Mix design of bitumen-stabilised materials – South Africa and abroad

The need for sustainable road infrastructure maintenance has led to a significant growth in pavement recycling and bitumen-stabilisation technology. This, in turn, has created a need for robust mix design and pavement design procedures for bitumen-stabilised materials (BSMs), using either foamed bitumen or emulsified bitumen binders.This paper outlines the research developments in the field of BSM technology and testing and their link to a standardised mix design. At the same time, the link between mix design and structural design is established, creating a platform for laboratory test results to be used in the evaluation of the life of the pavement structure. In particular, the challenging areas of mix design are highlighted, namely: Development of a laboratory compaction method for BSMs that effectively simulates field compaction,Improvement of laboratory curing procedures to simulate the dry-back phenomenon that occurs in the road, after construction,Development of triaxial testing equipment and proced...