Improvement of the Parametric Fire of Eurocode 1 based on Experimental Tests Results

The basic equations, the limitations and the main features of the parametric fire proposed in Annexe B of Eurocode 1 are given. 48 experimental fire tests are used to assess the validity of
this model. The model has been applied to these tests and the comparison has been made, for
each test, on the maximum temperature in the air and on the maximum temperature calculated in 2 hypothetical steel sections, one thermally protected and one unprotected. The agreement is very poor for the air and for the unprotected steel temperature, and somewhat better for the protected steel temperature. Some proposals are made which allow to improve the agreement, while keeping the same expressions for the parametric fire. These modifications concern the equivalent thermal properties of multi material walls, and the introduction of a minimum duration of the fire and a of a ventilation effect in case of fuel-bed controlled fires.