Fatigue Damage Modeling of CFRP Strengthened Reinforced Concrete Beams

Improvement in the short-term behavior of deficient reinforced concrete (RC) beams is very well known through extensive testing of reinforced concrete beams strengthened by externally bonded carbon fiber reinforced polymer (CFRP) strips. However, long-term performance of such beams needs to be assessed before the method can gain full acceptance. Modeling of the overall system of CFRP strengthened RC beams requires modeling of the individual components that ultimately leads to failure i.e., concrete, CFRP and concrete-CFRP interface. Component elasto-damage constitutive models are developed for concrete crushing, CFRP plate rupture and concrete-CFRP interface failure, calibrated by data from both suitably designed experiments and from experiments reported in literature, and are utilized to investigate the low cycle fatigue behavior of reinforced concrete beams strengthened by CFRP strips. The predictive ability of the models is tested by comparison to data from two different beam strengthening schemes i.e., with end anchorage and without end anchorage.