Analytical modelling has opened the door for fire behaviour prediction of not only building materials as concrete and steel but also of quite complicated concrete structures in general. This paper reflects some of the progress made within this field. A behaviour model of steel is used for coupling results from steady state and transient state tests. A recently developed procedure is shown on how to interpret and make such results comparable for practical use. The computational capability and reliability are illustrated for TASEF-2 temperature program and CONFIRE structural program developed at Lund Institute of Technololgy (LTH), Sweden, and Norwegian Institute of Technology (NTH), Norway, respectively. The success of computation is decisively dependent on reliable material models. The influence of axial restraint on failure time is exemplified.