Ice Prevention Technical Information
Anti-icing is the application process of chemicals (brine) that not only de-ice, but also remain on the pavement surface and continue to prevent the bonding of frozen precipitation for a certain period of time, or prevent the bonding prior to a winter storm event. Anti-Icing saves money by allowing easier mechanical snow and ice removal. Studies show anti-icing reduces the effort required to break the bond of packed snow and ice by 10 to 1.
Anti-icing increases traction, maintains roads and pavements for drivers and pedestrians, and helps reduce costs and equipment uses in a variety of ways. In the city of Kamloops, BC an independent study showed a reduction of collisions in the city of 54%, and a 77% reduction on highways. The report showed savings to the city of $334,000 per month in insurance claims alone, not to mention the human cost of life and limb.
What is
Pre-wetting?
Pre-wetting is the process of adding a liquid de-icer to a salt stockpile. The technique allows pre-wetted rock salt to melt ice and snow at lower temperatures, to stay in place longer when broadcast from application vehicles (reducing losses from bounce and scatter by as much as 40%) and yield a more workable and flowing inventory that handles and stores well over the summer.
Both public and commercial users report reductions of 25% to 40% of salt tonnage as a result of the extra melting power and reduced bounce and scatter obtained from pre-wetting at their stockpile.
Pre-wetting also eliminates costly and troublesome saddle tanks and spray systems that require constant maintenance.
Benefits of Anti-Icing
Use of prewetted stock jumpstarts the melting process (salt needs moisture to be effective).
The pavement surface is kept clearer during inclement weather and returns to normal faster, resulting in fewer accidents and delays.
Brine doesn’t bounce or blow off and maintains its melting power and effectiveness ahead of additional frozen precipitation.
Increased efficiency results in the use of less salt, significant cost savings, safer working conditions, and less environmental concerns.
List of De-icers
Liquid de-icers are available in granular solids and in liquid and work to chemically lower the freezing point of water. The chemical mix in premium de-icers create an exothermic reaction for an even stronger melting power. The chemicals most commonly used in commercial de-icers are:
Sodium Chloride (NaCl or table salt; the most common de-icing chemical)
Magnesium Chloride (MgCl2, often added to salt to lower its working temperature)
Calcium Chloride (CaCl2, often added to salt to lower its working temperature)
Potassium Chloride (KCl)
Calcium Magnesium Acetate (CaMg2(CH3COO)6)
Potassium acetate (CH3COOK)
Potassium formate (CHO2K)
Sodium formate (HCOONa)
Calcium formate (Ca(HCOO)2)
Urea (CO(NH2)2, a common fertilizer)
Methanol (CH4O)
Ethylene Glycol (C2H6O2)
Propylene Glycol (C3H8O2)
Glycerol (C3H8O3)
Environmental impact
Sodium chloride (rock salt) is inexpensive and readily available in large quantities. However, salt water freezes at 0 °F, causing the brine to be completely ineffective as temperatures fall. Rock salt also causes corrosion and rusting in vehicles and in the rebar in concrete bridges. Excess deicing salts such as sodium chloride or calcium chloride leach into the ground, and can eventually become toxic to area organisms and plants. Larger concentrations can also reach water bodies and damage ecosystems.
In response to environmental concerns, organic compounds have been developed that reduce concerns with salts and have longer residual effects when spread on pavements. These compounds are by products of agricultural operations such as in sugar beet refining and the creation of ethanol. Additionally, mixing common rock salt with organic compounds and magnesium chloride results in spreadable materials that are both effective in much colder temperatures (−25 °F) and use less material.
Planning Ahead
All de-icers, liquid and granular must be transported into the region via truck or rail. To maintain the necessary reserves:
First, measure your de-icer usage per storm and then multiply by 3 to compensate for any delays, weather changes, etc. that might deplete your supply.
Second, determine the de-icer usage amount needed for the season. This is commonly based on the average number of storms in a given season in your area.
Here at Gee Asphalt, we measure our de-icer volumes in the same manner by taking the collective total needs of our de-icer clients and making projections accordingly. We take pride in our dedicated team who makes deliveries frequently in less than twenty four hours from the time the call is received. For bigger needs, we can help you correctly size your liquid de-icer equipment package. Typically an MD300 pickup size spray unit and a bulk storage tank will handle all but the biggest jobs. Gee will dispatch personnel to set up and install your spray equipment and bulk storage and train your drivers and operators in correct application practices. Because we want to serve you better and anticipate your needs, we have the storage necessary to meet and significantly exceed client demands even during the toughest winter weather.
