Current Issue
This Month's Print Issue

Follow Fast Company

We’ll come to you.

How to Save Billions in Building and Bridge Repair: Coat Them In Burnt Coal Ash

concrete repair with burnt coal ash

A new coating for concrete structures could result in seriously tough structures that better resist damage and thus saves money in reconstruction and repair. Better yet, the coating relies on waste ash from burning coal in power stations.

Research in a joint project between academics at Florida Atlantic University and industry player Blue World Crete has discovered a novel use for the millions of tons of fly ash that's a by-product of the coal-burning power generation industry. The ash by itself, amounting to some 130 million tons per year in the U.S. alone, poses a serious waste-disposal issue—and although a small percentage does get recycled, most of it (around 70%) ends up landfills. Converting it into a coating for concrete that prevents the construction material from crumbling as quickly as it ages would solve many infrastructure problems for the coal industry. And by extending the life span of concrete buildings (the construction of which is an oft-overlooked but serious carbon-polluting process), some of the carbon footprint of both industries could be compensated for.

Details of the coating itself aren't revealed, but it is reported to be half as expensive as existing coating materials used to coat the exterior surface of concrete to protect it from the ravages of wind, temperature changes, and rain, and to cover the structural steel rebar inside reinforced concrete to prevent it from corroding and weakening the surrounding concrete.

It's also useful for covering already damaged concrete. In lab tests, the science team has shown it's strong, durable, and can resist heat, cold, and simulated acid rain tests that were 100,000 times more acidic than usually found in the environment. Its life span in the test was over a year, compared to uncoated concrete subjected to the same conditions, which lasted just a few days.

To read more news like this, follow Fast Company on Twitter: Click here. Or keep up with the author, Kit Eaton's, own tweets.

[Image via Flickr user Surroundsound5000]