Chip Sealing is done in many
in the U.S. It is a cost-effective way to
maintain roads and saves significant tax dollars. Chipsealing is a yearly
process on selected roads that puts a coating over the asphalt of a street
to protect it from water and weather damage and to keep the roads in good
During the 2016 Chip Seal season, ACHD will resurface 500 miles of
roadway. The 2016 Chip Seal season will begin on Tuesday June 14, 2016 and last
until late August, or early September.
View a video of Chip Sealing
2016 Chip Seal Areas
In preparation for the Chip Seal season, ACHD crews perform
Seal maintenance on streets within the Chip Seal zone.
The sealant forms a long-lasting, resilient seal which is flexible and
expandable in varying and extreme pavement temperatures. Crack Sealing
prevents the invasion of surface water between the layers of asphalt and
layers of roadway below it. Not all roads that receive a crack seal will
receive a Chip Seal within the same year.
Asphalt deteriorates in time because of the sun and weather. A Chip Seal helps seal
the surface and provides an armor coat for skid and weather resistance. The best
aspect of Chip Sealing is simple economics.
In 2009 the cost for chip Sealing was $23,000 a mile. Chip Sealing saves
taxpayer dollars because it protects the road from deterioration and greatly
delays the need for a new asphalt overlay to repair a deteriorated road. At
this time, asphalt overlays (new blacktop) cost up to $265,000 per mile
Some preparation work will take place throughout the spring, and the Chip Seal process
traditionally begins the first week in June. The work involved
consists of four phases: applying the Chip Seal, sweeping excess chips, applying
the fog coat, and microsealing cul-de-sacs. On-street parking will be affected during
We appreciate your patience during this time, and we realize that while the surface
is not very compatible with skates or roller blades, it is still the most economical.
For area boundary descriptions for our operations this year, please call 387.6325
at our urban division and 387.6350 for our rural division.
“I’d like to give credit to ACHD for chipsealing our subdivision, they
did a beautiful job. They operate like a well oiled machine, and it was hot
out there. My wife and I appreciate everything they did," said Ken Weland of
As a part of maintenance program, crews Chip Seal street surfaces (including new
streets) to protect then from water and weather damage and to keep them in good
A Chip Seal application to a road or street has many positive objectives:
- Chip Seal to maintain the existing pavement in its present condition by delaying further aging due to water and sun - this is equally important to new streets;
- Chip Seal to change the texture of the road for skid resistance;
- Chip Seal to supply minimal additional strength to the pavement;
- Chip Seal to provide a moisture barrier;
- Chip Seal to give better resistance to studded tires;
- Chip Seal to correct existing pavement problems by sealing cracks.
A Chip Seal is an application of asphalt followed with an aggregate "rock" cover.
It is constructed to produce an initial placement or maintain an existing asphalt
- First, the road surface needs to be properly cleaned of debris and any holes patched.
- Next, an asphalt distributor truck starts by shooting only one lane at a time with
liquid asphalt to assure an even application. The asphalt used is applied at
a temperature between 140 and 180 degrees Farenheit. After cooling, this asphalt
remains slightly flexible to maintain its hold on the rocks.
- Another piece of equipment, the 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 rubber-tire roller is used to set the rock into the fresh oil. This is done
to get the flat sides of the rock down and produce a tighter Chip Seal. It takes
two to four passes of the roller to set the rock.
- After the first lane has been shot, covered with rock and the rolling has begun,
the equipment starts the second lane. The operation is the same as the first shot.
- Sweeping is done at the completion of the Chip Seal process to remove surplus rock
from the surface. This loose rock can grind and loosen rock set in the Chip Seal
and damage the project. Sweeping is done as soon as possible after the asphalt has
set up (three to seven days).
- ACHD follows each Chip Seal with a Fog Seal that helps set the rock and control fly-rock
and dust. Fog Sealing also adds life to a Chip Seal. This is a separate process that
follows sweeping by up to three weeks.
- ACHD Seal Coats all old and new streets in a neighborhood to save money and prolong
street surface life. On residential streets, six years will pass before the Seal Coating
process is again necessary.