Aeolian Sands as Material to Construct Low-Volume Roads

Aeolian sands are widespread in many semiarid to arid areas of the world and often provide the only economic source of construction materials for low-volume roads. Experience in southern Africa over a number of decades has shown that provided aeolian sand materials are correctly selected and constructed, they can make effective subgrade, subbase, and base layers for low-volume roads. Research into their use has shown that the use of standard geological (sedimentological) techniques for classification allows the differentiation of sands that will perform well or badly as road base and subbase materials. The technique discussed uses the phi classification system, which defines the sands by their mean particle size and the standard deviation about this mean. Simple techniques for assessing the suitability of these materials for use and innovative construction methods for their use are described. The results obtained during monitoring of various roads indicate the benefits of well-compacted sand subgrades.