New laboratory testing procedures for mix design and classification of bitumen-stabilised materials

In this study, new testing procedures for bitumen-stabilised materials (BSMs) are developed to address the main inadequacies of the current laboratory procedures, which do not simulate the performance of BSMs relative to the representative field conditions. The shortcomings are identified, and areas of concern for the mix design of foamed bitumen and bitumen emulsion mixes are addressed. The proposed review undertaken in this paper focuses on the need for the development of more appropriate testing procedures for assessing mix properties and performance, such as flexibility, shear resistance and moisture durability. These procedures involve a new compaction method, a moisture-conditioning method and triaxial testing. The findings show that the newly developed testing procedures can consistently produce BSM specimens and reliably classified BSMs for mix design as well as pavement design purposes.