Toward a standardized uniformly distributed cellulosic fire load

This paper describes a series of experimental tests performed on uniformly distributed fire load made of wood sticks. The aim of this campaign was to define a fuel load arrangement that would lead to a fire with the characteristics recommended for office building occupations in EN 1991-1-2. This means a fire load density of 511 MJ/m² and a medium fire propagation.
The ignition procedure that was developed is described as well as the fuel arrangement that leads to a continuous isotropic fire propagation. For the 11 tests performed, the evolution of the radius of the fire is given as a function of time as well as the constant tα that characterises the t² fire. The size of the sticks is not the dominant parameter that influences the fire spread, whereas the presence or not of a ceiling has an overwhelming influence and the volumetric ratio of wood in the fire load allows controlling the fire spread. Values of the volumetric ratio are proposed that should lead to a slow, a medium or a fast fire.