Concrete-Filled Multicellular Steel-Tube Shear Walls with FRP Tubes Embedded in CFST: Concept and Seismic Performance

Abstract

In this study, a new composite shear wall is proposed, which consists of fiber-reinforced polymer (FRP)-confined concrete cores embedded in the concrete-filled steel tubular (CFST) columns as boundary elements of concrete-filled multicellular steel tube shear walls (MCSTWs). In order to study the seismic performance of this new composite shear wall, the following five different shear-wall specimens were designed and tested under constant axial load and cyclic lateral loading: (1) two reinforced concrete (RC) shear walls with glass FRP (GFRP) tube-enhanced CFST boundary elements; (2) an MCSTW with only CFST columns as boundary elements; and (3) two MCSTWs with FRP-confined concrete cores embedded in CFST columns as boundary elements. The failure modes, hysteretic performance, skeleton curves, strength and stiffness degradation, energy dissipation capacity, and deformation characteristics of the specimens were compared and discussed based on the test results. The results show that the proposed shear wall has a better seismic performance than the RC shear wall with GFRP tube-enhanced CFST boundary elements, such as a higher energy dissipation capacity and a more gradual strength degradation. For MCSTWs, incorporating a GFRP tube in the CFST boundary leads to a higher energy dissipation capacity, a higher load-carrying capacity, more gradual degradation of strength and stiffness. It can be concluded that the newly proposed shear walls have excellent seismic performance and are well-suited for application in high-rise buildings and other structures where the demand for seismic resistance is high.