Self-Healing Concrete Tests Are Underway in WalesEngineering360 News Desk | October 30, 2015
One of the UK’s first major trials of self-healing concrete is underway in Wales. The test is being led by university researchers who are testing ways of repairing concrete without human intervention.
The project, entitled “Materials for Life,” is piloting three separate concrete-healing technologies with the goal of incorporating them into a single system that could be used to repair.
The aim of the project is to develop a single system that can be embedded into concrete when it is initially set, and then automatically sense when damage occurs. Once damage is detected, the system will be able to repair itself without the need for human intervention.
The trial is being undertaken in collaboration with Costain, an industrial partner, and is taking place at one of their construction sites on the Heads of the Valleys road improvement in South Wales.
The research team, includes academics from the University of Cardiff, the University of Bath and the University of Cambridge.
The first technique uses shape-shifting materials, known as shape-memory polymers, to repair large cracks in concrete. When these materials are heated with a small electric current, they can transform into a different shape that the material has “memorized.” The researchers say that these materials can be embedded into concrete and used to close cracks or make them smaller.
In the second technique, researchers will pump both organic and inorganic healing agents through a network of thin tunnels in the concrete to help repair damage.
In the third technique, the team will embed tiny capsules, or lightweight aggregates, containing both bacteria and healing agents into the concrete. Once cracks occur, these capsules are designed to release their cargos and, in the case of the bacteria, the nutrients that will enable them to function and produce calcium carbonate, which the researchers expect will heal the cracks in the concrete.
The researchers have cast six concrete walls at the test site, each containing the different technologies. Over time the team will load the concrete at specific angles to induce cracks, and then monitor how effective each of the self-healing techniques is.