Electric concrete designed to make winter roads safer
Conductive concrete is here and it can clear your driveway all by itself, making snow shovels and salt a history.A 200-square-foot slab of seemingly...
Conductive concrete is here and it can clear your driveway all by itself, making snow shovels and salt a history.A 200-square-foot slab of seemingly ordinary concrete sits just outside the Peter Kiewit Institute as snowflakes begin parachuting toward Omaha on a frigid afternoon in late December.
The snow accumulates on the grass surrounding the slab and initially clings to the concrete, too. But as the minutes pass and the snow begins melting from only its surface, the slab reveals its secret: Like razors, stoves and guitars before it, this concrete has gone electric.
Its designer, UNL professor of civil engineering Chris Tuan, has added a pinch of steel shavings and a dash of carbon particles to a recipe that has literally been set in concrete for centuries. Though the newest ingredients constitute just 20 percent of Tuan's otherwise standard concrete mixture, they conduct enough electricity to melt ice and snow in the worst winter storms while remaining safe to the touch.
A unique bridge that resides about 15 miles south of Lincoln has given Tuan reason to feel confident. "Bridges always freeze up first, because they're exposed to the elements on top and bottom. 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 or have potholes," Tuan said.
Tuan noted that the conductive concrete could also prove feasible for high-traffic intersections, exit ramps, driveways and sidewalks. Yet the technology offers another, very different application that doesn't even require electric current.
By replacing the limestone and sand typically used in concrete with a mineral called magnetite, Tuan has shown that the mixture can also shield against electromagnetic waves.