Comportamento estrutural de lajes pré-moldadas treliçadas com adição de resíduos de borracha de pneu
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Data
2011-08-22
Autores
Fazzan, João Victor [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
O uso do concreto na elaboração de estruturas de concreto armado está ligado à capacidade das mesmas em resistir aos esforços solicitantes, por meio da aderência que existe entre os materiais aço e concreto. Considerando-se que a maioria dos concretos à base de cimento apresenta uma pequena resistência à tração, se comparada à compressão, algumas alternativas para melhorar o seu comportamento em relação a esse aspecto vem sendo estudadas com sucesso, como, por exemplo, a adição de diversos tipos de fibras. Em outro contexto, a incorporação de resíduos no concreto surge como uma possibilidade para se atenuar impactos ambientais. Um exemplo desses resíduos é o de borracha de pneu, gerado em abundância durante o processo de recauchutagem. Observa-se, no entanto, que a inclusão desse resíduo pode provocar uma diminuição da resistência e do módulo de deformação longitudinal. Atualmente, em muitos casos, a utilização de lajes treliçadas têm sido mais vantajosa que o uso de lajes maciças, tanto do ponto de vista de execução, como do ponto de vista econômico. Para as situações de pequenos e médios vãos, e para cargas não muito elevadas, é possível que as lajes treliçadas não tenham o seu desempenho estrutural muito prejudicado em função da incorporação da borracha no concreto, uma vez que a limitação de sua capacidade resistente não seria dada pelo esmagamento do concreto mas sim pelo alongamento excessivo da armadura. Sendo assim, este trabalho tem como objetivo a utilização de resíduos de borracha em substituição parcial dos agregados do concreto que compõem a capa e as vigotas de lajes pré-fabricadas treliçadas unidirecionais. No total, foram ensaiados seis modelos, sendo três deles sem adição de borracha e os outros três com substituição de 10% do volume de areia por resíduo. Os modelos de lajes foram instrumentados...
The use of concrete in the manufacture of reinforced concrete structures is related to the ability of this material to resist the loads by the bond that exists between the reinforcement and the concrete. Considering that most of the cement-based concrete has a small tensile strength when compared to compression, some alternatives to improve their behavior in relation to this aspect has been studied successfully, as the addition of several types of fibers, for example. In another context, the incorporation of residues in the concrete emerges as a possibility of attenuating the environment impacts. An example is the tire rubber residue, generated in abundance during the retreading process; however, it is noted that the inclusion of this residue can cause a decrease in the compressive strength and in the module of elasticity. Currently, in many cases, the use of lattice slabs is more advantageous than the use of solid slabs, both in terms of execution, as the economic point of view. For small and medium spans, and for not high loads, it is possible that lattice slabs do not present a bad performance due to the incorporation of rubber into concrete since the limitation of its strength capacity would not be given by the concrete crushing but by the excessive reinforcement strain. Therefore, this work aims to use rubber tire residue as an aggregate in the concrete of the cover and in the concrete of the joist of the lattice precast unidirectional slabs. The residue partially replaced the fine aggregate. In total, six models were tested, being three of them without the rubber addition and the other three with replacement of 10% in the volume of sand per residue. The models were instrumented and tested for flexure at 28 days old, and the vertical displacements, the strains in concrete and in the reinforcement were recorded. The cracking... (Complete abstract click electronic access below)
The use of concrete in the manufacture of reinforced concrete structures is related to the ability of this material to resist the loads by the bond that exists between the reinforcement and the concrete. Considering that most of the cement-based concrete has a small tensile strength when compared to compression, some alternatives to improve their behavior in relation to this aspect has been studied successfully, as the addition of several types of fibers, for example. In another context, the incorporation of residues in the concrete emerges as a possibility of attenuating the environment impacts. An example is the tire rubber residue, generated in abundance during the retreading process; however, it is noted that the inclusion of this residue can cause a decrease in the compressive strength and in the module of elasticity. Currently, in many cases, the use of lattice slabs is more advantageous than the use of solid slabs, both in terms of execution, as the economic point of view. For small and medium spans, and for not high loads, it is possible that lattice slabs do not present a bad performance due to the incorporation of rubber into concrete since the limitation of its strength capacity would not be given by the concrete crushing but by the excessive reinforcement strain. Therefore, this work aims to use rubber tire residue as an aggregate in the concrete of the cover and in the concrete of the joist of the lattice precast unidirectional slabs. The residue partially replaced the fine aggregate. In total, six models were tested, being three of them without the rubber addition and the other three with replacement of 10% in the volume of sand per residue. The models were instrumented and tested for flexure at 28 days old, and the vertical displacements, the strains in concrete and in the reinforcement were recorded. The cracking... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Concreto armado, Lajes pré-moldadas treliçadas, Borracha de pneu - Resíduos, Reinforced concrete, Tire rubber residue
Como citar
FAZZAN, João Victor. Comportamento estrutural de lajes pré-moldadas treliçadas com adição de resíduos de borracha de pneu. 2011. 169 f. Dissertação (mestrado) – Universidade Estadual Paulista, Faculdade de Engenharia de Ilha Solteira, 2011.