Experimental study on seismic behavior of precast concrete beam-column joints with wrapped steel tube and tensile reinforcement in the joint area

The connecting method of beam-column joints is the key to affecting the seismic performance of assembled concrete frame structures. A prefabricated beam-column joint with a wrapped steel tube and tensile reinforcement in the joint area is proposed to achieve efficient construction of assembled structures and ensure good seismic. Four full-scale beam-column joints were designed and manufactured for low cyclic loading tests by changing the thickness of the wrapped steel tube and reinforcing plates. The seismic behavior indexes such as hysteretic behavior, ductility, stiffness degradation, and energy dissipation capacity of this type of joint are discussed. The results show that the plastic hinge of the beam end develops away from the joint core area with the thickness of the wrapped steel tube increasing. The failure phenomenons of the specimens mainly manifest as the crushing and falling off of the concrete, the bulging deformation of the wrapped steel tube, and the buckling deformation of the short steel beam flanges. The load-displacement hysteretic loops of the joints are relatively plump. Under the low cyclic loading test, the joints exhibit good ductility and energy dissipation capacity. Increasing the wrapped steel tube thickness can significantly improve the joint’ s bearing and energy dissipation capacity, but the ductility will decrease. The reinforcing plates are beneficial to improve the ductility and energy dissipation capacity but have little effect on the bearing capacity. The calculation method of flexural bearing capacity is proposed. The calculation results agree with the experimental results, which can provide a reference for practical engineering applications of this type of joint. © 2024 Science Press. All rights reserved.