As part of the County's asphalt maintenance program, Public Works annually chip seals some of the asphalt roads in the unincorporated area. Chip seal is a highly cost effective way to maintain, protect, and extend the life of an asphalt road. The Public Works department first implemented the chip seal program back in 2007, and each year chip seals an average of 30 miles. By self performing the chip seal, the cost is about $12,000 per mile versus an overlay cost of about $100,000 per mile.
A thin film of heated asphalt liquid is sprayed on the road surface, followed by the placement of "chips" (small rocks). The chips are then compacted to orient them for maximum adherence to the asphalt and the excess chips are swept from the surface. A few days following the chip seal application, traffic will notice loose chips on the road. This is a normal part of the process and traffic will further help to embed the chips into the asphalt. While the road "cures" over the next couple of weeks, loose chips may be swept up again and new pavement markings are painted.
Maintain, Protect, and Extend The Life
Chip seal is a common preventive maintenance activity, with many state road agencies and cities across the nation using it. It helps to protect the pavement from the effects of sun and water, increases skid resistance, and fills small cracks and other surface defects. Many studies about the performance and effectiveness of chip seal have been done and chip seal is agreeably one of the most economical treatments for paved roads. Chip seal extends the life of an asphalt pavement by up to 7 years, thus saving County taxpayers money.
Day of Application
One Year After Application