Fire resistance of steel columns filled with bar-reinforced concrete

Parametric studies, using mathematical models, were carried out to determine the influence of various factors on the fire resistance of steel hollow structural section (HSS) columns filled with bar-reinforced concrete. Data from the parametric studies were used to develop simple expressions for calculating the fire resistance of bar-reinforced concrete-filled HSS columns with circular and square cross sections. The validity of the calculation procedure was established by comparing the calculated fire resistances with those obtained from fire tests on columns. The procedure, which is suitable for incorporation in design codes, provides a rational and easy-to-use design method for evaluating the fire resistance of hollow steel columns filled with bar-reinforced concrete for any value of the significant parameters that determine it, such as load, cross-sectional dimensions, effective length, and concrete strength.