Experimental Study On Bond Behavior Of Interfaces Between Concrete And End-anchored CFRP Sheets

In recent years, with the increasing investment of rehabilitation for concrete structures, strengthening structures using carbon fiber reinforced polymer (CFRP) is widely applied in civil engineering. CFRP material possesses many good performances such as lightness in weight, high strength and high corrosion resistance. But the anchor in reinforced concrete structure strengthened by externally bonding CFRP can be debonding easily, in which case the CFRP may not make full use of the strength of materials. Given this situation, this research uses a self-locked CFRP anchor device invented by Professor Chaoyang Zhou at Central South University and a double shear test to understand the interface mechanical characteristic between CFRP and concrete. The main work and results are summarized as follows:1. Considering the effect of end anchorage, this thesis studies on theoretical derivation of interface bonding shear stress distribution, and a calculation formula is given here.2. Through the experiment, it is found that the ultimate bearing capacity of the member with the end anchorage increases compared with the traditional bonding ways, and the ductility of the specimen improved as well. Therefore, it illustrates that the end-anchored system is reliable.3. Observed the shear failure process and the failure pattern, and then analyzed the interface bonding failure mechanism. Furthermore, the influences of bonding length, bonding width on the ultimate bearing capacity were investigated.4. Through analysis of experimental results, the evolution laws of interfacial shear stress and the bond stress-slippage curves are obtained. The experimental results are in a good agreement with the calculated ones. It shows that the calculation formula could be a reference for research.