Winter Leaves Behind Corrosion From Road Salt
CHICAGO (CBS) — After the brutal temperatures and nearly 80 inches of snow, many of us would like to forget this past winter, but we could be dealing with its side effects for years to come.
Look around Chicago and corrosion isn’t hard to find. Civil engineer Dr. Gongkang Fu says it will likely only get worse.
The biggest culprit: salt found in the sodium chloride Chicago and most cities use for winter de-icing.
Last winter, the city used 436,000 tons of salt. That’s more than three times the amount used 145,000 tons used the winter before, 145,000 tons, and more than four times the 102,000 tons used for the 2011-2012 winter.
The salt eventually seeps through the concrete and corrodes the steel inside.
“When the steel corrodes, the structure gradually loses its capacity,” said Fu. “Eventually it will cause significant failure of the structure.”
“If we used to say this structure can be there for another 20 years or so, then it might become 10 or 15.”
The more immediate concern is the falling concrete caused by the corrosion.
The city tries to stay ahead of it by using protective barriers and sending crews to knock off loose pieces before they fall.
The salt doesn’t just affect the steel and concrete, it can also have an impact on wildlife and plant life in the area.
The salt can also have an impact on wildlife and plant life in the area. Along Lake Shore Drive the grass is brown and dying, but a few feet away it’s green and lush.
The sodium and chloride can also end up in area waterways, so the Illinois EPA monitors the levels to make sure there is no danger to fish or people.
There are more environmentally-friendly ways to de-ice, but salt is cheaper and easier.