Development of self-healing concrete moves closer
Bio-mineralisation is the process by which living organisms can produce minerals and has potential to help masonry crack remediation. Scientists at the Structural Engineering Research Centre (SERC) in Chennai now believe they are getting closer to developing a ‘self-healing’ concrete for commercial use.
SERC director Nagesh R Iyer said the bacteria could produce the minerals to help repair building cracks. Self-healing obviates the need for expensive and time-consuming repair work, and could reduce the cost of concrete structures by enabling engineers to dispense with steel reinforcement, the traditional method of preventing cracks from becoming too large.
The Delft University of Technology in the Netherlands has also been working on incorporation of bacteria into concrete. The bacteria produce calcium carbonate – akin to mineral limestone, as a waste product, which can naturally fill the cracks or holes.
Green building start-up bioMason has developed a method for “growing” bricks using bacterial colonies, dispensing with the need for energy-intensive manufacturing processes. The biomass bricks also make use of raw materials like salt and yeast extracts, and are capable of recycling waste products such as urea.
Meanwhile Ecovative, a company founded to develop alternate uses for mushroom mycelium, has developed a microscopic, fibrous fungus which, when bound to agricultural waste, creates a strong, resilient matrix that can be moulded into any shape.
Architecture firm The Living and structural engineers Arup were the first collaboration to use the mushroom bricks in a building open to the public. Their fungal tower was on show at MOMA in New York.
The structure comprised 10,000 organically grown bricks that reached 40 feet in height and inverted the logic of load-bearing brick construction to create a gravity-defying effect — instead of being thick and dense at the bottom, it was thin and porous.The structure was calibrated to create a cool micro-climate in the summer by drawing in cool air at the bottom and expelling hot air from the top.