Cities of the future could essentially repair themselves as scientists discover a way to create low-cost, sustainable, self-healing concrete.
Cracked concrete, be it in buildings or on pavements, is such a common sight these days that you are likely to never even notice it.
Despite its rigidity, the wear and tear of fluctuating weather and punishment from the everyday world means the lifespan of concrete can only go so far, resulting in costly, time-consuming and unsustainable repairs.
Or, in extreme cases such as in a nuclear power plant, cracks in concrete could potentially put thousands of lives at risk.
But what if concrete could actually heal itself?
That’s the breakthrough achieved by a team of engineers in the US, which has found an ingenious way for concrete to heal itself in an environmentally friendly manner.
Lies dormant until needed
In a paper published to Construction and Building Materials, the team revealed how it was inspired by the healing nature of the human body, which takes nutrients that can produce new substitutes to repair the damaged parts.
So, after much searching, the team finally found an unusual answer in the form of a fungus called Trichoderma reesi.
When mixed with concrete, the researchers found that it could lie dormant for extended periods of time, until the first crack appears.
“The fungal spores, together with nutrients, will be placed into the concrete matrix during the mixing process,” explained Congrui Jin of Binghamton University.
“When cracking occurs, water and oxygen will find their way in. With enough water and oxygen, the dormant fungal spores will germinate, grow and precipitate calcium carbonate to heal the cracks.”
More importantly, when the cracks are completely filled again and the fungi can no longer receive oxygen and water, it will once again form spores.
This means that, further down the line, the already-repaired concrete could once again be wakened to perform its healing abilities.
Full potential of fungus
As the research is still in the early stages, the biggest focus now is to ensure the survivability of the fungus within the harsh environment of concrete.
With further adjustments, however, Jin believes the fungus could achieve its full, self-healing potential.
“There are still significant challenges to bring an efficient self-healing product to the concrete market.
“In my opinion, further investigation in alternative microorganisms such as fungi and yeasts for the application of self-healing concrete becomes of great potential importance.”