Study On Bonding Fatigue Performance Of CFRP Reinforced Concrete Structures

Carbon Fiber Reinforced Polymer(CFRP) reinforcement is new heating technology in structure strengthening nowadays. Due to its favorable features of high strength, light weight, corrosion resistance and convenient construction etc, carbon fiber composite materials have became to the constant focus for study and analysis by scientists and engineers. When it's utilized in strengthening concrete structures, CFRP is wrapped in resin bonding, and firmly attached to the tension zone of concrete, bearing shearing force transmitting through resin bonding slayer caused by external force. Since the CFRP's effect on concrete structure lies in the performance of resin bonding interface, it is critical for researchers to conduct mechanical performance of the bonding slayer. This article carries out experiments on static loads and fatigue performance of the bonding slayers between CFRP and concrete by presenting a twin-shear specimen, leading to experimental studies as well as theoretical analysis, the working procedure lies as follow:(1) Static Loads experiments are conducted by using two different types of resin bondings in strengthening concrete specimen with CFRP, analyzing deveplopments of stress and strain within the bonding interface, interfacial damages variating process and ultimate bearing capacity of different resin bondings of the bonding interface. Use two types of interface theoretical models to simulate the interface of the ultimate bearing capacity, compared with the theoretical results and test results, found the shear stiffness should be considered when calculate ultimate bearing capacity of the interface.(2) The fatigue loading experiment explores the fatigue properties of bonding slayer, preliminary discusses the stress and strain distribution of bonding interface between CFPR and concrete under fatigue loading, the generating and developing models of depriving crack and fatigue damage accumulations.(3) Considering the influence of different bonding length of CFPR and thickness of CFPR's resin bonding on the fatigue performance of the interface, this article compares and analyzes the difference of the fatigue damage speed and damage accumulation along the CFRP under varying parameters, determining the influence of various parameters on fatigue performance of the bonding interface.(4) Utilizing ANSYS software to establish a simple finite element model, Conducted a simulation analysis of the test with this model. The analysis results proved to coincide with the experimental results.