The use of liquid Anti-Icing is just another tool in our Winter Operations. Anti-Icing and Deicing are both practices that address the problem of snow and ice buildup on pavement. An important note: all solid deicers (salt) must turn into a brine solution in order to melt snow/ice. There are no chemical differences between a solid deicer (salt) and the same deicer in liquid form (salt brine). The difference is in time of application, the application process, and the results.
Anti-Icing 101 Video (Alaska):
https://youtu.be/TL9dvD1hyEQ
Key points of Anti-Icing:
- Anti-Icing and Pre-Wet applications focuses on the City’s environmental benefits, sustainability and cost reductions of our overall winter operations.
- Anti-Icing and Pre-Wet applications will “buy us time” at the onset of emergency call-ins (frontend of the storm), which is crucial during snow events that begin during peak commute times.
- Anti-Icing and Pre-Wet applications will improve the “clean up efforts” (backend of the storm) by reducing the amount of salt up to 4x the amount needed to break the snow/ice bond to the pavement.
- Using both a pre-wet & Anti-Icing solution, we expect to see a 30% cost savings compared to using dry granular salt only applications. This is based on findings from the Salt Institute.
- Anti-Icing/Treated Salt (pre-wet) applications will reduce the amount of salt scatter as well as lower the temperature of salt effectiveness, therefore, less salt is needed, which will bring a reduction in corrosiveness to infrastructure and vehicles.
Summary:
Anti-icing is intended to disrupt the bond that forms between ice particles and the pavement surface; this allows more response time to snow events and reduces the amount of salt otherwise required after the event to break the ic-road bond. Applying anti-icing liquids is sort of like spraying cooking oil to your frying pan, preventing your egg from sticking to the frying pan. In that same principal, preventing snow/ice from bonding to the pavement. Pre-wetting is the process of spraying granular salt with liquid ice melting chemicals before spreading the salt on the roadway. Pre-wetting the salt helps it cling to the road instead of bouncing off or being swept off by traffic. To be effective as a deicing agent, salt requires moisture. Pre-wetting provides the necessary moisture to dissolve the salt, releasing heat, and thereby melting the ice and snow, as well as breaking the ice-road bond.
Every winter storm is unique. The variables of precipitation type (sleet, wet snow or fluffy flakes), temperature (air and surface; dropping or rising), time of day (day, night, weekend and/or rush hour), wind speed and direction, event duration and post-storm weather prediction, all affect the manner and the type of tools needed for effective snow fighting.