New model for post-fatigue behaviour of CFRP to concrete bond interface in single shear

In this paper, a finite element model using ABAQUS 6.10-1 is developed to simulate the CFRP-to-concrete bonded joint behaviour in single shear pull-out tests. The model adopts the cohesive surface approach and the simulation results are checked against the authors' test results (monotonic and post-fatigue) in order to demonstrate the accuracy of the model. Parametric studies using the validated model were carried out to investigate the effects of varying the bond length, the thickness of FRP, the type of FRP, the concrete strength, and the bond width ratio. The results were then used to assess the various existing design code approaches for predicting the FRP-concrete bond behaviour. The post-fatigue numerical results indicate that the existing design code methods all have significant discrepancies. Based on the work conducted a simple and potentially more accurate model for predicting the debonding strain of CFRP plate in single shear is then presented.