ABSTRACT

Geotechnical evaluation of sub grade and subbase materials from Redemption camp and Igbesa and Ijuri area within the sedimentary terrain of Eastern Dahomey basin of South-Western Nigeria were analyzed for their physical and engineering properties required for construction purposes. Total of 13 soil samples were taken, 6 from the location Redemption Camp and 7 from Igbesa and Ijuri area for analysis. The physical characteristics such as Grain Size, Specific Gravity, Moisture Content, Consistency limits tests, California Bearing Ratio, Compaction tests were determined. The data obtained were subjected to statistical analysis. The degree of sorting in the three areas ranged from fair to good. The Plasticity Index ranged from 19-27, and higher than the recommended value. Specific Gravity of the three studied areas is 2.61,even though it is higher than the required standard of 2.60, it shows that it falls with the same range. California Bearing Ratio for soaked and unsoaked ranged from 19-30 and 43-48 respectively and considered to be low. Higher Optimum Moisture Content of laterites in the areas have ranged from 13.80- 16.35. The laterite in Redemption Camp is good for sub base while Igbesa and Ijuri laterites could be used for filling the foundation and can also be improved upon by adding cement, sandy and rock fragment in order to use it as sub base.