Seismic behavior of innovation steel-embedded precast concrete beam-to-column joints

Abstract

This study proposes a novel joint using embedded steel connections in columns and beams to further improve the seismic performance and assembly efficiency of hybrid precast concrete joints. Five joint specimens, comprising four newly designed prefabricated joints and one monolithic joint, were subjected to axial and cyclic loads to evaluate their seismic performance. In this investigation, the effects of various configurations of steel connectors and steel fiber-reinforced concrete (SFRC) in the core area and the connecting portion on the joint performance were considered. Recorded failure modes and hysteresis curves were used to analyze the seismic parameters, including strength, stiffness, ductility, and energy dissipation. The proposed joints were found to be reliable, depending on the test results. The novel precast concrete beam-to-column joints exhibited significant advantages over cast-in-place joints in terms of several performance characteristics. The use of SFRC in the panel zone and the connecting portion can inhibit the development of cracks. The embedded square steel tube may reduce the shear deformation owing to its restraining effect on the concrete. The inclusion of horizontal–vertical connecting plates benefits the internal force transfer and improves the bearing capacity and ductility of the joints. Hence, these novel joints with steel connectors in columns such as specimen PC3 or PC4 and H-steel in beams could be preferred for precast concrete beams after further improvement.