T0546 Collaborative Research 2023-2025

The asPECT tool has become established as the method for producers to carbon footprint asphalt mixtures that are used on the SRN and beyond. asPECT was last updated in 2020, having originally been developed in 2009. As the net zero agenda has gathered pace in recent years, demand for a tool such as asPECT has increased, in order to provide mixture-specific carbon footprints for individual schemes, which often incorporate innovations that are specifically aimed at reducing carbon emissions, such as lower-temperature mixtures, high recycled contents and bitumen with novel additives.

Furthermore, the methodology for carbon footprinting has evolved and is now tending towards use of the climate change impact categories of Environmental Product Declarations (EPDs) as a perceived 'reliable' source of data, including the forthcoming whole-life cost-carbon tool for road schemes. Other core impact categories of EPDs produced in accordance with EN 15804:2012+A2:2019 are also coming more into focus, as broader sustainability strategies are published and there is realisation that pursuing carbon reduction at all costs can sometimes lead to unintended consequences. In 2020, TRL produced a report "Review and update of the asPECT carbon footprinting tool" which reviewed the potential for asPECT to be re-developed into an EPD generator. asPECT provided a method to consistently calculate carbon footprints, such that those generated by one supplier could be directly compared to those of another. This same consistency of measurement is now required for EPDs. Ease of use of the method should also be an underlying aim, for producers on all scales of operation.