Experimental Study on Seismic Behavior of Lightweight Concrete-Filled Cold-Formed Steel Shear Walls Strengthened Using Horizontal Reinforcement

To improve the seismic behavior and thermal property of traditional cold-formed steel (CFS) walls for satisfying the requirements multistory structures, a new type of fiber-reinforced lightweight concrete (FLC)-filled CFS shear wall strengthened using horizontal reinforcement is proposed in this study. Four full-scale specimens were tested under reversed cyclic loading to investigate the seismic behavior, including failure mode, hysteresis curve, shear capacity, deformability, stiffness degradation, and energy-dissipating capacity. Test results indicated that the restrictive effect of FLC on the studs and its diagonal-bracing effect improved the wall's hysteretic behavior, making the wall exhibit the ductile shear failure. Increasing the wall thickness increased the shear strength, lateral stiffness, and energy-dissipating capacity, whereas installing the coupling-section interior studs enhanced the ductility. Finally, a simplified strut-and-tie model was proposed to evaluate the shear capability of FLC-filled walls, and the calculated values exhibited good agreement with the test results, but the further verification is required.