Analytical Prediction of Flexural Behavior of Concrete Beams Reinforced by FRP Bars

Abstract

An analytical model to predict the flexural strength and deformations in concrete beams reinforced with fiber reinforced plastic (FRP) bars is presented. It is based on the equilibrium of forces and compatibility of deformation. The model uses a more rational representation of the behavior of all composite constituents. It also accounts for the concrete tensile stresses, the variation of stresses, strains and curvature over the depth of the cross section and the length of the beam. The model predicts the moment-curvature, load-deflection, and load-strain of any of the composite constituents. The model predictions were checked against the experimental results of nine test beams reinforced with steel or FRP bars. The behavior of the concrete tested beams were characterized by their moment-curvature, load-strain in the reinforcement, and load-deflection response up to failure. The results indicate that the analytical model predicts the behavior of GFRP reinforced concrete beams with good accuracy. Furthermore, the accuracy of the model was checked by comparing its capacity prediction with that of a parallel model available in the literature based on measured data and reported by other researchers. Results of the comparison showed that the suggested model provided better prediction.