Fiber Sheet Reinforced Concrete Beam Flexural Capacity

Nowadays, the technology of using carbon fibre reinforeced plastic(CFRP) sheets to strengthen the concrete structure is a new type of strengthed method in the field of concrete structure strengthed. In our country , the basic research on the technology of carbon fibre sheets strengtheded is relatively weak,and its application still have some problems that haven't sloved. But now, for the present construction market, China has already stepped into the second stage that to construct the new buildings and to strengthed the old buildings are all the same important. Therefore , as time goes by, a large amount of buildings will step into the scheduled time aging , it is necessary to carry out strengthening handling for the further using. Facing so enormous demand of strengthening market, a strengthening and repair method which is rapid ,effective and reliable is urgent. Because the carbon fibre sheets to strengthed concrete structure technology is a simple, direct, and fast concrete structure strengthed technology , deeply accepted by the home and abroad scholars and get extensive application and development, and the meaning of the research of this issue is significant. Through the analysis of the research of the carbon fibre sheet to strengthen the concrete beam, some useful conclusions are obtained through the study, the majoy contents are mainly summarized as follow:1. Through the theoretical analysis of pasting carbon fibre sheet to strengthen the reinforce concrete beam, three kinds of failure state are summed up for the carbon fibre sheet to strengthen reinforce concrete beam, there are the limit failure state , the break of the carbon fibre sheet, and the crush to pieces of the concrete beam and ect. Combine the current criterion, after the analysis of the force feature and the break mechanism, in this paper, we put forward three calculate formulas of the flexual bearing capacity for the three different types of the failure states of the beams. And it's checked to be right in the real projects, also it's satisfied for the damand of the real projects.2. To analyse the interface mechanics function of the concrete beams which are strengthened by the carbon fibre sheet, we get a new kind of failure states, we call it for the failure of felt-slippage, and study the mechanism for this failure.3. Through the analysis of the strengthening mechanism theory, we expound the strengthening principle from the microcosmic. thus, from the analysis of the stiffness and the crack, we can conclude that the increase of the bearing capacity of the carbon fibre sheet strengthening concrete beams is mainly depended on the improve of the stiffness and control the progress of the micro-crack which is inside the concrete beams, there will be significant influence on improve the durability and resisting capacity of the common steel-concrete beams.4. Through the analysis of the ANSYS what is a software for the nonlinear finite element, we obtained the performance fo bearing capacity for the reinforce concrete beans, and also get the value research method from them. Through comparative analysis of the finite element results of the strengthened beams and the nonstrengthened beams, we can know that, the resisting flexual bearing capacity of consolidating beam can get remarkable improvement, in addition, relatively for the nonstrengthened beam, under the same load, the flexibility of the strengthened beams is obviously less than the nonstrengthened beams, and all the conclusions are accord with test results of the experiments which are carried out by the home and the abroad scholars.5. through the real projects, to expound the application of the strengthened by the carbon fibre sheet in real projects.