Seismic behavior of concrete columns with ends transformed via perforated H-shaped steel and engineered cementitious composite

Abstract

A novel structural detail is proposed to strengthen or shift the plastic hinge regions of concrete column-footing connections by using perforated H-shaped steel and engineered cementitious composites (ECC) in this study. Two transformed concrete columns and a normal concrete column were tested under a constant axial load and quasi-static reversed cyclic load to explore their seismically important features, including failure modes, hysteretic response, energy dissipation, stiffness degradation, and strain. Furthermore, a numerical study was also conducted to investigate the influences of critical parameters on seismic performance, and a formula for predicting the shear capacity of concrete columns is proposed. The results reveal that the seismic performance of concrete columns can be improved by embedding perforated H-shaped steel and using ECC at each end, and the plastic hinge can be relocated away from the column ends. The finite-element results agreed well with the experimental results. A high shear-span ratio adversely affects the seismic performance of the transformed concrete columns. An increase in the axial load ratios and H-steel insertion depth can enhance the load-carrying capacity of the models.