Research Of CFRP Application In Reinforcement Of Concrete Girder Bridge

Recently, with the development of communication, a great deal of highway bridges are need to be reinforced in china. Among those methods using to reinforcing RC structures, more and more attention has been paid to the method strengthening RC girders with carbon fiber reinforced polymer (CFRP). It has a bright future for its outstanding performances such as high strength, low weight, corrosion resistance, together with the handy operations comparing to traditional retrofitting methods.Aimed at the practical failure state of concrete girder bridge, an experimental investigation is conducted on the performance of RC beams strengthened in flexure and shear. The Experimental program investigated in this program include pre-cracking load, installation load level and tension reinforcement ratio. The experimental results indicate that strengthening pre-cracked beam with CFRP can not only enhance its stiffness and capacity in flexure and shear, but also decrease crack width on the surface of beams and reduce tensile strain of steel. Results show that the formats used to predict the capacity in shear of available beams strengthened with CFRP is conservative and acceptable. This paper presents a primary analysis and the equations for computing the bearing capacity of RC beams using prestressed CFRP. Experimental results and analysis show that, in comparision with the one without prestress, prestressed CFRP can farther improve the flexural bearing capacity and rigidity of beams by taking full advantage of its performance. Taking Wucheng bridge of Dezhou city as project background, The paper made a brief introduction to specifications of CFRP and reinforcement method, describe the failure of CFRP used in RC beams and give some approaches to avoid failure. Finally, nonlinear finite element analysis is carried out on the capacity in flexure of RC beams strengthened with CFRP by using ANSYS program. The validity of finite element analysis is proved and relevant experimental conclusions are further testified by comparison with ultimate experimental capacity in flexure and load-deflection curve.With the research of this paper, the design of calculation and rein-forcement method is improved, the construction technique is developed and application experience is accumulated on the reinforcement technique for CFRP in the concrete girder bridge.