A special concrete mix, studded with electricity-conducting ingredients, could help airports and other places run on time during inclement weather — such as the weekend blizzard that paralyzed the U.S. Northeast.
So the Federal Aviation Administration is funding research to make this costly conductive concrete more affordable.
The new formula being tested at University of Nebraska-Lincoln uses byproducts from the coal and steel industries to reduce costs 60 percent compared to earlier trials, according to professor of civil engineering Chris Tuan. The 200-square-foot patch has embedded steel rods attached to electrodes, he says, that connect to a 120-volt AC power source. The conductivity comes from “coke breeze,” a carbon byproduct of coal mining, and steel shavings that are considered industrial waste.
“We keep it barely above freezing … somewhere around 40 degrees,” Tuan says, noting it doesn’t take much heat to make the slab impervious to snow. “It doesn’t get hot at all.”
Some heated driveways and roads use a system of underground coils, or radiant heat, but Tuan says they provide uneven warming, with cold spots in-between the tubes.
“When you use conducting concrete, the entire concrete heats up,” he says. “There is no cold area.” He adds that his system is virtually maintenance-free, and takes only about 13 watts of energy per square foot.