Experimental Behavior of UHPC Shear Walls with Hybrid Reinforcement of CFRP and Steel Bars under Lateral Cyclic Load

Abstract

A new kind of structural system, ultrahigh-performance concrete (UHPC) shear walls reinforced with carbon fiber–reinforced polymer (CFRP) and steel bars, is proposed in this study. CFRP bars were used in the web region of the shear walls to obtain favorable self-centering capacity, and steel bars in the boundary element were used to achieve high energy-dissipation capacity. Quasi-static tests of four shear-wall specimens were conducted. The self-centering capacity, energy-dissipation capacity, and strength and stiffness degradation of the specimens were analyzed. The tested UHPC shear walls exhibited favorable self-centering and good energy-dissipation capacity. The experimental results showed that the stress in the CFRP bars is the key factor to determine the effectiveness of CFRP bars. The authors proposed a formula for calculating the proper location of CFRP bars and a design axial-load ratio limit for UHPC shear walls with hybrid CFRP/steel reinforcement bars.