Damage-Resistant Reinforced Concrete Low-Rise Walls with Hybrid GFRP-Steel Reinforcement and Steel Fibers

Fiber-reinforced polymer (FRP) bars and fiber-reinforced concrete (FRC) are composite materials that have found acceptance in current construction systems due to their high strength-to-weight ratio, durability, and ease of installation. This study presents an experimental and analytical study on the potential of these materials to improve the seismic behavior of low-rise shear walls. Two low-rise concrete shear walls with similar geometry were tested up to failure under pseudostatic lateral cyclic loads. The first wall was a steel-RC low-rise shear wall, compliant with seismic considerations of North American codes for structural reinforced concrete. The second was a steel fiber-reinforced concrete (SFRC) wall reinforced with a hybrid scheme of FRP-steel bars as flexural reinforcement. The FRP bars had the purpose of enhancing the self-centering capacity of the wall, while the SFRC helped to mitigate the damage experienced by the concrete. The goals were achieved reasonably in the testing phase. A finite-element analysis model for low-rise hybrid shear walls was developed and verified with experimental results. The analysis model is able to predict system performance variables with satisfactory accuracy for both walls, such as force-displacement relationship, stiffness, and energy dissipation. The experimental and analytical results show that the hybrid glass fiber-reinforced polymer (GFRP)-steel reinforced walls can achieve similar strength, stiffness, and ductility levels to RC construction while experiencing less residual displacements.