Bulk Salt Application Rates (2022 Refresh)

The Canadian Journal of Civil Engineering (Volume 49Number 1, January 2022) had release updated information on application rates. The article discusses the application rate of winter road maintenance (WRM) materials and how it depends on various factors such as application methodologies, air and pavement temperatures, amount of snow on the ground, and steepness of the roadway. There are two main tactics involving the application of chemicals, namely deicing and anti-icing, and that deicing operation typically requires more chemicals than anti-icing operation (Levelton Consultants 2007). The article mentions that pre-wetted salt works faster, at lower temperatures, and at reduced application rates, while pre-wetted abrasives tend to have less material loss from the pavement via bounce and scatter. In fact, pre-wetting can increase the material retention on the roadway by 26% (O’Keefe and Shi 2005). The optimal application rate always depends on the material type, pavement temperature, dilution potential, presence or absence of ice–pavement bond, plow circuit time, and LOS requirements. The surface temperature of a snow- or ice-covered road is particularly critical because it determines the snow melting capacity, dissolution, and penetration rates of the chemicals and that as the temperature decreases, the amount of deicer needed to melt a given quantity of snow and ice increased significantly (Salt Institute 2016). The article also indicates that agencies also develop their own specifications and memoranda for material applications and that over the past 10 years, most agencies have developed new or revised guidelines.