Experimental investigation on joints between steel-reinforced concrete T-shaped column and reinforced concrete beam under bidirectional low-cyclic reversed loading

Abstract

Steel-reinforced concrete T-shaped column-beam structure system has superiorities of both steel-reinforced structure and special-shaped column structure. This research focuses on steel-reinforced concrete T-shaped column-beam joint design and experimentally investigates seismic behaviors of the proposed joints. Pseudo-static tests are carried out on three steel-reinforced concrete T-shaped column-reinforced concrete beam joints and one reinforced concrete T-shaped column-reinforced concrete beam joint. The experiments were conducted under bidirectional low-cyclic reversed loading to simulate realistic loading conditions under earthquake. Hysteresis loops of all the specimens, including load–deflection, moment–rotation, and load–shear deformation loops, are plotted for the evaluation of seismic reaction. The working index, ductility coefficient, and equivalent viscous-damping coefficient are calculated for comparisons. Meanwhile, the ductility, capacity of energy dissipation, stiffness degradation, and the function of steel reinforcement in resisting shear force in the joint core area are intensively studied. Based on experimental results, this research analyzes shear-resistant capacity and the inner force transmission in these joints. It is found that the steel-reinforced concrete T-shaped column-reinforced concrete beam joint performs well under seismic conditions; moreover, shear-resistant capacity, ductility, and reliability are satisfactory. Conclusions derived from this research are useful for engineering practice.