As nerdy as it probably sounds, I can’t even begin to put into words how excited I am for products like this. Back in January of 2014, I wrote about the winners of the 2013 Cradle to Cradle Product Innovation Challenge, including the inventors of self-healing bio-concrete. Cracked concrete is a frequent allegation in construction defect claims.
Researchers at the Delft University of Technology in the Netherlands got some nice publicity recently about the novel bacteria-activated self-healing properties of their advanced concrete material. Lead researcher Henk Jonkers explained that the first challenge was finding the right species of bacteria for producing limestone. But that was only part of the equation:
In order to produce limestone the bacilli need a food source. Sugar was one option, but adding sugar to the mix would create soft, weak, concrete.
In the end, Jonkers chose calcium lactate, setting the bacteria and calcium lactate into capsules made from biodegradable plastic and adding the capsules to the wet concrete mix.
When cracks eventually begin to form in the concrete, water enters and open the capsules.
The bacteria then germinate, multiply and feed on the lactate, and in doing so they combine the calcium with carbonate ions to form calcite, or limestone, which closes up the cracks.
No news of when the material will begin testing prior to approval for use in various applications.