Washington Almeida Moura

Concrete Performance With Admixtures of Electrical Steel Slag and Copper Copper Concerning Mechanical Properties

The generation of solid residues and an adequate final destiny for them is a subject that has attracted more and more research. The recycling of solid by-products as construction materials can be an alternative to reduce costs of the latter and it can also reduce the impact on the environment. Nevertheless, it is fundamental that the characteristics of these new materials be equivalent to the traditional ones or even better, if possible. In this context, the use of electric steel slag and copper slag can be a potential alternative to the admixtures used in concrete and mortars. Results of physical, chemical and physical-chemical characterizations of electric steel slags from Rio Grande do Sul and copper slags from Bahia, both in Brazil, are presented in this work. Also presented are results of compressive tests, flexural tests and Brazilian tests in concrete specimens with these admixtures, indicating the viability of their use.

Estudo da viabilidade da produção de blocos com utilização de resíduo de serragem de rochas ornamentais para alvenaria de vedação

Brazil is the fifth largest producer of dimension stones in the world, and the states of Espirito Santo, Bahia, Ceara e Paraiba are the major producers in this country. In this sector, the generation of waste during processing is quite significant. When the production of dimension stones in 2004 was 6,450,000 tons, the estimated volume of waste at the processing stages was 1.610.000t/year (Chiodi Filho, 2005). Currently, this waste has been deposited in the land of the companies, which implies a cost to them. In general, the generation of solid waste has been one of the major problems faced by national and international industries. Especially in regards to the disposal and handling of these wastes because they are generally expensive and difficult to implement. In this study, we assess the feasibility of using waste dimension stone sawing dust (DSSD) in pre-cast blocks for masonry. The DSSD was used to partially replace cement in the contents of 5%, 10% and 15% by weight. The blocks produced were evaluated for compressive strength and absorption. The results shows viability for the use of DSSD as partial replacement of cement.

Avaliação do uso de resíduo de serragem de pedra Cariri (RSPC) para produção de concretos convencionais

No estado do Ceara, na regiao do Cariri, um minerio calcario laminado, comercialmente conhecido como pedra Cariri, e muito explorado. Os processos de exploracao e beneficiamento desse minerio sao causas da geracao de residuos. Um dos tipos de residuo gerado e o decorrente da serragem de pedra Cariri, denominado de residuo de serragem de pedra Cariri (RSPC). Nesta pesquisa, avalia-se a viabilidade do uso de RSPC como substituicao parcial do cimento na producao de concretos convencionais. Foram determinadas as caracteristicas quimicas e fisicas do RSPC. A influencia foi avaliada atraves das propriedades mecânicas (resistencia a compressao axial e diametral) e parâmetros de durabilidade (absorcao por imersao e por succao capilar). Foram produzidos 9 tracos, variando a relacao a/c (0,45; 0,55; 0,65) e os teores de substituicao (0%, 10% e 20%) do cimento. Os resultados demonstram que a utilizacao de RSPC no concreto proporcionou uma reducao nas resistencias a compressao e a tracao por compressao diametral. Entretanto, em relacao aos parâmetros de durabilidade, os concretos com RSPC apresentaram comportamento compativel com os concretos de referencia. De um modo geral, do ponto de vista tecnico, o RSPC nao proporcionou resultados satisfatorios para aplicacao em concreto.

Avaliação de propriedades mecânicas de concretos contendo escória de cobre como agregado miúdo

This work presents the results of the study about the use of copper slag as fine aggregate for concrete. The influence of the use of different percentages of granulated copper slag, as fine aggregate, in the mechanical properties (compression strength and splitting tensile strength) of the concrete was evaluated. The results show that the use of copper slag as fine aggregate, up to 40% of substitution in volume, promotes an increment in the mechanical performance of the concrete. The work shows the possibility of using copper slag in partial substitution of the natural aggregate.