From Emissions to Solutions: The Rise of Carbon-Storing Highways

The UK is at a turning point in road construction. As the government shapes its Road Investment Strategy (RIS3), the focus must shift towards sustainable and carbon-neutral roadbuilding. Traditional construction methods are high emitters of CO₂, but new innovations like carbonated recycled concrete aggregate (cRCA) and carbon-negative asphalt aggregates offer a pathway to decarbonizing UK highways.

The National Highways supply chain saw an alarming increase of 63,000 tonnes of CO₂ emissions last year, pushing total emissions to 1.4 million tonnes over four years. One solution to counteract this? Carbonated recycled concrete aggregates (cRCA)—a technology pioneered by Neustark in Switzerland. This method stores CO₂ permanently in recycled concrete by accelerating mineralization, turning roads into carbon sinks rather than emitters.

If implemented in major UK projects like the A66 Northern Trans-Pennine and Lower Thames Crossing, this could sequester over 19,000 tonnes of CO₂, equivalent to the emissions from 4,750 flights between London and New York.

Another breakthrough is happening in asphalt production. Low Carbon Materials (LCM), in partnership with National Highways, is developing a carbon-negative aggregate for asphalt mixes. The UK produces 25 million tonnes of asphalt annually, covering 95% of the road network. Using carbon-storing aggregates, roads can absorb more carbon than they emit, making net-zero asphalt a reality.

By integrating these cutting-edge materials, UK road construction can lead the way in climate-friendly infrastructure, creating economic opportunities while reducing the carbon footprint of highways.