BENEFITS OF CALCIUM CHLORIDE
Calcium chloride is used in prewetting, anti-icing and solid blend applications to maintain safe, ice-free driving conditions.
Prewetting
Prewetting rock salt with calcium chloride enhances salt’s performance at any temperature. Liquid calcium chloride provides salt with the moisture it needs to form liquid brine and initiate melting action. Once melting begins, the bond between ice and pavement can be broken, which enables mechanical removal.
For more than four decades, prewetting rock salt and abrasive materials with liquid calcium chloride has been proven highly effective in achieving better ice melting performance and improving traction on winter pavement. A study by the Province of Ontario, Canada showed that calcium chloride was “much more effective” than other brines used as prewetting agents for rock salt. The study showed calcium chloride reduced snow cover 27% better on average than magnesium chloride brine and also was more effective than salt brine.1
Prewetting salt and abrasives with calcium chloride also reduces scattering, keeping granular materials on the road where ice melting and traction are needed and reducing impact on the surrounding environment. Tests conducted in 2012 by the Michigan Department of Transportation (MDOT) validated results obtained by MDOT in the early 1970’s, which found that pre-wetting salt reduces salt loss due to bounce and scatter by close to 30%. The 2012 results showed that salt treated with a liquid calcium chloride blend scattered less than dry salt at three different speeds and with two different types of distribution systems. 2
Conventional abrasives can also benefit from prewetting treatment with calcium chloride. Sand and cinder particles prewetted with calcium chloride stay free-flowing and embed more securely in packed snow and ice, reducing losses from bounce and scatter to help ensure maximum traction improvement on pavement surfaces.
Anti-icing
Anti-icing is the practice of applying ice melting chemicals before or at the start of freezing precipitation to prevent the formation of ice-to-pavement bonds. Compared to deicing after weather events, anti-icing requires considerably smaller amounts of deicing material, reducing product and application costs, as well as potential runoff to the environment.
The savings provided by anti-icing can be significant. The U.S. Environmental Protection Agency (EPA) says anti-icing techniques can reduce deicer usage by up to 75%.3
Dry Blending
When blended 1:4 with rock salt, solid calcium chloride can reduce overall road salt requirements by as much as 60%. This is especially helpful in “reduced salt areas” where contamination of surface and ground water by rock salt is a concern.4 Blending is also useful in very cold climates and on critical road sections such as bridges, highway ramps, and sharp turns or grades because it can significantly reduce the time required to break the bond between ice and pavement, particularly at temperatures below 15oF.
Spot Use of Solid Deicer
Solid calcium chloride can be used to quickly penetrate and undercut ice around burst water mains, in culverts where flow is dangerously impeded by ice, and in other locations where deicing delays or waiting for ice to melt naturally could create a hazard, result in greater damage, or impede repairs. DOWFLAKE™ Xtra 83-87% Calcium Chloride Flakes are used to apply high potency deicing action directly to small areas of problem ice. The highly concentrated, hygroscopic calcium chloride material releases heat as it attracts moisture, quickly dissolving to form ice-melting brine and break the bond between ice and the subsurface.
1 Ontario Ministry of Transportation, L. Fu, R. Sooklall and M.S. Perchanok, 2006
2 Salt Bounce and Scatter Study, Michigan Department of Transportation, 2012
3 Water Protection Practices Bulletin, United States Environmental Protection Agency, August 2010
4 “How Massachusetts cut salt use and costs,” Better Roads, January 1992