Developing Global Warming Potential Criteria for Balanced Asphalt Mixes with Emerald Eco-Label EPDs

This study integrates balanced mix design (BMD) thresholds with Environmental Product Declarations (EPDs) for asphalt mixtures at three nominal maximum aggregate sizes (NMAS): 9.5, 12.5, and 19 mm. The primary objective is to evaluate both performance and environmental sustainability by combining BMD performance testing with EPD assessments, and to compare the resulting EPD values with current benchmarks for the State of Minnesota. Performance testing highlights that rutting resistance and cracking performance vary considerably among different NMAS mixes and are significantly influenced by binder content. In parallel, EPD analysis of the A1 stage (raw material processing) demonstrates that mix composition and binder content strongly influence CO2 emissions. Higher binder contents enhance cracking resistance but increase emissions, while lower binder contents reduce emissions and favor rutting resistance. The findings underscore the need for regional adjustments to EPD thresholds within a BMD framework and offer state-specific recommendations for Minnesota. By integrating life cycle assessment early in the mix design process, this study provides a practical methodology for developing asphalt mixtures that balance mechanical performance with environmental objectives.