Bacteria often get a bad rap, but in many cases they’re helpful little critters. Engineers have now developed a protective coating for buildings that’s loaded with bacteria, which absorb CO2 to produce a barrier against erosion by the elements.
As strong as concrete and stone are, they’re not impervious to the relentless pounding of wind and rain. Over time the weather will win, which can leave buildings requiring regular maintenance or at risk of damage or collapse.
To help shore up buildings against the elements, researchers at the University of Hertfordshire are developing a new protective limewash. This special coating is bio-active, meaning it contains harmless bacteria that play a key role in strengthening the surface. Through photosynthesis, the microbes absorb carbon dioxide from the atmosphere, and use it to create a layer of calcium carbonate, which acts as a buffer against erosion.
A pre-production prototype of the coating is being developed by the University’s Zero Carbon Lab and a company called UK Hempcrete, and a testbed is already lined up. The limewash will first be trialed at the Whyte & Mackay whisky distillery on the Isle of Jura, off the coast of Scotland. Here, wind-swept rain regularly pounds against buildings, meaning the distillery needs a new coat every year. This regular maintenance impacts productivity and tourism, and increases carbon emissions from transporting materials to the island.
The team hopes that the new limewash will not only cut these carbon emissions by reducing the frequency of re-coating the buildings, but will counter some of the distillery’s other emissions by actively absorbing CO2 from the atmosphere.
If all goes to plan, the prototype coating should be applied to the distillery buildings by July, and a test run will be conducted for three to six months. After that, the team hopes to scale it up for commercial use.
Source: University of Hertfordshire
