How do winter anti-icing/deicing liquids such as Liquid Snow Shovel work?
Anti-icing is the newest snow and ice control practice. It was pioneered in Europe and involves preventing the formation of bonded snow and ice by timely applications of chemical freeze-point depressants. Relatively small amounts of a liquid chemical applied before or immediately at the start of precipitation. This strategy either eliminates the need for further action or reduces the task of clearing roadways, parking lots and side walks to bare pavement conditions. At the same time, it requires smaller chemical amounts than would be required under conventional deicing practices. As a result, anti-icing is quickly becoming a vital strategy for many end users.
Liquid Snow Shovel is hygroscopic and deliquescent. This means it attracts moisture from the air and its surroundings and goes into a solution quickly as it attempts to return to, or remain in, its natural liquid state. Liquid Snow Shovel retains this ability even under conditions of very low humidity. For dry forms of calcium chloride these properties allow rapid brine creation for faster deicing action. For Liquid Snow Shovel it means longer- lasting effects as the solution resists evaporation to remain an effective brine even as dilution occurs. Generally, anti-icing techniques are more efficient than deicing, because it requires far less energy to prevent a bond from forming than to break it. Think of holding two magnets close together but not joined. It takes little energy to keep them apart. But once the magnets are linked "like ice bonded to the pavement " it takes a lot of energy to break them apart. And so it is with anti-icing versus deicing techniques. Less chemical is required to prevent the bond than to break it. In a typical winter storm, both techniques may be necessary to provide safe working conditions. Pavement surface temperature, ambient temperature and pavement chemical concentration levels are all variables that affect pavement refreeze. Refreezing occurs when ice control chemicals dilute sufficiently that the brine solution turns to ice. Monitoring the variables closely allows for timely reapplication before refreeze.
Why does MDOT use winter anti-icing/deicing liquids?
MDOT uses winter anti-icing/deicing liquids as tools to improve safety, improve the efficiency of time spent plowing, and address environmental concerns resulting from other methods of snow removal. States that use winter anti-icing/deicing liquids have had reductions in wintertime motor vehicle crashes. Additionally, the anti-icing/deicing liquids can be cheaper than sanding and will reduce the amount of time spent plowing.