SHEAR TRANSFER BEHAVIOR OF FIBROUS CONCRETE

Abstract

Fibrous concrete's shear strength behavior is important in structural design. Brackets, corbels, and ledger beams are examples of concrete members that might collapse in shear. Such a failure might be brittle and sudden. Fibers improve concrete's behavior by increasing residual shear transfer and reducing crack development and extension. In an experimental study, nine push-off specimens were divided into three groups and examined as part of the experiment. Conventional concrete, conventional concrete with 1% glass fiber, and conventional concrete with 1% steel fiber were the groups. There were three push-off specimens with various shear reinforcement ratios in each of the groups that were examined (0.0, 0.45, and 0.68%). The specimens utilized had dimensions of 500mm x 250mm x 125mm. The vertical slip and horizontal separation at the shear plane were measured using two-stroke linear variable displacement transducers (LVDT). The effect of fiber type and the ratio of transverse reinforcement across the shear plane were the parameters evaluated. The presence of fibers enhances final shear strength, which is more obvious in specimens without stirrups in the shear plane. Where the addition of 1% of glass fiber to normal strength concrete increased ultimate shear strength by 32.26%, 12.38%, and 12.5%, while adding 1% of steel fiber to normal strength concrete increased ultimate shear strength by up to 53.22%, 19%, and 25%, respectively, for the specimens without stirrups, two stirrups, and three stirrups. The fibrous specimens were stiffer and ductile failure was seen. Steel fibers improved overall concrete shear behavior better than glass fibers.