Study On The Bond Performance Of The Interface Between Prestressed CFRP Plates And Concrete

It is prestressed CFRP plates strengthening technique that is combined with the advantages of bonding technology and strengthening technology,which has become the leading edge and hotspot in the research of structural reinforcement.However,whether the prestressed CFRP plates strengthen reinforced concrete technique can make a difference,that mainly depends on two aspects.On the one hand the effective exertion and maintainment of prestress,for the end of CFRP plates without reliable anchorage of prestressed carbon fiber plates strengthening technology may trigger big problems;Relatively speaking,for the end of prestress CFRP plates have reliable anchorage,the effective prestress can be preserved better;Then,the debonding failure of cohesiveness between CFRP plates and reinforced structures should try to avoid.For the end of prestressed CFRP plates with reliable anchorage,the distribution mechanism between CFRP plates and concrete is quite different from CFRP plates without reliable anchorage,such as whether the end can be avoided? How the central debond of CFRP plates caused by bending cracks or shear cracks evolve? So it is necessary to solve these new problems.In this paper,the reinforcement experiments were designed,the distribution and variation principles of bonding stress were explored and the detail results as follows:(1)In the whole loading process,there was no peeling phenomenon founded in the end of CFRP plates(including double layer of prestressed CFRP plates),and the result demonstrated that the end of CFRP plates with reliable anchorage can overcome peeling failure of the end completely.(2)The test proved that due to the end of CFRP plates set up the reliable anchorage(remarkable anchorage capacity of wave-shaped-gear-grip and prominent force transfer property of anchor pedestal),in the end of CFRP plates(near the end of the anchor),relatively speaking,in spite of the increasing tension in the CFRP plates,bonding shear stress is always in a state of low.The test results show that the reliable anchorage of the end of CFRP plates can reduce the shear stress of the end,and can explain that the end anchorage can avoid peeling failures in the end of CFRP plates.(3)In this paper,the bonding mechanism,debonding mechanism and peeling failures of the interface between CFRP plates and concrete were analyzed by the way of analyzing or testing the bonding and debonding phenomenon between the central part of CFRP plates and concrete;The finite element models of Prestressed CFRP plates strengthen reinforced concrete T-beams were established and the distribution and variation of interfacial shear stress were studied by comparing the experimental data.Because of uneven cracks and the influence of process procedures,the actual shear stress is complex,and there is a certain deviation compared with actual models.(4)It was the analysis models of bonding shear stress of end-anchored CFRP plates that were presented with the method of experiment and theoretical analysis.