Cyclic response of FRP-to-concrete adhesive joints: effect of the shape of bond-slip model

Although the strengthening of reinforced concrete (RC) structures using externally bonded fiber-reinforced polymers (FRPs) have been widely accepted as an excellent technical solution for structural strengthening, only few studies have been conducted to understand and predict the behaviour of FRP-to-concrete bonded joints under cyclic loadings. This paper summarizes the results of a theoretical study aimed at investigating the effect of the shape of bond-slip models on the behaviour of the FRP-to-concrete bonded interfaces under cyclic loading. Two bond-slip model shapes, one with a linear descending branch and another with an exponential descending branch were used in this study. Evolution of damage for each bond-slip model was defined using the existing test data on Carbon FRP (CFRP)-to-concrete bonded joints under cyclic loading. These bond-slip models were then used to predict the behaviour of a CFRP-to-concrete bond joint subjected to cyclic loading. The results are then compared with the experimental results from a CFRP-to-concrete single shear pull off test under cyclic loading