Preliminary mechanical and environmental assessment of bituminous mixtures including a graphene-based compound

The constant increase in the performance request and the need to preserve the environment for future generations drive to the development of sustainable technologies and materials. Within this framework, extending pavement service life, reducing maintenance frequency, and limiting the consumption of virgin raw materials are key targets. Also, the reuse of reclaimed and end-of-life materials can contribute to these objectives, provided that the resulting mixtures maintain adequate mechanical and functional performance. In this perspective, this study investigates an innovative graphene-based additive incorporating selected recycled hard plastics for asphalt wearing courses. For this purpose, different mixtures have been produced with the additive via dry process and subjected to both functional and mechanical characterization, in order to compare the modified solutions with conventional and high-performance reference mixtures. The test results indicate that the use of a compound based on graphene and recycled hard plastics can improve selected mechanical performance indicators of the mixtures, especially indirect tensile strength, stiffness and rutting resistance. The investigated surface indicators remained within the relevant specification limits, although some variations with respect to the reference mixtures were observed. For a more robust evaluation of the experimental mixtures, they were also comparatively studied in terms of environmental impact using the Life Cycle Assessment (LCA) methodology. Within the adopted cradle-to-gate boundary, the results indicate reductions in energy consumption and related emissions for the modified mixtures. Overall, the findings support the technical feasibility of the proposed additive for the investigated asphalt mixtures, while conclusions regarding long-term durability, service-life extension and whole-life sustainability require further validation.