Researchers at Drexel University are experimenting with imbuing concrete with living organisms to extend the building material’s lifespan. And although the new approach is based on cutting-edge technology, the underlying engineering strategy originates within the human body.
Concrete is second only to water as the most consumed material on Earth—a particularly problematic statistic, given the enormous carbon emissions of its manufacturing process. A number of promising, green updates to the millennia-old structural material are already in the works, but another avenue to reduce concrete’s environmental impact is to extend its longevity. Depending on the surrounding environment, concrete can begin to weaken and break down barely 50 years after setting. Delaying this degradation using innate real-time repair mechanisms could offer a solid way to get more out of the material.
[Related: Dirty diapers could be recycled into cheap, sturdy concrete.]
As detailed in a new paper recently published in Construction and Building Materials, a team of engineering researchers at Drexel University have developed a new polymer “BioFiber” coated in bacteria-infused hydrogel, all within a damage-responsive casing half a millimeter thick. The BioFiber is then arranged in layers of grid patterns as concrete is poured, serving as a reinforcing additive much in the way builders have used straw or horsehair to strengthen bricks for millennia. Of course, these reinforcements can only do so much—but when the team’s BioFibers begin to falter is when they really shine.
“In our skin, our tissue [repairs] naturally through multilayer fibrous structure infused with our self-healing fluid—blood,” Amir Farnam, an associate professor in Drexel’s College of Engineering and research co-lead, said in a December 8 university profile. “These BioFibers mimic this concept and use stone-making bacteria to create damage-responsive, living, self-healing…
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