Research On The Flexural Behavior Of RC Beam Strengthened By NSM CFRP Bar

The studies on strengthening and retrofittings structures has been one of the most concerned topic on the world.In virtue of the advantages of FRP,light-weight, high-strength, non-corrosive and fatigue resistibility It has been widely used in the field of strengthening structures.More recently, a new technology of strengthening structures with near-surface mounted FRP has been proposed by foreign researchers. The beams are strengthened through inserting FRP bars or strips into grooves first cut at the tension surface. It’s a promising technology for increasing flexural and shear capacity of a deficient reinforced concrete (RC) member effectively.Based on testing of the eleven beams, we investigated the failure mode and failure criterion, as well as the ultimate loading capacity and deflections of the flexural strengthened RC beams with NSM FRP bars, by using the parameters such as FRP bond lengths, initial loading level, CFRP amount, grooves amount and position. The testing results showed that the NSM method is a promising technique to enhance the flexural capacity of RC beams. A remarkable increase in stiffness and cracking resistance was also obtained.In addition, this paper introduces the theory of the finite element analyzes model which is concluded by finite element method. And the paper compare test results and finite element result to verify the correctness of the model, providing analysis tools for further research.