The science behind the salt
Published: Tuesday, February 12, 2013
Updated: Tuesday, February 12, 2013 12:02
USU students experienced a large amount of snowfall piling up on campus as January came to a close. USU Facilities manages snow removal before and during snow storms by using a blend of different chemicals as ice melt.
This ice melt is made up of 85 percent brine, or salt water, 10 percent beet juice derivative and 5 percent magnesium chloride, another form of salt.
The beet juice is used as a bonding agent to hold the active ingredients — magnesium chloride and brine solution — onto the sidewalk, preventing them from melting onto the sides and seeping underground.
“The purpose of that is so when we go and scrape it off, it comes off easier,” said Rob Reeder, director of landscape operations and maintenance. “It kind of creates a layer between the concrete and the snow or the ice to keep it from bonding to the concrete.”
The beet juice is what stains the snow brown and makes it smell. It can pool up in depressions on the sidewalk when it melts.
“It’s harmless,” Reeder said. “We found it doesn’t track into the buildings. We have more problems with the magnesium chloride and the salt that stick to your shoes when you go into the building and when you pick up dirt.”
Cole Blakely, a senior in mechanical engineering, said the salt smells distasteful but accepted the salt for its benefit of creating safe pathways.
“Compared to ice-induced cracked tail bones, diarrhea pools are the lesser of two evils,” Blakely said.
Blakely said he’s noticed some areas of campus where people have slid on the icy surface.
Reeder said the beet juice solution doesn’t work as well as he’d like.
“The ice melt does work, but it’s slow, so we chip and work,” Reeder said. “We’ll probably continue to adjust the formulas until we get the best possible effects we can.”
Facilities first began using beet juice last year, but the ratio of beet juice to magnesium chloride was too strong. This year, they have altered the mixture and continue to work with it.
“We use to use more of magnesium chloride, which gives us a better ice melting capability,” Reeder said. “But we found that as it percolates into the ground, it started to cause some damage to underground piping. It’s salt against steel.”
Facilities found minimal corrosion in the pipes along the sides where the ice would run off the edges of the sidewalk and seep underground. They started trying new products three years ago as a preventative strategy to avoid high replacement costs for the underground pipes.
Beet juice doesn’t cause as much damage as some harsher salt solutions, but the ratio of beet juice to magnesium chloride and brine, the active ingredients producing heat, can change.
“This beet juice is the bonding agent that holds the active ingredients to keep them from running off of the sidewalk when it gets wet,” Reeder said. “So when it starts to precipitate, the water comes down and it would wash it off without this bonding agent.”
Reeder said some walkways are salted more for safety. Areas with the most traffic are the first to be cleared of snow, such as sidewalks on the outer edges of campus and some inner routes.
Amber Judd, a sophomore majoring in art, usually travels the more-cleared routes and doesn’t encounter difficulty traversing campus. Her perspective is different when she walks on packed down snow.
“I don’t like it at all. If it gets really cold, it just ices over,” Judd said. “I almost want powdered snow because you don’t slip on that as easily.”
Reeder said when the beet juice solution reaches a certain temperature it becomes ineffective, so his teams use zeolite powder.
“It’s a natural product that stays on the surface,” Reeder said. “It’s organic, so when it gets into the landscape, it’s beneficial to the landscape and allows it to hold more moisture.”
For some students, ineffectively cleared walkways are dangerous.
Addie James, a sophomore majoring in art, said she walked home from a class one night after an ice storm and was slipping along her route.
“There was no traction” she said.
For ice patches like this, Facilities uses a granular ice melt product coupled with zeolite. This ice melt penetrates through the ice while the zeolite creates traction. Once the ice melt penetrates through, the ice can be scraped off.