Seismic Performance of SFRC Shear Walls with Window Opening and the Substitution Effect for Steel Bars

Shear walls are important vertical and lateral bearing element in structures. While shear walls with openings are fragile due to stress concentration and the quasi-brittle behavior of concrete in tension. Therefore, additional strengthening rebars are required for the shear walls with openings. However, it aggravates the problem of dense reinforcement which increases the steel cage manufacturing and concrete compaction problem and still lacks countermeasures against concrete damage and cracking. To reduce the rebar demand and improve the damage tolerance of squat reinforced concrete (RC) shear walls with openings, an optimized steel-fiber-reinforced concrete (SFRC) was adopted to understand the seismic performance by cyclical loading test. The tested specimens included a plain RC shear wall without strengthening bar around the opening (for comparison), an SFRC shear wall, and an SFRC shear wall with a reduced distributed steel bar. This paper mainly studies the effect of using SFRC to improve the seismic performance of the open shear wall and to replace the reinforcement around the opening and the shear reinforcement. The hysteresis curves, skeleton curves, stiffness degradation, bearing capacity degradation and energy dissipation of the specimens were analyzed. The results show that the failure can be delayed and relieved, the deformation capacity and energy dissipation can considerably improve, and rebars can be partially replaced by using SFRC.