Liquid Anti-Icers, Granular Deicers, and Aggregates: What's the Difference?
Winter road maintenance products ultimately have one thing in common: they must become a liquid/brine to perform. However there are numerous differences associated with how quickly each solution dilutes and how long it is effective. In this industry, there is a place for liquid anti-icers and deicers, granulars, and aggregates. The key is understanding where, when, and how each of these products achieve optimal performance.
What are Liquid Anti-icers?
Liquid anti-icers are solutions that can be used to pre-treat surfaces to prevent ice from forming and bonding to the pavement. They are typically sprayed over walkways and roads before snowfall occurs. Each batch must be mixed to proper concentrations depending upon the temperatures of both the air and pavement. Some manufacturers add liquid chloride solutions to solid granular deicers to increase their brine making performance. The liquids can leach out and separate over time since they are not in a homogeneous blend with the solids.
What are Liquid Deicers?
Liquid deicers are typically a combination of 23-30% active materials and water. A liquid deicer is an excellent choice when the goal is to remove a light/thin frost, and freezing temperatures are not a threat. When a liquid deicer is applied during a heavy storm, it is diluted at an even higher rate and loses effectiveness quickly. Many DOT and street maintenance personnel will not apply liquid dicers below 20°F because of the risk of refreeze. Liquid deicers are always limited in high precipitation conditions.
What are Granular Deicers?
Granular deicers are solid salt based granules that vary in size, shape, coarseness, and chemical or mineral composition. They are applied to walkways and roads to form brine and melt ice that has already bonded with the pavement. They can also prevent continual ice accumulation, depending upon the performance of the product. Granular deicers are also used to provide extra traction and improve pavement friction.
What are Aggregates?
Aggregates are a broad family of coarse grain solids that stay solid and do not melt into liquids. They are sometimes applied to increase traction and improve pavement friction on weather affected roads and paths. The most common aggregates are sand, gravel, crushed stone, and a variety of geo-synthetics.
Liquid Pros and Cons
- Liquid anti-icers do not bounce and scatter when applied to the road surface, so they can usually be applied with precision.
- They also embed well in the nooks and crannies of the surface and provide good coverage.
- Liquids begin working immediately, as there is no wait time for it to turn into brine.
- Part of the downside to liquid anti-icers lies in the name itself...anti-icer, not deicer. These products are intended to be used as a preventative measure, but are not effective when applied to roads where ice and snow have already accumulated. When you attempt to use liquid anti-icers on pre-existing ice, conditions can become even more slick and dangerous.
- In general, liquids are more difficult to store and transport than solids and require specialized tanks.
- They also require additional personnel training with freeze point curve tables to make sure they are mixed in the correct concentrations for certain temperature ranges. During very cold temperatures, if the ratios are not right, they can actually create ice instead of preventing it.
- Liquids run off of sloped surfaces, making it difficult to ensure even coverage on inclines or tilts.
- Liquid anti-icers and liquid deicers can also be washed away by rainfall. Winter weather can be unpredictable and fluctuate above and below 32° F. When you receive a sleety mix of rain and snow, all of your efforts can be washed down the storm drain before they even have a chance to work.
- When working with liquid anti-icers you have a much more narrow window of use between: timing, weather conditions, and differences between air and pavement temperatures.
- It is difficult to tell which roads have already been treated.
- Liquids anti-icers and deicers cannot provide additional traction. At times, additional aggregates must be used to improve pavement friction.
Granular Pros and Cons
- Granules work effectively on ice and snow that has already accumulated. Their mass allows them to vertically penetrate ice and snow in order to reach the pavement surface.
- Solids are easier to store and transport than liquids and don’t require specialized tanks. Because of this, granular deicers can be distributed in a much wider variety of vehicles. This is extremely helpful for operations using a fleet of vehicles or municipalities that use subcontractors for deicer application.
- Granular deicers provide skid resistance without the use of additional aggregates. The best deicers have a myriad of granule sizes so the smaller granules melt quickly into brine and the larger granules melt slower and provide needed traction.
- With granules, it is much easier to see which roads have already been treated. This reduces the likelihood of wastefully double applying deicer.
- Granular deicers can be applied much more quickly than liquids.
- When using granular deicers, there is much less room for user error. Because there are no concentrations to mix, pavement and air temperatures to take, dilutions to calculate, and sprayers to operate, it is easier and more efficient to use granules rather than liquids.
- Granular deicers do not dilute as quickly.
- Lighter granules can bounce and scatter. Choose a coarse grained deicer with a mixture of large and small granules to help keep your product where you need it.
- After periods of storage, granular deicers can clump together. Before applying to the road surface, make sure clumps are broken up for more even distribution.
- For some, it is easy to get carried away and use too much. Overuse of deicers can increase costs, corrosion, and environmental impact. Be sure to use a high performing deicer that will give you more with less.
The Power of Ice Slicer
With the exception of certain very high-performance liquid deicers, granular deicers are more effective in colder temperatures and in high precipitation conditions. Ice Slicer is proud to offer all of the benefits of granular deicers, without the drawbacks.
Our special mixture of coarse granule sizes reduces bounce and scatter, making it easier to keep your deicer where it is needed most. With a homogeneous blend of over 60 naturally occurring minerals, our grains are high performing, less corrosive, and safer for the environment than traditional white salt. More powerful performance means you can save money by getting greater deicing benefits with a smaller amount of product.