How much CO2 can we sequester within our roads?

The UK Net Zero Highways initiative aims to achieve net-zero emissions in road construction and maintenance by 2040, addressing the significant carbon footprint of materials like asphalt, concrete, steel, and aggregates. To meet this goal, the Net Zero National Highway roadmap proposes strategies such as the use of low-carbon materials, recycled content, enforced carbonation, and carbon capture and storage techniques. However, these strategies face challenges related to technology readiness, market adoption, and compliance with building codes, requiring further development and validation through comprehensive life-cycle assessments (LCAs). This research aims to develop a low-carbon sequestration strategy for road infrastructure that efficiently captures and stores CO2 at both laboratory and pilot scales. The strategy focuses on three key areas: (i) Material Development, creating scalable carbon-sequestering materials suitable for integration into road components like concrete and asphalt; (ii) Performance Modelling, evaluating the long-term performance of these materials under diverse environmental conditions; and (iii) Carbon Offsetting Validation, conducting cradle-to-grave LCAs to quantify the carbon offset potential of the materials. The project seeks to advance practical solutions that can be deployed to transform road infrastructure into effective carbon sinks and contributing to the UK's net-zero targets.