Design of sustainable asphalt pavements: a parametric model for Global Warming Potential

The increasing attention on sustainable infrastructures has required the development of innovative methods to assess and reduce the environmental impact of pavements. This research presents a parametric, LCA-based model designed to estimate CO₂ equivalent emissions from asphalt layers. The study focuses on hot mix asphalt produced in batch-type plants considering the potential incorporation of up to 30% reclaimed asphalt pavement. The proposed estimation method aligns with the level of detail which is commonly required for comparative analysis during the preliminary design stage of road infrastructure projects and adheres to a cradle-to gate perspective. The model employs typical design parameters as input data and uses linear impact functions to relate the input variables to Global Warming Potential. The equations are based on unit impacts, for which reference values have been provided. The impacts have been calculated using inventory data from Ecoinvent 3.6 database and the impact models adopted by TRACI 2.1 methodology. Where feasible, datasets with European geographic representativeness were prioritized. Nevertheless, the methodological framework behind the model ensures its validity regardless of the specific unit impact values, thereby enabling users to adopt it in various contexts and laying a solid foundation for future enhancements. Ultimately, this study delivers a practical, user-oriented tool that combines simplicity with accuracy, enabling designers to compare the environmental performance of alternative pavement solutions at an early stage. By providing a solid foundation for future refinements, the model contributes to advancing sustainable practices in road infrastructure development.