What are the most common causes of asphalt failure and deterioration?

Weight: Heavy garbage trucks, delivery trucks and trailers can overload the asphalt by over flexing and eventually cracking the surface.

Solutions: Remove and replace the areas that are cracked. A thicker asphalt thickness should be considered to help prevent future damage. In cases that involved the front areas of dumpster pads, the concrete slab should be extended to carry the heavy weight of the trash trucks as they load and unload.

Water: Water from sprinkler run off and rain can cause a number of problems. For areas that have lots of fall, the water rushes over the asphalt washing away the critical oils and fine aggregates that help keep the asphalt in tact. For areas that hold water, the water seeps into the base material creating a spongy base material. This allows the asphalt to over flex creating small cracks that are very close together, alligator cracks. These alligator cracks eventually spread and break apart creating pot holes.

Solutions: Keeping the sprinklers and irrigation water within the landscape areas is the first and most important step. Keeping the landscape material down and away from curb cuts is another common mistake. The water is designed to flow off of the asphalt through the curb cuts only to find a large pile of landscape rock or over grown grass keeping the water on the asphalt. Alligated areas can be surface patched in low traffic areas to eliminate the low spot and force the water away from that area. Removing and replacing the affected areas is preferred in high traffic areas. Proper crack filling and sealcoating will help prevent these problems from occurring and expanding.

Age: Many of the valley sites have been around for years with a lack of preventative maintenance. The affect of age is greatly determined by how the site was maintained.

Solutions: Sealcoat is not a good solution for asphalt that has out lived itself. For a 3-5 year solution, Type II Slurry Seal is a good alternative to new asphalt.

Before

  Paving and Striping (City of Phoenix Storage Yard)

After Type II Slurry Seal

  Paving and Striping (City of Phoenix Storage Yard)

For the long term hold, a fabric overlay is very effective for properties that have not been overlayed in the past and have good drainage.

Fabric Overlay @ Shea Plaza: The geo textile fabric is used to help prevent reflective cracking.

Fabric Overlay (Bashas 32^nd Street & Shea)

For properties with extensive drainage or base problems, a pulverize and pave or a full depth removal and replacement would be required. When these processes are done there is always the possibility of having to replace some or all of the base material if it is not suitable for paving because of clay and water damage.

Pulverizing Machine         

  Pulverize, Grade & Pave  (American Truck)

Demolition Crew: Full depth removal and replacement.(Drainage Problems)

A clay pocket found after pulverization

Regardless of what method the budget allows you to take, protecting your new surface with cracksealing and sealcoating is very important for the beautification and long term money savings.