Study Of Mechanism, Design Method And Application For Strengthening RC T-Beam Bridge With Sheet Materials

Sheet materials reinforcement technology (paste the steel plate or the fibre reinforced polymer), becomes the focus of strengthening the research field both at home and abroad rapidly as its outstanding mechanical property and handy construct etc. However, because of the restriction of experiment scale and the data share problem, the reported research fruits, especially the experiment achievements, have great one-sidedness problems. As research of strengthening method of sheet materials in" Code for strengthening highway bridges " in advance, basing on the experiments for 18 models of RC T-beams which model the real 16m T-beam bridges built in the 1960s in China for the first time and bonded experiments of 12 specimens, this paper have studies the mechanism, design methods of strengthening RC T-beam bridge and put forwards the suggestion of designing systematically.In the bonded experiments, the concrete surface treatment; sheet material quantity and material kind were studied. The conclusion as follows: the concrete surface processing has influence on the bond strength remarkably; Increased sheet material quantity does increase the bond strength; The material strength utilization will be lower as the sheet material quantity increased; The steel plate bond effect is worse than fiber's etc.In the reinforcement experiments of right section, the influence of RC T-beam the mechanics behavior by FRP, steel plate was studied. The conclusion as follows: the cracking load, yielding load ,and limiting load are improved after reinforcing by sheet material and among them the improvement of limit loads is the most remarkable; the increasing of sheet material quantity improved bearing capacity but the effect is not linearly; In case of initial loading, sheet material puts smaller affect on yield load but has certain influence on the extreme limit load; Bonding sheet material can reduce the beam deflection effectively ;Before concrete fracture, sheet material put smaller contribution to sectional stiffness, however, after concrete fracture, the affect on sectional stiffness is outstanding; after reinforcement T-beam, fracture interval and width were diminish and quantity is increased; Ductility of T-beam is lower obviously after reinforcement, and the more quantity of material is increase, the more ductility is reduced.