Experimental Study On The Seismic Performance Of Steel Tube Columns Filled With Mixed Recycled Aggregate Concrete

Because of the construction waste that is produced constantly in the construction of the city,more and more construction waste needs to be solved urgently.Recycling construction waste is an effective solution.Recycling and using of construction waste is the best way to deal with construction waste.At present,there are many researches on recycling of waste concrete in construction waste,but few on recycling of waste brick.In order to make efficient use of waste concrete and waste brick,combining steel tubes with recycled aggregate concrete,the steel tubes can effectively restrain the core recycled aggregate concrete,so then,the strength and availability of recycled concrete with mixed brick aggregate can be improved,and the corrosion in pipe can be prevented by filling concrete in steel tube,and the core recycled aggregate concrete can also ensure that the steel tubes will not buckle prematurely.It can improve the working performance of steel tubes filled with recycled aggregate concrete by the interaction between steel tubes and core recycled aggregate concrete.Although scholars at home and abroad have done a lot of researches on static and dynamic performance of steel tubes filled with recycled aggregate concrete structures,there are few researches on steel tube columns filled with mixed recycled aggregate concrete.In this paper,steel tube columns filled with mixed recycled aggregate concrete is studied,which provides a reference for expanding the utilization ratio of construction waste and developing the steel tube columns filled with mixed recycled aggregate concrete.Under constant axial load and horizontal low cyclic load,pseudo-static tests on the seismic performance of square steel tube columns and circular steel tube columns filled with mixed recycled aggregate concrete were done,and the influence of steel pipe wall thickness and other factors on the seismic performance of the specimens was studied.By means of the experiment,the failure mode,hysteretic curve,skeleton curve of the specimens were obtained,on the basis of this,the change regulation of seismic performance of deformation capacity and ductility,stiffness degradation,energy dissipation and strength degradation were analyzed.Experimental phenomena and results show that the failure behavior of specimens is very similar to those of ordinary steel tube columns specimens filled with concrete.They are both compressive and bending failure,and have good deformation capacity and hysteretic performance.The wall thickness of the steel tube has a significant effect on the resistance of steel tube columns filled with mixed recycled aggregate concrete,and the resistance of the columns with high steel content is large.The displacement angle values of the specimens all meet the requirements of the seismic design code,and the wall thickness has an obvious effect on the ductility coefficient,and it shows that steel tube columns filled with mixed recycled aggregate concrete have good deformation capacity.The stiffness degradation trend of the specimens is basically the same.The wall thickness of the steel tube affects the stiffness degradation of the specimens to some extent.The stiffness degradation of the thick tube wall is smaller than that of the thin tube wall,but the degradation trend is approximately the same.The?_eqq of steel tube columns filled with mixed recycled aggregate concrete is larger than that of ordinary steel tube columns specimens filled with concrete,which indicates that the steel tube columns filled with mixed recycled aggregate concrete have better energy dissipation capacity,and the total energy consumption I of the specimens with thick tube wall is much larger than that of thin tube wall,and it shows that the wall thickness of steel tube has obvious influence on the energy consumption of the specimens.The steel tube columns filled with mixed recycled aggregate concrete has good seismic performance.