Experimental Study On The Performance Of Recycled Aggregate Concrete-filled Steel Tube Columns Under Cyclic Reversed Loading

The mechanical properties of recycled concrete is lower than that of normal concrete,and so as the performance of recycled concrete structure, which makes the applicationof recycled concrete in engineering practice in the subject to certain limitations. Andmostly used for subgrade backfill, underground structure and so on, they have less stressin common.The appear of recycled aggregate concrete-filled steel tube structure, can make theapplication of recycled concrete to embark on a new level. The main mechanism of thiskind of structure can play the mechanical properties of common concrete filled steeltubular structure on the performance of the core, under constraint of the steel pipe, thestrength and deformation ability of recycled concrete will improve, while the stability ofsteel tube wall is heightend. In addition, the pipe will be the core of recycled concretesurrounded in a closed environment, the creep and the problem of poor durability ofrecycled concrete can be advanced. The application of recycled concrete in compositestructure, not only has the advantages of composite structures, but also has a strongtheoretical significance and practical value of ecological.In order to study the seismic performance of recycled concrete-filled steel tubularmembers, this paper designed3Thin-walled circular steel tube recycled concretebending members，The specimen is225mm in diameter, wall thickness of steel pipe is2mm and5mm, the axial compression ratio and steel ratio are as the control parameter,the research mainly read the theory and method of recycled concrete filled steel tubularmembers for reference, and amend the recycled concrete and normal concretereasonable in different material properties. The quasi static test of recycled concretefilled steel tube columns, obtained a series of failure characteristic of the components.by hysteresis curves, skeleton curves and stiffness degradation curves, The paparobserves ductility deformation and energy dissipation of different parameters. Further，By using the finite element software ABAQUS to simulate and validate the test process,test characteristics curve is obtained, and agreement well with the test results. Finally,according to the existing research results at present concrete filled steel tube, and makecorrections in the different material properties of the recycled concrete and normalconcrete, gives the calculation method of P-Δ skeleton curve theory of circular recycledaggregate concrete-filled steel tube columns. which can approximate the simulation of hysteretic characteristics.