Alfred Niamien KOUAMÉ^1,, Léon Koffi KONAN¹, Bi Irié Hervé GOURE DOUBI², Monique Tohoue TOGNONVI², Samuel OYETOLA¹

This study is part of the development of eco-building materials based on clay, cement, and agro-industrial wastes. The main objective was to study the mechanical and microstructural properties of compressed earth bricks (CEB) incorporating shea waste and stabilized with cement. To do this, three clayey raw materials denoted F (Fronan), K (Katiola) and Y (Yaou) consisting essentially of kaolinite, quartz, micas and ferric phases and the shea butter waste mainly composed of lignin (32%); cellulose (28%) and hemicellulose (19%) were used. Several samples of bricks with different compositions by mass percentage of clay, shea wastes (0 to 10%) and 5% cement were developed and characterized. The addition of shea butter wastes generates of porosity within of the compressed earth bricks. Results of the mechanical tests showed a possible substitution of 4% of clay F against 6% of clays K and Y by shea wastes. Thus, with these substitution rates, compressive strengths of 2.88 MPa, 3.01 MPa, and 2.49 MPa were obtained for F, K and Y, respectively. Also, the calcium silicates formed due to the addition of 5% of cement, allowed to keep mechanical performances despite the poor adhesion between the organic material and the clay-cement matrix linked to the low crystallinity of the shea wastes. Adding shea wastes to the clay-cement matrix therefore led to a less homogeneous microstructure.

clayey materials, Compressed Earth Brick (CEB), shea wastes, mechanical properties, microstructure