The recent so-called “snowmageddon” that hit the East Coast of the USA grounded flights, and even led to an all-out travel ban in New York City as blizzards deposited 26 inches of snow on the city in a short space of time. While snow on this scale is rare and unlikely here in the UK, we are still subject to travel disruption and weather related hazards after even a small dusting of snow. That could all be about to change, thanks to a great combination of civil engineering and materials science.
Professor Chris Tuan from the University of Nebraska – Lincoln has incorporated electrically conductive steel shavings and carbon particles into concrete that does not normally possess the ability to conduct electricity. The addition of these materials, making up around 20% of the total ingredients of this new concrete, make the concrete electrically conductive. When a current is applied across this concrete, the surface gently heats up while still allowing the concrete to be safely used. If any snow or ice is present on this concrete, it will rapidly melt as shown in this brilliant video.
Prof. Chris Tuan stands on some conductive concrete (Photo Credit: Scott Schrage / University of... [+]
The conductive concrete is currently undergoing rigorous testing by the Federal Aviation Administration (FAA) in the United States of America, which is due to finish in March. If the concrete meets the requirements they have set out, this special concrete could soon be de-icing tarmac at an airport near you. The implementation of this new composite material could slash airport delays, although for reasons you may not have expected. Tuan said, "To my surprise, they don't want to use it for the runways. What they need is the tarmac around the gated areas cleared, because they have so many carts to unload - luggage service, food service, trash service, fuel service - that all need to get into those areas. They said that if we can heat that kind of tarmac, then there would be (far fewer) weather-related delays.”
A slab of conductive concrete demonstrates its de-icing powers outside the Peter Kiewit Institute in... [+]
Conductive concrete slabs have been in successful use for over a decade. The Roca Spur Bridge in Nebraska was the first bridge in the world to incorporate 52 of these conductive concrete slabs in the construction of the bridge road, which have been busy de-icing the bridge road ever since. While tarmac is usually de-iced with salt and chemicals that can corrode tarmac, this new method could prevent potholes from forming by reducing the number of holes and cracks that are formed by such chemicals. These small holes can allow liquid water to seep into them before freezing, expanding and weakening tarmac by dislodging small areas of it through a freeze-thaw erosion process. De-icing roads using this method also benefit from lower costs than a chemical de-icing method, with engineers reporting that the Roca Spur Bridge road was de-iced using this method for around $250, which is a lot less than the cost of the chemicals that would have been required to achieve the same outcome.
Like all of the best engineers, Tuan has been benefitting from his handiwork through some awesome home hacks. "I have a patio in my backyard that is made of conductive concrete," he said. "So I'm practicing what I preach." Well, it certainly beats shovelling snow!
