Hubert @ stock.adobe.com
By adding natural healing agents into the concrete mixture, it is possible to create self-repairing cementitious construction materials, solving the concrete's susceptibility to corrosion. This can be achieved by combining Bacillus spores and calcium lactate nutrients, which together possess self-healing capacities. Since concrete's pH has a high value, only this kind of alkaliphilic bacteria can survive and remain dormant for years without the need for food or oxygen. This limestone-producing bacteria gets activated when in contact with water and oxygen, so when a crack appears in the concrete, they multiply and close the split in a few weeks. This could be applied in underground containers for hazardous waste, for instance, but also to any concrete structure in order to reduce maintenance costs and improve safety.