrado em Engenharia Civil (área de especialização em Estruturas, Geotecnia e Fundações); Este trabalho pretende constituir prova das potencialidades da utilização madeira como material estrutural, quer em acções de reabilitação quer em construções novas. Para tal, numa primeira fase, realiza-se uma síntese das principais propriedades da madeira como material de construção. De seguida, descrevem-se os estudos experimentais realizados no Laboratório de Engenharia Civil da Universidade do Minho, e que se podem agrupar nas três seguintes etapas: validação da metodologia de cálculo estabelecida pelo Eurocódigo 5 para as ligações tipo cavilha, utilizando para o efeito a espécie de madeira mais comum em Portugal (pinus pinaster); estudo do comportamento das ligações mistas madeira-betão leve, verificando a adequação da metodologia proposta no Eurocódigo 5 sobre este tema; realização de ensaios de corte à escala real sobre alguns sistemas de ligação madeira-betão disponíveis no mercado. O trabalho incluiu, ainda, a apresentação da técnica construtiva das lajes mistas madeira-betão, descrevendo-se a evolução das tipologias, os vários sistemas de ligação possíveis e os procedimentos de cálculo. Por fim...

Corn cob lightweight concrete for non-structural applications

Pinto, Jorge; Vieira, Barbosa; Pereira, Hélder; Jacinto, Carlos; Vilela, Paulo; Paiva, Anabela; Pereira, Sandra; Cunha, Vitor M. C. F.; Varum, Humberto
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2012 ENG
Relevância na Pesquisa
48.42804%
A lightweight concrete using granulated corn cob (without corn) as an aggregate is proposed in this research work. Taking into account that corn cob, after extracting the corn, is generally considered an agricultural waste, an interesting economic and sustainable benefit may result by using it as a building material. Therefore, it can be an alternative sustainable lightweight aggregate solution in comparison to the most currently applied ones such as expanded clay, particles of cork, particles of expanded polystyrene (EPS), among others. The density, the compressive strength and the thermal insulation properties of a corn cob concrete were experimentally quantified. An expanded clay concrete was also studied as reference. The main results obtained are presented and discussed showing that the proposed corn cob concrete may have the adequate material properties required for a lightweight concrete for non-structural application purposes.

Corn cob lightweight concrete for non-structural applications

Pinto, J.; Vieira, J.; Pereira, H.; Jacinto, C.; Vilela, P.; Paiva, A.; Pereira, S.; Cunha, V.; Varum, H.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
48.42804%
A lightweight concrete using granulated corn cob (without corn) as an aggregate is proposed in this research work. Taking into account that corn cob, after extracting the corn, is generally considered an agricultural waste, an interesting economic and sustainable benefit may result by using it as a building material. Therefore, it can be an alternative sustainable lightweight aggregate solution in comparison to the most currently applied ones such as expanded clay, particles of cork, particles of expanded polystyrene (EPS), among others. The density, the compressive strength and the thermal insulation properties of a corn cob concrete were experimentally quantified. An expanded clay concrete was also studied as reference. The main results obtained are presented and discussed showing that the proposed corn cob concrete may have the adequate material properties required for a lightweight concrete for non-structural application purposes.

Multiscale modeling of the elastic moduli of lightweight aggregate concretes: numerical estimation and experimental validation

Farage,Michèle Cristina Resende; Beaucour,Anne-Lise; Barra,Luis Paulo da Silva; Ke,Yang; Sanábio,Diogo Ferreira dos Santos; Ferreira,Anna Paula Guida
Fonte: Escola de Minas Publicador: Escola de Minas
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2009 EN
Relevância na Pesquisa
38.359658%
This study concerns the numerical simulation of effective elasticity modulus of lightweight concrete by means of Asymptotic Expansion Homogenization. Taking as input data the elastic properties of the aggregate and mortar employed in the concrete composition, it is possible to evaluate a homogenized elastic tensor for the resulting material. The present work deals with lightweight concretes made of the same mortar and five families of low density aggregates, with varying aggregate volumetric fractions. The multiscale model employed to represent the geometric and mechanical properties of the concrete is characterized by a great deal of simplicity. The validation of the adopted procedure consisted of comparisons of the numerical results with experimental measurements, showing good agreement.

