An Experimental Study Of The Seismic Behavior Of Recycled Aggregate Concrete Filled Steel Tube Columns

It has a huge ecological benefits, saving the natural aggregate resources, easing the contradiction between supply and demand of aggregate, reducing the pollution of urban environment, to re-use scrap concrete as replacing the natural aggregate preparation for new construction with the waste concrete block. From the1950s, scholars began a systematic study of the re-use scrap concrete, but due to performance limitations of waste concrete, recycled concrete in the actual project using the level is still relatively low. Recycled aggregate concrete filled steel tube columns, steel tube has confinement effect on core of recycled concrete (constraints), so that the core of recycled concrete is in three state of compression and the recycled concrete has high compressive strength and deformation capacity, at the same time, the use of the concrete filled enhance the stability of the steel pipe wall. This new type of composite structures to promote the use and development of recycled concrete in the structure of civil construction, provide an effective way for the abandoned concrete resources. At present, many scholars to study the mechanical properties of recycled concrete-filled components, but research is still mainly concentrated base on the axial compression experiments, the seismic behavior of recycled aggregate concrete filled steel tube is still rarely reported, especially the thin-walled steel pipe rising in recent years.In order to examine whether the methods and results applied in aseismic normal concrete filled steel tube structure are suite to apply to the recycled aggregate concrete filled steel tube structures, In this paper, ten recycled aggregate concrete filled steel tube columns under cyclic loading were tested to investigate the aseismic behaviors by using the optimum mix proportion of the recycled aggregate concrete and the steel ratio as the basic parameters, diameter of165mm, wall thickness of4mm and2mm. Failure patterns, hysteretic curves, skeleton curves, ductile coefficients, energy dissipation and strength degeneration of specimens are obtained to study the aseismic behavior, to examine the influence of the recycled aggregate replacement rate to the seismic performance, to compare the seismic performance of the thin-walled specimen in the different recycled aggregate replacement rate and compared with the thick-walled, providing practical experience for the development of the recycled aggregate concrete filled steel tube structures.