Experimental and numerical investigation of punching shear capacity of corroded reinforced concrete slab-column connections

Abstract

Rebars in reinforced concrete (RC) slab-column structures may become corroded under adverse conditions, rendering slab-column connections (SCCs) more susceptible to punching shear (PS) failure. In this study, four RC SCC specimens were designed and fabricated, and their rebars were subjected to accelerated corrosion using an electrochemical approach. Next, pseudo-static tests were performed to determine the PS capacity of the RC SCC specimens with different corrosion ratios. The test results showed that the corrosion of the rebars in an RC SCC significantly reduced the angle of its PS plane and consequently lowered its PS capacity. On this basis, a high-fidelity finite-element model was generated using LS-DYNA, and its accuracy was validated through a comparison of the simulation and test results. Based on this model, numerical simulations were performed to examine the effects of four parameters, namely, the size of the corroded area, the reinforcement ratio, the slab thickness, and the boundary conditions, on the PS capacity of corroded RC SCCs. The numerical simulation results show that increasing the size of the corroded area reduces the PS capacity of an RC SCC and increasing slab thickness weakens the effect of rebar corrosion on the PS capacity of an RC SCC, while increasing the reinforcement ratio has a limited effect on the improvement in the PS capacity of a corroded RC SCC. Additionally, increasing the horizontal boundary stiffness significantly enhances the PS capacity of a corroded RC SCC.