Effect of end anchorage on bond behavior of CFRP-to-concrete interface subjected to temperature variation

Abstract:

To reveal the effect of additional end anchorage on the bond behavior of carbon fiber reinforced polymer (CFRP)-to-concrete interface, the debonding process model of CFRP-to-concrete bonded interface subjected to temperature variation was established by means of analytical theory. Based on the interfacial bonding theory and bi-linear bond-slip constitutive, a series of analytical models were deduced, including the distributions of interfacial slip, interfacial shear stress, and CFRP axial stress. The calculation models of load-slip curve and interfacial debonding load were also given. By comparing the experimental and numerical results, the correctness of the analytical models was verified, and parametric analysis was then carried out. Results show that compared with external bonded interface, the end anchorage increased the interfacial debonding load and effectively decreased the interfacial slip and shear stress caused by temperature variation. Besides, CFRP axial stress increased when subjected to the same temperature variation, which enhanced the strength utilization of the CFRP material. For CFRP-to-concrete bonded interface with end anchorage, the bearing capacity of the interface increased with increasing temperature before the temperature reached the glass transition temperature of adhesives. The decreasing temperature led to the premature interfacial debonding at the load end of the bonded interface, which reduced the interfacial bearing capacity. Further, when the thickness or modulus of the CFRP material increased, the effect of temperature variation on the bond behavior was more significant.