A moment resistant beam end connection using energy dissipative couplers for precast concrete structures

There is an increasing demand for precast reinforced concrete (RC) structures due to their undeniable advantages, such as rapid assembly, material standardization, and labor quality. The structural performance of precast RC structures depends not only on the quality of the precast members but also on joints and connections. In recent years, significant attention has been given to replaceable energy-dissipative devices for beam-to-column connections in precast RC structures. This paper proposes a novel moment-resisting energy-dissipative beam end connection in precast RC systems. The proposal is based on the results of intensive experimental and numerical studies conducted in the research project. The beam longitudinal reinforcements are connected to the joint using the developed fuse-type mechanical couplers (FTMCs) that have energy dissipation capability. While the bending moment in the connection is transformed into an axial force couple and transferred by FTMCs, the shear force is transmitted through the steel hinge at the center of the beam. The cyclic behavior of the proposed connection was experimentally investigated, resulting in a robust numerical model for the connection. The experiments demonstrated that the proper configuration of FTMCs in the connection enables reaching a 4% drift ratio without causing major damage to the RC beams. Macro models adopting pivot and kinematic hysteresis approaches for FTMCs were built in the numerical part. The pivot model reasonably and consistently predicted the experimental force–displacement relations of the proposed connections. The ability of the pivot model to estimate the energy dissipation capacities varies almost 6 ~ 16%.