Debonding Failures of Rc Beams Strengthened with Externally Bonded Frp Reinforcement: Behaviour and Modelling

Both the flexural and shear strengths of reinforced concrete (RC) beams can be substantially enhanced using externally bonded fibre reinforced polymer (FRP) composites. Failures of such FRP-strengthened RC beams often occur by debonding of the FRP plate from the RC beam in a number of forms. Despite numerous theoretical and experimental studies on debonding failures of FRP-strengthened RC beams, considerable uncertainty still exists with the understanding of the failure mechanisms and with the accurate prediction of debonding failure loads. This paper provides a summary of the author’s understanding of the subject largely based on the research of the authors and their co-workers. The paper addresses the following three issues: (a) classification of debonding failure modes; (c) mechanisms and processes of debonding failures; and (e) theoretical models for debonding failures. The information presented in this paper may serve as a useful basis for the future development of design provisions in design codes and guidelines.