Study On Mechanical Behavior Of Reinforced Concrete Beams And Columns After Strengthening

The structure's strengthening and retrofitting will become the main mode of construction in the engineering to a certain stage as the structure development shown.The theoretical research and technical application of reinforcement and reconstruction become gradual maturity.Most researches focused on the mechanical properties of reinforced frameworks or components after strengthening,less involved in the reinforcement engineering evaluation.Combined with the engineering practice,the mechanical behavior of reinforced concrete beams and columns were studied by using the test and the finite element method.This article research provide scientific basis and technical support for evaluation of the actual reinforced concrete reinforcement retrofit project.The reinforced concrete beams strengthened with carbon fiber-reinforced polymer laminates were tested and studied at two symmetric point loads,and the improvement of bearing capacity is 7.5%,13.4% and 19.4%,the test results show that the stiffness and the normal service range of beams are improved.The low-cycle and repeated load was imposed on the reinforced columns until they were broken.The research focuses on the seismic behavior such as failure mode,hysteretic behavior,lateral capacity,ductile and deformable performance,stiffness,energy dissipation of the retrofitting column with different section enlargement methods.It is indicated that different enlarging sections improve the seismic behavior in varying degrees from the experimental results,the horizontal bearing capacity increases about 22% to 59%,energy consumption increase about 24% to 253%,showing good seismic behavior.The flexural behavior of reinforced concrete beams reinforced by CFRP are studied in this paper by finite element analysis.The finite element analysis is relatively close to the experiment results,so this finite element model was used to analyze the mechanical behavior of the rest reinforced beams.The mechanical behavior of the reinforced beams under the secondary load are analyzed by this finite element model,and the results show that the secondary load reduces the ultimate bearing capacity of the beam,and the influence of the secondary load should be considered when the beams under high load.The seismic behavior of reinforced concrete columns by enlarging section are studied in this paper by finite element analysis,the finite element analysis is relatively close to the experiment results,and this finite element model was used to analyze the mechanical behavior of the rest reinforced beams.In conclusion,the mechanical behavior of reinforced concrete beams and columns after strengthening are studied by test and finite element method in this paper.This results were used to evaluate the effectiveness of strengthening about this project,and it provide reference for other similar engineering evaluation.