Self-healing concrete

A group in Wales is testing concrete that can heal itself. Three different techniques are being pursued:

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 current, they can transform into a different shape that the material has ‘memorised’. The researchers believe 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. 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.

Concrete-patching bacteria. Cool! (via @CharlesCMann)

Update: Dutch microbiologist Hendrik Jonkers has been working on self-healing concrete as well, with products coming to market soon.

(via digg)

• science