Analytical models of the whole debonding process of CFRP-to-concrete interface with end anchorage

Abstract:

End anchorage is an effective measure to control the debonding of CFRP-to-concrete bond interface and improve the interface bearing capacity. To study the debonding process of CFRP-to-concrete interface with end anchorage, the exponential bond-slip model was introduced to establish analytical models. The distribution expressions of interfacial slip, bond stress, CFRP axial strain and stress were obtained. The proposed models were well verified by experimental results. Based on the analytical models, the calculation methods of the maximum bond force, effective bond length, and debonding load were established, and the influence of different bond lengths on the mechanical behaviors of the interface during the debonding process was analyzed. Results show that the effective bond length of the bonded interface with end anchorage was longer than that of the external bonded interface. The debonding load decreased with the increase of the bond length, approaching the ultimate bearing capacity of the external bonded interface. When the bond length was long, there was little difference between the debonding load and the maximum bond force, and the end anchoring force was small. When the bond length was short, the end anchorage would bear the load earlier, and the debonding load was close to the CFRP breaking load.