Analytical and Parametric Studies on Flexural Performance of Reinforced Concrete Beams Strengthened by Fiber-Reinforced Geopolymer Composites

This paper presents an analytical method to predict the flexural performance of reinforced concrete (RC) beams strengthened by fiber-reinforced geopolymer composites (FRGC). In addition, a parametric study was performed to determine the effect of the thickness and tensile strength of the strengthening material on the moment, ductility, and energy absorption capacity of the composite beam. The proposed model adopts sectional strip discretization and incorporates the constitutive relationship of each component material. The strengthening configurations considered in the analysis include bottom, two-sided, and three-sided jackets. Four failure conditions were simulated to account for the original failure of the RC beam and are described in terms of the steel reinforcement ratio in the range of 0.87 to 2.29%. The result showed a good agreement between the predicted and experimental values and that the proposed analytical method can be used to predict the moment-curvature response. The parametric study revealed that the change in the moment and ductility value is more sensitive in the variation of FRGC thickness than the tensile strength regardless of the jacketing configurations and failure type of the unstrengthened beam.