Binghamton University in the United States has used a type of fungus to produce self-healing concrete which could be used to repair and protect ageing infrastructure.
The university said ageing concrete infrastructure in the US was crumbling and becoming increasingly dangerous, yet the funding available for repair had decreased. Binghamton University assistant professor Congrui Jin said the problem stemmed from tiny cracks in the concrete which left the reinforcement open to damage from water, carbon dioxide and chlorides.
Jin said the team had experimented by mixing fungal spores called trichoderma reesei and nutrients into concrete. These lay dormant until they were exposed to water and oxygen as a result of a crack opening up, they then “woke up”, ate the nutrients and grew, filling the cracks.
“With enough water and oxygen, the dormant fungal spores will germinate, grow and precipitate calcium carbonate to heal the cracks,” explained Jin.
“When the cracks are completely filled and ultimately no more water or oxygen can enter inside, the fungi will again form spores. As the environmental conditions become favourable in later stages, the spores could be wakened again.”
The university said the research was still in its early stages, but was hopeful it could be developed further. The findings of the trials have been published in the a paper entitled Interactions of fungi with concrete: significant importance for bio-based self-healing concrete.
Research into similar self-healing concrete technologies is also being carried out at Delft University of Technology in the Netherlands, and trials are currently being carried out by a Cardiff University-led team at the Heads of the Valley road project in South Wales.