Friends link: C2010-590 C2010-599 C2090-913 CA0-001 CTFL-001 E20-324 HH0-130 JN0-101 JN0-692 M2020-622 1D0-525 1Y0-250 1Y0-350 1Z0-510 200-001 200-530 225-030 250-316 352-001 4A0-103 4A0-105 700-104 70-177 70-416 70-432 70-450 70-452 70-668 920-183 9A0-125 9A0-127 A00-260 A2010-570 A4040-224 ASC-029 C_TADM51_70 C2010-502 C2010-538 C2010-564 C2010-577 HP0-S41 640-722 JN0-102 300-208 070-483 1Y0-253 1Z0-478 640-461 1Z0-591 400-101
• Wednesday, March 28th, 2012

Chip Seal

What: An asphaltic binder is sprayed on the prepared flexible pavement surface, followed immediately by an application of aggregate.  The seal is then rolled to seat the aggregate in the binder.  After sufficient curing, the surface is broomed to remove any loose aggregate.  The binder may be applied as a water-based asphalt emulsion, a solvent-based asphalt cutback or hot applied asphalt.  A fog seal may be applied over the cured and swept surface to aid in chip retention and to blacken the surface.  Polymers, crumb rubber and other additives may be used to improve performance.

Where:  Chip seals have been successfully applied on all types of asphalt pavements, from low volume rural roads over a prepared base to heavily trafficked superhighways over hot mix asphalt.  The road should be structurally sound with only minor surface defects.

Why (advantages):  A chip seal seals and protects asphalt pavements from sunlight, rain and snow.  It improves skid resistance, seals minor cracks and surface imperfections, inhibits raveling, addresses bleeding and flushing when properly designed, protects pavement structure and extends pavement life.  The Strategic Highway Research Program found chip seals, which are a relative low cost treatment, to be one of the most cost-effective pavement preservation treatments.

Why not (disadvantages):  Chip seals are not appropriate over rutted, potholed, rough, moderately or severely distressed surfaces.  Problems with dislodged chips causing vehicle damage and damage by snow plows have been reported, but a fog seal application over the new chip seal or use of a high performance polymer asphalt binder can mitigate these problems.  Chip seals may be noisy under traffic, but use of single-sized aggregate can greatly reduce the noise.  Chip seals should be done in weather dry and warm enough to allow thorough curing, and with very strict traffic control to prevent damage before the seal has thoroughly cured.

When:  Ideally, chip seals should be applied when a road is still in good condition, with only minor surface problems, such as loss of friction, drying surface or very minor cracking.  They may also be applied as a wearing surface shortly after cold or hot in-place recycling or other treatment or over a prepared base on rural roads.  Chip seals are an excellent choice for keeping good pavements in good condition.

Estimated life extension: 6-8 years over pavements in good condition; 4-6 years on pavements in fair condition; 3-4 years for pavements in poor condition.

For more information on successful chip seals, consult the Chip Seal Checklist put together by the FP2 and FHWA.

You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.

Comments are closed.