26 April 2021 | Innovation | Collaboration | Environment

Aggregate Industries Completes UK’s First Carbon Neutral Pavement Scheme

Now complete, the road improvement project included full depth resurfacing of the dual carriageway between the M6 junction 36 and Brettargh Holt roundabout, along with the roundabout at junction 36. This forms part of the estimated £8million A590 scheme designed with a low carbon strategy to ensure safer, smoother journeys for road users on this vital route in Southern Cumbria.

Heavily trafficked, the surface had come to the end of its life with dangerous potholes and uneven surfacing posing a real safety risk for drivers. Hence, Highways England’s (HE) objective was to ensure the new road was constructed quickly, safely and with minimum disruption to customers and the local road network.

The project came with highly ambitious carbon reduction targets which saw Aggregate Industries’ expert technical credentials and value engineering approach help to achieve the UK’s first carbon neutral road improvement project.

Working in collaboration with principal contractor, AE Yates and designers AMEY, at the Early Contractor Involvement (ECI) stage over 18 months before the contract began, Aggregate Industries’ National Technical Manager, Neil Leake, recommended an innovative Foamix approach.

This  pavement design option meant that the structural layers of the existing road surface were recycled and encapsulated back into the pavement by producing an ex situ cold recycled asphalt which – when combined with the use of Aggregate Industries’ recently launched range of SuperLow asphalt helped to achieve a carbon neutral pavement construction. As the only Carbon Neutral asphalt available in the UK, SuperLow technology enables reduced carbon levels when compared to standard asphalt due to being manufactured at reduced temperatures.

Key to this, a dedicated SiteBatch mixing plant was placed on site to ensure continuous and consistent Foamix material was produced, supported by a fleet of Volvo Moxy dumper trucks to transfer material to site and return the extracted planings.

This approach allowed for maximum efficiency and saw the team lay over a 1,000T of Foamix asphalt per night, working 24 hours a day across two shifts, ensuring minimum disruption to the local area while keeping in advance of all key deadlines.

Working in this way, asides from the obvious benefit of improved circular economy and significant reductions in CO2 in the mixing process, negated the need for truck movements and waste disposal costs, hugely improving the sustainability aspects. The result was a huge 43% carbon reduction, as opposed to when using conventional resurfacing methods.

What’s more, as an industry first, through its partnership with Circular Ecology, Aggregate Industries purchased a number of credits to offset the remaining carbon on the scheme.

With Aggregate Industries advanced Site Operating Procedures (SOP) ensuring that construction could safely take place through the COVID-19 pandemic, in total, 50,000 tonnes of material was extracted from the original pavement and 38,887 tonnes recycled over the course of just six weeks.

This included 11,607 tonnes of asphalt and 27,280 tonnes of foamix laid using wide pavers (extended to eight metres). Meanwhile, circa 20,000 tonnes will be reused on the A590 Cross-a-Moor Roundabout Scheme and the strategic road network (SRN).

Guy Edwards, CEO at Aggregate Industries UK, said: “As the world’s first building materials supplier to commit to hitting net zero emissions by 2050, completing the UK’s first carbon neutral pavement scheme is a landmark achievement for us and demonstrates our commitment to achieving this goal.

“By working collaboratively with Highways England, AE Yates and Amey on the A590 M6 J36 to Brettarg Holt scheme during the early contractor involvement stage, we were able to identify a low-carbon approach designed to provide significant environmental; and in turn, cost benefits, by establishing a best practice approach to greener road surfacing.

“Looking forward, as we continue to work more closely together as an industry and utilise our expanding range of eco-friendly products and services, we can start to make a real difference when helping to deliver essential infrastructure projects.”