Effect of reinforcement ratios on shear behavior of concrete beams strengthened with CFRP sheets

Carbon fiber reinforcement polymer (CFRP) sheets are the most commonly materials that are used to strengthen reinforced concrete members due to high strength-to-weight ratio, excellent mechanical strength, and good fatigue properties. In this research program seven reinforced concrete beams were tested under four points loading with different shear span-to-depth ratios avd, longitudinal and vertical reinforcement ratios. A numerical analysis using ANSYS software program was done by modeling 27 reinforced concrete beams with and without CFRP sheets. The beam dimensions, concrete strength, strengthening configuration of the CFRP sheets (full wrapped, U shape, and side bonding), and FRP thickness were considered as the main parameters of the numerical analysis. A comparison between the finite element (FE) results and the ACI standard code demonstrated the validity of the computational models in capturing the structural response of FRP contribution with variation varied from (10-16)%, (12-20)% and (13-19)% for full wrapping, U-jacketing, and side bonding, respectively. The finite element models were able to accurately predict the load capacities for the simulated RC beams strengthened in shear with CFRP composites. The results obtained using ANSYS finite element are relatively identical to the experimental ones, showing reasonable agreement with variation not more than 5% in all the specimens.