Calculation Of Crack Width And Stiffness Of Reinforced Concrete Beams Strengthened With CFRP

In recent years, Fiber Reinforced Polymer Plastic (FRP) sheet strengthened concrete structures in hydraulic engineering and civil engineering have been the focus of research at home and abroad. Because of its lightweight, high-strength, excellent corrosion resistance and convenient for application, the reinforcement material is one of the wider application in the field of engineering until now.In order to meet the normal use requirement of the structure, checking the serviceability limit state of CFRP reinforced concrete beams, including cracks and deformation, is necessary. To lay the foundation of cracks and deformation checking, the calculation of crack width and deformation of reinforced concrete beams strengthened with CFRP is the research priorities. The main contents are as follows:(1)Based on the experiment results of CFRP reinforced concrete beams, the influencing factors of CFRP reinforcement in CFRP reinforced concrete beams is analysed.(2) Considered the influence of the layers of CFRP,"the reduction factor of CFRP thickness" is introduced. Based on the classical theory of reinforced concrete beams, the calculation formula of crack spacing and width in CFRP reinforced concrete beams are proposed.(3)Based on the analysis of classical theory of reinforced concrete beams, the calculation formula of flexural stiffness and deflection in CFRP reinforced concrete beams are proposed by using "The Principle of Minimum Stiffness".