Experimental Study On The Axial Compressive Performance Of The Thin-walled Steel Tube Without Clinker Cement

At present,with the rapid development of the construction industry,thin-walled concrete-filled steel tubes have been widely used in some arch bridge structures,industrial plants and other building structures due to their high bearing capacity and good seismic performance.When the concrete-filled steel tubular column is destroyed,it is prone to local buckling under axial load,especially when the cross-sectional shape is square or rectangular.Therefore,the use of stiffener structures in concrete-filled steel tubes can improve the performance of steel tubes and concrete.In addition,the steel column needs to be filled with concrete,which consumes a lot of concrete materials such as cement and aggregates.In order to improve the pressure performance of thin-walled steel pipe shafts,reduce environmental pollution,and increase resource recycling efficiency,this paper takes measures from the two aspects of pipe wall and filled concrete to change the form of different stiffeners,the ratio of width to thickness of steel pipes,and the rate of recycled aggregates.The axisymmetric behavior of thin-walled steel regenerated concrete short columns was tested and analyzed.Theoretical formulas were put forward to formulate the axial bearing capacity of thin-walled steel recycled concrete short columns.Specifically carried out the following research content:(1)By changing the form of different stiffeners and the ratio of width to thickness of steel tubes,the failure modes,ultimate bearing capacity,and axial compressive strength of a short-grained steel reinforced concrete recycled concrete short column are analyzed,and the stress-strain curve and load-displacement are plotted.curve.The results show that the use of stiffened ribs can improve the local buckling characteristics of the steel pipe columns and greatly improve the axial compression performance of the steel pipe columns.In terms of failure morphology,the buckling of steel columns with stiffened ribs is significantly smaller than that of steel columns without stiffeners.In the short column of thin-wall steel pipe without clinker in different stiffeners,the double-ribbed steel pipe has the highest failure load and the highest axial compressive strength.(2)Study the change of different recycled aggregates to study the compressive strength,tensile strength and elastic modulus of recycled concrete without clinker.The results show that both the compressive strength and the elastic modulus increase with the increase of the recycled aggregate dosing rate,first become larger and then become smaller,and the tensile strength becomes smaller.(3)Study the change of different recycled aggregates to study the failure mode,ultimate bearing capacity,axial compressive strength,draw the stress-strain curve,load-displacement curve of the thin column steel pipe without clinker cement recycled concrete short column..The results show that the ultimate load and axial compressive strength of the column are decreasing.(4)By analyzing the calculation formulas of axial compression members of concrete-filled steel columns at home and abroad,a formula for calculating the ultimate bearing capacity of short-grain steel tubes without clinker-recycled concrete short columns is proposed.(5)Using ANSYS finite element software to analyze the ultimate bearing capacity of the thin-walled steel clinker-free recycled concrete short columns under double-ribbed conditions and comparing with the experimental values,the simulation results are basically consistent with the experimental results.