Effect of fiber-reinforced polymer strengthening on moment redistribution in reinforced concrete members

A reduction in ductility after applying fiber-reinforced polymer (FRP) materials to strengthen existing reinforced concrete (RC) structures has been reported in previous research. Consequently, design standards worldwide employ cautious guidance for the design of FRP strengthening systems, which limits the exploitation of moment redistribution in continuous structures. This paper aims to experimentally investigate and quantify moment redistribution within FRP-strengthened continuous RC members. Innovative tests conducted on four continuous slabs and six continuous T-section beams are described, and the findings are presented and discussed. The main variables in each group include strengthening configurations and anchorage schemes. All strengthened specimens failed through FRP debonding at different ultimate strains. Significantly, the experiments confirmed that there should be no artificial restriction placed on allowing moment redistribution into strengthened zones. Additionally, moment redistribution out of strengthened zones was also achieved and quantified