Experimental Investigation on Seismic Behaviour of Hybrid Precast Beam-column Joints with Different Connection Configurations

Precast beam-column connections, which are difficult to prefabricate and assemble, are critical members of concrete frames in high seismic regions. In this study, a novel type of precast hybrid connection with different connection configurations is developed for an easy and rapid construction. This steel-concrete connection involves a concrete column with an embedded steel skeleton, a concrete beam with an embedded H-steel, and a connection device including steel band plates and high-strength bolts. To investigate the effectiveness of the proposed connections, three precast hybrid beam-column joints and one monolithic specimen were subjected to reversed cyclic loading and tested. During the test, load-displacement hysteresis curves and failure modes were obtained. The seismic behaviour was investigated in terms of stiffness degradation, load-carrying capacity, energy dissipation, ductility, and shear deformation in the joint core region. Experimental results indicated that the proposed precast hybrid connections exhibited satisfactory performance in terms of ductility, energy dissipation, rotation capacity, strength, and stiffness. The shear deformation of the proposed hybrid connections was reduced owing to the effective confinement of the steel skeleton, while the shear strength improved. Plastic hinges of precast joints with a square steel tube occurred in the beams, and these specimens exhibited flexural failure, which is consistent with the principle of strong columns and weak beams. Therefore, these proposed connections can resist high seismic loads.