Surface Treatments

In addition to the previously mentioned type of plant mix asphalt pavement or black top, there is another type of pavement performed by our company called Surface Treatment, also known as “tar and chip” or “chipseal.” This type of road surface is used by VDOT on secondary roads that do not have a high traffic volume. Surface treatment is installed by spraying liquid asphalt from a distributor truck on a prepared stone base, covering the liquid asphalt with a layer of crushed aggregate and compacting it with a roller. This is usually done in 2 layers (prime and seal) or 3 layers (prime and double seal). The color and texture of the final surface is determined by the aggregate used on the final seal.

Aggregate color varies according to its source (i.e. type of rock – granite (grey), basalt (green), and crushed river gravel (light brown). Surface treatment has a “float” of loose gravel on the surface that some think offers a more “rural” and less “urban” feel to the surface. The cost is a little less than plant mix. However, it is not as thick a surface as plant mix and is, therefore, less durable.