Char depth of several wood species under single or double heat exposures

For many engineering and fire investigation applications, understanding the behaviour of materials exposed to fire often relies on fairly simple measurements (e.g. char thickness) to deduce the quantities of interest (e.g. fire size or duration) by trying to account for a number of complex phenomena (e.g. influence of wood species, dimensions or moisture content). The aim of the work presented here is to analyse the charring process as a function of different experimental parameters, mainly a varying heat flux. The robustness lies in the large number of cone calorimeter experiments, as the char characteristics of 783 samples were measured. The results show promising correlations between the char depth (combination of missing and remaining char thicknesses) and the cumulative exposure, which represents the energy received by the sample, for a single or a double exposure and independently of the other experimental conditions.