Analysis of the fatigue behavior of reinforced concrete beams strengthened in flexure with fiber reinforced polymer laminates

This paper presents an analytical study on the fatigue response of reinforced concrete beams strengthened with fiber reinforced polymers (FRP). The study gathers the experimental results from the international literature and from authors' experiments and investigates the critical parameters that affect fatigue performance of reinforced concrete (RC) beams. A new analytical model is proposed for predicting the fatigue life of FRP strengthened RC beams. The parameters used are the maximum stress of tensile steel (σmax) to the yielding strength (fy) ratio, as well as the axial rigidity of longitudinal steel (ks) and FRP (kf) reinforcement. The predictions of the proposed model are compared against the experimental results as well as against the predictions of fatigue models in the literature.