Study On Bond-slip Behavior Between Section Steel And Recycled Aggregate Concrete

Section steel reinforced recycled concrete structure is a structure that makes three materials of section steel,rebar(longitudinal bar and stirrup bar)and recycled concrete work together to resist external effects.Compared with the recycled concrete structure,the section steel reinforced recycled concrete structure has the characteristics of high bearing capacity,large stiffness,good deformation and good seismic performance.Compared with the steel reinforced concrete structure,it has the characteristics of green environmental protection,it makes the construction waste recycled and solves the problem of environmental pollution caused by construction waste.In a word,section steel reinforced recycled concrete structure has a great significance to popularize and apply.If we want to make the section steel reinforced recycled concrete work normally,we must ensure that there could be a good bond-slip behavior between section steel and recycled concrete,in addition,it is because of the bond-slip behavior between section steel and recycled concrete,section steel can work and bear loads together with recycled concrete to become a real "combination" structure,so it is very necessary to study the bond-slip performance between section steel and recycled concrete.In order to conduct a more systematic research on bond slip performance between section steel and recycled aggregate concrete,on the basis of experimental research,17 steel section reinforced recycled concrete push-out specimens were simulated by ANSYS software based on two cases in this paper: considering the position function and not considering the position function.And the correctness of the establishment of the finite element model in this paper was verified by comparing the test results with the simulation results.In addition,the results of two cases were compared and summarized in order to get the more accurate simulation method.The analysis of influence parameters about section steel reinforced recycled concrete push-out specimens was done based on the results of finite element analysis.And the influence regulations about the strength of recycled concrete,the embedded length of the section steel,the thickness of the section steel protective layer and the volume stirrup ratio on the bond strength of section steel reinforced recycled concrete were obtained.Based on the results of finite element analysis about bond-slip performance of section steel reinforced recycled concrete,the constitutive relationship of bond-slip of section steel reinforced recycled concrete was modified.In addition,the correctness and the applicability of the modified bond-slip constitutive relationship was verified by ANSYS simulation.The finite element simulations of section steel recycled concrete columns were carried out respectively based on the two circumstances of considering the bond-slip behavior and not considering the bond-slip behavior,and the influence of bond-slip performance on the mechanical performance of section steel recycled concrete columns was analyzed through the simulation results.The influence of eccentricity and the replacement rate of recycled aggregate on the ultimate bearing capacity of recycled steel reinforced concrete columns under eccentric compression and the influence of slenderness ratio and the replacement rate of recycled aggregate on the ultimate bearing capacity of recycled steel reinforced concrete columns under axial compression were analyzed.