| Recently, an advanced composite material named Carbon Fiber Reinforced Plastics (CFRP) has emerged as an alternative to traditional strengthening materials. The existing reinforced concrete structures can be strengthened by externally bonding CFRP to improve their mechanical behaviors. Many advantages of CFRP such as lightweight, non-corrosive, simple construction and high tensile strength make it widely used in strengthening field.First of all, the paper introduces the current research situation of strengthening RC (Reinforced Concrete) components both at home and abroad, discusses the existing strengthening methods, coupled with present problems puts forward the research contents.Second, in this paper, nine simply supported RC beams reinforced with CFRP sheet are studied. Based on the experiments of nine models of RC beams, the ultimate shear capacity of RC beams strengthened with different paste formats under secondary load is evaluated. The test results indicate that stiffness, cracking load and ultimate load of RC beams strengthened with CFRP sheet are improved by different degrees, which influences the distribution of crack and the failure mode . Meanwhile, the fundamental laws of stress changing in the CFRP sheet are obtained from the test results.Third, the shear failure of RC beams strengthened with CFRP sheet is analyzed according to the theory of "truss-arch mechanism", and the effective length of the CFRP sheet is introduced, then the simplified calculation formula of the ultimate bearing capacity of RC beams strengthened with CFRP sheet is put forward.Finally, the full experimentaion of RC beams is analogied with the nonlinear finite element software—ANSYS5.7, which offers concrete mass element—SOLID65 and the birth and death capabilities. The numerical analysis method of RC beams strengthened with CFRP sheet is expounded. |
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