Experimental Research on Seismic Behavior of Haunched Concrete Beam-Column Joint Based on the Bolt Connection

Studying the seismic performance of assembled beam-column joints is essential for the development of assembled frame structures. In this paper, a novel dry connection beam-column joint with a high degree of modularity and a simple structure is proposed and tested using a pseudostatic test. The joint is composed of a precast concrete beam with a steel axillary plate at the end and a precast concrete column connected by long bolts. By analyzing the characteristics of the hysteresis curve, skeleton curve, and stiffness degradation curve, we were able to investigate the seismic performance of this novel new joint under low circumferential reciprocating load as well as the impact of bolts of various strength grades on the joint's seismic performance. The results illustrated the robust overall bearing performance of the newly assembled beam-column joint. However, when connected with common bolts, the joint deforms more, exhibits good ductility, clearly displays semi-rigid characteristics, and performs better in terms of energy dissipation. This contrasts with connecting with low-strength bolts, which cause the joint to deform little and have poor energy dissipation capacity. The prefabricated columns and beams remain undamaged, making it possible to quickly repair the assembled building structure after an earthquake; however, the joints are harmed due to the bending and fracture of the connection bolts. It has been suggested that researchers add damping energy dissipation devices to the new joint to increase its energy dissipation capacity and control the joint's overall deformation because the joint's energy dissipation capacity is insufficient under the low circumferential reciprocating load.