Seismic performance of precast single-row reinforced concrete shear walls connected by grouted joints with button-head bars

Abstract

With the need for well precast shear walls (PSWs), ensuring sufficient connection joints between precast and cast-in-place components has become challenging. An innovative grouted joint with button-head bars and a PSW with boundary elements using this joint, called a precast single-row reinforced concrete wall, were proposed in this study. Quasi-static cyclic loading tests of four specimens, including three PSWs and one cast-in-place shear wall (CSW), were carried out, which emphasized verifying the reliability of the grouted joint and PSWs and analyzing the effect of different axial compression ratios and distributions of grouted joints on the seismic performance of this PSW. The bond strength between the button-head bar and grouting and between the grouting and precast components was tested. Additionally, mechanical characteristics in terms of failure characteristics, hysteretic properties, stiffness degradation, energy dissipation, and reinforcement strain were investigated. The theoretical predicted bearing capacity of the PSW containing flexural and shear capacities and the shear strength of the connection interface using different codes was calculated. The results show that the grouted joints with button-head bars in this paper had satisfactory bond strength of the interface between different materials and provided adequate strength and stiffness for PSW to prevent connection interface failure early. The PSW had approximately the same hysteresis behaviors as the CSW. The reliable connection method and the cast-in-place concealed column effectively limiting the horizontal wall-foundation slippage, although cracks along the construction joints between the precast members occurred. With the increase in the axial compression ratio, the bearing capacity and cumulative energy dissipation of PSW are improved due to the growth of the area of the concrete compression zone. Reasonable design of the arrangement of the grouted joints was conducive to ductility of the wall and force distribution over the cross-section. The current codes for calculating the CSW reliably predicted the bearing capacity and failure mode of the PSW.