Slippery conditions caused by ice and snow is a scourge of vehicles and pedestrians alike, causing slip-and-falls on sidewalks, motor vehicle accidents and snarling traffic on roadways all winter long. Researchers have been developing and testing a multitude of methods of making concrete that radiates heat from the inside, ensuring they remain snow-free without a plow, a shovel or a single grain of rock salt.
Researchers at the University of Nebraska have created a new form of conductive concrete that can, through electric current, maintain a temperature inhospitable for ice or snow accumulation, as reported by Huffington Post. The concrete is formed in part by adding steel shavings and carbon particles to the mixture, composing approximately 20% of the material. Dr. Chris Tuan, a civil engineering professor at the university told Huffington Post. The concrete is intended for use where accidents are most likely to occur, including bridges, intersections and exit ramps, but not necessarily for entire roadways just yet.
“It’s not cost-effective to build entire roadways using conductive concrete, but you can use it at certain locations where you always get ice,” Tuan said in an interview with UNL.
The concrete is intended for use where accidents are most likely to occur, including bridges, intersections and exit ramps, but not necessarily for entire roadways just yet.
Tuan says the concrete works by connecting to a power source, which enables it to generate heat from within the slab, which then radiates to the surface. Back in 2002, 52 slabs of the researchers’ concrete were placed on sections of a 150-foot bridge near Lincoln, Nebraska. According to Huffington Post, the bridge has been automatically melting ice and snow every winter since.
Airports are a natural next fit for the technology, but according to a statement from Tuan, they were more interested in using it for parking lots and the tarmac than for the runways, explaining that clearing the gated areas on which luggage carts, food and trash carts and fuel vehicles must operate between flights could cut down significantly on weather-related delays.
Not far from Nebraska, Iowa State University researchers are testing slabs of their own design of heated concrete at Des Moines International Airport. The two 15-by-13.5-foot slabs were installed into the apron of a hangar devoted to smaller aircraft to test their viability in real-world scenarios. The concrete has a different composition than the U of Nebraska researchers’, but both operate in basically the same way, using electricity to generate heat from within. The slabs can even be controlled via smartphone app. The test was a success, and Iowa State research head Halil Ceylan calls it a proof of the concept in a university news release.
“We have proven this technology does work,” he said. “Our goal is to keep airports open, safe and accessible. We don’t want any slips or falls, or any aircraft skidding off runways. Our technologies can contribute to providing a safe environment and fewer delays.”
Tuan says heated concrete will cost about $300 per cubic yard as opposed to $120 for typical concrete.
The inevitable question raised is, of course, how much more expensive is this than regular concrete and what does it mean for a structure’s electricity use? Well, according to Huffington Post, Tuan says heated concrete will cost about $300 per cubic yard as opposed to $120 for typical concrete. So the installation costs would be significantly higher. As for electricity costs, the Iowa State researchers pegged the operating cost of their heated concrete at approximately 19 cents per square meter, using roughly the amount of electricity needed to run 3 light bulbs for 7 hours. Which, Ceylan said in the release, “is way more than enough to melt an inch of ice or snow.”
It’s not just roadways and sidewalks getting the heat treatment, fed up with the annual ritual of shoving driveways, residential neighborhoods with heated driveways that keep ice and snow at bay have started cropping up. Rather than use electrical current to generate heat, many of the driveway systems being installed use pumps that cause hot water (or even antifreeze) to flow through tubes installed inside the slabs, which raise their temperature and repel ice and snow. It’s not cheap, but most systems can be installed without needing to replace the entire driveway, and it’s hard to put a price on a driveway that stays ice-free all year long.