This technique is a cost-effective measure used in Sturgeon County’s road maintenance program. It can be applied on a variety of roadways, from low-volume subdivision streets to high-volume highways.
What is a thin lift asphalt overlay?
It is an asphalt mixture applied over the existing pavement structure at a thickness of 40 – 60 mm. The mixture is similar to regular hot mix asphalt but may use smaller aggregate pieces to improve compaction. It can be applied using conventional processes and equipment.
A thin lift asphalt overlay is best used when the underlying pavement structure is in good shape. Overlays generally aren’t used if the pavement has full-depth cracks or if the base structure has deep ruts or underlying base problems.
What is a mill and overlay?
A mill & overlay involves the top 40-60 mm of asphalt being ground off, it is then replaced with 40-60 mm of new asphalt.
How long will one last?
It can extend the life of the pavement by eight to nine years and reduces the need for more costly road maintenance.
- Improve surface smoothness to achieve a better, quieter ride
- Improve traction
- Reduce wheel path rutting to improve safety
- Prevent water damage to the road surface which preserves the pavement structure
- Maintain or create adequate drainage