Pavement Section

Pavements are typically comprised of several layers of material with each layer having it's own function and purpose. The most important part of a roadway is the subgrade condition. If the subgrade is good, less asphalt is required to provide a stable pavement section. If the subgrade is poor, more asphalt is required.

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Pavement Section Layers

1. Surface – top surface (wearing course) with fine aggregate to seal out water - responsible for a smooth ride and skid resistance

2. Intermediate (if necessary) – medium sized aggregate used to distribute load from surface layer to base layers

3. Base – bottom asphalt layer – uses coarse aggregate – aids in drainage, frost resistance and pavement stabilization

4. Subbase - (if necessary) – used to stabilize the pavement – can be aggregate or other stabilization treatments to the soil

5. Subgrade – existing, untreated soil