Experimental Study On Bending Performance Of RC Beams Strengthened With Near-Surface Mounted CFRP Sheets

Near-surface mounted (NSM) is a new application of fiber material in concrete-strengthening. Compared with surface-bonded technique, NSM is simpler and more convenient in construction work, use less material, has a higher intensity, and is corrosive-resistant. Research production makes it clear that, in the same condition, NSM obviously has a better effect in concrete-strengthening than surface-bonded technique does. At the present time, domestic research on NSM is a fledgling. Therefore, as a promising new technique of concrete-strengthening, NSM needs a great deal of researches to reveal its integrated performance.This thesis expatiates that, the experiment selected carbon fiber-reinforced polymer sheets' different bonded lengths and amounts, clear spacing of notch, intensities of RC and ratios of reinforcement as parameters. Load test was made on 8 rectangular cross section RC beams. And the purpose of these tests was to study out the distinct effects of strengthened RC beams' failure mode, stiffness variety, crack spread situation and ultimate bearing capacity on different strengthening conditions. Stimulations on the process of loading all members were made by using finite element analysis software ANSYS. At the same time, basing on surface-stuck interface intension model, according to the features of NSM, computational formulas of ultimate bearing capacity controlled by carbon fiber-reinforced polymer sheets' tip shearing stress were deduced. By making comparison among simulated value, theoretical value and experimental value, Feasibility of finite element analysis and theoretical arithmetic was verified under certain conditions. The thesis illustrates fixing damaged positions three-dimensionally and making failure analysis by using acoustic emission collected from experiments.