Effect of mid-thickness rebar mesh on the behavior and punching shear strength of interior slab–column connection

Abstract

Punching shear failure is a major problem encountered in the design of reinforced concrete flat plates. The utilization of shear reinforcement via shear studs or other means has become a choice for improving the punching shear capacity. In this study, a new alternative of reinforcement, the introduction of rebar mesh at the middle of flat plate thickness covering the punching zone and anchored outside this zone, is proposed. Nevertheless, in this investigation, the proposed reinforcement system is examined for interior columns only.An experimental work consisting of eight specimens, of normal and high strength concrete, and an expanded analytical work using the finite element method had been carried out in order to investigate the effect of this additional reinforcement for both normal strength and high strength concrete. The computer program ANSYS-V12.0 has been utilized in the finite element analysis.The obtained results indicate that, the proposed shear reinforcement system has a positive effect in the enhancement of both the punching shear capacity and the strain energy of interior slab–column connection of both normal and high strength concrete. The general finite element software ANSYS can be used successfully to simulate the punching shear behavior of reinforced concrete flat plates.