Large-scale fire test of unprotected cellular beam acting in membrane action

This paper describes a full-scale fire test performed recently on a composite floor for analysing the possibility for tensile membrane action to develop when unprotected steel beams in the central part of the floor are made of cellular beams. The natural fire was created by a wood crib fire load of 700 MJ/m2 and the 9 m × 15 m floor survived the fire, which peaked at 1000°C and lasted for about 90 min. Blind predictions of the air temperature development by the software 'Ozone' and of the structural behaviour by the software 'Safir', which proved quite satisfactory, are also described.