T0669 Future Asphalt Surfacecourse linking to NH Net Zero Phase 3

National Highways' Net Zero plan includes ambitious strategic objectives for our Pavements. C&P, OD and SES have developed a Net Zero Asphalt Roadmap to support Net Zero by 2040 for pavement construction and maintenance activities. This roadmap includes exploring emerging technologies to face the increasing requirements for climate change resilience. The focus of the asphalt road map is A1 to A3 carbon. However, the scope includes innovations which extend life and resilience linked to climate change and severe weather.

This project has already successfully delivered Phase 1 (feasibility) and Phase 2 (implementation) is due for completion in March 2025. During these phases, five innovative low carbon trials (A30, A2, A34, A12 and A21) have been installed successfully on the Strategic Road Network (SRN) working in collaboration with Operations and advancing the innovations technology readiness level (TRL). These include bio-binders, bio-binders in combination with warm mix and reclaimed asphalt content, graphene, and high reclaimed asphalt content.

In Phase 3 the SES Pavements team is seeking to further expand the implementation stage by trialling in the SRN additional low carbon technologies for asphalt surface courses (which remains the main driver for RIS3 and onwards for pavement-related expenditure within the Operations) in isolation of stacked together in order to support their effective adoption and quickly realise their whole life benefits.

The main activities of this phase of the project are: continue the monitoring of the innovative low carbon trials delivered so far and demonstrate progress in TRL; design and delivery additional trials and laboratory testing of high potential low carbon technologies/levers; engagement with stakeholders; knowledge transfer; comprehensive assessment of single and/or combination of low carbon technologies; review and recommendations for amendments to standards to enable their early adoption.

Based on trials conducted to date and further trials in this phase, the ultimate output of Phase 3 will be a forward-facing review of the National Highways standards and proposal for amendments for the early adoption of these technologies as well as recommendations for next steps linked to the Net Zero Asphalt Roadmap. This is pivotal to achieve early realisations of potential whole life benefits from these technologies as well as effectively support the 2040 target by adopting them in the SRN as Business as Usual (BAU) from RIS4. Updates to standards are data driven and this project is essential to developing these outputs; including, rapid durability assessment to avoid overlong network monitoring periods.

The Contract is anticipated to commence in May 2025 and is planned to run until the end of March 2026. (The start and end dates may vary depending on contract award).