Agricultural and forest soils contain various species of Trichoderma. Several species of this soil fungi are also used as biocontrol agents to inhibit root disease. One species, Trichoderma reesei, is showing promise in a whole other realm—it appears to be the key to self-healing concrete.
It works like this: Scientists mix fungal spores and nutrients with the concrete. The concrete is poured and sets as usual. Over time, cracks develop. These fissures allow water and oxygen to penetrate the concrete, and this triggers the fungal spores to germinate. The fungi grow, reproduce and precipitate calcium carbonate, an ingredient in cement. The calcium carbonate fills in the cracks, which stops the flow of air and water. Back in an inhospitable environment, the fungi form spores. When cracks form again, their dormancy will break and the cycle is repeated.
Source: Interactions of fungi with concrete: Significant importance for bio-based self-healing concrete. Jing Luo, Xiaobo Chen, Jada Crump, et al. Construction and Building Materials. 2018. Volume 164. Pages 275-285.
- Janet Wallace