Performance-based fire resistance design of concrete-filled steel columns

A simplified design equation for evaluating the fire resistance of concrete-filled circular and square hollow structural steel (HSS) columns is presented. The equation is expressed in terms of various structural design parameters affecting the fire resistance, and hence can easily be integrated into conventional structural design. This equation can be used to evaluate the fire resistance of HSS columns filled with various types of concrete filling. The use of the design equation greatly facilitates the calculation of the fire resistance of structural members on a performance basis. It also enables the designer to find cost-effective solutions in providing the required fire resistance performance for structural members, simply by varying the parameters of the members. The applicability of the proposed equation to a design situation is illustrated through a numerical example. Practical guidelines that can be implemented during the design and construction phase, and which have beneficial effects on the fire resistance behaviour concrete-filled of hollow steel columns, are also presented.