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 road users' journeys on this vital route in Southern Cumbria, north-west England.
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 built quickly, safely and with minimum disruption to customers and the local road network.
A scheme like no other, the project came with highly ambitious carbon reduction targets which saw Aggregate Industries' expert technical credentials and value engineering approach helps 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 existing road surface's structural layers were recycled and encapsulated back into the pavement by producing an ex-situ cold recycled asphalt. When combined with Aggregate Industries' recently launched SuperLow asphalt range, this 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.
Critical 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 the 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 (a non-profit organisation), Aggregate Industries purchased credits to offset the scheme's remaining carbon.
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 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."
A spokesperson for AE Yates added: "Combining the technical excellence and innovative technologies of AI and the industry-leading project management and passion for collaboration of A E Yates has once again delivered a highly successful project. Completing this scheme is testament to what can be achieved through teamwork and collaboration!"