DEBONDING ALONG A SOFTENING FRP-CONCRETE INTERFACE OF PLATED BEAMS

In order to investigate the debonding process of the interface between the FRP(fiber reinforced poly- mer) and the concrete for the FRP strenthening structure, both the strengthened beam and the strengthening FRP are modeled as two linearly elastic Euler-Bernoulli beams bonded together through a thin adhesive layer. For the FRP-concrete structure, there are two types of debonding failures: The plate end debonding and the intermediate crack (IC) induced debonding. For the second type debonding failures in the FRP-concrete bonded joint model where the FRP plate is subject to tension at both ends, the debonding process of the FRP-concrete interface is discussed in detail, and the closed-form solutions of the bond slip, the interface shear stress, and the axial force of the FRP in different stages are obtained. The results of theoretical analyses are confirmed by experiments. Parametric studies are further carried out to investigate the effect of the thickness of the adhesive layer and the bond length on the bond behavior of the FRP-concrete interface.