A new approach to assessing the durability of basic crystalline rocks as road aggregates

Abstract

Despite ongoing research covering more than 60 years in southern Africa, the assessment of the potential durability of basic crystalline rock aggregates for use in road construction is still a major problem. Over the years various innovative test methods and specifications have evolved to the point where currently, more than half a dozen tests are carried out with specifications for each. Frequently, the materials pass most of the tests but may be rejected by one or two, leading to indecision about their use and often probably incorrect rejection of a potentially useful material source. This paper describes the development of a weighted durability rating system, as used in a variety of road engineering disciplines, to quantify the potential durability and allow a better- informed decision on the material usage.