Studies On Compressive And Flexural Performance Of Recycled Aggregate Concrete Filled Stainless Steel Tube

Stainless steel can be used in engineering structures as high performance steel owing to its good durability, corrosion resistance, ductility and toughness, excellent fire resistance and alluring appearance as well as low maintenance costs. Recycled aggregate concrete (RAC) is one kind of green concretes, because RAC can achieve the recycling of construction resources and resolve the environmental pollution problem due to the landfill of construction waste and the shortage of natural aggregate resources. However, the application of stainless steel and RAC is limited due to high cost of stainless steel and poor performance of RAC. A good method is to fill RAC into stainless steel tube to produce RAC filled stainless steel tube (RACFSST), and in this form the stability of thin-walled stainless steel tube is improved due to the supporting of core RAC. Meanwhile, the drawbacks of RAC are ameliorated because of the confinement and protection of outer stainless steel tube. All of these make it possible to use RACFSST in real project.In this paper, the compressive and flexural performance of RACFSST is experimentally and theoretically investigated, and the completed works are summarized as follows:(1) The studies related to this thesis, including the properties of stainless steel and RAC as well as the mechanical properties of recycled aggregate concrete filled steel tube (RACFST) and concrete filled stainless steel tube (CFSST), are reviewed, the main studies of this thesis are clarified as well.(2) To investigate the effect of sectional type, type of recycled aggregate and recycled aggregate replacement ratio on the structural performance of RACFSST members, a total of28specimens, including14stub columns and14flexural specimens, are tested.(3) Based on the determination of reasonable constitutive models of stainless steel and core RAC, the finite element analysis (FEA) model is developed for the simulation of RACFSST stub columns and flexural members. Generally, the simulated failure patterns, load versus deformation curves and bearing capacities agree well with the experimental results.(4) The influences of type of stainless steel, concrete strength, steel ratio and recycled aggregate replacement ratio on the compressive and flexural performance of RACFSST members are investigated using the FEA model. Finally, the simplified formula for the bearing capacity of RACFSST stub columns and flexural members is proposed.