Comparative study of square stirrup-confined concrete-filled steel tubular stub columns under axial loading

• The ultimate bearing capacity with internal studs was no improvement.
• Cross ties provide optimal confinement.
• Stirrup-confined CFT behave superior to CFT stub columns.

This paper presents a comparative study and a 3D finite element (FE) model of square stirrup-confined concrete-filled steel tubular (stirrup-confined CFT) stub columns. The FE results agreed well with the experimental results. The results indicated that: (1) The ultimate load-bearing capacity of CFT stub columns with internal studs was no improvement; (2) All three forms of stirrup confinement effectively reduced local bucking of the steel tube, and the cross ties was optimal, followed by spiral stirrups; (3) With the same overall steel ratio, the behavior of the square stirrup-confined CFT stub columns was considerably higher than in the square CFT stub columns.