Propriedades mecânicas do concreto com adição de borracha de pneus para pavimentos rodoviários

Brazil is considered a very rich laboratory of tropical soil and climate of great importance to geotechnical engineering and transport infrastructure. Paving consumes an extremely large quantity of materials, being the source of rational application of waste and rejected materials, being natural, altered, processed or modified. The production of waste by tire industry has been a growing problem, indicating the need for research to find out new ways for its reuse. This study deals with the evaluation of the mechanical properties of modified concrete with the addition of rubber fibers provided from tire crushing to be used in roadway pavements. Different concrete traces were produced, within which part of the fine aggregates were substituted by tire rubber in 10%, 20%, 30% and 40% in mass. Material characterization and mechanical experiment testing were performed, which show that, due to the great resistance loss and operational difficulties, the addition of tire rubber in concrete for pavements is not recommended. Key words: reuse, waste, tire rubber, paving, concrete, mechanical properties.O Brasil é considerado um laboratório riquíssimo de solos e clima tipicamente tropicais de grande importância para a geotecnia e a infra-estrutura de transportes. A pavimentação consome uma enorme quantidade de materiais, em que pode ser feita a aplicação racional de resíduos e rejeitos, sejam in natura, processados ou modificados. Os resíduos produzidos pela indústria de pneus têm representado um problema nacional crescente, o que tem incentivado pesquisas para determinar novas formas de reaproveitamento do material. Este estudo trata da avaliação das propriedades mecânicas do concreto com adição de fibras de borracha provenientes da trituração de pneus para emprego em pavimentação. Foram produzidos diferentes traços de concreto nos quais parte de agregado miúdo foi substituída por borracha de pneus nas porcentagens de 10%, 20%, 30% e 40% em massa. Os resultados experimentais mostram que, devido à perda de resistência e dificuldades operacionais, não é recomendável a incorporação de borracha de pneus em concreto para pavimentação. Palavras-chave: reaproveitamento, resíduos, borracha de pneus, pavimentação, concreto, propriedades mecânicas

EVALUATION OF TIRE RUBBER DISPOSAL IN CONCRETE FOR PAVEMENTS

The production of waste by the tire industry has been a growing problem, indicating the need for its reuse. More than thirty million tires are discharged per year in Brazil, where regulation for the environment states that for each four new tires, five unusable ones must be adequately disposed by manufacturers and importers. Paving consumes an extremely large quantity of materials, which can be the source of rational application of waste and rejected materials. Research shows that tire rubber can be added to asphalt, which increases its durability and improves pavement quality and safety conditions by absorbing the rubber elastic properties, and also be used for architectural applications, among others. This study deals with the addition of rubber fibers from tire crushing in concrete for roadway pavements in order to provide proper indication about the alternative material disposal through an evaluation of the mechanical behavior of the modified concrete. Different concrete mixes were produced, within which, part of fine aggregates were substituted by tire rubber and mechanical experiment tests were performed, which show that, due to great resistance losses, the disposal of this alternative material in concrete should be considered for light traffic pavements, with the addition of rubber ranging up to 10% in mass

Evaluation of wind potential in Caraguatatuba, northern coast of Sao Paulo

This study aims to assess the potential for wind power generation in the town of Caraguatatuba – Sao Paulo North Coast - Brazil. The statistical analysis of wind speed will contribute to this evaluation. Data of wind speed from 2004 to 2013, corresponding to the meteorological station Caraguatatuba (code 32521) Sinda/INPE system were used. Weibull distributions for the four seasons were analyzed, and their shape and scale parameters for the wind speed data, from which an extrapolation of the vertical profile of the wind to height of 100m was performed. It was found that the average power of the wind speed is favorable to the installation of wind turbines in all seasons