On a frigid afternoon in late December, 2015, a 200-square-foot slab of seemingly ordinary concrete sits just outside the Peter Kiewit Institute as snowflakes begin parachuting toward Omaha, Nebraska, USA. The snow accumulated 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.
The designer, Chris Tuan, Professor of Civil Engineering-University of Nebraska-Lincoln, 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% 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.
Tuan’s research team demonstrated the concrete’s de-icing performance to the Federal Aviation Administration (FAA) during a testing phase that ran through March 2016. If the FAA is satisfied with the results, Tuan said the administration will consider scaling up the tests by integrating the technology into the tarmac of a major U.S. airport. “To my surprise, they don’t want to use it for the runways,” Tuan said. “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. We’re very optimistic.”
A unique bridge that resides about 15 miles south of Lincoln has given Tuan reason to feel confident. In 2002, Tuan and the Nebraska Department of Roads made the 150-foot Roca Spur Bridge the world’s first to incorporate conductive concrete. Inlaid with 52 conductive slabs that have successfully de-iced its surface for more than a decade, the bridge exemplifies the sort of targeted site that Tuan envisions for the technology. “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.”
He added that besides bridges, the conductive concrete could also prove feasible for high-traffic intersections, exit ramps, driveways and sidewalks.
Tuan’s collaborations have him dreaming big about the future of conductive concrete, but he is also currently enjoying its benefits much closer to home. “I have a patio in my backyard that is made of conductive concrete, so I’m practicing what I preach,” he said with a laugh.”
Tuan developed the concrete with the assistance of Lim Nguyen, Associate Professor of Electrical and Computer Engineering; Bing Chen, Professor of Electrical and Computer Engineering; and Sherif Yehia, Professor-American University of Sharjah-Sharjah, UAE and Civil Engineer-UNL The team’s research is being funded by the FAA, as well as past support from the Nebraska Department of Roads.
To read the entire article and another, very different application that doesn’t even require electric current,
please go to: http://phys.org/news/2016-01-de-icing-concrete-roadway-safety-corporate.html.
Photo: Chris Tuan stands on a slab of conductive concrete that can carry enough electrical current to melt ice during winter storms. Tuan is working with the Federal Aviation Administration and U.S. Strategic Command on multiple applications for his patented concrete mixture. Credit: Scott Schrage/University Communications.
To read the ISCP January 2016 article titled “Shovels Nor Plows Needed: Special Concrete Could Melt Mounds of Snow”, please go to: https://www.concretepavements.org/2016/01/27/shovels-nor-plows-needed-special-concrete-could-melt-mounds-of-snow/