Researchers create concrete that can repair its own cracks

Concrete is one of the most common building materials in the world. The foundation for the home you live in right now is probably made from concrete. Many of the huge buildings in downtown areas around the world are also made from the material. Even the Romans used concrete as a building material. Researchers are looking into away to make the material more durable and a professor from Delft University of Technology in the Netherlands has created a new type of concrete.

One concern for buildings made from concrete is cracks that develop in the material over time. These cracks let water in and the water can corrode the internal structure of metal inside the concrete and lead to a full structure collapse over time. The answer that Professor Henk Jonkers has come up with is a concrete that can repair its own cracks.

The professor and his team have invented something dubbed bioconcrete. The material is concrete that heals itself using bacteria. This concrete is mixed like normal concrete with an extra ingredient added. That extra ingredient is the healing agent and when mixed into the concrete the material remains intact and does nothing to the material.

However, over time when cracks develop the healing agent activates when exposed to water. The bacteria used inside the concrete is bacillus bacteria chosen for its ability to survive years with no food or oxygen. That bacteria produces limestone when exposed to a food source and water. The food source mixed into the concrete in this case is calcium lactate. The calcium lactate was placed into biodegradable capsules in the concrete that dissolve when hit by water, releasing the food source for the bacteria activated by the same water. The result is a self-repairing crack in the concrete.