ABSTRACT
Concrete Filled Steel Tubular (CFST) columns used in multi-storey buildings are generally designed as continuous members. The fire behaviour is predicted based on the results of experimental standard fire testing where the same temperature is applied to the column over the full column height. This paper has focused on continuous CFST columns filled with plain concrete, bar reinforced concrete and steel fibre reinforced concrete loaded axially. The result shows that, the significant initial longitudinal expansion of the steel tube relative to the concrete reported by many researchers did not occur, due to the restraining effect of the unheated column. The use of steel fibre reinforced concrete increased the FRR recorded for columns loaded concentrically while, for eccentrically loaded column, the use of rebar reinforcement had a higher FRR. A design guide to calculate the axial capacity of a CFST columns in fire was validated against over 230 laboratory experiments.
