Finite Element Analysis Of Seismic Behavior Of Fiber Lithium Slag Concrete Column In Saline Soil Area

To investigate the deterioration of polypropylene fiber lithium slag concrete column in saline soil area,by means of laboratory accelerated erosion tests and finite element analysis methods,the compressive strength,splitting tensile strength and compressive stress-strain curves of the corroded concrete are studied.The finite element model of polypropylene fiber lithium slag concrete column is established,then extended analysis using the model.The effects of axial compression ratio,longitudinal reinforcement ratio,concrete strength,stirrup spacing,longitudinal reinforcement strength and shear-span ration on the seismic performance of members are considered.The test results show that,with the increase of erosion time,the strength of ordinary concrete and polypropylene fiber lithium slag concrete increases first and then decreases.The tensile strength of fiber lithium slag concrete and ordinary concrete shows a variation of increasing first and then decreasing.The failure mode of concrete is changed by fiber.Based on the experimental data,the constitutive model of fiber lithium slag concrete can well reflect the three stages of concrete failure.Through the test data,the reliability of the model is verified.The research shows that the vertical axial compression has a great influence on the seismic performance,the smaller the axial pressure is,the better seismic performance is,the peak load of component under 0.3 axial compression ratio is 40.8% higher than that of the component under 0.1 axial compression ratio;The ultimate bearing capacity can be improved by increasing the ratio of longitudinal reinforcement and concrete strength.Changing stirrup spacing has little effect on the ultimate bearing capacity of members.The peak load of the member with 30 mm stirrup spacing is 2% higher than that of the member with 70 mm stirrup spacing.With the increase of the longitudinal reinforcement strength,the descending section of the skeleton curve becomes more gentle.The ultimate bearing capacity of the 60 MPa concrete member is 17.5% higher than that of the 40 MPa concrete member.The higher the axial compression ratio is,the greater the stiffness is,but the faster the stiffness degradation rate is.When the reinforcement ratio increases from 3.0% to 3.8%,the displacement ductility of the member decreases by 1.17.With the increase of concrete strength,the displacement ductility of the member increases first and then decreases.Changing stirrup spacing has little effect on stiffness degradation of members.The higher the strength of longitudinal reinforcement is,the greater the stiffness of the component is.The ductility of the component decreases with the increase of axial pressure.With the increase of the ratio of longitudinal reinforcement,the ductility of the member increases first and then decreases.When the strength of concrete increases,the displacement ductility of the member increases first and then decreases.The ductility of the member increases with the increase of stirrup spacing.Increasing the strength of the longitudinal bars can greatly improve the displacement ductility of the members.When the component is close to failure,the larger the reinforcement ratio is,the stronger the energy dissipation capacity is.The energy dissipation performance of members decreases with the increase of concrete strength.The larger the stirrup spacing is,the stronger the energy dissipation capacity is.The lower the longitudinal reinforcement strength is,the better the energy dissipation capacity is.