February 11, 2016
Special Concrete Mixture
Can Melt Ice And Snow
By Reece Ristau
OMAHA, Neb. (AP) - Imagine if battling slick and dangerous road conditions caused by snowstorms could be as easy as flipping a switch.
Chris Tuan, a professor of civil engineering for the University of Nebraska at the Peter Kiewit Institute, has been perfecting an electrically semiconductive concrete over the past 20 years.
The mixture includes a 20 percent mix of steel fibers, shavings and carbon added to a traditional concrete mix. Steel reinforcing bars serve as the conductor, and once electricity is added, the concrete heats to 35 to 40 degrees - just enough to melt the ice and snow.
In a demonstration outside the Peter Kiewit Institute, Tuan threw a handful of snow on a small area of fenced-in concrete. Within about 90 seconds, it melted.
Mitchell Kowalewski, Tuan’s graduate research assistant, sees myriad future benefits.
``You’re no longer having the city people out to de-ice it, you’re no longer having to shovel it, and in industrial applications, you can use this on loading dock areas so you’re no longer having injury on the job,’’ Kowalewski said. ``It’ll decongest and make areas safer.’’
Tuan said the concrete is likely too expensive to be universally applied. But his hope is that accident-prone roads - bridges, interstate exit ramps and intersections - will eventually all be paved with the mix. He also envisions an Internet-connected system that can monitor weather conditions and turn on automatically prior to a winter storm.
For now, the concrete can’t be used in public spaces. Anything exposed and electrified above 48 volts - much less than the 208 volts used in Tuan’s concrete - is considered high voltage and is not allowed. Federal law will have to be rewritten to change that.
Although the concrete is more expensive - about $180 more per cubic yard than regular concrete - he said the long-term benefits pay off.
``You have to compare apple with apple,’’ Tuan told the Omaha World-Herald (http://bit.ly/1UNXmZ1 ). ``Compare $300 versus $120 - $300 you have a de-icing function, and $120 you don’t have anything, and you have to spray salt or de-icing chemicals and that degrades your concrete.’’
Tuan said traditional concrete needs to be replaced every five years or so. Without chemical use, the electric concrete lasts much longer, with fewer potholes. His concrete is also maintenance-free, because the power cords and conductive rods are encased in the concrete and not exposed to the elements.
This concept is different from the hydraulic system often used for residential driveways, Tuan said. Traditionally, heating fluids, such as antifreeze or warm water, are pumped through pipes embedded in the concrete, a method Tuan said is expensive and wastes more energy.
The Federal Aviation Administration is monitoring Tuan’s work and is considering integrating the technology into airport tarmacs.
However, he said the FAA isn’t interested in runways; those can be cleared in a matter of minutes with plows. The concrete would be used in the fenced-off luggage and food-loading areas near planes, which are often the cause of flight delays.
The method itself is safe, Tuan said, but each project would require individual specifications to ensure safety. He said conductivity, the spacing of the electrodes and the size and thickness of the slab of concrete are all factors to consider. In warmer weather, the electricity would simply be shut off, the concrete back to normal until the next snowfall.
The de-icing concrete has already been tested in the real world. In 2003, Tuan installed 52 slabs of the concrete onto the 150-foot Roca spur bridge 15 miles south of Lincoln. The five-year test showed the method was workable. Melting snow on the bridge cost about $250 per major snowstorm.
In 2013 Tuan also implemented his concrete on ramps in China. He recently installed a private driveway in Regency using the legally allowed 48-volt limit, which is less energy efficient.
``If the government or if insurance agencies approve this technology, then everybody can use it,’’ Tuan said. ``But right now, it’s almost cost prohibitive.’’
Snow Master For Pyeongchang Olympics Is Wyoming Cowboy
By Andrew Dampf
AP Sports Writer
Jeongseon, South Korea (AP) Cattle rancher Tom Johnston is a Wyoming cowboy gone global who’s the master of snow for Alpine skiing events at the Pyeongchang Olympics.
Johnston, the chief of race for ski events at the 2018 Olympics, is responsible for preparing the snow to world-class conditions at the next Winter Games.
Having honed his craft at annual World Cup races and last season’s world championships in Beaver Creek, Colorado, the snow maestro prepared courses for the 2002 Salt Lake City Games and 2014 Sochi Games. Skiers got another taste of Johnston’s skills over the weekend at the Alpine test event for the 2018 Games.
There was a chorus of approval for the ``hard, aggressive and grippy’’ snow, which is just the way racers like it whether on European or U.S. slopes. ``It’s nearly identical,’’ said Italian racer Dominik Paris, who finished second in Saturday’s World Cup downhill. ``It’s like cooking. If you’ve got a good chef, the food is always good.’
Tom Johnson, Snow Master’
From Boulder, Wyoming, a town Johnston describes as essentially a single gas station, he learned how to prepare ski courses in nearby Jackson Hole. When the U.S. nationals were held in the Wyoming resort in 1998, the U.S. Ski Team hired him as a technical adviser _ a role he’s held ever since.
``This job was always just to support my cow and my tractor habit. That’s all,’’ Johnston said in an interview at the finish area of Sunday’s race. ``And they just kept asking me to move to the next level and the next level so this is my third Olympic venue. I did Salt Lake, I did Snowbasin for the women and Sochi for the women and then this new one.’’
