Winter’s Effects on Your Parking Lots
Has this winter’s extreme temperatures wreaked havoc
on your parking lots?
By Michael Coletta, PCM Asphalt Division Manager | March 20, 2014
This winter has been one of extremes for those of us in Maryland, Washington DC, and Virginia. With record-breaking freezing temperatures, snow, ice, and salt, it’s safe to assume your parking lots aren’t in the best shape.
The havoc this winter has wreaked on your pavement is caused by a variety of factors, including the impact of freeze-thaw cycles, application of deicing chemicals, and mechanical damage caused by snow removal equipment – all of which contribute to the degradation of your asphalt.
The primary culprit is the freeze-thaw cycle of the Baltimore-Washington metro area. You may wonder what exactly happens to your asphalt during this time. Well, it’s pretty simple. When water freezes it expands, a process referred to as volumetric expansion. When water goes from a liquid to a sold, frozen state, it requires about ten percent more space. If this water is already in a small crack in your pavement, as it freezes, it pushes outward, making the crack bigger.
What can get tricky is that roads begin to thaw from both the top and bottom. As ice in the pavement melts, water floods the road’s base and subgrade, causing these layers to lose strength. As thawing continues, melted water becomes confined in the upper subgrade, unable to drain away through the frozen soil below.
Now think about what this is like in Maryland, DC, and Virginia with our extreme temperature changes. A freeze on Monday may create cracks in your asphalt; while a thaw on Tuesday invites water into the vulnerable area, followed by another freeze on Thursday that pushes the pavement apart even further.
Pavements weaken considerably in a very short time under these conditions, especially when deicing chemicals are involved. The weakness can continue for weeks, sometimes even months after the pavement is completely thawed. While the pavement will eventually regain its strength, it’s critical to take extra care of your asphalt during this time. That means pressure wash the salt away, patch those potholes, fill any cracks, and avoid heavy, load-bearing vehicles or machinery.
Questions? Need an estimate? We want to help! To discuss your projects please email us at email@example.com or call 301-595-3700.
Is your parking lot ADA compliant? Read up on the latest requirements here.