Experimental investigation into the failure process of exterior beam-column joints with high-strength reinforcements

Abstract

Although using high-strength reinforcements (HSRs) have economical and execution benefits, their possible negative effects on the performance of structures such as ductility, energy dissipation, and damage process caused them to be restricted by building codes in seismic areas. In this research, the HSR effects on the cyclic behavior, cracking process, and damage indices of exterior beam-column joints were experimentally investigated under cyclic loading. Three exterior beam-column joints with HSRs (with the yield strengths of 500 and 580 MPa) were designed based on the special seismic provisions of ACI 318-19. These specimens were subjected to cyclic loading and their responses were obtained. The results showed that using HSRs led to increasing the width and depth of the cracks. Then, two methods of calculating damage indices (introduced by Promis et al., 2009) were applied based on the experimental results. Considering the damage indices, it was observed that using HSRs increased the damage indices of the specimens and the damage distribution in them.