Self-Sealing Concrete Uses Fungus To Repair Cracks
A lot of us have to deal with some uncomfortable rides through the city on a daily basis. That has to do with the cracks and potholes in the roads that can damage tires and cause some big bumps in your commute. Road construction crews can only do so much to keep up with cracks that appear (especially in the winter time), but thankfully that might be coming to an end.
Researchers at Binghamton University are developing a special type of concrete that can heal itself when cracks appear. What’s even more interesting is that this concrete uses a fungus to seal these cracks.
The researchers from Binghamton (Congrui Jin, Guangwen Zhou and David Davies) were inspired to create this concrete based off of the human body. Much like humans can repair damage to itself, the hope is that this concrete can do the same. Another similarity is that humans don’t overdo it with healing.
The same theory goes into the concrete, as some pondered if the fungus would just continue to grow after the cracks have repaired. Instead, the spores in the concrete would become dormant once the crack is filled, as they wouldn’t be able to get anymore water or oxygen. It’s only when cracks are present that the fungus is able to germinate and fill the void. Professor Jin said that “As the environmental conditions become favorable in later stages, the spores could be weakened again.”
If the concrete is to work and take off, it could save billions of dollars in repairs and damage. “Without proper treatment, cracks tend to progress further and eventually require costly repair,” Jin said. “If micro-cracks expand and reach the steel reinforcement, not only the concrete will be attacked, but also the reinforcement will be corroded, as it is exposed to water, oxygen, possibly (carbon dioxide) and chlorides, leading to structural failure.”
The fungus used in the experiment is trichoderma reesei. The fungus originated on the Solomon Islands during World War II. This fungus has also been used in other products to help prevent damage, including in clothing. Jin knows the massive benefit that this fungus could create. “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,” she said.
According to reports, the amount being invested into America’s infrastructure is only around half of what it was in the 1950s and 1960s. The development of this concrete could increase in investments once again, especially since the concrete is both low cost and sustainable, making it a one-time investment hopefully.
To create the concrete, Jin explained that “The fungal spores, together with nutrients, will be placed into the concrete matrix during the mixing process. 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.”
There’s currently no timeline on when this concrete can be rolled out into public roads. The belief is that the concrete will start in private use, including businesses and homes. If successful, that could be extended into the public sector and potentially save an endless amount of money in infrastructure repair.