Experimental Study On Bearing Performance Of Shaped Steel Reactive Powder Concrete Axial Compression Column

Steel reinforced reactive powder concrete structure combines the excellent mechanical properties of ordinary steel reinforced concrete structure and reactive powder concrete,and further improves the bearing capacity,stiffness,ductility,fire resistance and seismic performance.This structure has been widely used,especially in super high-rise and super long-span building structures.Steel reinforced reactive powder concrete structure has become a research hotspot in recent years.Therefore,six steel reinforced reactive powder concrete columns are designed in this thesis.Considering the influence of stirrup ratio(0.12%,0.16%,0.25%,0.49%)and steel ratio(4.14%,4.89%,5.73%),the axial compression bearing performance test is carried out,the failure phenomenon and failure morphological characteristics of column specimens are observed,and the ultimate bearing capacity,ultimate displacement,load displacement curve and load strain curve are analyzed,The test results obtained are as follows:(1)With the increase of stirrup ratio,the crushing and spalling degree of reactive powder concrete decreases,and the crack width on the surface decreases,indicating that the restraint effect of reactive powder concrete is significantly enhanced.With the increase of steel ratio,the number of cracks on the surface is decreasing,but the crack width is increasing,and the characteristics of strength failure are more obvious.(2)According to the analysis of ultimate load,ultimate displacement and load displacement curve of steel reactive powder concrete columns under axial compression with different stirrup ratio,the ultimate bearing capacity of the specimens increases with the increase of stirrup ratio,with an increase range of4.22% ? 8.33%,and the ultimate displacement increases with an increase range of9.02% ? 19.60%,with little change in stiffness.(3)According to the analysis of ultimate load,ultimate displacement and load displacement curve of steel reactive powder concrete columns under axial compression with different steel ratio,the ultimate bearing capacity of the specimens is greatly improved with the increase of steel ratio,with an increase range of4.18% ? 8.45%,the ultimate displacement is increased,with an increase range of5.30% ? 11.75%,and the stiffness is improved to a certain extent.(4)Based on the experimental results and theoretical analysis,the calculation formula of bearing capacity of steel reactive powder concrete columns under axial compression is proposed.(5)Based on the appropriate material element and constitutive model,the steel reactive powder concrete axial compression column is simulated and analyzed by using the finite element software.The finite element results are compared with the experimental results to verify the effectiveness of the model,which provides a reference basis for the application of steel reactive powder concrete column in practical engineering in the future.