Résumé
Nowadays, the construction field is responsible for a quarter of french emissions of greenhouse gases and it represents the economic sector that consumes the most energy in France. A part of the solution is to promote the use of local and biobased materials with a low carbon impact. These biobased resources can be mixed with a binder to produce light (150 – 500 kg/m3), medium (500 – 1200 kg/m3), or high density (1200 – 1800 kg/m3) biobased concretes. The fire performance of these materials is poorly documented and therefore deserves further investigations. Consequently, it is hard for building professionals to demonstrate that building fire regulations can be fulfilled when using these materials. Thus, in order to study the fire behavior of these biobased concretes, at first, the flammability of the biobased resources was studied through tests carried out in the Pyrolysis Combustion Flow Calorimetry (PCFC), under aerobic and anaerobic conditions, and in the bomb calorimeter, to quantify their gross heat of combustion (GHC). Then, cone calorimeter experiments were carried out to study the ignition occurrence of biobased concretes. In the present study, more than 150 different formulations were studied. Results highlight that only the lightest biobased concretes ignite and, more precisely, it appears that fire ignition criterion relies on two parameters: the density of energy which bioconcrete can release and the energy required to heat the material surface, taking into account endothermic processes. Finally, a model to predict the ignition of bioconcretes was proposed