A Concrete Idea
Concrete is concrete, right?
Not if you’re talking about Christopher Tuan’s special concoction — one that can melt driveway snow, de-ice bridges and shield top secret conversations from enemy ears.
The electrically conductive concrete mix consists of cement, steel fibers and carbon particles. When paired with an electric current it melts roadway and driveway ice and snow. When used to wall a room, it provides a barrier to cell phone signals and eavesdroppers.
A professor of civil engineering at UNO’s Peter Kiewit Institute under the auspices of the UNL College of Engineering, Tuan (pictured) began developing the product in 1994 while working as an Air Force contractor. His goal was to remove runway ice to prevent aircraft from skidding during landings. He perfected the concrete in 2001 while with the university.
That same year the Nebraska Department of Roads used Tuan’s charged material on a Roca, Neb., spur bridge (over,ironically, Salt Creek). Keeping bridges ice-free is particularly challenging, and when de-icing chemicals are used they can damage concrete and corrode its reinforcing bars.
With Tuan’s mix, chemicals and plows are unnecessary.
“Our product is anti-icing,” Tuan says. “You keep the system on and the concrete stays warm. When the snow or ice hits the surface, it melts.”
Tuan says it costs the state $250 for the electrical energy needed to keep the Roca bridge ice-free during a three-day storm. Sending a plow truck with chemicals would cost $1,000.
“But a bridge is a high-value asset,” he says. “You don’t want to use chemicals on it that will degrade it prematurely.”
Tuan also tested his invention on an Omaha residential driveway.
“Part of the driveway was under a tree where ice would not melt,” he says. His fix cost $3 per month for the ongoing electric current and brought a smile to his customer, who preferred flipping a switch to chopping ice.
While the product has proven successful, its future as a roadway melting agent is in limbo. Tuan has patented the concrete, but awaits inspection by UL, a global independent safety science company, before he can market it. Problem is, there are no current standards developed for the product and Tuan says it will cost $250,000 to develop them — $250,000 he and his business partners don’t have.
He and fellow engineering professors Bing Chen and Lim Nguyen have formed a company, NU-Concrete Corporation, and hope to market the magic concrete for pavement de-icing. Currently, the product is being marketed for other applications where no electricity — and therefore no UL inspection —is required.
There’s no doubt need exists for a product like Tuan’s invention.
About 10 to 15 percent of all roadway accidents are directly related to weather conditions, according to industry reports, causing thousands of injuries and deaths and millions of dollars in property damage annually.
“If it catches on, there is a big potential,” Tuan says.
— Tom McMahon
— Photo by Eric Francis
See more at www.conductive-concrete.unomaha.edu