A self-healing concrete developed by a Dutch researcher has been recognized as a 2015 finalist for a prestigious European Inventor Award, from the European Patent Office. Hendrik Jonkers is one of three finalists in the research category. According to a press release:
To heal cracks in the concrete, Jonkers chose bacteria (Bacillus pseudo?rmus and B. cohnii), that are able to produce limestone on a biological basis. The positive side-effect of this property: the bacteria consume oxygen, which in turn prevents the internal corrosion of reinforced concrete. However, the bacteria do not pose a risk to human health, since they can only survive under the alkaline conditions inside the concrete. Based on these findings, Jonkers and his team of researchers developed three different bacterial concrete mixtures: self-healing concrete, repair mortar, and a liquid repair system. In self-healing concrete, bacterial content is integrated during construction, while the repair mortar and liquid system only come into play when acute damage has occurred on concrete elements. Self-healing concrete is the most complex of the three variants.