Influencia da taxa de armadura transversal na resistência ao cisalhamento direto dos concretos convencional e autoadensável
Self-Compacting Concrete (SCC) came as a solution for the demand of concrete technologies that could fill up the entirety of the concrete elements even with high reinforcement ratios without the occurrence of segregation, which is a problem widely seen when working with Conventional Concrete (CC). I...
| Autor principal: | Hirano, Eduardo Lovera |
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| Formato: | Trabalho de Conclusão de Curso (Graduação) |
| Idioma: | Português |
| Publicado em: |
Universidade Tecnológica Federal do Paraná
2022
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| Assuntos: | |
| Acesso em linha: |
http://repositorio.utfpr.edu.br/jspui/handle/1/27027 |
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| Resumo: |
Self-Compacting Concrete (SCC) came as a solution for the demand of concrete technologies that could fill up the entirety of the concrete elements even with high reinforcement ratios without the occurrence of segregation, which is a problem widely seen when working with Conventional Concrete (CC). In parallel, with the advent of agile construction methodologies, such as the adoption of precast and pre-fabricated structures, designers and researchers paid attention to the study of direct shear in the discontinuity plans of elements. The rupture mode in these interfaces is known as fragile and often lead to catastrophic behavior. Several studies were carried out to understand the behavior and adequately design such interfaces of conventional reinforced concrete. The mechanisms of shear resistance are divided into three: resistance by interlocking aggregates and intermolecular forces (cohesion), friction and dowel action. The first two are given by the literature as the most relevant regarding the ultimate strength to direct interface shear (Vu). As for self-compacting concrete, its behavior must be evaluated since it has coarse aggregates with lesser graduation and even smaller volume in its composition. Such difference can mainly influence the portion of resistance caused by the interlocking of the aggregates. This paper aims to compare the ultimate direct shear strengths of conventional concrete and self compacting concrete, using push-off specimens with variable transverse reinforcement ratios. The results demonstrate that the CAA presents an ultimate shear strength on average 13.51% lower than the CC, which can be explained by the lesser presence of coarse aggregates, reducing the resistance made by aggregate interlock. However, a certain tendency to greater strength was observed as the reinforcement ratio increased, reaching very approximate values for both concretes. This phenomenon may be explained by the improved bond between the CAA concrete and the reinforcement when in comparison with the CC. Comparing the results found to the equations in the literature, it can be concluded that the estimates of the ACI 318 (2019) and Eurocode 2 (2004) normatives are conservative, as pointed in the literature. |
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