Mechanical behavior of recycled lightweight concrete using EVA waste and CDW under moderate temperature

Santiago,E. Q. R.; Lima,P. R. L.; Leite,M. B.; Toledo Filho,R. D.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/09/2009 EN
Relevância na Pesquisa
38.545117%
Many benefits can be achieved by using recycled waste as raw material for construction. Some of them are the reduction of the total cost of the construction, the reduction of the consumption of energy and the decrease in the use of natural materials. The construction sector can also incorporate the waste of the other industries, like the waste of the shoes industry, the Ethylene Vinyl Acetate (EVA). EVA aggregate is obtained by cutting off the waste of EVA expanded sheets used to produce insoles and innersoles of the shoes. In this work two types of recycled aggregate were used - construction and demolition waste (CDW) and EVA. The aim of this work was to study the influence of the use of these recycled aggregates, as replacement of the natural coarse aggregate, on mechanical behavior of recycled concrete. The experimental program was developed with two w/c ratio: 0.49 and 0.82. Four mixtures with produced with different aggregates substitution rates (0, 50%EVA, 50%CDW and 25%EVA-25%CDW), by volume. Compressive tests were carried out to evaluable the influence of recycled aggregate on strength, elastic modulus and Poisson coefficient. In addition, it was evaluated the effect of the moderate temperatures (50, 70 and 100º C) on stress-strain behavior of concretes studied. The results demonstrated that is possible to use the EVA waste and RCD to produces lightweight concrete. The influence of temperature was more significant only on elastic modulus of the recycled concrete with 50%EVA.

Efficiency factor and modulus of elasticity of lightweight concrete with expanded clay aggregate

Moravia,W.G; Gumieri,A. G.; Vasconcelos,W. L.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/06/2010 EN
Relevância na Pesquisa
48.327866%
Nowadays lightweight concrete is used on a large scale for structural purposes and to reduce the self-weight of structures. Specific grav- ity, compressive strength, strength/weight ratio and modulus of elasticity are important factors in the mechanical behavior of structures. This work studies these properties in lightweight aggregate concrete (LWAC) and normal-weight concrete (NWC), comparing them. Spe- cific gravity was evaluated in the fresh and hardened states. Four mixture proportions were adopted to evaluate compressive strength. For each proposed mixture proportion of the two concretes, cylindrical specimens were molded and tested at ages of 3, 7 and 28 days. The modulus of elasticity of the NWC and LWAC was analyzed by static, dynamic and empirical methods. The results show a larger strength/ weight ratio for LWAC, although this concrete presented lower compressive strength.

Leachability of Heavy Metals from Lightweight Aggregates Made with Sewage Sludge and Municipal Solid Waste Incineration Fly Ash

Wei, Na
Fonte: MDPI Publicador: MDPI
Tipo: Artigo de Revista Científica
EN
Relevância na Pesquisa
37.596707%
Lightweight aggregate (LWA) production with sewage sludge and municipal solid waste incineration (MSWI) fly ash is an effective approach for waste disposal. This study investigated the stability of heavy metals in LWA made from sewage sludge and MSWI fly ash. Leaching tests were conducted to find out the effects of MSWI fly ash/sewage sludge (MSWI FA/SS) ratio, sintering temperature and sintering time. It was found that with the increase of MSWI FA/SS ratio, leaching rates of all heavy metals firstly decreased and then increased, indicating the optimal ratio of MSWI fly ash/sewage sludge was 2:8. With the increase of sintering temperature and sintering time, the heavy metal solidifying efficiencies were strongly enhanced by crystallization and chemical incorporations within the aluminosilicate or silicate frameworks during the sintering process. However, taking cost-savings and lower energy consumption into account, 1100 °C and 8 min were selected as the optimal parameters for LWA sample- containing sludge production. Furthermore, heavy metal leaching concentrations under these optimal LWA production parameters were found to be in the range of China’s regulatory requirements. It is concluded that heavy metals can be properly stabilized in LWA samples containing sludge and cannot be easily released into the environment again to cause secondary pollution.