For months, Johnston has been directing a crew of Koreans on the intricacies of laying down the 2.8-kilometer (1.8-mile) track with artificial snow, grooming the surface to perfection with huge snowcats, then shaping the terrain and jumps according to World Cup standards.
``It’s similar conditions (to Colorado) _ pretty cold weather and dry,’’ Johnston said. ``We have about a meter (3 feet) everywhere. Some places with the terrain we had to put in 3-4 meters (9-12 feet). Some places were down to 2/3 of a meter (2 feet).
``With a new track you have to think a lot about what’s going to happen with the racers so we had to put a lot of extra snow in some places _ a lot,’’ he said.
A sign of success came when not a single racer fell or crashed in Saturday’s downhill. After an overnight dusting, things got a little more complicated for Sunday’s super-G, when most of the favorites struggled.
With such a perfect surface, skiers have to be careful not to dig their edges in too hard.
``It’s really aggressive so if you overdo it, then you’re slow. So there’s a lot of tactics involved,’’ said Canadian downhiller Erik Guay, the 2011 world champion. ``The snow is amazing. It’s just so much fun to lay it over.’’
Unlike previous Olympics, Johnston will be preparing the course for both men and women as there is only one track at the newly developed course in Jeongseon, which was designed by Bernhard Russi, the 1972 Olympic champion.
``He has an amazing knowledge of prepping snow and working with people,’’ U.S. men’s head coach Sasha Rearick said. ``There’s no better guy to do the job and there’s a reason why Gunter (Hujara, the International Ski Federation’s technical specialist) wanted him and he only wanted him.’’
While the snow conditions are Colorado-style, that doesn’t necessarily mean that U.S. skiers have a home advantage.
``It’s not like he’s preparing it in a specific way for our guys,’’ said Luke Bodensteiner, the U.S. Ski & Snowboard Association’s executive vice president for athletics. ``He’s just made it a good, reliable surface. He’s definitely known as the expert worldwide.’’
Still, it helps having a friendly face in a faraway place.
``He’s been sending us pictures and telling us, `It’s good, guys. This is your hill and let’s see it,’’’ U.S. racer Steven Nyman said before finishing third in the downhill test. ``They have that cold Siberian air that moves in here and it’s that Colorado, very aggressive, very responsive snow and it’s a joy to ski.’’
Johnston credits Tim ``Swampy’’ LaMarche, his predecessor at the USSA, for teaching him the job. He never studied it.
``I just do it. Just experience,’’ he said. ``A lot of atmospheric stuff whether it’s high pressure, low pressure, high or low humidity. I know there’s guys that try to put science to it but I’m not one of them. I just do my thing.’’
93 Year Old WWII Vet Sets Out To Meet With War-Time Love
Norfolk, VA (AP) A World War II veteran has embarked on a 10,500-mile journey to visit his wartime girlfriend after more than 70 years apart.
The Virginian-Pilot reports that 93-year-old Norwood Thomas boarded a plane from Norfolk to Australia on Sunday to reunite with Joyce Morris.
Joyce Morris and Norwood Thomas
They first met in London shortly before D-Day but ended up going their separate ways after the war had ended.
Thomas calls Morris ``the one that got away.’’
They recently reconnected via Skype. After their story went public, hundreds of people made donations to help fund Thomas’ trip to Australia. Air New Zealand arranged the flight to send Thomas to his long-lost love.
It will take two days to reach Australia. Thomas says he would rather die traveling there than sit at home wondering ``what if?’’
Indian Scientists Study Object That Fell From Sky, Killed Man
By Nirmala George
New Delhi (AP) Scientists are analyzing a small blue object that plummeted from the sky and killed a man in southern India, after authorities said it was a meteorite.
The object slammed into the ground at an engineering college over the weekend, shattering a water cooler and sending splinters and shards flying. Police say a bus driver standing nearby was hit by the debris and died while being taken to a hospital.
College principal G. Bhaskar said he heard a loud thud from his office, where several window panes shattered when the object hit the ground.
The crater left at the site
Local officials and scientists from the Indian Institute of Astrophysics on Tuesday examined the 5-foot-wide (2-meter-wide) impact crater at the college near Vellore city, but said they had yet to determine whether the object was from outer space or possibly a passing airplane or man-made satellite.
College officials said window panes of the building shattered with the impact of the loud explosion. Several buses parked nearby were also damaged and bits of glass from broken windows were scattered in the buses.
The hard, jagged object is dark blue and small enough to be held in a closed hand. The scientists used metal detectors to check the crater for the presence of metals and dug up the soil.
``The object that police have recovered from the site would have to undergo chemical analysis’’ to confirm its origin, said the dean of the institute, Prof. G.C. Anupama. She said that while it was rare for meteors to reach the ground before burning up in the atmosphere, it happens.
In February 2013, a meteor blazed across southern Urals that scientists said was the largest recorded strike in more than a century. More than 1,600 people were injured by the shock wave and property damage was widespread in the Siberian city of Chelyabinsk.
Tamil Nadu’s top elected official J. Jayalalithaa said Sunday that the bus driver had been killed by a meteorite and offered compensation to his family.