South East Wales

'Self-healing' concrete trial launched in south Wales

The concrete test walls that have been erected at the Heads of the Valleys road Image copyright Cardiff University
Image caption The concrete test walls erected at the Heads of the Valleys Road

Scientists have launched a trial of "self-healing" concrete in the south Wales valleys in a bid to combat potholes and structural damage.

The Cardiff University-led project is piloting the technologies in real-world settings for the first time.

It aims to create a system which senses damage and repairs it without human intervention.

The trial is taking place at Costain's construction site at the Heads of the Valleys Road (A465) in Blaenau Gwent.

Prof Bob Lark, principal investigator on the project, said: "Our vision is to create sustainable and resilient systems that continually monitor, regulate, adapt and repair themselves without the need for human intervention.

"These self-healing materials and intelligent structures will significantly enhance durability, improve safety and reduce the extremely high maintenance costs that are spent each year."

Image copyright Cardiff University
Image caption 'Shape-memory polymers' are embedded into the concrete, working like steel reinforcements

In 2014 alone, the estimated cost of getting roads in England and Wales back into a "reasonable" condition increased to £12bn.

As they try to slash this cost, researchers have cast six concrete walls at the test site, each containing different technologies.

The Materials for Life team, which also includes academics from the University of Bath and the University of Cambridge, is trialling shape-shifting memory polymers to repair large cracks.

A second technique involves researchers pumping organic and inorganic healing agents through a network of thin tunnels in the concrete to help fix damage.

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Media captionMarje Harris is frustrated by the potholes on an unadopted road in Swansea

The third will see the team embed tiny capsules, containing both bacteria and healing agents, into the concrete which react when cracks occur.

Over time, the researchers will load the concrete at specific angles to induce cracks and then monitor the effectiveness of each technique.

Oliver Teall, a civil engineer at Costain, said: "We will be monitoring properties such as stiffness, permeability and the mechanical damage recovery of the trial walls in comparison with conventional reinforced concrete walls."

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