Some Practical Aspects regarding the Handling of Dolerite for Base and Sub-base Construction

Good quality base and sub-base material for road pavement construction is becoming increasingly scarce. Dolerite is one of the more abundant natural road building materials in South Africa. Yet, it seems that the road design and construction fraternity shy away from using it in favour of more expensive commercially produced crushed material – and so artificially increase the scarcity of natural base and sub-base material. Could this actually be because the knowledge and know-how of handling dolerite is being lost? This paper intends to assist in reversing this dwindling spiral by exposing some of the myths regarding the application of dolerite material for base and sub-base pavement layers. The nature and background of dolerite as a road building material is discussed as well as the traditional road building cautions as they relate to the latest understanding of the material – based on the experience of the authors, supported by the findings of a CSIR research programme that they are involved in.