Influence of Axial Load Ratio on the Seismic Behavior of Steel Fiber–Reinforced Concrete Composite Shear Walls

Abstract

The seismic behavior of shear walls is significantly influenced by the axial load ratio (ALR), and a maximum ALR limit is generally specified by current seismic design code. To achieve improved performance under a high axial load ratio, steel fiber–reinforced concrete (SFRC) composite shear walls with improved lateral bearing and deformation capacity under high ALRs were developed in this work. Owing to their excellent seismic performance, SFRC composite shear walls are recommended for use in earthquake-prone regions. However, current specifications of ALR may lead to considerable material waste associated with SFRC composite shear walls. To evaluate the influence of different ALRs on seismic performance, three SFRC composite shear walls (ALR=0.36–0.68) were designed for testing under quasi-static cyclically increasing lateral loads and a constant vertical load until failure. The results revealed that the SFRC composite shear wall exhibits good seismic performance under high ALR. In addition, (1) the bearing capacity increased significantly and rigidity degradation was gradual; (2) the proportion of shear deformation increased; and (3) the development of bottom curvature decreased with increasing ALR. Furthermore, the applicability of the current code to the ultimate lateral bearing capacity is discussed.