Debonding Failure in RC Beams Strengthened in Flexure with CFRP Strips: Mitigation Using CFRP U-jackets

Ke Y., Zhang S. S., Nie X. F.

10th International Conference on Fibre-Reinforced Polymer (FRP) Composites in Civil Engineering (CICE), İstanbul, Turkey, 8 - 10 December 2021, vol.198, pp.1677-1685 identifier identifier

  • Publication Type: Conference Paper / Full Text
  • Volume: 198
  • Doi Number: 10.1007/978-3-030-88166-5_146
  • City: İstanbul
  • Country: Turkey
  • Page Numbers: pp.1677-1685
  • Keywords: Near-surface mounted (NSM), Fiber-reinforced polymer (FRP), Flexural strengthening, Debonding, FRP U-jacket, Reinforced concrete (RC) beams
  • Istanbul Technical University Affiliated: No


The excellent performance of near-surface mounted (NSM) fiber-reinforced polymer (FRP) method in enhancing the flexural capacity of reinforced concrete (RC) beams has been proved by abundant experimental studies over the last two decades. However, premature debonding of FRP in NSM FRP flexurally-strengthened RC beams was still frequently observed, which significantly limited the utilization of expensive FRP materials. To delay/suppress debonding failures and further improve the beam performances, the use of FRP U-jackets as the anchoring measure for NSM reinforcement in the strengthened beam is an attractive approach. Although there have been a number of relevant experimental studies, tests on the large-scale RC beams are still very limited. Against this background, an experimental study consisting of 4 large-scale RC beams strengthened with NSM CFRP strips was carried out to investigate the effect of CFRP U-jackets on the flexural behavior of such strengthened beams. Test results show that the CFRP U-jackets arranged at the ends of NSM FRP strip can effectively suppress the end concrete cover separation failure and thus enhance the load and deflection capacities of the NSM FRP strengthened beams.