Numerical study of hybrid GFRP-steel reinforced concrete shear walls and SFRC walls

Experimental results show that concrete shear walls reinforced with a hybrid scheme of steel and fiber-reinforced polymer (FRP) bars are able to achieve similar strength, stiffness and ductility to the walls constructed of conventional steel-reinforced concrete (RC). The elastic response of the FRP bars provides self-centering capacity to the system and mitigates the post-yield strength deterioration observed in the typical hysteretic response of RC walls, while the steel reinforcement provides ductility and energy dissipation capacity. Evidently, adoption of this innovative type of wall in construction requires a better understanding of performance of the hybrid system at the material and system levels, both through experimental testing and development of reliable numerical models. In this study, the finite-element analysis model developed by the authors is used to conduct a comprehensive parametric study on hybrid GFRP-steel reinforced shear walls. First, the validated model is used to address some other design aspects of tested specimens such as presence of axial load and arrangement of GFRP bars. Next, the reliability of the section analysis based on CSA A23.3-14 code for design of conventional and hybrid squat walls are investigated. The self-centering and economic aspects of design of hybrid GFRP-steel reinforced walls are also addressed. Using the analysis model, a promising structural application of SFRC (steel fiber-reinforced concrete) shear walls is also proposed. Findings of this study can assist practitioners with a more reliable and convenient shear wall design.