Bioconcrete: the "living concrete" that can heal itself

"We have invented bioconcrete -that's concrete that heals itself using bacteria", says Henk Jonkers of Delft University of Technology in the Netherlands.

No matter how its mixed or reinforced, concrete cracks. These cracks can often lead to collapse.

If you have cracks, water comes through -- in your basements, in a parking garage. Secondly, if this water gets to the steel reinforcements -- in concrete we have all these steel rebars -- if they corrode, the structure collapses."

Jonkers, a microbiologist, has discovered a way to give concrete a longer life by mixing concrete with a "healing agent". Meet Bioconcrete.


Bioconcrete is mixed like normal concrete but with added bacteria that can dissolve and activate once the concrete cracks and water gets in.


Jonkers had to find a bacteria that could survive the harsh, dry, alkaline conditions of concrete but also able to produce the repair material.


He chose bacillus bacteria because they thrive in alkaline conditions and produce spores that can survive for ages without oxygen or food. 


The next issue was to find a food source for the bacteria so they could create the repair material - limestone. Sugar was an option, but adding it straight to the concrete mix made the mix soft and weak.

Jonkers chose calcium lactate, and combined it with the bacteria then set it in capsules to be added to the mix. The capsules would only open once cracks form in the concrete and water gets in.

The bacteria germinate, feed on the lactate and multiply. They then combine the calcium with carbonite ions to form calcite (limestone) which fills in the cracks.

Is this a new age for biological buildings? Read more at CNN.com.