Static and Fatigue Bond Assessment of CFRP-Concrete Joints Extracted from 60-Year-Old Bridge Girders after 7 Years of service

This paper investigates the bond behavior under static and fatigue loading of a carbon fiber reinforced polymer (CFRP) external strengthening system applied to 60-year-old bridge girders after exposure to 7 years real service conditions. The experimental results on CFRP-concrete joints were compared with the results of control tests carried out on new samples prepared in the laboratory. The results indicate that the bond strength of the CFRP-concrete joints extracted from the bridge was decreased by 38.8 % in comparison with the reference samples. In addition, it was revealed that the failure mode changed from cohesive failure in the concrete to failure of the adhesive/concrete interface and cohesive failure of the adhesive layer after exposure to service conditions. On the other hand, fatigue test results showed that the CFRP-concrete joints extracted from the bridge showed a significant degradation in fatigue life and interfacial bond stiffness compared to the control samples.