Winter is a uniquely challenging time for asphalt pavement in Minnesota. While asphalt is flexible and stretchy during the warm spring, summer, and fall seasons, plummeting winter temperatures cause the pavement to become harder, stronger, but significantly more brittle.
However, the extreme cold itself isn't the biggest winter threat to your parking lots and roadways — the most severe seasonal asphalt damage is caused by the freeze-thaw cycle.
What Is a Freeze-Thaw Cycle?
A freeze-thaw cycle occurs when the ambient temperature fluctuates from above freezing (32°F) to below freezing, and then back above freezing again.
In Minnesota, properties experience dozens of these cycles each winter, especially during transitional months when daytime snowmelt is followed by sub-zero nighttime temperatures.
How Freeze-Thaw Cycles Destroy Asphalt Surfaces
To understand why freeze-thaw cycles are so destructive, you have to look at how water behaves.
When temperatures rise above freezing, highly mobile rainwater or snowmelt finds its way into microscopic hairline cracks in the pavement. When temperatures inevitably drop back below freezing, the trapped water turns to ice.
Water expands by approximately 10% when frozen, exerting upwards of 25,000 psi of pressure against the surrounding asphalt. This acts like a hydraulic wedge, forcing the pavement apart from the inside out.
When the ice melts again, the water flows deeper into the newly widened crack, restarting the destructive cycle.
Major Pavement Damage Caused by Freeze-Thaw
The freeze-thaw process in Minnesota often leads to significant asphalt pavement damage:
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Frost Heave: Water freezing in the base and subgrade layers forms large chunks called “ice lenses." The immense pressure of these ice lenses pushes asphalt pavement upward, physically deforming the surface.
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Potholes: As the weather warms and the ice lenses melt, they leave behind large, empty voids in the weakened base layer. When heavy vehicles drive over these unsupported voids, the asphalt may collapse, quickly forming a pothole.
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Alligator Cracking: Rapid snowmelt can saturate the gravel base under your asphalt, turning the ground mushy. As vehicles drive over the unsupported, flexible asphalt, it snaps into interconnecting patterns that resemble reptilian scales. Alligator cracking cannot be fixed with a simple crack filler; it requires a full-depth patch to restore the foundational base.
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Contraction & Shrinkage: The bitter cold makes asphalt brittle, causing the pavement to physically shrink and pull apart under the added stress.
3 Ways to Protect Asphalt Pavement From Freeze-Thaw Damage
The best way to stop the freeze-thaw cycle is to prevent water from penetrating your asphalt in the first place.
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Proactive Cracksealing: Having a professional contractor crackseal your pavement every 1 to 3 years is the most effective way to keep surface water from reaching the vulnerable base layers.
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Thoughtful Drainage Design: Properly sloped pavement and underlying drainage tile piping quickly direct water off the surface and away from the subgrade, eliminating the moisture needed for frost heave.
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Mill + Overlay: If freeze-thaw cycles have already caused widespread surface damage, a mill and overlay is an excellent rehabilitation option to restore the pavement's integrity.
Planning Your Spring Asphalt Repairs in Minnesota
Local asphalt plants do not open until the Spring, and Minnesota enforces seasonal road weight restrictions that prevent heavy commercial paving trucks from driving on the roads. Therefore, the best course of action during the winter is to document the areas of your property that are holding water, heaving, or cracking.
By noting these high-risk zones now, you can schedule a consultation with our Minnesota asphalt pros, so we can repair your lot first thing in the Spring once restrictions are lifted.
Monitoring Winter Asphalt Damage: Related Reading
If you want to protect your retail business, medical center, or apartment complex, it is critical to keep an eye on your pavement throughout the winter. When you spot a sign of damage, schedule asphalt repair in the spring as soon as possible.
Check for Standing Water
As detailed in a recent blog, Winter Damage Check: Asphalt vs. Rain, Snowmelt, & Standing Water, keeping an eye out for puddles that sit for more than 24 hours can help you identify areas with base failures or poor drainage before they expand into major springtime hazards.
Understand Winter's Impact
To learn more about how cold weather stresses your pavement and why high-quality asphalt installation matters, read What Winter Does to Your Asphalt & How Good Paving Decisions Pay Off in Spring.
Frequently Asked Questions: Winter Asphalt Damage
Don’t fall for any asphalt misconceptions! Reach out to our local experts for transparent answers to common questions about maintaining asphalt surfaces in Minnesota.
How can I prepare my asphalt surface for winter?
The best time to prepare asphalt for winter is in the fall. You should fill large cracks, repair existing potholes, and ensure the edges of your asphalt are intact.
Additionally, designate snow storage areas that are off the asphalt and at lower elevations so melting snow doesn't constantly run across your pavement.
Can asphalt withstand harsh weather conditions?
Yes, when properly maintained and prepared for winter, asphalt handles harsh weather and freeze-thaw cycles better than rigid surface materials like concrete. Its inherent flexibility allows it to shift with the temperature-induced expansions and contractions, reducing the severity of cracking and heaving.
When should I resurface my asphalt surface?
You should consider asphalt resurfacing (such as a mill and overlay) if your asphalt shows widespread signs of raveling, fading, massive interconnecting cracks, structural potholes, or significant standing water.
Contact Bituminous Roadways for Asphalt Services in the Twin Cities
With more than 75 years of experience, Bituminous Roadways, Inc. is the Twin Cities’ most trusted asphalt pavement contractor. Call us today at 651-686-7001 to request a free consultation and get your spring pavement projects on the schedule!