Abstract
Concrete shear strength for elements without shear reinforcement and longitudinally reinforced with FiberReinforced Polymer (FRP) bars is considered one of the critical issues that has been enormously estimated by many researchers as well as different code provisions. The implementation of various design codes for the estimation using similar input parameters observes the broad predictive spectrum of shear strength for FRP-reinforced members without stirrups. The element cross-section width and effective depth, the ratio of shear span to effective depth, concrete compressive strength, FRP-reinforcement ratio, and FRP-modulus of elasticity are mostly used as input parameters in various standards to predict the shear strength. This paper focuses on evaluating the efficiency of predicting equations used in different code provisions to estimate the shear strength compared to the nominal shear test-results of 501 tested samples collected from different literatures. An analytical study was conducted to determine the influence of each input parameter on the shear capacity as a pre-step to improve the efficiency of different code provisions when used at specific range of input parameters to predict the shear strength of members reinforced with longitudinal FRP bars. An optimized model was proposed based on refining of the Canadian Standard Association (CSA S806-12) formula and numerical analysis. The study concluded that the CSA S806-12 formula has high efficiency for predicting shear strength of FRP-reinforced members without stirrups. While both the American Concrete Institute (ACI 440.1R15) and the American Association of State and Highway Transportation Officials' (AASHTO LRFD-17) are significantly conservative in predicting shear capacity for these members. The proposed model's performance was found to be considerably higher as compared to the CSA S806-12 formula and other studied code provisions.