Asphalt Surface Treatments Process
The Town is divided into 15 maintenance sections. On average, this equates to 9.4 linear miles of streets per section that require an annual asphalt surface treatment.
Public Works staff identifies which street will require what type of surface treatment needed by using a rating scale called a pavement condition index (PCI). The PCI rates the condition of the surface of a road network. The PCI provides a numerical rating for the condition of road segments within the road network, where 0 is the worst possible condition and 100 is the best. These measurement are based on roughness, surface distress, skid resistance and deflection, pavements can be assigned a score that reflects their overall condition.
Public Works primarily uses two types of asphalt surface treatments on Town roads:
1.Mill & Overlay: This treatment is used when asphalt has reached the end of its life cycle. Milling 1” to 2” of existing asphalt and replacing with new asphalt extends the life of the street and provides a quality driving surface.
2.High density mineral bond for residential streets. High density mineral bond is comprised of a dense mixture of fine aggregates and polymers suspended in an asphalt emulsion. By applying this treatment, it reduces cracking, raveling, effectively deflects UV rays and effectively preserves the existing asphalt binder.