Temperature-dependent debonding behavior of adhesively bonded CFRP-UHPC interface

The adhesively bonded structure, comprising carbon fiber-reinforced polymer (CFRP) and ultra-highperformance concrete (UHPC), enhances structural strength while reducing brittleness and strain softening behavior. However, the adhesively bonded structure is inevitably influenced by temperature variations throughout its service life. When the adhesive layer's temperature surpasses the glass transition temperature (Tg), significant damage occurs to the bond layer joint. To investigate the debonding behavior of the CFRP-UHPC interface at various temperatures, a series of three-point-bending tests were conducted at room temperature, 120 %Tg, 150 %Tg, and 160 %Tg. This study introduced a temperature degradation factor, employing a proposed maximum load capacity prediction formula to adjust both the test results and data from other researchers. By adjusting the cohesion parameters with the temperature degradation factor, a temperature-dependent mixedmode cohesive zone model (CZM) was developed. The model's validity was confirmed through finite element (FE) analysis, considering two distinct experimental scenarios. The paper concludes that the proposed model effectively simulates interface debonding behavior across varying temperatures.