Conductive concrete can help to de-ice the road in winter
Snow can be as much fun as it can be a nuisance, especially for traffic. Chris Tuan, professor of civil engineering from the University of Nebraska-Lincoln in the US, introduces conductive concrete, a type of concrete than can melt snow with only the use of electricity.
The ingredients for concrete that Tuan uses are the same as ordinary concrete. The only difference is that he adds steel shavings and carbon particles to the mix, which constitute for 20 per cent of the mixture. When exposed to electricity, these ingredients conduct enough to melt snow and ice, but the concrete remains safe to the touch.
Bridges are especially susceptible for ice and snow, as they are exposed to the elements on top and bottom. In 2002, Tuan and the Nebraska Department of Roads provided conductive concrete to a 45.7 m (150 feet) long bridge, which proved its worth in the following five years. The power to decide this bridge during a three-day storm cost about $250, which is less than a truckload of chemicals would have cost.
In March this year, another trial was done by the Federal Aviation Administration to see how effective the conductive concrete is to keep off-runway spaces near airport gates ice and snow free.
It is not cost effective to build entire roadways using conductive concrete, but Tuan suggests to use it in certain locations where that ice up often, or that have potholes. These potholes often originate from salt or chemicals that are used to melt ice and snow as they corrode concrete. In addition, they contaminate the groundwater over time.
If the electricity used to heat the conductive concrete is green as well, for instance coming from solar panels or wind turbines, this could be a great alternative for harmful chemicals, while keeping the roads clean from snow.
And for those of you who are worried about being spied upon, we have good news. If the limestone and sand typically used in making concrete is replaced by a mineral called magnetite, the mixture can shield against electromagnetic currents, which includes radiofrequency waves transmitted and received by cell phones. No electricity necessary!
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, a professor at the American University of Sharjah.
Photos via unl.edu