Influence of lightweight aggregate on the bond properties of concrete with various strength grades

Mo, K.H.; Alengaram, U.J.; Visintin, P.; Goh, S.H.; Jumaat, M.Z.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Publicado em //2015 EN
Relevância na Pesquisa
47.9397%
Abstract not available.; Kim Hung Mo, U. Johnson Alengaram, Phillip Visintin, See Heng Goh, Mohd Zamin Jumaat

Lightweight Aggregate Potentialities of Some Indiana Shales

Murray, Haydn H.; Smith, John M.
Fonte: Indiana Geological Survey Publicador: Indiana Geological Survey
Tipo: Relatório Formato: 16655371 bytes; application/pdf
EN_US
Relevância na Pesquisa
69.150166%
Indiana Geological Survey Report of Progress 12; Laboratory tests show that some Indiana shales are potential sources of manufactured lightweight aggregate. Bloating, the process by which lightweight aggregates are manufactured, is caused by various constituents acting singly or in combination. Chemical composition and mineral composition of the shales and particle-size distribution of the mineral constituents are interrelated, and all of these factors contribute to the bloating of shales. This study was made to test the potential use of some Indiana, shales as raw materials for manufacturing lightweight aggregate. Such aggregate was produced in Ohio, Illinois, and Kentucky before any interest was shown in Indiana. A new plant is now producing lightweight aggregate from shale of the Borden group near Brooklyn, Ind., but other plants are needed to meet the increasing demand for lightweight concrete in the State. It is hoped that this report will stimulate interest in developing lightweight aggregate from shale and will enable future producers of lightweight aggregate in Indiana to evaluate better the location, thickness, extent, and physical properties of various shale formations.; Indiana Department of Conservation

Lightweight concrete masonry units based on processed granulate of corn cob as aggregate

Faustino, J.; Silva, E.; Pinto, J.; Soares, E.; Cunha, Vitor M. C. F.; Soares, S.
Fonte: Consejo Superior de Investigaciones Científicas (CSIC) Publicador: Consejo Superior de Investigaciones Científicas (CSIC)
Tipo: Artigo de Revista Científica
Publicado em //2015 ENG
Relevância na Pesquisa
38.680051%
A research work was performed in order to assess the potential application of processed granulate of corn cob (PCC) as an alternative lightweight aggregate for the manufacturing process of lightweight concrete masonry units (CMU). Therefore, CMU-PCC were prepared in a factory using a typical lightweight concrete mixture for non-structural purposes. Additionally, lightweight concrete masonry units based on a currently applied lightweight aggregate such as expanded clay (CMU-EC) were also manufactured. An experimental work allowed achieving a set of results that suggest that the proposed building product presents interesting material properties within the masonry wall context. Therefore, this unit is promising for both interior and exterior applications. This conclusion is even more relevant considering that corn cob is an agricultural waste product.; En este trabajo de investigación se evaluó la posible aplicación de granulado procesado de la espiga de mijo como un agregado ligero alternativo en el proceso de fabricación de unidades de mampostería de hormigón ligero. Con esta finalidad, se prepararon en una fábrica diversas unidades de mampostería no estructural con granulado procesado de la espiga de mijo. Además, se fabricaran unidades de mampostería estándar de peso ligero basado en agregados de arcilla expandida. Este trabajo experimental permitió lograr un conjunto de resultados que sugieren que el producto de construcción propuesto presenta interesantes propiedades materiales en el contexto de la pared de mampostería. Por lo tanto...

Lightweight concrete with Algerian limestone dust: Part I: Study on 30% replacement to normal aggregate at early age

Kitouni,S.; Houari,H.
Fonte: Associação Brasileira de Cerâmica Publicador: Associação Brasileira de Cerâmica
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/12/2013 EN
Relevância na Pesquisa
58.607705%
The mechanical characteristics of the lightweight aggregate concretes (LWAC) strongly depend on the proportions of aggregates in the formulation. In particular, because of their strong porosity, the lightweight aggregates are much more deformable than the cementations matrix and their influence on concrete strength is complex. This paper focuses on studying the physical performance of concrete formulated with substitution of 30% of coarse aggregates by limestone dust. In this article an attempt is made to provide information on the elastic properties of lightweight concrete (LWC) from tests carried out under uniaxial compression conditions. The results of Young modulus, Poisson's ratio, and compressive and flexural tensile strength tests on concrete are presented. The concretes obtained present good mechanical performances reaching 34.99 MPa compressive strength, 6.39 MPa flexural tensile strength and in front of 36 MPa Young modulus.

