Research On CFRP Application In Reinforcement Of Concrete Girder Bridge

As a part of infrastructure, Reinforced Concrete Bridge is very important for the development of society and economy. With the increase of traffic and the weight of vehicle, lots of bridges cannot meet the requirement of modern traffic, and the carrying capacity of some bridges declined for the limitation of reconnaissance and design. Nowadays, to strengthen bridge by externally bonded carbon fiber reinforced polymer is widely used for its great efficiency and economy. Compared to the traditional strengthening methods, it has a bright future for its outstanding performances such as high strength, low weight, corrosion resistance, together with the handy operation.At present, there are few research on reinforced concrete curved beam strengthened with CFRP. Studies in the paper focus on the capacity in flexure of the curved beam strengthened with CFRP. In order to gain the relation curves between load and deflection, CFRP strain and deflection, and the character of cracking, 36 reinforced concrete beams were test in three points bending test to simulate bridge strengthening. Those are reinforced concrete plane beams strengthened with CFRP, reinforced concrete curved beams strengthened with CFRP and plain concrete beams strengthened with CFRP. According to the existing calculate formulas for capacity in flexure of reinforced concrete plane beam strengthened with CFRP, the calculate formulas for capacity in flexure of reinforced concrete curved beam and plain concrete curved beam strengthened with CFRP are gained through some necessary modification. The character of unqualified resin used to bond CFRP is also studied through the three point bending test. Finally, the strengthening design and construction of the Gaoxin-bridge are carried out by combining new technology of CFRP strengthening with the technology of obturating cracks using epoxy resin with high penetrability.Based on the research of this paper, the experimental data of concrete curved beam strengthened with CFRP is given. The calculation of concrete curved beam strengthened with CFRP is obtained and practical experience is accumulated on the reinforcement technique of CFRP in the reinforced concrete girder bridge.