PHYSICOCHEMICAL AND MINERALOGICAL PROPERTIES OF CLAYS FROM FOUR SITES IN SENEGAL FOR THEIR USE IN THE PRODUCTION OF COMPRESSED EARTH BRICKS

This study aimed to characterize four types of Senegalese clay (Diamniadio, Daga Kholpa, Beer, and Diender) for producing compressed earth bricks (CEB). The study methodology included geotechnical tests, chemical analyses (X-ray fluorescence), and mineralogical analyses (X ray diffraction, thermogravimetric analysis, and infrared spectroscopy). The results show that the materials have varied grain-size distributions: clayey for Diender and Diamniadio (44.5% and 33.4%, respectively), silty for Beer (53.6%), and sandy for Daga Kholpa (64.9%). The high plasticity indices of Diamniadio (35.9%) and Diender (60.1%) indicate significant plasticity. X-ray fluorescence revealed a predominance of SiO2, Al2O3, Fe2O3 and CaO,whereas XRD identified quartz, kaolinite, calcite, illite, and depending on the site, montmorillonite, feldspar, dolomite, and anhydrite. These result allow to propose different stabilization methods: the most plastic clays (Diamniadio, Diender) can be stabilized with lime and/or a lime-cement mixture, while the less plastic clays (Daga Kholpa, Beer) are better suited for cement stabilization to produce cement-stabilized soil (CEB).