Filling Up the Cracks in Our Construction Capabilities to Reach a Sustainable Future

The human excellence is rooted in a myriad of different things, but more importantly than the rest, it is rooted in our tendency to grow on a consistent basis. This tendency, in particular, has already enabled the world to clock some huge milestones, with technology emerging as quite a major member of the group. The reason why we hold technology in such a high regard is, by and large, predicated upon its skill-set, which ushered us towards a reality that nobody could have ever imagined otherwise. Nevertheless, if we look beyond the surface for one hot second, it will become abundantly clear how the whole runner was also very much inspired from the way we applied those skills across a real world environment. The latter component, in fact, did a lot to give the creation a spectrum-wide presence, and as a result, initiated a full-blown tech revolution. Of course, the next thing this revolution did was to scale up the human experience through some outright unique avenues, but even after achieving a feat so notable, technology will somehow continue to bring forth the right goods. The same has turned more and more evident in recent times, and assuming one new discovery ends up with the desired impact, it will only put that trend on a higher pedestal moving forward.

The researching team at Drexel University’s College of Engineering has successfully developed a new technique to improve the durability of concrete. According to certain reports, the stated development will try and enhance a centuries-old method of fiber reinforcement, and it will do so by turning reinforcing fibers into a living tissue system that rushes concrete-healing bacteria to the site of cracks to repair the damage. Talk about the concept on a slightly deeper level, named as BioFiber, it came to life when the researchers took a  polymer fiber core, capable of stabilizing and supporting concrete structures, and coated the whole thing with a layer of endospore-laden hydrogel. Next up, they encased it into a damage-responsive polymer shell like skin tissues, thus making up a component which was little over half a millimeter thick. Once ready, they placed the BioFiber in a grid throughout the concrete as it is poured. Now, while this is where the material acts as a reinforcing support agent, it actually conceives a bigger and more important use case after a crack penetrates the concrete enough to pierce the fiber’s outer polymer shell. You see, as water slides through the newly-appeared crack and reaches BioFiber, it causes the hydrogel to expand and push its way out of the shell and up towards the surface of the crack. Such a mechanism leverages the presence of carbon and a nutrient source in the concrete to activate bacteria from its endospore form. After the bacteria is activated, it reacts with the calcium in the concrete so to produce calcium carbonate, which then acts as a cementing material to fill the crack upto a given surface.

“This is an exciting development for the ongoing efforts to improve building materials using inspiration from nature,” said Amir Farnam, Ph.D., an associate professor in the Drexel University’s College of Engineering, who was a leader of the research team. “We are seeing every day that our aging concrete structures are experiencing damage, which lowers their functional life and requires critical repairs that are costly. Imagine they can heal themselves? In our skin, our tissue does it naturally through a multilayer fibrous structure infused with our self-healing fluid—blood. These biofibers mimic this concept and use stone-making bacteria to create damage-responsive living self-healing concrete.”

To understand the significance of such a development, we must acknowledge how current concrete structures can degrade in as little as 50 years, the timelines varying based on their environment. This doesn’t just create a big financial hassle, but it also affects the wider environment to a degree greater than we think. A simple statistic explaining the same translates to how the process of making ingredients of concrete, a proves which involves burning a mixture made from minerals like limestone, clay, or shale at temperatures exceeding 2,000 degrees Fahrenheit, is literally responsible for an estimated 8% of global greenhouse gas emissions.

“One of the amazing things about this research is how everyone comes at the problem from their different expertise, and the solutions to creating novel BioFibers are so much stronger because of that. Selecting the right combination of bacteria, hydrogel, and polymer coating was central to this research and to the functionality of BioFiber. Drawing inspiration from nature is one thing, but translating that into an application comprised of biological ingredients that can all coexist in a functional structure is quite an undertaking—one that required a multifaced team of experts to successfully achieve,” said  Caroline Schauer, Ph.D., a researcher involved in the study.

As for the time in which BioFiber will likely complete the entire healing process, it is going to heavily depend upon the size of a particular crack and the activity of bacteria. However, if we were to put-together a rough idea, the best-case scenario says that it should not take more than one to two days.

“While there is much work to be done in examining the kinetics of self-repair, our findings suggest that this is a viable method for arresting formation, stabilizing and repairing cracks without external intervention,” Farnam said. “This means that BioFiber could one day be used to make a ‘living’ concrete infrastructure and extend its life, preventing the need for costly repairs or replacements.”

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