For many centuries, builders have created concrete by mixing sand with various substances that can make it as durable as possible. Unfortunately, scientists have still not been able to develop a composition that gives the material popular in the construction of houses maximum durability. Variants of concrete today are destroyed sooner or later, but scientists from the US state of Colorado managed to solve this problem. The composition of the concrete they developed contains the so-called cyanobacteria, which are able to multiply under the influence of the sun and oxygen. Yes, created using this technology is no stronger than concrete, but it is easy to restore if damaged.
The properties of living concrete were described in The New York Times. According to foreign journalists, the new material is a mixture of sand, regularly feeding the composition with liquid hydrogel and bacteria of the genus Synechococcus. The gel-like mass provides the microbes with the substances necessary for growth, and they, as they develop, produce calcium carbonate. It is this substance that gives the material strength.
American scientists claim that the composition they created with bacteria under certain conditions is able to fully recover. For example, if you break a brick created using the new technology, you can re-grow it by dousing it with a mixture of hydrogel and sand. Under the influence of the sun and nutrients from the hydrogel, bacteria literally come to life and help the brick to find its original shape. The main thing is that there should be whole bricks around the damaged material, which will prevent the mixture from spreading around the edges and help maintain shape.
The resulting material is as strong as concrete. However, in too dry conditions, bacteria can die and bricks can lose their self-healing properties. At the moment, researchers want to achieve maximum survivability of microorganisms in the usual conditions for us. It is known that at a relative humidity of about 30%, bacteria live for about a month, but scientists intend to improve this indicator.
But even the results now achieved are very interesting. The author of the scientific work, Chelsea Heveran and his colleagues broke the brick they created in half and, by adding hydrogel and sand, were able to grow eight exactly the same bricks from one fragment. They assured that the building material does not break, even if you step on it. Although scientists are confident in the strength of the bricks, it seems that it is too early to build buildings from them.
However, in the future such bricks will be very popular. From them it will be possible to build houses and even dwellings for the first colonizers of Mars. Not only will the structures made of such material be easily repaired, moreover, the bacteria contained in it will be able to warn of an increased concentration of harmful substances in the air. And all because they actively interact with the environment.