Mechanical Behavior Of CFRP-concrete Interface Under Sulfate Attack

The success of Carbon fiber reinforced composites (namely CFRP) reinforcedconcrete structure mainly depends on the bonding properties of interface betweenCFRP and concrete. The key of reinforcing technology lies in the interfacialproperties of CFRP-concrete. Harsh environment has a great influence on theinterfacial bonding properties of CFRP reinforced concrete structures, and will resultin the failure and degradation of its bonding properties. Therefore, the key ofassessing the durability of CFRP reinforced concrete structures is that the durability ofinterfacial bonding properties of CFRP reinforced concrete structures.So far, the discuss of the impact of salt erosion on interface bonding properties ofCFRP-concrete is mainly concentrated in the eastern sea (salt chlorine-based)environment, and lack of sulfate attack in cold and dry environment in Western area.As for as salt erosion is concerned, the chloride mainly corrode steels, sulfate mainlyoccurs physical and chemical changes with concrete, so sulfate has greater effect oninterfacial bonding properties of CFRP-concrete than chloride. In this paper, on thebasis of the latest research on bonding-slip relationship of sulfate attackCFRP-concrete interface, the mechanical behavior and debonding failure ofCFRP-concrete interface under sulfate attack are studied.First, on the basis of the latest research on bonding-slip relationship of sulfateattack CFRP-concrete interface, in order to predict the whole process of spread of theinterfacial shear stress and peel damage, the mechanical behavior and debondingfailure of CFRP-concrete interface under sulfate attack are contained.Secondly, according to the analytical expression deduced front, the effect ofCFRP bond length, CFRP stiffness and sulfate attack on the load-displacementcurves and ultimate load is researched, therefore the behavior of stress transfermechanism and interface crack expansion is explained.Finally, the entire destruction process is reproduced using finite element software(ANSYS) simulation, load-displacement curve under different bond length of CFRP,interfacial shear stress distribution and CFRP axial normal stress distribution arestudied, and it is analyzed comparatively with the numerical solution. Through theabove work, the whole process of the mechanical behavior and interfacial debondingproblem of CFRP-concrete interface under sulfate attack is understood to some extent,providing theoretical basis for CFRP reinforced concrete structures in cold and dryenvironment in western under sulfate attack.