Paved Surfaces

All paved surfaces are subject to wear and tear, as no paved surface is permanent. During the first 75% of a pavement’s life cycle, it performs well and keeps a good appearance. But after that, deterioration occurs rapidly.
Pavement breaks down due to the following conditions:

• Weathering: noticeable by the change of colors (from blackish gray to light brown) and the surface smoothness of the pavement
• Temperature changes: cause shrinking and expanding of the pavement and result in cracks, trenches, and potholes. Freezes and thaws weaken the surface and subgrade underneath the pavement. Heat can soften the pavement and cause heavy trucks to create tracks in the pavement
• Improper drainage: causes depletion of elements that hold the pavement together
• High traffic volume: causes ruts—especially with frequent usage by heavy vehicles
• Gasoline spills: break down the surface of the pavement

Trouble Areas for Pavement

In dealing with pavement, there are several things to be aware of, including:

• Pot holes: to correctly repair, the base should be removed and replaced. A short-term solution is to sweep loose debris and standing water out of the hole. A wet surface will not allow the repair material to adhere. Fill the hole to a slight crown to allow for compaction. Depths greater than three inches require compacting in two-inch layers. Compact with a shovel or a tamper or simply drive over the repaired area.
• Catch basins: maintenance is important to prevent storm sewer blockages and minimize the pollutants entering storm sewers that discharge into detention basins or directly into storm water systems. Staff must regularly inspect the grate and remove debris. Catch basins should be cleaned out before the storage area is half full. Once that level is reached, debris begins to wash into the sewer pipes. Cleaning should be done in the spring after the first large snow melt, in the fall after trees have shed their leaves, and as needed.
• Washouts: can occur when shoulders, side ditches, culverts, and embankments have been damaged, and water remains on the road or seeps back into the base, saturating and weakening the base/road. Surface cracks also allow water to penetrate and weaken the base. Too much water remaining in the surface, base and sub grade combine with traffic action to cause potholes, cracks, and pavement failure.
• Expansion joints in concrete: the most common type of movement cracks. They allow sections of the concrete floor or building to expand and contract freely in response to temperature changes in the surface. These cracks are the floor’s weakest spots and when combined with moderate to heavy traffic, they have a potential for constant damage. Several products are available to maintain and repair expansion joints. Common products include flexible epoxy and elastomeric concrete.
• Underground storage tanks: can cause cracks and erosion underneath the pavement above them.

Tips for Paved Surfaces

To help maintain the life of paved surfaces, here are some tips to be aware of: 

• Filling cracks is the least expensive and most cost efficient way to prevent future repairs.
• Pavements must be inspected annually. Depressions might indicate base failure and need for repair.
• Sand that builds up around drainage basins is due to oxidation of the surface. Fine sand in the blacktop ravels (loses fine particles from the upper layer of asphalt) and becomes brittle. Sealcoat should be applied to the asphalt.
• On specifications, work to be done must be stated in specific terms, e.g., two-inch compacted overlay vs. two-inch overlay or full-depth patches vs. patches.
• On job bids, the property manager must be wary of ambiguous terminology, quotes that are 20% higher or lower than other vendors, and estimates that recommend against correcting the cause of the problem.
• Work must always be inspected to confirm the work is being done according to specifications.