A team of researchers at Drexel University in Philadelphia has created self-healing concrete enriched with “BioFiber”, that employs bacteria to patch up cracks that gradually form in the material. Despite being an excellent construction material, concrete is highly susceptible to deterioration due to continuous exposure to weather events. Once moisture seeps into the cracks, a series of corrosion processes are activated, diminishing its outstanding structural capabilities. Consequently, concrete structures require constant maintenance, which also impacts the environmental footprint of this material, especially notable in many famous brutalist buildings.
BioFiber refers to fibers that act not only as physical reinforcement but also as a self-healing mechanism. These fibers are coated with a layer of hydrogel containing endospores, dormant forms of bacteria capable of withstanding even extreme environments, awakening when conditions become more favorable. The hydrogel layer is further coated with a thin protective polymeric shell. When water penetrates the concrete, the BioFiber’s hydrogel expands, exiting the shell and moving toward the surface. The dormant bacteria are awakened and begin to feed on carbon and calcium from the surrounding concrete. Their metabolism produces calcium carbonate, a cementing material that fills and thus repairs the crack, seemingly in just one or two days.
There is still much research work to be done before BioFiber concrete can hit the market. However, it holds the concrete possibility of reducing building maintenance costs and carbon dioxide emissions associated with cement production.
Foto di Fahrul Razi su Unsplash.