Fire resistance of columns in steel frames

The standard fire resistance test is not appropriate for predicting the behaviour of steel frames under fire conditions. The simplified theories that have been published in approved national and international documents apply to some restricted particular cases of single elements (beams, columns). In most practical circumstances beams and columns are subjected to a combination of axial forces and bending moments and have variable restraint and displacement conditions at their ends. The problem is particularly complicated for columns. For this type of situation advanced computer programs can at the present time provide a satisfactory method for the determination of the fire resistance. This paper illustrates the preceding comments by evaluating the fire endurance of an unbraced steel frame with two loading conditions.