Could fungi repair cracks in concrete?
The goal of a study was to explore a new self-healing concept in which fungi are used as self-healing agent to promote calcium mineral precipitation to fill the cracks in concrete.
Although many species of fungi have been reported to be able to promote calcium mineralisation, they have not yet been investigated in the application of self-healing concrete, thus an initial screening of different species of fungi has been conducted.
Trichoderma reesei spores germinate
The experimental results showed that, due to the leaching of Ca(OH)2 from concrete, the pH of the growth medium increased from its original value of 6.5 to 13.0. Despite the drastic pH increase, Trichoderma reesei spores germinated into hyphal mycelium and grew equally well with or without concrete. The researchers employed material characterisation techniques including X-ray diffraction (XRD) and scanning electron microscope (SEM), both of which confirmed that the crystals precipitated on the fungal hyphae were composed of calcite.
More detailed studies are necessary
Of course, there is much work ahead to determine whether the spores will survive in concrete. But the early results provide reason to study this in more detail.
The study is pushlished online at https://arxiv.org/.
