Abstract:
The bond interface between steel and carbon fiber reinforced polymer (CFRP) plate is the weak part of steel structure strengthened by CFRP at high temperature. In order to explore the influence of temperature on the adhesive mechanics of steel to CFRP joints, some double lapped joint specimens were manufactured, and static tensile tests were conducted with three types of adhesives under four kinds of temperatures, which include 25℃, 55℃, 70℃ and 90℃. Thereafter, the failure modes, the load-displacement relationships, the strain distribution of CFRP plates and the bond-slip relationship of specimens were explored respectively. The results show that the failure modes of specimens are more related to the type of adhesive, when the temperature is lower than 55℃; but the failure modes of different adhesives are similar, and all the CFRP plates occur fracture when the temperature is higher than 70℃. The influence of temperature on the capacity of bond specimens is different, which depends on the type of epoxy resin adhesive. The capacities of HJY-4105 high toughness epoxy structural adhesive (HJY adhesive) specimens increase with the temperature increasing, and the capacities of LICA-100A/B epoxy structural adhesive (LICA adhesive) specimens are instability under different temperatures, and Sikadur-30 CN two-component epoxy structure reinforced carbon plate adhesive (SIKA30 adhesive) specimens have the highest capacity at 55℃. The shear strength of adhesive layer, the peak shear stress of interface and the shear stiffness decrease as the temperature increasing, but the ultimate tensile strength has no concern with the peak shear stress. Temperature has a significant effect on the bond-slip relationship, the ductility of the bond-slip constitutive of HJY adhesive increases with the increase of temperature, and the failure mode changes from brittle failure to ductile failure. The research shows that the reasonable high temperature resistant adhesive applied to steel structure reinforcement can adapt to the adverse effects of the natural high temperature environment.