Investigating the Geotechnical Properties of Clay-Gravel Mixtures

The suitability of soil for engineering purpose depends largely on their ability to remain in place and support whatever load that is placed upon it. Clays are detrimental to stability. Therefore, this study evaluated the influence of gravel on the geotechnical properties of clayey soil. The clayey soil samples were obtained from a dug pit from two different locations in Osogbo, Osun State and the gravels were collected locally. Three different gradations of gravel (2mm-6mm, 6mm-12mm, and 12mm-20mm) were mixed in a dry state in percentages of 5%, 10%, 15%, 20%, 30%, 40% and 50% with the two clayey soils collected respectively. Geotechnical properties including Index property test and Compaction were determined in accordance with BS 1377 and analyzed. The addition of gravel to the clayey soil led to an increase in Maximum Dry Density (MDD) and reduction in Optimum Moisture Content (OMC) as the concentration of gravel increases with size in the clay-gravel mixtures.