Over seven per cent of the world’s CO2 emissions come from cement production, so any means of prolonging the material’s life would help to reduce greenhouse gases. Researchers at Cardiff University, the University of Cambridge, and the University of Bath are taking part in a £3m project to create self-healing concrete. The material would be able to mend itself with the help of bacteria contained within microcapsules that would germinate and produce limestone when water enters a fissure.
Self-healing concrete could extend the life of paving and structures by 50% and do away with the need for manual repairs. Since concrete is highly alkaline, making it a difficult place for bacteria to thrive, researchers are trying to find an organism that is not only able to flourish, but able to produce a large amount of spores. The team will also have to determine the pore size of the concrete so that it is small enough not to crush the forming bacteria as it densifies during the drying process. Micro-capsules will enclose and protect the bacteria while providing nutrients and calcium lactate, which will be converted by the bacteria once water is present.
This novel form of concrete could make steel framework less vulnerable by avoiding the corrosive effects of oxygen. The scientists are now looking at several different species of bacteria and assessing their viability. With the addition of microbes, buildings and roadways could take on an organic element that combines biology, chemistry, and arch.