Prediction of shear behavior of steel fiber-reinforced rubberized concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars

Abstract

A combination of fiber-reinforced polymer (FRP) reinforcing bars and steel fibers can be employed in locations of a structure with reinforcement congestion instead of the conventional combination of steel rebars and stirrups. In this study, first, the shear performance of the FRP bar-reinforced concrete beams containing steel fibers and crumb tire rubber without shear reinforcement was evaluated, and then an analytical model was proposed to predict their shear capacity and achieve a relationship between the first cracking moment and the shear capacity. Furthermore, an empirical equation was derived from the experimental data of 30 beams of the present research together with a database extracted from the results reported in other research to calculate the share of concrete in the shear capacity of this type of beam. Through evaluating the proposed equation against those given by different codes and those developed by other researchers, it was revealed that most existing shear strength prediction equations give an underestimated value for this parameter in beams having FRP reinforcing bars, while the present equation provides more accurate results. These results make the proposed model suitable for accurately designing FRP bar-embedded concrete beams containing steel fibers and crumb tire rubber.