Preliminary mineralogical and geotechnical characteristics of Zogbodomey clays in the coastal sedimentary basin of Benin (West Africa)

Abstract

The Benin coastal sedimentary basin is filled with deposits of clays of diverse nature. This study focused on the characteristics of clayey materials of Zogbodomey in sight of their valorization in the construction and ceramics sectors. The clay deposit is covered by a lateritic layer of 2.5 m thickness around. The reserve updated of the deposit is estimated at 53,198,437 tons. The Clays are composed of 56.7% of kaolinite, 31.96 smectite and 6.79% of quartz. The plastic and liquid limits are 38% and 118%, respectively, with a plasticity index of 80%. Drying and firing shrinkage of the bricks of 3.125% and 3.25%, respectively, are acceptable. The compression strength of the bricks of 10 and 15, hollow block 15 and facing bricks is 1.3; 1.5; 2.7 and 8.6 MPA, respectively. These values are consistent with the standards recommended by the National Test Center and Research of Work Public (CNERTP). The characteristics of Zogbodomey clays are favourable for their use inr the manufacture of baked bricks.