Experimental study of precast concrete shear walls with spiral-confined lap connections under cyclic loads

In this paper, full-scaled precast concrete shear walls (PCSWs) with spiral-confined lap connections were tested under low reversed cyclic loading tests with axial compression ratios of 0.12 and 0.24. Both one-row and two-row connections were considered in the test program. The spirals in the connections were used to provide additional confinement and to shorten the lap length (a reduced lap length of 1.0laE was used). Results showed that all PCSWs suffered flexural-shear failure mode, and their load-carrying capacity, hysteretic behavior, energy dissipation and stiffness degradation characteristics were similar to the monolithic reference specimens. The ductility of the PCSWs under the axial compression of 0.12 was 3.86 and 4.00, which was close to that of the monolithic wall (4.19). Under the axial compression of 0.24, the spiral-confined lap splices prevented the earlier failure of the PCSWs, leading to significantly higher ductility (4.08 and 4.07) than the monolithic wall (3.05). The test results also indicated that the reduced lap length of 1.0laE was validated to be acceptable under simulated earthquake actions. In addition, the PCSWs with one-row and two-row connections exhibited comparable structural performance, and they could both be considered as emulative structures.