Improving seismic performance of precast concrete shear walls through UHPC boundary connections

UHPC offers high bond strength with rebar, enabling shorter lap splices and lower construction precision for precast concrete shear walls (PCSWs). This paper innovatively proposes a PCSW structural system using UHPC exclusively in boundary connections, simplifying wall panel installation and improving construction efficiency. To evaluate its seismic performance, low-cycle reversed loading tests were conducted on eight full-scale specimens. Key indicators-failure modes, bearing capacity, ductility, energy dissipation, and stiffness degradation were systematically studied. The results showed that the main seismic performance indicators of the three UHPC-connected precast specimens were comparable to, and in some cases superior to, those of cast-in-place specimens. The UHPC connection zones enhanced the precast panels, delaying concrete failure at the wall foot. At the low axial compression ratio this resulted in higher ductility and energy dissipation, and at the high ratio the benefit was retained in the T-flange configuration. Thus, the proposed PCSWs with UHPC boundary connections exhibit excellent seismic performance and are suitable for promotion in seismic regions.