A team of scientists from Swansea University and King’s College London, in collaboration with scientists in Chile, is designing a new type of self-healing asphalt that can mend its own cracks without the need for maintenance or human intervention.
Self-healing asphalt roads, made from biomass waste and designed with the help of artificial intelligence (AI), could offer a promising solution to the UK’s pothole problem, which is estimated to cost £143.5 million a year.
Cracks form when bitumen—the sticky black material in the asphalt mixture—hardens through oxidisation, but the exact processes behind this are not entirely known.
The team has found a way to reverse cracking and develop methods to “stitch” asphalt back together, creating more durable and sustainable roads.
During the research, a type of AI known as machine learning was used to study organic molecules in complex fluids like bitumen. The team developed a new data-driven model to accelerate atomistic simulations, advancing research into bitumen oxidation and crack formation. They are also collaborating with Google Cloud to simulate the behaviour of the bitumen on a computer.
To make the asphalt “self-healing”, the team incorporated tiny, porous materials known as spores, which are smaller than a strand of hair and produced by plants. These spores are filled with recycled oils, which are released when the asphalt begins to crack, helping to reverse the process.
In laboratory experiments, this advanced asphalt material was shown to completely heal a microcrack on its surface in less than an hour.
Dr José Norambuena-Contreras (pictured), a Senior Lecturer in the Department of Civil Engineering at Swansea University and an expert in self-healing asphalt, said: “As part of our interdisciplinary study, we have brought together experts in civil engineering, chemistry, and computer science, combining this knowledge with the state-of-the-art AI tools of Google Cloud.
“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.”
A substantial portion of carbon emissions from roads is linked to asphalt production. As the highway sector increasingly prioritises carbon reduction to support the UK Government’s goal of achieving net-zero emissions by 2050, advancing innovative bituminous materials for asphalt roads has become a key research priority.
Pic: Swansea University