Using recycled materials for asphalt road pavement pothole repair to reduce carbon in construction

The physical condition of motorways and trunk roads in Scotland is monitored by specialist contractors on behalf of Transport Scotland by annual condition survey to provide information about the structural, surface and safety condition of the road surface or pavements. Flexible asphalt pavement is subjected to continuous vehicular and environmental loading causing potholes that needs to be reinstated to maintain functional requirements. However, traditional pothole repair materials have sustainability concerns and can deteriorate quickly after installation. The longevity and durability of pothole repairs is important as repeat treatments incite additional costs. Innovation can enhance sustainable development and for road transport infrastructure, the challenge is to utilise innovations without affecting the performance of the product. The action research focused on an ongoing road maintenance project and evaluated if sustainable innovative materials provided durability and longevity in comparison to traditional pothole repair materials and methods. The research was based on a trial of three sustainable materials. The findings suggest that creating a durable and long-lasting repair using cut and fill method that is excavated to the depth of the sound pavement is imperative. ‘G’, with reclaimed asphalt pavement performed well in comparison with existing baseline cold mix asphalt Viafix which also provides equivalent durability. The methyl methacrylate resin-based innovative materials ‘D and P’ provided strong resistance to dishing comparable with the baseline products. ‘D’ provided repairs that bonded well with the existing pavement and resisted ravelling whilst ‘P’ resisted polishing failures. All the innovative materials provided enhanced polishing resistance in comparison to the existing baseline cold mix asphalt Sandcarpet.