Self-repairing pothole research could have application for Cork roads

Scientists at Swansea University and Kings College in London, alongside colleagues from Chile, are designing a ‘self-healing’ asphalt that may be the answer for potholes, the curse of Cork’s 12,000km-plus road network.

The self-healing asphalt, made from biomass waste, would enable the roads to mend cracks caused by traffic but without the need for maintenance or human intervention. Cracks form when bitumen, the sticky black material in the asphalt mixture, hardens through oxidisation, but the exact processes are not entirely known.

Now, a way has been devised by scientists, with the aid of AI, to reverse cracking and to develop methods to ‘stitch’ asphalt together again to create more durable and sustainable roads.

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.

Cork Social Democrats county councillor and civil engineer, Éamonn Horgan, said it would be interesting to see the cost of scaling up the technology to ‘real world application’ and how it compares to current methods.

“It may be some way off yet, but if there are any further studies requiring a full-scale test of the method, it could be an idea for Swansea University to collaborate with Cork County Council on some of our roads,” Mr Horgan said.

Oliver Moran, the Green Party member of Cork City Council, said that ‘an astonishing’ amount of money was being spent on the repair of estate roads and he would welcome anything that would reduce this cost.

“Every year, we can pay €50,000 to €100,000 to resurface just a short stretch of an estate,” he said. “Multiply that by the number of estates that need to be resurfaced each year and it simply devours the budget we have for local works.”