Stabilization of maiduguri black cotton soils of Nigeria with sand

The Lake Chad Basin is an extensive Quaternary lacustrine deposit of black clay soils. Laboratory investigations show that this soil consists of abundant proportions of montmorillonite and generally poses a major problem for Civil Engineering construction due to high volume changes. Alternative soils or aggregates suitable for base construction are very difficult to obtain in these localities and hence soil stabilization is of great economic importance to the construction industry. Methods of stabilizing this soil include lime stabilization, cement stabilization, mechanical stabilization, or heat treatment. This paper is primarily concerned with sand stabilization because of the presence of large deposits of dune sands at these locations. The result indicates that sand stabilization shows promise for improving the value of black cotton clays in pavement construction and is the most economical of all the applicable methods. However the method is recommended only for improving the subgrade and as a sub-base.