What Is The Freeze-Thaw Cycle In Asphalt?
A freeze-thaw cycle is when the temperature fluctuates from above freezing (32F), to below freezing, and then back to above freezing.
This happens in New Jersey throughout our winter months over and over and over. When temperatures are above freezing rain, snow, or any type of liquid water can work its way into any sized crack in the your parking lot. When the temperatures drop below freezing, the water freezes within the pavement begins to expand in that area.
See Diagram On Water & Ice Expansion:
The effects of freeze-thaw are usually highest after a large snowstorm and the following days of melting snow. As the snow begins to melt, the water will seep into any open cracks in the pavement. At night, the temperatures will still drop below freezing. The water that has stayed or become stuck inside the cracks will expand as it freezes. (Water expands approximately 10% when frozen) This expansion eventuallty breaks the blacktop apart. As a result, as normal traffic resumes, the asphalt begins to weaken and will eventually fall apart.
Another factor in freeze-thaw is your base and subgrade. What most people don't understand is that water underneath your parking lot is meant to drain away from the pavement. However, in the winter months there are not enough warm hours for the ground to thaw and allow proper drainage during these cycles. The water then gets trapped in the base and subgrade of your pavement. This causes unraveling at the base level.
See Diagram Below
What Can I Do To Combat Freeze-Thaw Damage
To My Parking Lot?
The best way to protect your asphalt from the dangers of the freeze-thaw cycle is to make sure that your pavement has proper drainage and that you crack seal your parking lot before winter.
Did You Know Hot-Rubberized Crack Sealing Is The #1 Most Cost-Effective Way To Protect Your Parking Lot?
Top 5 Reasons To Crack Seal Your Asphalt Parking Lot Before Winter:
1.) Waterproof: Crack sealing prevents water from infiltrating down to the sub grade
2.) Prevent Potholes: Crack sealing prevents potholes
3.) Extends The Life Of Your Asphalt Parking Lot: Studies performed have proven when crack sealing is completed as part of a preventative maintenance plan it will extend the life of your asphalt parking lot by as many as 10-15 years
4.) Safety: Prevents trip and falls
5.) DELAY THE OVERLAY: Crack sealing will help extend the life of your parking lot and delay costly milling & paving.
Drainage and crack repairs will keep water from getting into your pavement via cracks and causing problems when it freezes and thaws.