Effect of steel fiber on the shear transfer strength across a crack in reactive powder concrete

In structural concrete members that have geometrical discontinuities, the type of failure is called direct shear failure when there is no; the same member may change its response when the load arrangement is changed. This kind of failure is related to the cracks along the plane where the loaded member slides along the stationary support system and cracks are perpendicular to the axis of the member. Numerical analysis on push-off specimens were conducted in this study to investigate the shear strength in reactive powder concrete, which has cementitious compositions. The validation of the material and geometrical model to check the efficiency of the constitutive model to simulate the behavior of shear strength of RPC was achieved through comparison with the experimental result of previous work. The effects of volume fraction, aspect ratio, shape of steel fibers on the shear strength were considered to be the variables of the study. The data analyzed showed that the increase in volume fraction of steel fiber from 0% to 0.5% resulted in an increase in the shear strength of RPC by 40.3%, while, an increase in the volume fraction of steel fiber from 0% to 1.5% increased the shear strength of RPC by 140.3%. Using hook ended steel fiber increased the shear strength of RPC by 62.5%. Furthermore, the shear strength of RPC increased by 49.8% when the aspect ratio increased from 75 to 100. The stiffness and ductility of RPC members increased when the volume fraction, aspect ratio increased and provided shape of steel fiber.