Experimental study on seismic behavior of local post-tensioned precast concrete beam-to-column connections

To improve the assembling construction efficiency for precast concrete moment resisting frames, a new dry-wet combined precast concrete beam-to-column connection with local post-tensioned tendons was developed. In the construction stage, a temporary frame structure with dry connections, capable of withstanding subsequent construction loads, was established using local post-tensioned tendons to realize bay-by-bay and top-and-below stereoscopic construction. In the serviceability stage, wet connection was achieved through cast-in-place top concrete above precast beams and slabs to form a monolithic frame structure with the dry-wet combined connections. Four precast and one monolithic full-scale specimens were tested under reversal cyclic loading to evaluate the earthquake resistance and relevant details that may affect the structural performance, including the type of post-tensioned (PT) arc tendon, the bonding condition of PT tendons and composite beam top longitudinal reinforcements, and the type of grouting materials in the longitudinal reinforcement duct. The results show that the proposed connection fails in a flexural mode at beam ends, which satisfies the design principle of strong-column and weak-beam. The experimental strength is consistent with the theoretical value, and has a sufficient margin. Compared with the monolithic connection, it shows better deformation capacity, comparable ductility and lower energy dissipation due to the steel bar slippage. © 2019, Editorial Department of Journal of Southeast University. All right reserved.