Vigas compostas de concreto com laje pré-moldada ligada mediante nichos: análise da resistência da interface

• Autor(a) principal: Borges, Vanessa Elizabeth dos Santos
• Data de Publicação: 2012
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/6729
• topic: Vigas compostas; Ligação de cisalhamento; Concreto pré-moldado; Rugosidade; Composite beams; Precast concrete; Shear connection; Roughness; ESTRUTURAS::MECANICA DAS ESTRUTURAS

Currently, the civil construction industry has presented some changes. This is due to the recent economic growth that Brazil had achieved. These changes increased the employment of precast concrete structures. The front of this, some studies about the precast concrete connections had been developed. This work objective was to study the shear stress transference mechanism, which appears in the beam-slab connection interface – the composite beams. It was tested three different roughness degrees of the slab shear pockets: naturally rough surface, intentionally rough surface and surface with shear-key. For this, push-out tests – double “L” – were carried out and they showed that the employment of surface setting retarder admixture (ARSP) achieves the roughness degree recommended by the NBR 9062 (ABNT, 2006) without significantly reduce the connection strength. Next, with the same model type, the influence of the percentage of steel across the joint above the strength connection was tested. Besides, another model type – three blocks – was carried out with the same aim. Through those tests, It was could ascertained that the increase of the percentage of steel across the joint provides a linear increase of the strength connection, in as much as, the minimum and maximum values were inspected. Furthermore, the double “L” tests allowed the proposition of two expressions to determine the strength shear connection. And, in a third moment, composite beams were carried out, the results indicated, for the roughness degree and percentage of steel across the joint tested, that the beam-slab connection presents a partial interaction degree, even as the connection degree. Ultimately, the similarity between the three different types of tests could be proved with the proposed expressions application in the tests results.