Theoretical Analysis And Numerical Simulation On Flexural Behavior Of Reinforced Concrete T-Beams Strengthened With Carbon Fiber Reinforced Plastics (CFRP)

The rehabilitation and strengthening of insufficiently strong or damaged RC structures by means of externally bonded Carbon Fiber Reinforced Plastics (CFRP) systems is a new-style and high technique method to reinforce the constructions. It has received great attention in recent years in China. CFRP is broad used in structure strengthening because of its high strength, low weight, easy installation, resisting corrupts. The basic material of reinforced fiber is the continuous fiber with high strength or high elastic module, which array the bundle at single direction, and soakage to form the Fiber Reinforced Plastics, namely CFRP systems, with the primer. Because the CFRP share the load with the reinforcing steel bar, which' stress is reduced, the constructions get rehabilitated and strengthened.This paper deals with the flexural strengthening of reinforced concrete T-beams by means of composite thin plates, glued or mechanically anchored to the tension surfaces of beams. At first, the paper summarizes the domestic and international research conditions and results of CFRP reinforcing the concrete structure at present, and then makes the analysis and study to the ultimate flexural resistance of flexural behavior of reinforced concrete T-beams strengthened with CFRP. The paper respectively carries through the deformation, stress and strain and ultimate flexural resistance of the reinforced concrete Tee-shaped beam under the different gluing forms.According to the classical rectangle beam theory concerning the flexural strengthening, a series of theoretical formulas are concluded. A FORTRAN program of the ultimate flexural capacity for the reinforced concrete Tee-shaped beam strengthening with CFRP is presented along with an easy flow chart on the Visual Fortran platform and also is proceed to the practical calculation in order that engineers can easily put this procedure into practice and ensure the effect. Then, parametric FEM modeling and simulation are followed with ADINA finite program.It presents a theoretical model, which was developed to study the effects of various parameters on the flexural behavior of strengthened beams. From aparametric study carried out with the model, it was found that the most significant parameters affecting the ultimate flexural resistance are the concrete compressive strength, the percentage of reinforcing steel, the yield intensity of reinforcing steel bar, the shear span to depth ratio, the flange breadth, and the thickness of the strengthening plate and so on. A numerical design example is provided to demonstrate the application of the approach. It is also believed to be useful for the practicing engineering.