The first major trial of self-healing concrete in the UK, led by a team of researchers from Cardiff University, is being undertaken at a site in the South Wales Valleys. The project, entitled Materials for Life (M4L), is piloting three separate concrete-healing technologies for the first time in real-world settings, with a view to incorporating them into a single system that could be used to automatically repair concrete in the built environment.
The first technique uses shape-shifting materials, known as shape-memory polymers, to repair large cracks in concrete, 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, and in the third technique, the team will embed tiny capsules, or lightweight aggregates, containing both bacteria and healing agents into the concrete. It is anticipated that once cracks occur, these capsules will 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 envisage will heal the cracks in the concrete.
The overall aim of the Cardiff-led 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 autonomously without the need for human intervention.
The trial is being undertaken in collaboration with one of the major industrial partners on the project, Costain, and is taking place at one of their construction sites on the Heads of the Valleys road improvement scheme in South Wales – the A465.