Influence of Shea Butter Residues on the Physico-Mechanical Properties of Earth Renders

This paper studies the influence of shea butter residues on the physical and mechanical performance of earth renders. Mineralogical and microstructural characteristics of shea butter residues as well as the physical and mechanical parameters of earth renders were evaluated. The results showed that shea butter residues are mainly composed of fatty substances. To enhance physical and mechanical performance of earth renders, contents varying from 0 to 6 wt% of shea butter residues were added to a local clayey soil, predominately composed of kaolinite (60 wt%), quartz (31 wt%) and feeble amount of goethite (2 wt%). This study showed that the incorporation of shea butter residues to earth renders improved meaningfully their physico-mechanical properties such as water and erosion resistance. This is particularly attributable to the hydrophobic properties of fatty substances contained in shea butters. Furthermore, shea butter residues incorporation increases earth renders porosity which contributes to reduce mechanical resistance and thermal conductivity and making the renders more insulating. Taking into account construction standards based on the protection of earth buildings and also their advantageous hydric properties and insulating power, earth renders amended with shea butter could be an adequate and affordable habitat building material throughout tropical regions of the world. Shea butter residues addition to earth renders decreases their linear shrinkage.Earth renders amended by shea butter residues have good water resistance.Shea butter residues addition to earth renders decreases their thermal conductivity.Lipidic molecules in shea butter residues explain these observed improvements.