Performance and cost analyses of pavements made with stone matrix asphalt and high-level Superpave mixtures incorporating alternative aggregates

Stone Matrix Asphalt (SMA) and high-level Superpave mixtures are widely used in the United States due to their durability and suitability for heavy traffic, but they typically require high-quality aggregates that are costly and not always locally available. Identifying feasible, cleaner, and cost-effective local aggregate alternatives is therefore critical for sustainable pavement construction because they can reduce transportation-related emissions, conserve natural aggregate resources, and improve supply-chain sustainability. Previous work demonstrated acceptable aggregate properties and promising laboratory performance for several Missouri aggregates (gravel, steel slag, chat, limestone, and dolomite) used as alternatives to standard-specified aggregates like traprock in SMA and high-level Superpave mixtures, but the evaluation was limited to material-level testing. This study extends that effort by assessing pavement-level performance and life-cycle cost-effectiveness of these mixtures. Laboratory-measured material properties were used as inputs to mechanistic pavement simulations to predict fatigue, rutting, and thermal cracking over a 20-year design life using a representative pavement structure under site-specific traffic and climate conditions. A life-cycle cost analysis (LCCA) was conducted based on material costs and predicted rehabilitation timing. The results indicate that SMA mixtures with alternative aggregates exhibited slightly higher predicted fatigue damage than the control mixture, while high-level Superpave mixtures showed minimal differences. Rutting resistance of candidate mixtures was comparable to or better than that of the control mixtures, and all mixtures were predicted to perform adequately against thermal cracking under local minimum pavement temperatures. The LCCA results demonstrate that all alternative aggregate mixtures are more cost-effective than the controls. Overall, the findings support the use of locally available alternative aggregates as cleaner materials capable of delivering satisfactory pavement performance while improving the economic and environmental sustainability of asphalt pavement construction.