Structural performance and corrosion resistance of fiber reinforced polymer wrapped steel reinforcing bars

Structural behavior and corrosion resistance of hybrid fiber reinforced polymer (FRP) wrapped steel bars is investigated for use in reinforced concrete structures. Experiments were conducted in the laboratory to assess the axial tensile capacity and corrosion resistance of the composite bars, and flexural behavior of beams reinforced with these hybrid bars. Data from short term and long-term corrosion experiments were used to evaluate the resistance to degradation provided by the FRP, including applied defects to determine any gain in corrosion resistance over standard epoxy-coated bars. Corrosion experiments are performed by placing bars with and without applied defects in an aggressive solution that mimics a concrete pore environment. Corrosion rates of standard epoxy-coated bars and hybrid carbon and glass FRP wrapped steel bars were compared considering the crevice corrosion at applied defects. In addition to their contributions to the strength capacity of steel bars confirmed by the tensile tests, FRP-wrapped steel reinforcing bars have high corrosion resistance. The overall behavior of beams reinforced with hybrid FRP-steel bars was similar to those reinforced with epoxy coated bars. During the experiments, no debonding was observed between the hybrid bars and concrete inside the beams before failure.