Uncertainties in determination of fire resistance by experimental testing and by calculation

In Europe, certification of the fire resistance of building construction elements can be assessed by experimental testing or by calculation. To date, both communities (testing and calculation) express the fire resistance results in a deterministic way, i.e. each fire resistance result consists in a single number as if there was no uncertainty. However, when asking different partners within a community to assess the fire resistance of a given element of building construction subjected to a given fire scenario (a so-called “round robin” exercise), the reported results exhibit a very significant variability. Recent efforts have been undertaken to evaluate the extent of the scatter for fire resistance results, i.e. a process of "uncertainty evaluation". This process recognizes the fact that, for a given element of building construction and a given fire scenario, only a probability distribution (as opposite to a deterministic value) can be attributed to the fire resistance result. This approach opens the door to probabilistic reporting as an alternative to deterministic one.