Growing bricks
Existing bendable concrete is very impressive in its ability to resist damage, but even more so is concrete that grows and even repairs itself.
With concrete/brick manufacture being a hugely energy-intensive process, scientists and entrepreneurs are working to reduce its considerable environmental impact by creating products that are grown, not fired. There are several variations on a solution, but biotechnology start-up company BioMason recently won an innovation award for creating bricks made from bacterial by-products that bind sand particles together in a matrix strong enough to be used in residential construction.
In a mould, sand is mixed in alternating layers with a solution of bacteria, urea and calcium chloride, before resulting chemical reactions yield a mineral growth between the sand layers which binds them strongly together into a brick. This process has a long way to go and needs to be tested in vary conditions such as extreme cold and high wind. Soon we may be growing our homes and saving the planet at the same time, and these homes may also be able to repair themselves, again with the use of humble bacteria.
During manufacture, concrete may be embedded with clay particles containing the bacteria in a dormant state. Once a crack appears and water enters, the microbes are activated and multiply, excreting calcium carbonate as they do so which then plugs the holes and prevents further damage.
An exciting future lies ahead.
