Analysis of the GHG savings and cost-effectiveness of asphalt pavement climate mitigation strategies

Abstract In order to achieve current sustainability and circular economy targets, the use of cleaner practices is required. Therefore, for the abatement of emissions in a cost-effective way, the use of waste materials, reduced manufacturing temperatures, and the increased use of bio-based materials should be explored in the asphalt pavement sector. In response to this need, this study carried out a carbon footprint and economic analysis for the three aforementioned strategies. To fully understand the potential of these pathways, the use of reclaimed asphalt (RAP) and crumb rubber (CR) in different quantities, the use of hot-, warm- and half-warm-mix asphalts, and the use of bio-based binders were considered both at the cradle-to-laid and 40-year life cycle level. The results of this study indicate high quantities of RAP and producing mixtures below 100 °C would provide the greatest environmental and cost benefits. At lower amounts of RAP, the use of CR was found to be more viable; especially with a higher durability. Bio-based materials also provide a large GHG saving potential, but would require commercialisation to be viable. The results of this study serve as a primer for researchers, industry and local authorities to better explore and combine climate mitigation and cost-effective strategies. Future work will cover the use of these results for their implementation in a decision-making system, including the novel indicator defined.