The Volumetric Performance of Modified Stone Mastic Asphalt

Stone mastic asphalt is a mixture of asphalt concrete composed of coarse aggregate gradation gaps and mastic materials in the form of asphalt, filler, and stabilization materials. A large amount of coarse aggregate and filler is required to prepare this mixture. Modified stone mastic asphalt is created to reduce the natural exploration of aggregates and to build sustainable roads. Steel slag is an alternative material for replacing coarse aggregate in the stone-mastic asphalt mixture. Hydrated lime was added to the mixture to improve stability. The challenge in producing stone mastic asphalt is preventing drain-down during layoff, maintaining stability, and meeting volumetric properties according to the target specification. An excellent volumetric performance of a mixture can improve the performance of an engineering mixture. This research studied stone mastic asphalt incorporating steel slag and hydrated lime. It analyzed the volumetric properties of the modified stone mastic asphalt mixture and evaluated its density and stability. Unmodified and modified stone mastic asphalt were compared. Volumetric performance and Marshall stability tests are carried out to assess the mixture. The results indicated that modified stone mastic asphalt of steel slag and hydrated lime meets the required volumetric targets and exhibits improved stability.