Seismic performance of precast RC Beam-Column Joints wrapped and connected by an outer square steel tube
Yun Chen,Xing Li,Boshan Chen,Tuo Lei,Qijun Zhang
Abstract
A novel prefabricated reinforced concrete (RC) beam-column joint, wrapped and connected by an outer square steel tube in the core area, has been developed and widely used. In this design, the column's longitudinal reinforcement is anchored to the inner diaphragm of the steel tube, while I-beams are pre-embedded at the beam ends. This design not only effectively protects the core zone from damage and prevents rebar congestion but also facilitates the formation of plastic hinges within the beam area, thereby reducing the risk of brittle failure during strong earthquakes. However, no prior study has investigated the seismic performance of this novel prefabricated beam-column joint. To address this gap, this study performed a quasi-static reversed cyclic loading test on two full-scale joints. The obtained test results demonstrate that the ductility coefficient and equivalent damping coefficient of the prefabricated reinforced concrete beam-column joint are 3.152 and 0.134 respectively. It exhibits strong abilities such as energy dissipation and deformation, which verifies the reliability of the joint design. And, the steel tube preserves the integrity of the connection under cyclic loading. Additionally, A new formula for calculating the shear strength of this type of joint was developed, and it is shown that the predicted results can be in good agreement with the numerical results.
