Chip seal to improve Canyon Road

Friday Aug 14 2009 3:50 PM

Weather permitting, Pierce County will apply rubberized chip seal coating to three miles of Canyon Road from Pioneer Road to 103rd St. E. on Aug. 17 and 18. Drivers should seek an alternate route while the application is underway. Canyon Road carries more than 16,000 vehicles per day.

The new Canyon Road surface will be smoother and better looking - the result of an improved chip seal product made from 5 percent recycled tire rubber and gravel that is pre-coated with paving-grade asphalt. This product was applied to 150 lane miles of county road this year, using the equivalent of 75 tons of recycled tires.

Chip sealing is the most common and economical surface treatment used to preserve county roads. The process consists of applying a layer of liquid asphalt to the road surface, which is covered immediately with a layer of crushed rock.

The rubberized product costs about 25 percent more than standard chip seals but lasts one to two years longer, resulting in lower long-term cost.

"When there isn't enough money to install completely new pavement, a rubberized chip seal provides a good short term solution," said Road Operations Manager Bruce Wagner. "It provides excellent cost benefit when applied to the right road at the right time."

The primary reason to chip seal an existing pavement is to seal and protect the pavement surface from deterioration caused by traffic and the effects of sun and water. Chip seals do not replace the need for new pavement, but can significantly extend pavement performance. Rubberized chip seal costs about $16,000 per lane mile compared to asphalt overlay that costs $65,000 to $100,000 per lane mile. In 2009, the county applied rubberized and standard chip seal to 230 lane miles in all, at a cost of $3.2 million.

Advantages of the rubberized product over traditional chip seals include:
- stronger, longer lasting finished product
- results in 40 percent less loose rock after the application, requiring much less sweeping
- cures in a matter of minutes - roads can be swept, striped and returned to normal usage the same day
- finished product is slightly more smooth than a traditional chip seal
- finished product is black - provides better contrast to striping and traffic markings, and is generally better looking than a standard chip seal
- because the liquid binder is not emulsified with water, it is more forgiving when applications encounter wet weather.

CONTACT: Bruce Wagner, road operations manager, 253-798-6051, or Hunter George, communications director, 253-798-6606, or hgeorge@co.pierce.wa.us