The resurfacing was carried out by GW Highways in partnership with materials supplier Heidelberg Materials UK. The asphalt mix was developed to reduce carbon emissions and limit reliance on imported primary aggregates.
Departure from standard specification
To achieve the higher recycled content, the project team applied for a departure from the standard specification to incorporate 60 percent reclaimed asphalt in the 20mm binder course. The material was laid to a thickness of 60mm.
A specialist additive was added to soften the residual bitumen in the reclaimed asphalt, which improved workability and allowed the recycled proportion to be increased without affecting performance.
The asphalt was supplied from Heidelberg Materials’ Allington plant, located near the scheme, and resurfacing works were carried out overnight to minimise disruption for road users.
Reducing reliance on imported aggregates
Kent does not have aggregates suitable for asphalt production, so materials usually need to be brought in by road, rail, or sea. This increases both project carbon emissions and exposure to supply chain fluctuations.
Using locally sourced reclaimed asphalt reduced the need for primary aggregates and supported Kent County Council’s approach to resource efficiency.
Paul O’Neill, Regional Asphalt Director at Heidelberg Materials UK, said: “This project is the first time we have supplied asphalt with 60 percent recycled content and its success demonstrates the opportunity to replicate it across the country.
“Our partnership with GW Highways, as its preferred supplier in Kent, has created a culture of trust, which promotes innovation and drives sustainability and best value for the client.”
Herbert Micallef, Technical Director at GW Highways, said: “Collaborative working is one of our core values and this scheme is an excellent demonstration of that. We are now looking to build on its success by trialling a higher reclaimed asphalt content in surface course asphalt laid in the county.”
Byron Lovell, Pavement Asset Engineering Manager at Kent County Council, said: “Reducing our reliance on primary aggregates is essential for both carbon reduction and long term resilience in Kent. This project demonstrates how working closely with our partners can deliver real progress towards more sustainable highways. It is an encouraging milestone as we look to trial the use of recycled materials across future schemes.”
The resurfacing forms part of wider efforts to increase recycled content in UK highway surfacing as local authorities seek to cut carbon emissions and improve long-term material supply.
