Prediction models of flexural behavior of concrete beams reinforced with FRP rebars

Five concrete beams reinforced with glass fiber reinforced polymer (GFRP) rebars were statically loaded under third-point flexure until failure. The development of cracks, the curvature in pure flexure zone and the deflection at mid-span were recorded during the test. Based on this, two series of approaches, i.e. the effective moment of inertia approach (EMOIA) and curvature approach (CA) which are used to predict the flexural deflection of concrete beams were evaluated. The evaluation indicates that all the selected EMOIA models only yield acceptable predictions of deflection development at rather early stage. As load level increases, the errors arise from EMOIA become more and more significant. The most desirable predictions of deflection at mid-span can be achieved by using complete curvature approach (CCA). However, CCA is too time-consuming to be applied in engineering practice. The simplified curvature approach (SCA) is found to be almost as accurate as CCA in predicting the development of sectional strains in pure flexure zone of the beams, and SCA seems to be little more accurate than the EMOIA models in predicting the deflection at mid-span.