UNDER REAL FIRE SCENARIOS

Within two successive European research projects involving CTICM (France), ARBED (Luxembourg) and TNO (Netherlands), several fire tests have been performed on cars and on a real car park made of steel columns and steel beams connected to composite slabs. Although a drastic increase of combustible product in cars, the experimental results have given convinced evidence that fire protection of the steel structure is not necessary to get an overall stability. Parallel to above experimental investigations, numerical analysis has also been performed in which the fire development, the heating of the structure and structural behaviour during the fire are studied with different numerical models. However, the present paper will be focused mainly on the modelling of structural behaviour. It will be shown that the global structural behaviour (composite floor and steel column) subjected to localised heating from cars may be very accurately predicted by a 3D modelling in which the lateral buckling of steel beam, the membrane and diaphragm effects of the floor are taken into account. In addition, results of a parametric study is presented in which it is shown that the use of 3D modelling in the analysis leads to the possibility of building open car parks with a more economical steel and concrete composite structures