Análise experimental de blocos sobre duas estacas com concreto reforçado com fibras de aço

Abstract

The present work aimed to study the behavior of rigid blocks on two piles reinforced with steel fibers, submitted to the action of centered force, preserving the main reinforcement and varying the rates of secondary reinforcement, adopting piles of 20 cm in diameter and block with length of 100 cm facing the piles. The fiber content varied in 20 kg/m3 and 40 kg/m3, with a reference model. The stirrups were made up of a mesh shape, being vertical and horizontal, varying in one and two horizontal stirrups. In total, 12 blocks were built and tested. The instrumentation was performed on the main reinforcements and on the lateral faces of the blocks, with steel and concrete strain gauges, respectively. The main objective is to analyze the effect of the steel fiber in relation to the reinforcement rate used, regarding the development of cracks, stiffness and rupture load of each block. The experimental results indicated that the use of the steel fiber in conjunction with horizontal stirrups provided a higher rupture load to the blocks, reaching an increase of 23% in relation to the reference matrix. The blocks with fibers presented more discrete cracks, greater rigidity and lower displacement, thus, it is concluded that the use of steel fiber promotes less robust blocks and resistant to higher loads, having a significant role in the performance of the set.