Numerical Study on Moment Redistribution in Continuous Concrete Beams Reinforced with FRP Bars

In harsh environments, steel rebars in concrete corrode; therefore, fiber-reinforced polymer (FRP) bars should be considered due to their non-corrosive nature. Moment distribution in continuous FRP-reinforced concrete beams is prohibited by the design code due to the insufficient ductility of FRP bars. However, studies have shown that FRP-reinforced concrete continuous beams exhibit considerable redistribution of moment. In this study, a nonlinear finite element model of a continuous concrete beam reinforced with basalt FRP bars is developed to numerically investigate the effect of reinforcement configuration on the redistribution of moment. The models exhibit a considerable level of moment redistribution at the internal support (hogging zone) and midspan (sagging zone). When the amount of tensile reinforcement in the sagging zone increases compared to the hogging zone, the moment redistribution at the internal support (hogging zone) increases significantly. Therefore, it is not justified to completely overlook the redistribution of moment in the design of FRP RC continuous beams.