Creep of high strength concrete filled steel tube columns

High strength concrete filled steel tube (HSCFT) members have found wide applications. However, there are few reports on the test and model of their creep. This paper investigates the creep of axially loaded HSCFT columns by testing eight specimens for 380 day. A creep model, considering the state of triaxial stress and autogenous shrinkage of the high strength concrete core, has been proposed and validated against the test data. Parametric analysis demonstrates that there exists an obvious difference in the creep between HSCFT columns and normal strength concrete filled steel tube columns, additionally, concrete composition influences the creep of HSCFT columns considerably.

► We studied the creep of high strength concrete filled steel tube (HSCFT) columns.
► Eight specimens were tested for creep under axial loads and shrinkage for 380 days.
► We found that the creep of HSCFT columns developed mostly in the first 100 days.
► The proposed creep model has been proved in good accordance with the test data.
► Parametric analysis showed concrete mix obviously affects the creep of HSCFT columns.