Optimisation of a road asphalt solar collector for energy harvesting

The sector of road paving is facing new challenges in environmental preservation and sustainability. Asphalt solar collectors (ASCs; structures embedded inside pavements for the extraction of heat due to solar irradiation) are modern devices for eco-friendly and energy-optimised roads. Fluids circulating inside collectors allow energy harvesting for building heating integration. The paper presents an optimisation of an ASC based on sustainability, thermal and mechanical concerns. Sustainability was evaluated through a life cycle assessment (environmental- economic impacts of real-scale ASCs). Thermal simulations were executed with computational fluid dynamic modelling software. The optimisation allowed the establishment of suitable ASC technical details (asphalt mix, collector material, dimension, layout and working mechanisms). A laboratory-scale testing was executed assessing the thermal response of ASC and rutting-related mechanical performance. The results indicated that a conductive asphalt (SBS AC12 with 15% graphite filler), together with a copper serpentine (50-mm installation depth) can constitute a sustainable and effective ASC.