Flexural behaviour of RC members strengthened with FRCM: State-of-the-art and predictive formulas

The experimental and theoretical research on FRCM composites is still quite limited if compared with the amount of work carried out on fiber-reinforced polymer (FRP) systems. In addition, the knowledge gained on FRCMs so far has never been collected and reviewed in a systematic framework. This paper contributes to filling this gap by collecting and reviewing the main experimental research available in the literature on flexural strengthening of RC members with FRCM composites. A large database focused on the flexural behavior of strengthened RC beams is compiled. The experimental evidence is critically examined. Comparison within groups of tests of the database is made in terms of flexural capacity and failure modes. Key aspects of the design of the FRCM reinforcement are also analyzed and open issues for possible future research areas are pointed out. For Steel-FRCM systems, a predictive formula for the strain corresponding to the debonding of the external reinforcement is proposed.