This study focuses on the use of heavy fuel oil in construction in Burkina Faso. Mixed with silty and/or clay soil, it is used as a coating to reinforce the walls of raw soil constructions which are very sensitive to water. The interest of this paper is to shed light on the thermomechanical and above all water effects of heavy fuel oil on a sample of silty clayey soil. To achieve this, we used heavy fuel oil added in different proportions to silty clayey soil, to make sample of bricks on which tests were carried out. At the end of the experimental tests carried out on materials made (bricks) with our soil sample, it appears that heavy fuel oil moderately reduces the mechanical resistance of bricks and slightly increases thermal diffusion through them. On the contrary, we note a very good water resistance of the bricks thanks to the heavy fuel oil, in particular their water absorption by capillarity. This confirms that the mixture of heavy fuel oil and a silty-clayey soil used as a coating makes it possible to prevent the infiltration of water into the walls of raw soil constructions. However, its use as a construction material does not guarantee very good mechanical resistance, and slightly increases thermal diffusion.

Thermomechanical and hydrous effect heavy fuel oil building material