Experimental Research On Flexural Performance Of Reinforced Concrete Beams Strengthened With CFRP Board

The use of fiber reinforced polymer (FRP) in civil engineering is a hot topic in research and development of the international civil engineering area. The technology of using carbon fiber reinforced polymer (CFRP) on strengthening and repairing concrete structures is the most extensive one in research, development and application.In this paper, the behavior of the flexural RC member bonded with CFRP board on its vertical sides was investigated by the authors recently. A total of seven reinforced concrete beams were elaborately devised and cast. The failure character, ultimate load, deformation, cracking, CFRP bonding scheme for the specimens were examined by static loading test. The experimental result shows that the flexural strength and flexural rigidity of this kind of retrofitted beam could be markedly increase, when the CFRP board access to bottom of beam especially. But the ductility of retrofitted beam will decrease; The distribution of crack in the bottom of beam could be markedly improved.Reinforced concrete structures strengthened with CFRP board are combination with three very difficult materials (reinforcing steel bars, concrete and CFRP board), moreover the concrete often endure loads with crack. The inherent complex nonlinear characters of concrete material and reinforcing steel bars and intricate felt identity between them, which entail many difficulties in design and analysis, many scholars both in domestic and overseas have worked much in this field. Based on the research of predecessors, this paper analyze the flexural ultimate strength of RC beams and RC beams strengthened with CFRP with nonlinear finite element method by using finite element program ANSYS, emphasis research on model establishment, mesh demarcate, parameter selection, element type, converge criterion and solution method. The simulation analysis method of RC beams strengthened with CFRP board through select reasonable constitutive equation was discussed. The agreement of FEM result between the experiment results is satisfactory. The result of this paper has reference value of structure strengthening engineers and researchers in reinforced concrete.