Mechanical Properties Research Of CFRP- Concrete Interface Under Sulfate Attack

With the wide application of Fiber Reinforced Polymer(FRP for short) reinforced concrete structure technology in the field of civil engineering, the durability of FRP reinforced concrete structure has caused great concern of scholars. Among the fiber reinforced polymers, CFRP has a wider range of application. Although the CFRP material can resist such structures often encountered: the corrosive effect of acid, alkali, salt, etc., with good durability, but the durability factor CFRP reinforced concrete structures affected by many, not just their own by CFRP material wherein the binder resin and durability of concrete durability of the interface can also have a significant impact. Many studies have shown the merits of CFRP reinforced structural durability depends on the durability of CFRP-concrete interface. In practical engineering, the various erosion environment will affect the durability of CFRPconcrete interface, Sulfate attack which caused the deterioration of CFRP-concrete interface is a very important factor, So the discussion about mechanism of bond-slip on CFRP-concrete interface under sulfate attack has a very important scientific significance. In this paper, a double shear model was build to analysis the mechanism of bond-slip on CFRP-concrete interface under sulfate attack. The article mostly study underside contents:(1)Through the bond strength and interfacial adhesion model- slip model were analyzed, of which the bond strength model can only react ultimate bearing capacity of member of the force component can only be a more macroscopic description; and bonding-slip model is able to analyze each section and stress at different loading stages interface.(2)States scholars multiple interfacial bond- slip model for a more in-depth comparative analysis. Although each model are given a detailed calculation formula, but did not consider the effect of a variety of complex factors influence the interfacial properties under. Based on the existing bond- slip model analysis, based on the analysis of the original bilinear model of the interfacial bond under consideration of the role of sulfate attack- slip model.(3)Using numerical method, based on the analytical solution expression, for double shear model of CFRP- concrete interface numerical simulation, the situation of the load according to the changing rule of the strength of concrete under sulfate erosion, Analysis of sulfate attack on the interface of CFRP- concrete are discussed, such as load- displacement curve and ultimate load.(4)The interfacial behavior on CFRP-concrete interface has been simulated by ANSYS software. This paper mainly discusses different results calculated by two different modeling methods and finds the best modeling methods conforming to the actual situation. Then show the comparison between the elastic finite element analysis and the numerical simulation analysis.Based on the research of the interfacial behavior and the interfacial debonding on CFRP-concrete interface, reveals the mechanical properties and the debonding failure mechanism on the interface under sulfate attack, in order to provide theoretical basis for the application of strengthening concrete structures with CFRP.