What Is the Difference between Summer and Winter Asphalt?

Most people probably don’t realize that there are different types of asphalt used across the paving industry on a seasonal basis. To be completely honest, asphalt pavement pretty much looks the same to the untrained eye. But to experienced asphalt contractors, gradation, texture, and aggregate material ratios make a big difference in terms of what type of asphalt mixture can be used during certain times of year.

Hot and cold mix asphalts both have unique merits and characteristics that make them the ideal choice for certain projects during specific times of year. From thin overlays and porous asphalt to noise-cancelling pavement and perpetual pavement, each of these variations have unique qualities that help them serve different purposes. Industry experts know that there’s a major difference between summer and winter asphalt.

What Is Summer Asphalt?

Hot or hot mix asphalt is used for summer paving projects. It’s usually available from April until December. Ideal for paving large surface areas, hot mix asphalt is typically used for commercial parking lots, long residential driveways, as well as major and minor side roads. In some cases, hot mix asphalt has also been applied to airport runways.

Hot mix asphalt is mixed at around 270-275 degrees Fahrenheit. In order to fully adhere to the ground, it’s crucial that the asphalt mixture either remains at its mixing temperature or higher. If the asphalt cools down, then it could lose some of its binding capability and won’t adhere completely to the ground or it will take longer to cure, which could cause some businesses to lose money due to extended downtime. It’s possible for the asphalt to cool a little during the transportation process from the plant to the worksite. If this happens, then the asphalt needs to be reheated until it reaches the appropriate application temperature again.

Having to reheat the asphalt adds more time to the project at hand, so this isn’t an ideal situation but it’s necessary to ensure that the asphalt is applied properly and adheres to the ground. Propane or diesel heating systems can be used to reheat the asphalt quickly on the jobsite, so that it doesn’t have to be transported back and forth numerous times.

Hot mix is the asphalt of choice for summertime applications because the ground is already dry and warm from the higher daytime temperatures and prolonged hours of sunlight exposure. Applying cold mix asphalt to warm and dry substrate in the summer heat would not only prevent the new mixture from binding with the existing substrate, but it would also form a weak foundation that’s prone to damages and incapable of withstanding heavy vehicular and foot traffic. The end result would be a very weak and brittle foundation that will only require a series of expensive repairs and asphalt replacements in the future.

What Is Winter Asphalt?

On the flip side, winter asphalt is composed of what’s aptly referred to as cold mix aggregate. It’s usually only available during January, February, and March because those are typically the coldest months of the year in the Northern hemisphere. Since asphalt pavement installation projects are usually done in the summer when the ground is warm and more flexible, winter is known as the season of patch jobs in the asphalt pavement industry.

Patching requires significantly smaller batches of asphalt than paving an entire parking lot, driveway, or road. As a result, asphalt pavement production moves at a much slower pace during the winter months because not as much asphalt aggregate is needed—at least not for paving purposes. Don’t forget, asphalt is still an essential ingredient for a number of other applications aside from road paving, so the industry is still very much alive and well during the winter months.

Due to the wet and cold conditions, asphalt paving projects pretty much come to a halt during the winter months. While you could certainly pave an entire parking lot during the winter, the snow and ice don’t make for ideal working conditions. Plus, it would take a lot longer for the asphalt to fully cure, which would extend the downtime in terms of business and road closures. This would cause major inconveniences business and property owners, not to mention motorists and city workers as well.

Unlike hot mix asphalt, winter asphalt doesn’t have to be kept at a certain temperature to be usable. If you happen to have leftover winter asphalt from a patching or repair project, you can store it at any temperature and save it for later use if need be.

One of the main downfalls is that it’s a lot harder to shutdown busy streets and intersections during the winter to do roadwork. Not only are the working conditions harsh for the crew, but there’s a strong chance that the high moisture levels in the ground will prevent the asphalt from adhering completely to the substrate. Plus, the contraction and expansion caused by the freeze-thaw cycle during seasonal transitions will be especially harsh on asphalt pavement that hasn’t set properly.

However, if you’re asphalt parking lot really needs some maintenance work as a result of winter damages, then you can always schedule to have the repairs done during your off-peak or closing hours to minimize your downtime.

How to Choose the Right Asphalt Mixture for Your Property

There are three main factors that determine the type of asphalt mix you need for your property.

• Time of year. As the names suggest, whether you need summer or winter asphalt depends on the current season.
• Type of paving project. Based on the applications of hot and cold mix asphalt, the type of the paving project greatly influences the type of asphalt aggregate that’s required.
• Your exact regional location also makes a difference because countries in different time zones have different winter and summer climates.

Do You Have an Upcoming Paving Project?

Trust the asphalt experts at Sure-Seal Pavement Maintenance Inc. to get it done for you right the first time. From asphalt pavement installation to minor and major repairs, maintenance and overlay, there’s no paving job that’s too big or too small for us. We also offer a comprehensive seven-year labour and material warranty for all of our projects. Contact us today to learn more or to book a consultation.