Cyclic axial compression tests on concrete-filled elliptical steel tubular stub columns

To study the cyclic axial compression behavior of concrete-filled elliptical steel tubular columns, 18 stub columns were tested under monotonic and cyclic axial compression. The parameters in the study include the elliptical section ratio, concrete strength, and loading system. The experimental result indicates that the elliptical section ratio had a significant impact on the confinement effect between the steel tube and concrete but an insignificant effect on ductility. The increase in concrete strength had a negative impact on both the ductility of specimens and the confinement effect between the steel tube and concrete. Cyclic loading will result in strength degradation and residual deformation accumulation. The design rules based on standard and researchers at home and abroad were also assessed and compared with the experimental result. It was found that these design equations can give a reasonable prediction of the axial compressive bearing capacity of elliptical concrete-filled steel tube stub columns. The study could provide a reference for theoretical research and practical application of elliptical concrete-filled steel tubular (ECFST) columns. Copyright ©2020 Journal of Harbin Engineering University.