Experimental Study On Interface Characteristics Between CFRP And Concrete

Reinforced polymer fiber(FRP) is a new type of building material, which is widely concerned in the field of architectural engineering because of its advantages such as light weight, high strength and corrosion resistance. At present, FRP is used in the building structure combination, which is formed a unified force of the system through composing of FRP and concrete by epoxy resin. In this system, the failure mode is often caused by the failure of the bond slip, which is brittle failure, and there is no obvious symptom. And in this stituation the strain on the FRP is at a low level, and the failure of the strip will result in the decrease of the adhesive property and the waste of material. In order to predict the debonding failure of FRP- concrete, the interface bonding property of concrete must be understood.In this paper, the interfacial bonding properties of CFRP- concrete specimens were studied by means of single shear test on different bond length, width of plate, thickness of plate, bonding method and the effect of colloid curing period. The experimental basis is provided for the research and design of FRP reinforced concrete members. The main content and work of this paper are as follows:(1) The new optical measurement method of digital image correlation method measurement of FRP- concrete test pieces of the whole displacement, which using smoothing and fitting method has been interface bond slip relationship. Research results show that:compared with the traditional electrical measurement method and digital image correlation method can obtain more comprehensive displacement data; traditional electrometric method measured data are compared, the test methods and data processing methods are found to have adequate reliability.(2)In order to test supporting optical method and solve simple shear tests are easy to be eccentric, this paper developed a manual double acting perforation type hydraulic jack, a special positioning clamp, a lifting car series device. Advantages of the device is controlling the loading rate, recording optical displacement data timely, and managed to avoid the eccentric problem existing in the process of installation and loading, so as to ensure the smooth conduct of the test.(3) By a single shear test, utilization, residual friction(rate), the average bond force and failure modes,FRP- concrete interfacial strain distribution, the interface should force transfer,interfacial slip and the evolution rule of the community bonding surface, slip mechanism, is presented by considering the bond slip model under the influence of the parameters under the influence of the parameters of the limit load and slab is analyzed. The experimental results show that the external plaster are in good agreement with the existing bilinear bond slipmodel, and the embedded data are in good agreement with the existing exponential softening bond slip model.(4) The establishment of the FRP concrete strength model based on the theory of linear elasticity. The characteristics of the model is contains the corresponding bond slip relationship,the ultimate load of the experimental values and theoretical values are compared, once again proved the external plaster suit for the bilinear bond slip model and the embedded apply with exponential softening bond slip model.