Seismic behavior of a new type of precast concrete shear wall using UHPC connections at boundary elements

Abstract

Ultra-high Performance Concrete (UHPC) is an attractive choice for connecting Precast Concrete Shear Walls (PCSWs), because of its high bond strength with rebars allowing for reduced lapped rebar lengths and precision requirements. This paper proposes a new type of PCSW that uses UHPC connections only at the boundary elements, significantly streamlining the installation process of wall panels and improving construction efficiency. To evaluate its seismic behavior, a total of five walls comprising three PCSWs and two Cast-In-Place (CIP) walls were tested by cyclic loadings under both low and high axial loads. Similar failure modes characterized by bending-shear damage were captured in all five specimens. The proposed precast walls display 7.8%–8.1% greater bearing ability and 41.8% higher ductility in comparison to CIP counterparts. These precast walls also demonstrated superior energy dissipation ability, particularly under high axial loads. Following NEHRP, it was validated that the proposed precast walls using UHPC connections at boundary elements could be used in regions with high seismic activity. Moreover, the finite element (FE) models were developed, yielding simulated results that aligned reasonably with the experimental findings, and the parametric predictions were performed to further broaden the scope of experimental works.