Chip & Seal Program
"Chip & Seal" is a common pavement maintenance practice that extends pavement life and provides a good driving surface.
How is Chip & Seal Different from Asphalt Overlays?
Chip & Seal uses the same ingredients as asphalt paving, but the construction method is different. With Chip & Seal, a thin film of heated asphalt liquid is sprayed on the road surface, followed by the placement of small aggregates ("chips"). The chips are then compacted to orient the chips for maximum adherence to the asphalt, and excess stone is swept from the surface.
Why Use Chip & Seal?
Chip & Seal provides use with the opportunity to maintain the roads for very low cost. It is about one fourth to one fifth the cost of a conventional asphalt overlay. Additional benefits include:
- Strengthens the underlying road base;
- Eliminates the need to crack seal;
- Enhances safety by providing good skid resistance;
- Provides an effective moisture barrier for the underlying pavement against water intrusion by sealing cracks in the pavement;
- In hot weather, re-seals cracks by flowing back together.
What Is The Chip & Seal Process?
First, the road surface needs to be properly cleaned of debris and any holes patched. Next, an asphalt distributor truck starts by spraying each lane with hot liquid asphalt to assure an even application. The asphalt used is applied at a temperature between 150 and 185 degrees Fahrenheit. A chip spreader follows as rapidly as possible with a rock application, preferably within one minute. The asphalt must be fluid so the rock will be embedded by the displacement of the asphalt. The rocks are an aggregate crushed to a special specification for size and cleanliness. Next, a roller is used to set the rock into the liquid asphalt. Rolling orients the flat sides of the rock down and produces a tighter chip seal. It takes two to four passes of the roller to set the rock. Sweeping is done at the completion of the chip seal process to remove surplus rock from the surface.