Seashell-Like Concrete Fills In Its Own Cracks

Forget politics for a minute. America’s infrastructure–our roads, sidewalks, and bridges–is in bad shape. Recent assessments show that one in four U.S. bridges supports more traffic than was originally intended, or is in need of significant repair. A full third of all U.S. roadways are in sub-standard condition. There are lots of reasons why infrastructure has been allowed to decay, but most revolve around money.

In most cases, repairing a road or bridge just delays the inevitable. Truth is, after about 25 years, concrete that’s exposed to the elements 365 days a year is going to break down. But what if the next generation of roads and bridges weren’t built with the same old concrete? The Advanced Civil Engineering – Materials Research Lab at the University of Michigan recently unveiled a new type of flexible, self-repairing concrete that could revolutionize our infrastructure and save local governments millions.

concrete, roads, infrastructure, biomimicry, University of Michigan, self-healing materials

Image via design-dog/Flickr

Inspired by examples of self-healing in nature, like skin and bones that heal their own damage and vines that repair themselves when broken or torn, the scientists at the University of Michigan were determined to create a smarter building material. What they came up with is new a form of concrete that uses microfibers in the place of coarser bits of sand and gravel that traditional cement mix uses. The fibers allow the final composite to bend with minimal fracturing and if fracturing does occur, the cracks tend to be less than 50 microns wide.

“When these tiny cracks form, the dried concrete absorbs moisture from the air,” write the researchers. “When it does this, the concrete in the crack becomes softer and eventually “grows” until the crack is filled in. At the same time, calcium ions within the crack absorb the moisture along with carbon dioxide from the air. This reaction forms a calcium carbonate material that is similar to the material found in seashells. This regrowth and solidifying of calcium carbonate renews the strength of the cracked concrete.”

As Gas2.org points out, this revolutionary material could save municipal governments millions of dollars normally spent on skilled labor to remove and replace sections of road that have formed cracks and potholes. If commercially successful, maybe they can use the savings to fix those rickety bridges we drive over every day…

Beth Buczynski is a freelancer writer and editor currently living in the Rocky Mountain West. Her articles appear on Care2, Ecosalon and Inhabitat, just to name a few. So far, Beth has lived in or near three major U.S. mountain ranges, and is passionate about protecting the important ecosystems they represent. Follow Beth on Twitter as @ecosphericblog

  • http://twitter.com/korkin14 Conscious Consumer

    Now that is cool!

  • http://www.facebook.com/profile.php?id=1648032067 Brad Lednik

    I think this is long over-due and I really hope it catches on. The future problem this will cause is a loss of jobs in the field of concrete/road repair. But so it goes, as technology breaks new ground and helps create better products making them stronger and longer lasting, those that relied on it’s inefficiency for work lose out. It’s a good thing my son is great with math. There will always be a need for Engineers and scientists.

  • mjaldred

    Make reinforced concrete that is not corroded by de-icing salts, or any other of the 11 mechanisms of corrosion of reinforced concrete. Just as stainless steel is used instead of plain steel to eliminate corrosion over design life, by using additives to normal steel (nickel, chrome, etc.), so can normal concrete be made corrosion proof, once the designer understands that all normal concrete sucks. All normal concrete absorbs water and water brings into the concrete, all the corrosives. Simple. That’s why people spend time and money to put barriers between normal concrete and the water soluble, aggressive corrosives.

    Make concrete that never, ever gets wet. All corrosion is eliminated. Even acids. If this concrete will never absorb water it can never corrode internally. (As a side benefit, you can eliminate all old membrane ‘waterproofing’ of concrete structures too. Permanently.

    It is already been done. It’s already being done, internationally and in America. it is not new technology. The technology uses Hydrophobic Poreblocking Ingredients in concrete. HPI. To achieve hydrophobicity, permanently.

    And because it can be used in high strength, low cover concretes, it can be less expensive, in material useage and very low cost in speed of construction because there are no other corrosion proofing trades involved.

    The technology already exists, but there are, like any ‘new’ idea, some who want to stay with the buggy whip.

    Michael Aldred