Most damage to pavements is caused by freeze-thaw cycles

A freeze-thaw cycle is when the temperature fluctuates from above freezing (32F), to below freezing, and then back to above freezing.  When temperatures are above freezing, rainwater or snow melt will make its way into any small crack in the pavement. Then, as temperatures drop below freezing, the water within the cracked pavement begins to freeze and expand, causing the crack to expand and grow as well.  Warmer weather re-melts the ice, allowing the water to move deeper into the newly expanded crack, only to freeze and expand again during the next cycle.  Water underneath the pavement is meant to drain away, but during winter it freezes in the base and subgrade materials. Water freezing below the pavement can sometimes cause frost heave to occur.  Frost heave occurs when water is allowed to freeze and expand in large chunks The material above these chunks is heaved upward deforming the pavement.  When warmer weather comes, the ice begins to melt, weaking the base layer and leaving voids where the chunks were formed.  Eventually, potholes will then quickly appear.

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