An international team of scientists has developed a self-healing asphalt that can repair its own cracks without the need for human intervention, reducing the prevalence of potholes and extending the lifespan of road surfaces.

A team comprising scientists from Swansea University, King's College London, and collaborators in Chile has created a type of asphalt that incorporates tiny capsules filled with recycled oils. These capsules release their contents when cracks begin to form, sealing them almost immediately. According to initial laboratory tests, this process allows the pavement to regenerate instantly, sealing even the smallest micro-cracks in less than an hour.

"In our research, we want to mimic the healing properties observed in nature. For example, when a tree or animal is cut, their wounds naturally heal over time, using their own biology," said Dr. Francisco Martin-Martinez, an expert in computational chemistry at King's College London, according to IFLScience. The team used artificial intelligence and machine learning to model the movement of organic molecules in bitumen, the black sticky material in asphalt. This allowed them to optimize the self-healing capabilities of the new asphalt.

Cracks in road surfaces typically form when bitumen hardens through oxidation, leading to increased brittleness. Over time, the weight of traffic exacerbates these cracks, eventually leading to potholes. These defects pose a problem worldwide, compromising road safety and leading to repair costs for motorists and administrations alike.

The financial burden of potholes is high. According to Sky News, last year, a record £579 million was spent in the UK on repairing vehicles damaged by potholes, up from £474 million in 2023. Addressing this issue has become a priority for governments and transportation agencies.

"Creating asphalt that can heal itself will increase the durability of roads and reduce the need for people to fill in potholes," said Martin-Martinez. By proactively healing micro-cracks before they develop into serious damage, the self-healing asphalt could change road maintenance from reactive repairs to preventative care.

The new asphalt offers durability and environmental benefits. The material uses less oil and incorporates materials like biomass waste. This approach reduces dependence on petroleum and natural resources.

A portion of carbon emissions from roads is linked to asphalt production. By extending the lifespan of road surfaces and reducing the need for frequent repairs, the self-healing asphalt could contribute to carbon reduction efforts. Dr. Jose Norambuena-Contreras, lead researcher and expert in self-healing asphalt at Swansea University, believes this technology will contribute to the development of net-zero roads.

Working alongside researchers at King's College London and Google Cloud, the team utilized artificial intelligence to simulate and optimize the self-healing capabilities of the asphalt. Machine learning played an essential role by quickly simulating the material's behavior at the molecular scale, accelerating atomic modeling, and advancing understanding of crack formation.

Although the self-healing asphalt is still under development, the research group is optimistic about its potential. They believe this technology could enhance infrastructure and boost sustainability efforts worldwide, potentially revolutionizing road maintenance. As reported by Vroom, the self-healing asphalt represents an advancement towards more resilient and sustainable road infrastructure.

National Highways, the government agency responsible for the operation, maintenance, and improvement of motorways and major roads in England, is investing in such technologies. "This research will mean improvements and maintenance will be delivered more quickly with less disruption, and road users will have a far better end-to-end journey experience, with savings on time and the cost of travel," a spokesperson for National Highways said. 

This article was written in collaboration with generative AI company Alchemiq