Winter has officially returned, accompanied by characteristic low temperatures and seasonal weather systems. While the possibility of snow can be iffy in many sea-level areas in the Pacific Northwest, we certainly see our fair share of frosty conditions (especially in the early mornings and late evenings). Chilly weather may be the perfect excuse to hole up indoors where it’s warm and cozy, but when it’s time to hit the road for that New Year’s party or to return to work, frosty streets present a host of other concerns.
Icy roads can be thawed in many ways, but no de-icing agent is perfect. Depending on what de-icing product is used, its effects on asphalt, both positive and negative, can last long past the winter, and they can reach far beyond the asphalt itself.
Salt and Salt-Based Solutions
Sodium Chloride, or rock salt, is the classic de-icer, and probably the most common. Every year, approximately fifteen million tons of salt get spread on roads across the United States. Salted roads increase traction and significantly reduce accidents, but this method may be less effective in actually melting the ice without additional chemicals.
When the ice does melt, the salt goes with it into the soil, where it can cause damage to plant life. The salt and the chemicals that are often paired with it can be harmful to animals that come into contact with them outside. Over time, excessive salt can also slowly erode metal and concrete as it is left to sit.
Many different chemicals are used as de-icers either on their own or as a complement mixed in with salt. Some of the most common are calcium chloride, magnesium chloride, and acetates like calcium magnesium acetate (CMA). These de-icers can be very effective at melting ice or stopping ice from forming, especially at lower temperatures, when salt becomes less useful. Acetates are commonly used on airline runways because they don’t break down metal and they keep ice from sticking.
One of the biggest concerns about the use of chemical de-icers is the impact on pavement. These ingredients can contribute to stripping in asphalt, breaking down some of the chemicals holding it together and leading to cracks and other structural problems. There is less concern with these chemicals if used in limited amounts, but excessive use can cause accelerated wear and tear to asphalt and concrete. Beyond the road, they can cause increased rust on vehicles, and unfortunately, all of these chemicals will mix with ice melt runoff and may contaminate the local ecology (for example, in drains that empty in oceans).
Sand is another treatment used to improve road conditions. This is most useful for providing traction and increasing maneuverability on otherwise icy roads. Sand isn’t especially effective at melting ice, but it also isn’t as likely to cause lasting damage to the asphalt itself.
The primary downside of sand, besides its more limited effectiveness, is that it won’t conveniently wash away when the ice and snow melt away. The sand sticks around and may eventually collect and cause damage such as erosion. This can also be a long-lasting problem for asphalt pavement built for effective drainage as sand accumulates and blocks the flow.
In recent years, a number of other creative and unique solutions have appeared that can often be easily prepared at home. Some people have reported trying a home remedy, such as beet juice mixed with sugar or even cheese brine or pickle brine (especially on areas such as private driveways). However, these are not officially approved solutions. Alternative treatments also come with their share of downsides, such as odor, staining, and potential impact on local ecology.
Because de-icing is generally necessary to keep frosty roads safe for drivers during the winter, your best bet is to monitor the condition of the treated asphalt. When an asphalt surface calls for repair, contact a trusted asphalt paving company to ensure roads remain in optimal condition regardless of season.