Digital-image based performance analysis of CFRP-concrete interface bond under anchorage

This study investigated the bonding performance of Carbon fiber reinforced polymer (CFRP)-reinforced concrete interface under anchorage. The effect of positive compressive stress on the bonding performance of the interface was analysed using a single-sided shear test of the interface. The strain distribution on the CFRP surface during interface debonding was obtained using digital image technology. The shear-stress transfer law of the CFRPconcrete interface under anchorage was analyzed, and the bond-slip curve of the interface was obtained. Results showed that the increase in interfacial compressive stress improves the interfacial bearing capacity and slip behavior. After the interfacial compressive stress increases to a certain extent, the maximum strain of the CFRP specimens does not change with the positive stress. The principal model of bond slip in the anchorage zone under the anchoring action of the compressive steel plate was obtained; the models were tested and found to be consistent with the test results. The analytical solutions of the characteristic points of the interfacial load-slip curve in the anchorage zone under positive pressure were compared with the experimental values to prove the reliability of the fitted bond-slip intrinsic model.