HMA Home Page Section

Thin HMA Overlays - Your Cost-Effective Solution

Thin HMA overlays, 1 ½" or less, are the cost effective solution for pavement preservation primarily because of their ability to:
· Provide improved ride quality,
· Reduce surface distresses,
· Maintain surface geometrics,
· Reduce noise levels,
· Reduce life cycle costs, and
· Provide long-lasting service.

Thin HMA overlays should be placed before the pavement deterioration has reached a critical stage where more extensive rehabilitation is required. This will maximize your performance and yield a more cost-effective solution for your pavement.

Thin HMA overlays can be expected to provide 10 years or more on existing asphalt surfaces.

In 2008, Chou¹ and his colleagues found that in almost all cases, a thin asphalt overlay on an asphalt pavement was the most economical solution. He reported that thin overlays of concrete were not as cost effective, possibly due to increased deterioration of the underlying pavement.

Also, in 2008, the National Asphalt Pavement Association (NAPA) surveyed the state asphalt associations concerning the cost and effectiveness of various pavement preservation treatments. Thin HMA overlays had a longer expected life than the other treatments although the cost was higher. However, when that was divided over the expected life, the thin HMA overlay option was the most cost efficient as shown in the graph below.

1. Chou et. al., "Effectiveness of Thin Hot Mix Overlay on Pavement Ride and Condition Performance," for the Ohio Department of Transportation, 2008.



For more information on Thin HMA Overlays, click here.