SEISMIC PERFORMANCE OF SQUAT RC SHEAR WALLS WITH DIFFERENT FRP HORIZONTAL REINFORCEMENT

Abstract

This study investigates the influence of fiber-reinforced polymer (FRP) types used as horizontal reinforcement on the seismic performance of squat reinforced concrete (RC) shear walls. The specimens had rectangular cross-sections, vertical steel reinforcement, and an aspect ratio of 1.0. Four shear wall specimens were designed in accordance with ACI 440.11-22 and ACI 318-25 and tested under cyclic lateral loading. The specimens comprised a conventional steel-reinforced wall (SBSW), a CFRP bar-reinforced wall (CBSW), a GFRP bar-reinforced wall (GBSW), and a CFRP grid-reinforced wall (CGSW). The overall performance was evaluated in terms of crack patterns, failure modes, load–drift response, stiffness, energy dissipation. All walls exhibited typical shear failure, but the final failure modes varied with the type of horizontal reinforcement: walls with steel or FRP bars failed in diagonal compression, whereas the CFRP grid wall failed in diagonal tension. Squat shear walls with horizontal GFRP or CFRP bars achieved comparable maximum strength and deformation capacity to the conventional RC wall, while the CFRP grid reinforced shear wall showed more abrupt strength degradation after the peak load. Compared to the RC shear wall specimen, acceptable levels of energy dissipation and stiffness degradation were observed in FRP-reinforced walls, along with narrower residual crack widths due to the elastic properties of FRP reinforcement. It is concluded that squat shear walls with horizontal FRP reinforcement, when designed according to ACI 440.11 and ACI 318, can achieve seismic performance levels like conventional RC walls in terms of strength, stiffness, and energy dissipation.