APE APE February 2020 | Page 16

EXPERT ADVICE Fixing Potholes Avoid common problems, patiently follow the process By Krystal Strassman, DRS Paving, Fitchburg, Wis. www.callape.com I t happens to the best asphalt paved surface.... the dreaded pothole. Pot- holes are depressions in a paved sur- face that can vary in size and shape. They are caused by the expansion and contraction of water that gets into the ground under the pavement. When wa- ter freezes, it expands. Think of when ice cubes are made. A tray full of water is put into the freezer, and when removed from the freezer, it is easy to notice that the water has expand- ed. This same thing happens when water gets into the ground under the pave- ment. If it has a chance to freeze, it will take up more space under the pavement, [16] and the pavement expands, bends, and cracks, weakening the asphalt pavement. Then when ice melts, the pavement contracts and leaves gaps or voids in the surface under the pavement, where water can get in and be trapped. If the water freezes and thaws over and over, the pavement will weaken and continue cracking. In warmer climates, not subject to freeze-thaw cycles, the problem begins with heat-caused deterioration. Cracks from the heat allow water in, eroding the sub-surface layers. In either case, an air gap is formed in the sub-base of the pavement. 1.800.210.5923