Probabilistic design equations for the shear capacity of RC members with FRP internal shear reinforcement

FRP reinforcement for concrete has been developed to replace steel in several applications, particularly in corrosion-prone RC structures. FRP rebars, generally, have a lower modulus of elasticity compared to steel, which leads to wider cracks and larger deflections. Furthermore, the FRP rebars have a low transverse stiffness and strength which are usually neglected. Consequently, the effectiveness of concrete contribution to shear capacity in terms of aggregate interlock and dowel action of the longitudinal rebars is lower for FRP-RC members respect to steel. Eurocode-like design equations for predicting the shear strength of FRP-RC members are herein suggested. Based on a database containing 129 flexural tests on RC beams strengthened with FRP stirrups performed in different research institutions across the world, a statistical calibration of Eurocode-like design equations for the shear capacity of RC beams with FRP shear reinforcement has been performed according to two alternative regression-based proposals and the EN 1990-procedure that is used as a benchmark.