Estudo experimental de consolos muito curtos de concreto reforçado com fibras de aço.

Abstract

The corbels are structural elements widely utilized in the connections between prefabricated elements of reinforced concrete structures, but their conventional industrial production presents difficulties due to the large amount of steel reinforcement required in a restricted space, especially in very short corbels. Considering the structural behavior of these elements, the use of steel fibers added to the concrete presents itself as a solution to the presented difficulties, promoting optimization of the productive process. The present study consists of analyzing the structural performance of very short corbels with steel fibers added to the concrete and evaluating their use in replacement of the horizontal stirrup. The variables analyzed were the presence of horizontal stirrups and the presence of steel fibers in the rates of 0.5% and 1.0%, respectively. The cracking pattern, the cracking force and the resistant capacity of the corbel were evaluated. The presence of steel fibers altered the cracking pattern of the corbels, promoting slow and progressive formation of fissures and showing signs of better ductility and tenacity when compared to corbels without fibers. The cracking resistance increased due to the addition of steel fibers to the concrete, as well as the presence of horizontal stirrups, but the corbels with 1.0% steel fibers had a mean cracking resistance 85% higher than those without horizontal stirrups and 21% higher than those with horizontal stirrups. The presence of steel fibers promoted an increase in resistance of the corbels, since the addition of 0.5% of steel fibers resulted in the increase of 152% of the rupture resistance, but it was inferior to the maximum resistance achieved by the corbel with horizontal stirrups.