Experimental Research On Seismic Behavior Of CFRP-strengthened Seismic-damaged SRC Columns

In recent years,due to the excellent mechanical properties and good seismic performance of steel reinforced concrete structure,the steel reinforced concrete structure has been widely used in the high-rise and super high-rise buildings with large span structure and seismic area.For the steel reinforced concrete structures in the scope of the post earthquake,No matter from the economic point of view or to meet the needs of people living in the post disaster perspective,take the appropriate repair reinforcement technique measures are more practical significance than to rebuild.At present,the research on seismic damage of structure reinforcement is limited to reinforced concrete and concrete filled steel tube structure,steel reinforced concrete structure earthquake loss not covered by strengthening research,This topic is based on the current situation of research work,experimental and theoretical analysis on seismic behavior of steel reinforced concrete frame columns strengthened with carbon fiber sheet(CFRP),It has very important guiding significance for theoretical research and practical engineering.In this paper,the main research contents and results are mainly embodied in the following points.(1)To put forward the scheme of the steel reinforced concrete columns strengthened with CFRP sheets.The failure test of steel reinforced concrete columns under low cyclic loading is carried out according to the current relevant codes.(2)The analysis and comparison of specimens before and after reinforcement load-displacement hysteresis curves,skeleton curves,ductility,energy dissipation capacity and the stiffness and strength degradation parameters and so on,to study the carbon fiber reinforced seismic damage of the seismic performance of steel reinforced concrete column.The test results show that CFRP restrain concrete crack specimens showed good bending failure,meet the seismic design of "strong shear weak bending,reinforced specimen load displacement hysteretic curve is full,energy dissipation capacity.Force increased ductility and ultimate bearing,seismic performance has greatly improved,strengthening the bearing capacity and stiffness degradation degree were less than the unreinforced specimens,verify the feasibility and validity of this reinforcement method.(3)In order to understand the seismic behavior of steel reinforced concrete columns strengthened with CFRP sheets,the constitutive model of steel reinforced concrete structure is established based on the stress characteristics of steel reinforced concrete columns.Taking material parameters reduction and considering the effect of damage brought under the premise of using finite element analysis software ABAQUS,simulation results show that specimens under low cyclic loading stress performance analysis and simulation results are in good agreement.The effect of axial compression ratio,damage degree and the amount of CFRP on the strengthening effect is studied by simulation.It is indicated that the effect of material parameter reduction method to consider the damage is effective very much.