The development of earth-based bio-sourced materials requires a thorough analysis of the study
soil. For the present study, we took five (05) soil samples from a tunnel-digged quarry in the layer
between 0.5 m and 5 m : white clay (MSB-BL), red clay (MSB-RG), weak clay or sandy clay (MSBFB), strong clay (MSB-FR) and mixture (MSB-ME). To verify the quality of these five (05) soils
samples, their intrinsic properties were determined at the National Building and Public Works Laboratory (LNBTP). These included grain size, clay content, specific weight, loss on ignition and
moisture content. These analyses revealed that MSG-RG and MSG-BL clays have fine fractions of
64.28% and 47.85% respectively; clay fractions of 27.51% and 20.61% respectively; and
methylene blue values in the range (6;8). Their plasticity indices are in the range (20;40). These
two (02) clays thus meet the requirements in terms of granularity, and their relatively high clay
fraction will favor their adhesion with admixtures such as plant fibers. What's more, the particle size
distribution of these clays is within the ideal CRAterre range for soils used in the manufacture of
BTC or adobes, so they are all eligible.

Earth; granulometry; argillosity; composite materials