The Experiment Research On The Ole Wood Beams Strengthened By CFRP

Hangzhou, as one of the first batch of 24 national historical city, is famous for the glorious historical culture,the pleasant natural scenery,and the massive modern historical site. A large number of historic buildings with wooden structures,is an important carrier of historical and cultural heritage. As the long history, combined with a variety of natural, man-made factors, these wooden structures are urgently in need of repair and reinforcement.With the continuous development of material-science, based on the principle of "authenticity", "sustainability" and "an identification", using CFRP(Carbon Fiber Reinforced Polymer)to reinforce the historical buildings is prevail now in the advanced countries. By the advantage of easy-application, light quality, thin, reliable, endure, and so on, using CFRP to repair historical buildings obtained a very good reinforcement and outward appearance effect in the actual project.Wooden beams, is not only an important component of historic buildings, but also carries a large number of irreplaceable historical information of non-renewable. In this paper, based on field sampling, with "a layer of single-Hoop," "two-story double-Hoop," two methods on the research of the old wooden beams and reinforced. By experiment and calculation analysis, by contrast with the CFRP reinforcement and new wooden beams, we can get a conclusion that the bending strength of CFRP-reinforced old wooden beams is better than the new wooden beams. A "layer of single-hoop" method is more economical and practical reinforcement (which can improve the bending strength of 13% ~ 77%)."two-story double-hoop" is more security and stability. Even the old wooden beams with seriously damaged, reinforced by CFRP, their bearing capacity can significantly increased, even better than the new timber is not damaged.Meanwhile, based on Timberwork Design Specifications,we deduce the formula of bending strength. The study found, there is a big discreteness in the datum of bending strength in wooden beams. Wooden beams with their own conditions (such as wood Festival, shrinkage cracks, natural or man-made damage and other factors), and the way of CFRP reinforcement, is critical for ultimate bearing capacity.Nowadays, Hangzhou has a large number of traditional wooden structures. With the development of historic-building conservation, the application and technology of CFRP reinforce the old wood structure surely will get further spread and progress. Therefore, the research of wood construction reinforcement, means a vital significance from both the practical application and the scholarly research.