Seismic performance of precast lightweight aggregate concrete shear walls with supplementary V-ties

Abstract

This study examined the flexural behavior of a precast lightweight aggregate concrete shear wall (PLCSW). To minimize crosstie arrangement congestion in the boundary elements and improve ductility, the conventional reinforcing crosstie was replaced with the supplementary V-tie developed by Yang et al. Additionally, a bolting technique, which combines steel plates, bolts, and nuts, was applied to the PLCSW wall-to-base connection. The behavior of these specimens was compared with the flexural behavior of conventional precast concrete shear walls (PCSW) connected via the spliced sleeve technique. Eight PCSW specimens with different crossties (supplementary V-ties or conventional reinforcing crossties) were prepared and wall-to-base connection techniques (bolting or spliced sleeve connections) applied. All specimens were tested under constant axial load and cyclic lateral loads. The ductility performance of PCSW was verified through a comparative analysis of the displacement ductility ratio and work damage index between the PCSW with supplementary V-ties and those with conventional reinforcing crossties. The ductility performance of PCSW utilizing supplementary V-ties and the bolting technique exhibited superior ductile performance resulting in a high work damage index, which was 1.22 times higher than that of the PCSW with conventional reinforcing crossties. Meanwhile, even though the shear wall specimens connected via the spliced sleeve technique were produced with normal-weight aggregate concrete, their work damage indices were slightly lower than those of the specimens utilizing conventional reinforcing crossties and the bolting technique. Consequently, the PCSWs with the spliced sleeve did not satisfy the seismic connection performance requirements specified in NEHRP, whereas the precast sand-lightweight aggregate concrete shear walls with supplementary V-ties utilizing the bolting technique satisfied the requirements. Therefore, the ductility and seismic connection performances of PCSWs with a complex detail arrangement of the boundary element can be effectively improved by using a supplementary V-tie and applying bolting techniques.