Concrete is a mixture of many different materials, which usually used to resist a compressive force. Concrete itself is one of the oldest and common construction materials in the world because of its availability, reliability, and many other reasons to use concrete as our construction materials. The basic mixture of the concrete includes cement, water, fine aggregate, coarse aggregate, air, and many various kinds of chemical admixtures. But did you know that concrete can heal itself?
A study conducted in 2006 by Henk Jonkers discovered a new type of concrete, self-healing concrete. Jonkers is a microbiologist and professor at the Delft University of Technology in the Netherlands. The idea was to combine nature with construction materials that used limestone-producing bacteria to help to repair the cracks in concrete. Bacillus bacteria are a perfect pair for the task because the Bacillus will evolve well in the high-alkaline conditions of concrete and can produce spores that can live up to four years without any food or oxygen. His invention is finalized by adding calcium lactate to the limestone concrete mixture to feed the Bacillus so they can produce limestone to repair the cracks in the concrete. Therefore, by combining nature with construction materials, we can make the self-healing concrete that can fix its damage by itself and minimize the risk of concrete failure.
Henk Jonkers, & Erik Schlagen. (2008). Development of a bacteria-based self healing concrete. Tailor Made Concrete Structures-Walraven & Stoelhorst (eds), 425-430.