Research on Bond Behavior of Corroded Reinforcing Bar in Concrete Wrapped with Carbon Fiber Reinforced Polymer Sheets

Abstract

Right evaluation of the bond behavior between corroded reinforcing bar and concrete wrapped with fiber reinforced polymers (FRPs) is a chief problem to confirm the effect of FRP confinement. the pullout tests on 96 test specimens were conducted to study the effect of Carbon FRP (CFRP) confinement on the bond behavior between corroded reinforcing bar and concrete, test variables included reinforcing bar types, concrete covers, degrees of corrosion and CFRP confinements. The test results show that CFRP confinements can make the failure mode of deformed reinforcing bar specimens change from concrete splitting to bar pullout. When the degree of corrosion is less than 5%, the ultimate bond strength of corroded specimens increases by 5%~7%; and the CFRP confinement has less contribution on the ultimate bond strength, but it is effective on slowing down the bond stress descending speed and maintaining the bond strength. When the degree of corrosion is higher than 5%, the ultimate bond strength of corroded specimens drops gradually with the increase of degree of corrosion.