Sand is abundantly available in many countries in Africa and elsewhere in the world. However, very few of the pavement and material design guides currently in use worldwide cater for the use of this non-traditional material in its untreated state in the structural pavement layers, despite many instances of its good performance in low volume roads. This is the case largely because of an apparent lack of understanding of the characteristics and properties of sand, coupled with lack of compliance with conventional specifications – factors that have suppressed the more wide-spread use of this ubiquitous material in road pavement construction. This experience provided a strong motivation for the Association of Southern African National Roads Agencies (ASANRA) to initiate the development of a Guide on the Use of Sand in Road Construction in the SADC Region. In view of the above, wide-ranging investigations were undertaken of a large number of sand samples that were obtained both from existing roads and naturally occurring sand deposits located in Botswana, Malawi, Mozambique, Namibia and South Africa. These samples are considered to be representative of the wide range of sand types that occur in the southern African region and probably elsewhere in Africa. The objective of the investigations was primarily to ascertain the physical, mineralogical and engineering properties of a wide range of sands that could influence their performance in road pavements. On this basis, those sand properties that discriminate between good and poor performance could be isolated and included in appropriate specifications for selecting specific material types for use in road pavement construction. This, in turn, would lead to more wide-spread use of sand and the lowering of the overall cost of road construction..
Pinard, M.I.; Paige-Green, P.; Mukura, K.; Bofinger, H.; Motswagole, K.J.; Netterberg, F. Guide for the Use of Sand in Road Construction in the SADC Region. AFCAP/GEN/028/C. (2014) 102 pp.