Axial compressive behaviour of stainless steel tube-confined steel-reinforced recycled concrete stub columns

Abstract

Stainless steel tube-confined steel-reinforced recycled concrete columns (SSTCSRRC) have the potential to be widely used in engineering structures due to their advantages of aesthetic appearance and reutilization of waste materials. However, there is currently little research work on this new type of thin-walled stainless steel composite columns. This paper investigates the behaviour of SSTCSRRC stub columns under axial compression. Tests on seven circular and seven square stub columns were carried out, and the main variables include the thickness of the stainless steel tube, the recycled brick aggregate (RBA) replacement ratio and the specimen type. The results indicate that the confinement effect of the stainless steel tube improves the ultimate strength and ductility of the columns, and the ultimate strength decreases with an increase in RBA placement ratio. A high RBA placement ratio or using cross-shaped section steel can significantly improve the ductility of the columns. A finite element (FE) model was developed to simulate the axial compressive behaviour of SSTCSRRC stub columns. Based on the numerical data of 130 FE models, the design formulas for axial compressive strength and stiffness of SSTCSRRC stub columns were proposed.