Cyclic test and numerical analysis of the seismic performance of concrete columns reinforced by HRB600 steel bars

Abstract

As a new type of high-strength steel bar, hot-rolled ribbed bar (HRB) 600 reinforcement has an obvious yield platform and high elongation. To better understand the seismic performance of HRB600 steel bar reinforced concrete columns, cyclic tests are first conducted to examine the effect of the reinforcement strength, stirrup spacing, and axial compression ratio on their seismic performance. Then, finite element (FE) models of the column specimens are established by OpenSees, and the accuracy is verified by comparison with the experimental results. Finally, parametric analysis is conducted to investigate the effects of the concrete strength, longitudinal reinforcement strength, volume-stirrup ratio, and stirrup strength on the seismic performance of concrete columns. The research results show that the column specimens reinforced by HRB600 reinforcement can achieve an excellent drift ratio capacity of 4.2% when the axial load ratio is 0.5, and have a deformation capacity similar to that of normal-strength bar reinforced concrete columns. The established FE model can simulate well the behavior of HRB600 bar reinforced concrete columns under cyclic loading. The parametric analysis shows that when adopting equal strength replacement of longitudinal reinforcement, the columns built by high- and normal-strength reinforcement have similar strength and deformation capacity, but the high-strength bar reinforced columns have a slightly smaller energy dissipation.