Theoretical Analysis Of Recycled Aggregate Concrete-filled Square Steel Tube Short Column

Steel-concrete concrete has the characteristics of high bearing capacity,good shape and toughness,simple construction,and good economic effect;at the same time,the concrete-filled steel tube combines the advantages of steel pipes and concrete,and can effectively compensate for their respective shortcomings.When the core concrete is made of recycled aggregate concrete,it can effectively reduce the consumption of natural resources and at the same time it can realize the reuse of construction waste.Based on the test data of square steel pipe reclaimed aggregate concrete short column,this paper analyzes and fits the stress-strain relation equation curve of the short column component,which is in good agreement with the axial force-strain curve of the short column test.At the same time,on the basis of the test of square steel pipe recycled aggregate concrete short column,the ABAQUS nonlinear finite element software was used to simulate the 24 square steel pipe recycled concrete short column model,and the accuracy was compared with the test results,and then the accuracy was good.According to the simulation results,the replacement ratio r,the eccentricity e,and the steel bearing rate ? of the recycled steel aggregate reinforced concrete short column of the steel pipe were analyzed.Finally,nonlinear finite element simulations were carried out on the short column model of square concrete reclaimed aggregate concrete with different core strengths and cross-sections.The influence of different core concrete strengths and different sections on its bearing capacity was analyzed based on the simulation results.The results show that: When the steel containing rate ? is from ?=0.11 to ?= 0.17,the bearing capacity of the recycled steel concrete short column of square steel pipe increases by 49.1%,and at the same time,as the steel containing rate increases,The ductility is also better;when the substitution rate r changes,the influence of the load-bearing force of the recycled steel aggregate of the opposite party steel pipe is limited;when the eccentricity e is from e=0 to e=20 to e=40,the square steel pipe recycled aggregate concrete is short Column bearing capacity decreased by 24.9% and 33.7%,respectively,but its ductility remained good.The core concrete strength is C20,C30,C50,and C70.When the core concrete strength is from C30 to C50,the bearing capacity of the square steel pipe recycled aggregate concrete short column increases the most and reaches 19.2%;at the same time,according to the load-displacement The curve found that when the core concrete is a high-strength concrete,the ductility of the recycled aggregate concrete with square steel pipe is poor.The ductility of circular steel tubular recycled concrete short columns is better than that of square steel tubular recycled concrete short columns;but in the case of the same core concrete strength and the same steel tube wall thickness,the bearing capacity of circular steel recycled concrete short columns is smaller than that of square steel tubes.Recycled aggregate concrete bearing capacity.Under the same cross-section shape,the section size increases,and the load-bearing capacity of the square steel pipe recycled aggregate concrete short column increases,and the increase range is over 50%.