Research On Experiment Behavior And Calculation Method Of RC Columns Embedded With 600MPa High Strength Steel Bars Under Axial And Eccentric Compression

600MPa hot rolled ribbed high strength steel bar is a new type of high strength steel bar with yield strength of 600 MPa.It has the advantages of high strength,good ductility,stable performance,good weldability and plasticity.It has good application potential in large span,super high rise overload and bridge engineering.At present,the study of high-strength steel bars are mainly concentrated on 500 MPa,due to the particularity of its production process,the higher strength grade of steel has many limitations on other mechanical properties and less research.In addition,the existing codes of our country have not been stipulated for steel bars with a strength of 500 MPa or more.In order to promote the application of this new type of high-strength steel bars in engineering field,based on the material test of 600 MPa hot rolled ribbed high strength steel bar,the experimental study on the mechanical behavior of 600 MPa hot rolled ribbed high strength RC column is carried out.The research of this subject will provide theoretical basis and experimental basis for the application of 600 MPa hot rolled ribbed highstrength steel bar.In this paper,experimental studies on the mechanical properties of 600 MPa hot rolled ribbed high strength RC columns under axial and eccentric loads are carried out.The specific contents of this paper are as follows:(1)Twelve 600 MPa hot rolled ribbed high strength RC short columns under axial compression were tested.Longitudinal reinforcement ratio,stirrup strength,volume stirrup ratio of high-strength stirrups,aspect ratio,equal area and equal strength replacement with HRB400 ordinary steel bars were set as experimental parameters.The bearing capacity,failure mode and mechanism of 600 MPa hot rolled ribbed highstrength RC short columns under axial compression were studied,and compared with the standard bearing capacity formula.(2)Twenty 600 MPa hot rolled ribbed high strength RC eccentrically loaded columns were tested.Taking eccentricity,longitudinal reinforcement ratio,stirrup strength and aspect ratio as experimental parameters.The bearing capacity,failure mode and stress mechanism of 600 MPa hot rolled ribbed high strength RC eccentric columns are studied,and compared with the standard bearing capacity formula.(3)The numerical model of 600 MPa hot rolled ribbed high strength RC short columns under axial compression is established by ABAQUS software verify its accuracy.Based on the experimental parameters,the effects of concrete strength,longitudinal reinforcement strength,section area,equal strength replacement of longitudinal reinforcement and stirrup on the mechanical properties of 600 MPa hot rolled ribbed high strength RC short columns under axial compression are studied.Based on the design code and superposition principle of concrete structure,the bearing capacity formula of 600 MPa hot rolled ribbed high strength RC short columns under axial compression is proposed.(4)The numerical model of 600 MPa hot rolled ribbed high strength RC eccentric columns is established by ABAQUS software and verify its accuracy.Based on the test parameters,the effects of concrete strength,longitudinal reinforcement strength,volume stirrup ratio,section area,equal strength replacement of longitudinal reinforcement and stirrup on the mechanical properties of 600 MPa hot rolled ribbed high strength RC eccentric compression columns are studied.Based on the bearing capacity formula and superposition principle of 600 MPa hot rolled ribbed high strength RC short columns under axial compression,the bearing capacity formula of 600 MPa hot rolled ribbed high strength RC eccentric compression columns is proposed.