Study on the axial compressive behavior of circular steel tube-confined concrete short columns

Abstract

To study the axial compression performance of steel tube-confined concrete, nine short column specimens were designed for axial compression testing. The parameters are the diameter-to-thickness ratio of steel tubes and the contact treatment method at the steel-concrete interface. The failure mode, load-displacement curve, load-strain curve, and load-lateral deformation of the specimens were comparatively analyzed. The results show that the failure mode is mainly shear failure. The confinement effect of the steel tube is fully activated in the elastoplastic stage. The load-displacement curves of these specimens do not have obvious descending branches. A smaller diameter-to-thickness ratio leads to more significant improvements in both load-bearing capacity and ductility during the later loading stage. The use of film-type materials at the steel-concrete interface enhances the confinement effect of steel tubes on concrete, and this improvement becomes increasingly obvious in the later stage of loading.