Study On Mechanical Properties Of Recycle Concrete-filled Steel Tubes

With the rapid development of our economy,a lot of construction waste have been generated,which have a effect on sustainable development of china.Application of recycled concrete provides a good method for the construction waste disposal and provides the guarantee for the recycling of building resources.But compared with common concrete,the recycled concrete has less intensity,lager contraction and poorer durability.These make the promotion of recycled concrete very limited.In order to overcome the shortcomings of recycled concrete,recycled concrete-filled steel tube came into being.Recycled concrete-filled steel made is produced by filling the recycled concrete into steel tube,which provides a new approach to dispose the wasted concrete and to compensate the lack of bearing capacity of the recycled concrete itself.Basted on the previous studies,mechanical properties of the mechanical properties of recycled concrete filled steel tube column and recycled concrete-filled steel tube column-H shaped steel beam with outside reinforcing ring joint specimens were researched,by the means of finite element software ABAQUS.The major research content and results are as follows:(1)With the increase of eccentricity,Ultimate bearing capacity of Recycled concrete column with square steel tube and recycled concrete column with rectangular steel tube show clear decreasing trend.Meanwhile,the ductility of recycled concrete column with square steel tube and recycled concrete column with rectangular steel tube coefficient increases obviously.(2)Under the condition of bias load,the ultimate bearing capacity of recycled concrete column with rectangular steel tube are greater than recycled concrete column with square steel tube with the same consumption of steel.In the mean time,recycled concrete column with rectangular steel tube consumes less concrete material than Recycled concrete column with square steel Tube.(3)Steel ratio has great influence on the mechanical properties of recycled concrete-filled steel tube column-H shaped steel beam with outside reinforcing ring joint specimens.With the increasing of the steel ratio,specimens turn from joint core zone failure mechanism to the beam hinge failure mechanism.Meanwhile,with the increasing of the steel ratio,ultimate bearing capacity,equivalent viscous damping coefficients and stiffness show increasing trend.(4)When the specimens were joint core zone failure mechanism,the ultimate bearing capacity,equivalent viscous damping coefficients and stiffness of recycled concrete-filled square and rectangular steel tube column-H shaped steel beam with outside reinforcing ring joint specimens are greater than recycled concrete-filled square steel tube column-H shaped steel beam with outside reinforcing ring joint specimens which consumed equal steel material.When the specimens were beam hinge failure mechanism,the mechanical properties of recycled concrete-filled rectangular steel tube column-H shaped steel beam with outside reinforcing ring joint specimens and recycled concrete-filled square steel tube column-H shaped steel beam with outside reinforcing ring joint specimens show less difference.