Numerical Analysis of the Fire Performance of Innovative Steel-Concrete Composite Columns

Abstract

Previous investigations have revealed the limited fire resistance of concrete-filled steel tubular (CFST) columns in applications where the slenderness is important. Innovative solutions are therefore sought to help improving the performance of this typology of composite columns in the fire situation. This paper aims at designing strategies for maximizing the fire resistance of CFST columns using innovative solutions such as double-tube sections, embedded HEB profiles or embedded steel cores. Additionally, the fire performance of such columns may be enhanced by using high strength steels (HSS). In this paper, a numerical model is developed and, after being validated against experimental results available in the literature, it is used for conducting a parametric study. Different steel grades are considered for the inner profiles, in order to investigate the influence of HSS. Through the results of the parametric study, the fire performance of the different cross-sectional geometries is compared, and recommendations are given for enhancing the fire resistance of CFST columns.