Civil engineers would be better able to appreciate the cost that goes into repairing buildings, potholes and roads every year. According to a rough estimate, the cost is in billons. A microbiologist decided to do something about this and has created a concrete that can heal itself and is capable of mending cracks using bacteria. What’s so amazing about this is the fact that this bacteria can be added to a liquid and then sprayed upon the existing cracks to allow them to mend themselves.
For those of you who are not aware of this; reinforced concrete stress eventually gets small cracks, the process is gradual but assured. Water then penetrates the steel in the concrete and subsequently results in the rusting of steel and imparting brittleness to it. By making use of a bacteria that is usually found in vicinity of active volcanoes or soda lakes such as those close to Wadi Natrum in Egypt, the researchers mixed the material into the concrete as it was being manufactured. The bacteria is cold and heat resistant.
Inventor Hendrick Marius Jonkers from Delft University of Technology said, “The bacteria live in nature, usually in stones. The special thing about them is that they form spore meaning they are well suited to the concrete because they can survive for a long time.”
The bacteria is mixed with water along with calcium lactate and concrete components. Once cracks in the concrete appear and water enters, the bacteria is ‘awaken’. Oh and here’s an interesting fact; the bacteria is capable of lying dormant for about 200 years. Once active, the bacteria eats the calcium lactate and secretes limestone, thus resulting in closing of the cracks. The bacteria needs about 3 weeks to seal the cracks and the length that it can fix has no limits. However, the only limiting factor is that the crack has to be 0.8mm wide or less than that for the process to work effectively and efficiently.
Dr. Jonkers said, “The concrete [is] perfect for structures which are difficult to maintain, like underground buildings, motorways or oil rigs. It is extremely durable. The bacteria are specially adapted to extremely alkaline environments, and can survive dormant inside the concrete for years.”
The team owing to this invention has been nominated for a European Inventor Award.