Martin Product Sales LLC
Thin Hot Mix Asphalt Overlays
“The typical rehabilitation treatment for an aging low volume flexible (hot mix asphalt) pavement has been a thin hot-mix asphalt overlay. This treatment usually extends the [low volume] pavement serviceability about 10 years.” – MnRoad
Effective Pavement Preservation
Thin hot mix asphalt (HMA) overlays are plant-mixed combinations of asphalt cement and aggregate placed in depths of ¾ to 1½ inches over aging pavements as a pavement preservation treatment. The liquid asphalt binds the rocks together in a strong but flexible pavement structure. The HMA is designed to seal and protect the existing pavement, to correct surface deficiencies, and to improve rideability and surface friction. They are one of the most effective maintenance treatments for re-profiling and improving rideability.
For more distressed surfaces, the top ¾ to 1½ inches of the existing pavement may be removed by cold-milling with carbide-tipped cutting bits to a specified depth followed by the application of the thin HMA overlay.
The mixes used for thin HMA overlays can be dense-graded, open-graded or stone matrix asphalt (SMA). Open-graded overlays allow surface water to drain away quickly, preventing hydroplaning and improving visibility in wet weather.