The Study About Influence Of RC Beam Strengthened With SWR External Prestressing Under Different Dead Load Level When Strengthening

At present, the shear capacity of some concrete structures on duty is shortage, so the potential safety problems in urgent need to be solved. Now the main methods for the shear strengthening of reinforced concrete structures are Carbon fiber reinforcement, bonded steel plate reinforcement and ferrocement mortar and so on at home and abroad. The shear resistant with SWR (steel wire rope) external prestressing is a kind of new type of reinforcement technique. The advantages of the method are ideal reinforcement effect, durability, and convenient construction. So the method has been paid attention by more and more scientists and technical workers. The actual concrete structure withstands normal use and long-term load dead load effect, so the research of the concrete structure of shear reinforcement is extremely important. Through the experiment of1basic beam3strengthened beams which are in different dead load levels (53%、63%、74%), and3strengthened beam simulated by ANSYS in different dead load levels (20%、30%、40%) analysed the influence of damage degree of original beams and the dead load level of strengthened beams are analyzed. The reduction coefficient values of shear capacity under different dead load level are researched. The research is shown that:with the dead load level increasing, the improve degree of shear capacity of strengthened concrete beams is smaller. The mathematical model is established, which is about dead load level and reduction coefficient of shear capacity of strengthened concrete beams. Through comparison and analysis of the bearing capacity of experimental beams and the model beams when dead load level is less than60%of the limit load, the effect of dead load level against the shear capacity is small so this could be ignored, the when the dead load level more than60%the influence in bearing capacity should be, considered. So we suggested the coefficient is0.8for safety. Research results could be referenced by the shear reinforcement design to some extent.