Scientists identify bacteria that thrives in concrete
The findings may one day help engineers identify which structures are susceptible to damage before cracks even occur.
Some types of bacteria are incredibly hardy, able to survive in extremely harsh environments.
Here's a recently-discovered example, made by a team of researchers from the University of Delaware. It turns out Proteobacteria, Firmicutes, and Actinobacteria thrive in the dry and inhospitable habitat that is concrete.
The findings could provide warning signs of a phenomenon referred to as 'concrete cancer,' a moisture-induced issue that leads to structural damage.
This isn't the first research finding bacteria can live in concrete - but it is the first to zoom in on the specific microbes. Jule Maresca, one of the study's authors said in a statement there isn't much known about concrete microbes, even though concrete is one of the world's most popular building materials.
"It's in wet environments, sewer systems, bridge pilings and we know that microbes on surfaces can degrade it. But what's in there and does it do anything? Can it tell us anything?" Maresca added.
For their study, researchers kept an eye on 40 concrete cylinder samples placed on the roof of the lab for two years. Some were made of standard concrete, while others were tweaked to protect against the reactions that can lead to structural damage.
The most common bacteria found at the end of the monitoring period were Proteobacteria, Firmicutes, and Actinobacteria, and about 50 to 60 per cent of the bacteria likely came from gravel and other raw materials.
Bacteria diversity appeared to drop as time passed, with some types experiencing a bit of an uptick as seasons changed.
"It's possible they're eating the dead bodies of other microbes," Maresca said.
"If there's nothing to eat, some of them can form spores or form a dormant cell type and do nothing until it rains, then eat as much as they can and go dormant again."
The microbes don't appear to be damaging the concrete, but their presence could one day be used to identify which structures may become unstable before cracks appear, researchers say.
The paper has been published in the journal mSystems.
Thumbnail image submitted to The Weather Network by S. Farmand.