As the years go by, people in every industry are always finding ways to improve different aspects of their respective fields whether it be by coming up with a better process for something or making a better final product. The construction industry is no different. One of the most common materials used throughout the construction industry is concrete. It is the most commonly used man-made material on earth and is used in a wide range of applications from buildings, bridges, roads, pipes, and more.
One of the biggest problems with concrete is that it will eventually crack. Water then gets into these cracks which then can freeze and thaw and make larger cracks or get to rebar within the concrete causing corrosion and eventual failure. Scientists have found bacteria that allows concrete to “self-heal.” It took years of research to find one that wouldn’t compromise the integrity of the concrete, but that could also live dormant in a dry environment for years until needed. The way this works is that the bacteria are put into biodegradable plastic capsules along with a food source and added to the wet concrete mix. When cracks in the concrete occur, water finds its way through and causes the capsules to open. The bacteria then germinate and multiply, and in doing so, they produce limestone which is what closes the cracks. There are some disadvantages to using this self-healing concrete: it can be almost double the price of conventional concrete, and since it makes up around 20% of the volume it can create a shear zone or a fault line.
The ultimate goal is to develop concrete materials that will monitor, regulate, adapt and repair themselves. Self-healing concrete will be able to save lives and resources and significantly reduce life cycle carbon emissions. There is ongoing research to try to improve upon this idea of “self-healing” concrete and one solution being looked at is using a fungus that would act similarly to the bacteria. Other solutions include continuing to try different additives of nano-scale minerals and chemical additives. One other solution may be right in front of our faces though. The ancient Romans built structures such as the Pantheon that still stand today. The secret seems to be a pozzolanic reaction of the material with intrusive water that takes place after construction and produces calcium/aluminum silicate crystals that fill voids and cracks, which strengthens the structure long after the work has been finished.
Every day scientists and researchers are looking into better solutions for anything that will make our lives better. Phones, cars, and computers are things we use every day, and we notice when a new and improved model comes out. We also use concrete every day whether it be the sidewalk outside, the bridge you drove over, or the building your sitting in right now and we don’t notice them until something is wrong. Self-healing concrete will help to prevent any issues from arising. There will always be research and advancements in all different technologies that will usually go without notice.