Summer time in Michigan is the time for road repairs! The most common treatment we use to repair our roads is chip and seal.
The goal of this treatment is to provide a crack-free surface, mini-mize surface water infiltration and to prevent dust. All this is done without adding new structure to the road and at a fraction of the cost of a traditional hot asphalt treatment.
Chip and seal: The process
There are many options to repair a section of roadway. Chip and seal offers a solution at a somewhat reduced price tag. Generally, the cost is much lower than the cost of a 1 1/2 inch hot asphalt treatment. Chip and seal consists of a thin coating of emulsion (hot oil) with slag stones of a relatively small size rolled in. This treatment application is used on sections of roadway that are in semi-good condition, with respect to edges, drainage and surface. This treatment can be repeated if necessary.
Multiple seals: The process
This process is used when a single seal is not adequate because a road is badly deteriorated. Two or three “single seals” can be applied to a road to provide relief for rough surfaces. The additional seals also insure that all cracks are completely filled. This process is especially useful when there are larger cracks in the road surface.
The process includes a first layer of asphalt emulsion followed by a layer of 1/2” to 3/4” crushed stone. A second layer is put down directly over the first layer using the same process. A third layer or even a fourth can also be applied, if road conditions require it; however, it is usually best to let a year pass before putting the third or fourth layer down.
Chip and seal offers an effective treatment without the traditional traffic blockage problems. Since this treat-ment is a moving operation, roads are only closed for a short period of time. It is extremely important to follow the guidance of the traffic regulators on site, and not drive over the area before the stones are rolled into the emulsion.
The main problem that occurs for motorists is loose stones. These stones gather toward the middle and edges of the road. When driving at a high speed or passing another car, motorists should be aware of the potential spray of stones. The speed limit is posted at 25 mph for a short period of time after the chip and seal process to warn motorists to slow down.
In order to ensure that the entire county has roads in the best possible condition, CCRD starts its chip and seal operation in a different area each year.
The expected life of a chip and seal process is approximately seven years under moderate traffic conditions.