- Chip Seals
- Multiple Course Chip Seals
- Fog Seals
- Crack Seal Repair
- Scrub Seals
- Emulsion Distribution
Chip sealing primarily involves spraying an asphalt emulsion on the pavement, then immediately spreading a layer of uniformly sized aggregate chips. The new surface is rolled to set the aggregate in the emulsion. After a twenty-four hour curing period excess chips will be swept up. Chip seals can be performed on newly bladed and shape roads where a prime coat layer is added before the chip seal process begins. Chip seal is a pavement preservation treatment that provides a new skid resistance wearing course, can arrest raveling and seal some of the minor cracks. Chip seals are more economic than asphalt overlays.
Multiple Course Chip Seal
A multiple course chip seal consists of more than one application of emulsion and aggregate. A double chip seal consists of a spray application of emulsion, spreading a layer of aggregate, rolling the aggregate for embedment, applying an additional application of emulsion, spreading another layer of aggregate (approximately half the average least dimension of the base coat aggregate) and rolling once more. Sweeping should be done between applications. This process may be repeated, as necessary.
The Fog Seal Process
Fog seal is a great way to seal and protect. While it is commonly used to preserve old asphalt surfaces, it can also be applied to “cap off” a new chip seal. A fog seal on a new chip seal surface will result in better aggregate retention, dust elimination and will give the road a “new” appearance. A fog seal can add years to the life of a chip seal before another application is needed.
The Asphalt Emulsion Manufacturer Associates defines a fog seal as:
“A light spray application of dilute asphalt emulsion used primarily to seal existing asphalt surfaces to reduce raveling and enrich dry and weathered surfaces. It can also be used as a color coating and as a paint striping surface preparation.”
With time, sunlight oxidizes the oils in asphalt, causing the asphalt to become brittle and develop cracks. Cracks in asphalt roadways provide a place for moisture to reach the pavement base and will ultimately lead to more extensive deterioration. Crack sealing is a maintenance method to repair construction joints, and longitudinal cracks in the roadway. Crack sealing is necessary to prevent water from entering the base of the roadway.
The Crack Sealing Process includes the following steps:
- The cracks in the roadway may be non-routed or routed out to a specified depth.
- The cracks are then cleaned out and dried with high-pressure air and heat.
- A hot-pour crack sealant will be applied.
- Sand may be placed over the sealant to reduce stickiness.