Effects of sand addition on production of lightweight aggregates from Tunisian smectite-rich clayey rocks

Fakhfakh, E.; Hajjajia, W.; Medhioubb, M.; Rocha, F.; López-Galindo, A.; Setti, M.; Kooli, F.; Zargouni, F.; Jamoussi, F.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artículo Formato: 13824 bytes; application/vnd.ms-excel
ENG
Relevância na Pesquisa
37.837002%
10 pages, 7 figures, 3 tables.; Smectite-rich claystone–marlstone samples from 12 outcrops located in the Southern Atlas domain of Tunisia were investigated with regard to manufacture of lightweight aggregates (LWAs). The clayey materials mainly consist of smectite, kaolinite and illite, together with quartz, calcite, dolomite and feldspars as accessory components. 10–12 mm pellets were prepared from wet paste and initially heated to 600 °C, 700 °C or 800 °C (depending on the raw material) for at least 2 h in order to avoid any explosion of the aggregate. The pellets were then subjected to a quick firing process at 1180 °C. The addition of 15% of quartz sand (< 250 μm grain size) to the raw materials was found to improve some required pre-treatments and give better expansion properties to some of the aggregates. The addition of 1% used automobile oil to the clay and quartz sand mixtures caused the formation of more gas and a drop in bloating temperature. The obtained LWAs were characterized by physical properties such as apparent density, mechanical resistance, water absorption and expansion. The laboratory results were comparable to those of two commercial LWAs from France (Argidécor®) and Portugal (LECA®) and provide new openings for the utilization of Tunisian claystone in civil engineering work or in agricultural applications.; Peer reviewed

Delaware Clay Resources

Pickett, T.E.
Fonte: Newark, DE: Delaware Geological Survey, University of Delaware Publicador: Newark, DE: Delaware Geological Survey, University of Delaware
Tipo: Relatório
EN_US
Relevância na Pesquisa
48.618096%
Forty-eight samples of Delaware clays were collected and tested jointly by the Delaware Geological Survey and the U. S. Bureau of Mines. Clays potentially useful for face brick are common. The nonmarine Cretaceous Potomac Formation is a potential economic clay at virtually all locations sampled. Some Miocene and Pleistocene clays are also possibilities for brick clays. Other Potomac clays are potential sources for glazed tile, sewer pipe, refractory brick, and stoneware. Coastal marsh clays, frequently containing much organic debris, are potential source material for lightweight aggregate used in lightweight, strong concrete products. Lightweight aggregate has the potential for augmenting dwindling reserves of crushed stone and gravel aggregate.; In cooperation with the United States Bureau of Mines, Curtis Edgerton, Geologist, Pittsburgh Office

A methodology to obtain an analytical formula for the elastic modulus of lightweight aggregate concrete

Souza-Barbosa,Flávio de; Resende-Farage,Michèle Cristina; Lage-Bonifácio,Aldemon; Beaucour,Anne-Lise; Ortola,Sophie
Fonte: DYNA Publicador: DYNA
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/10/2015 EN
Relevância na Pesquisa
68.618096%
This work proposes a methodology to predict the elastic modulus of lightweight aggregate concretes. To this end an analytical formula is achieved by curve fitting experimental results from 135 concrete samples made of 45 different mixes. The validation of the proposed methodology is carried out by applying the obtained analytical formula to a set of 90 concrete samples made of 30 different mixes. Comparisons with other methods applied to predicting the elastic modulus of lightweight aggregate concretes indicate that the results show good agreement and suggest that the proposed methodology could be applied in practical situations.

Optimising dosage of Lytag used as coarse aggregate in lightweight aggregate concretes

Ahmad,S; Sallam,Y S; Al-Hashmi,I A R
Fonte: Journal of the South African Institution of Civil Engineering Publicador: Journal of the South African Institution of Civil Engineering
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2013 EN
Relevância na Pesquisa
68.960503%
Lytag, manufactured first by pelletisation of a mixture of fly ash, bentonite and water, and then by sintering the spherical pellets at about 1 300°C, is used as coarse aggregate for producing lightweight plain and structural concrete mixtures. The weight of lightweight concretes is reduced significantly without compromising the structural integrity. The reduced dead load results in significant savings in the cost of foundations and reinforcement, as well as reduction in the sizes of columns, beams and slabs, which in turn reduce the overall volume of concrete and the costs of formwork and scaffolding. This paper reports on the results of an experimental study which consisted of designing, preparing and testing different mixtures of lightweight aggregate concrete considering four dosages of Lytag, used as coarse aggregate. It was found that the density and workability of concrete mixtures significantly decreased with increase in the dosage of Lytag. Concrete mixtures containing Lytag were found to be stronger than normal weight concrete. However, the strength of the lightweight aggregate concrete is found to be maximum at an optimum dosage of the Lytag.