Geotechnical and Physical Characterisation of Alluvial and Lateritic Unfired Clays from Kadey (Eastern Cameroon) for Ceramic Applications

This study presents a geotechnical and physical characterization of eight alluvial clays and one lateritic clay from Batouri, eastern Cameroon (GPS coordinates: N 04. 42773°, E 014.36563°), to evaluate their suitability for pressed tile manufacturing. The sampled materials were dried, crushed, and sieved prior to analysis. The test program consisted of determining true density, bulk density, porosity, particle size distribution, Atterberg limits, and methylene blue value. The results indicate a significant variability in particle size distribution: sand content ranged from 29.31 to 85.9 wt.%, silt from 7.7 to 47.88 wt.%, and clay from 6 to 58.05 wt.%. Plasticity Index (PI) values varied between 6.7% and 33.38%, reflecting substantial differences in clay workability and pressing behavior. Methylene blue values, ranging from 0.53 to 2.23 g/100g, suggest variations in water absorption capacity and reactivity. The measured true density of the clays fell between 2.47 and 2.67 g/cm³, while bulk density and total porosity ranged from 1.53 to 1.68 g/cm³ and 34.08 to 42.56%, respectively. These findings demonstrate that while some clays are suitable for direct use in pressing, others require property optimization through blending or treatment. This study provides the first comprehensive geotechnical database for alluvial and lateritic clays from the Kadey region specifically for pressed tile applications, offering essential reference data for local ceramic industry development and establishing preliminary selection criteria for raw material formulation.