Use of a sedimentological technique for assessing the engineering performance of sands in roads

Abstract

Although sands cover vast areas of southern Africa, their use as road materials in an untreated state has been generally avoided. An investigation into the properties of various sands has indicated, however, that they can be used as subbase and even base course materials in low volume roads if carefully selected and tested. The investigation has shown that by expressing the particle size distribution of the sands as the mean particle size and standard deviation around this mean using the sedimentological Phi scale, it is possible to differentiate between sands that are likely to perform well and those that will not. The paper discusses this process and its application to selected sands from Botswana, Namibia, South Africa and Mozambique.