Could self-healing roads solve the UK's pothole problem?

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Could self-healing roads be the answer to the UK’s £143 million pothole problem?

A team of scientists from King’s College London, Swansea University, as well as scientists from Chile, is designing a new type of self-healing asphalt made from biomass waste that can fix itself over time, without needing any human intervention. Potholes are a big problem across England in Wales, with £143.5 million spent annually trying to fill them in, with an estimated £16.3 billion needed to bring the roads up to standard.

When the bitumen (the sticky black material in asphalt) hardens through oxidisation, cracks can develop, but the team have found a new way to reverse this. They have developed methods to “stitch” the asphalt back together, which will lead to more durable and sustainable roads.

The team used AI to study organic molecules in complex fluids like bitumen, and develop a new data-driven model to speed up atomistic simulations, which has rapidly developed research into bitumen oxidation and crack formation. Additionally, the team is working with Google Cloud to simulate the behaviour of the bitumen on a computer.

Tiny porous materials (‘spores’) make the asphalt ‘self-healing’, which are smaller than a strand of hair and made from plants. These spores are filled with recycled oils, which are released when the asphalt starts to crack, reversing the fracturing. The use of recycled materials reflects a wider movement from scorings to try reduce the use of fossil fuels and make roads more sustainable.

In laboratory experiments, this advanced asphalt material was shown to repair a “microcrack” on its surface in under an hour.

Dr Francisco Martin-Martinez, an expert in computational chemistry at King’s College London, said: “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. Creating asphalt that can heal itself will increase the durability of roads and reduce the need for people to fill in potholes.

“We are also using sustainable material in our new asphalt, including biomass waste. This will reduce our dependence on petroleum and natural resources. Biomass waste is available locally and everywhere, and it is cheap. Producing infrastructure materials from local resources like waste reduces the dependence on petroleum availability, which helps those areas of the world that have limited access to petroleum-based asphalt.”

Dr Jose Norambuena-Contreras, an expert in self-healing asphalt at Swansea University, said: “In our interdisciplinary study, we are bringing together experts in civil engineering, chemistry, and computer sciences to investigate the self-healing properties of modified bitumen. By combining the knowledge with the state-of-the-art AI tools of Google Cloud, we aimed to enhance our understanding of bitumen’s healing capabilities through a bottom-up molecular design approach.

“We are proud to be advancing the development of self-healing asphalt using biomass waste and artificial intelligence. This approach positions our research at the forefront of sustainable infrastructure innovation, contributing to the development of net-zero roads with enhanced durability.”