Pavement Overlay, Lanham, MD

Case Study 

Application	Pavement Overlay	Job owner	National Asphalt Pavement Association
Location	Lanham, MD	Asphalt Contractor	Gray & Son
Product	Mirafi® MPV500	Contractor	American Paving Fabrics
Quantity		Date of Installation (m/y)

THE CHALLENGE

The existing asphalt pavement in The National Asphalt Pavement Association (NAPA) parking lot was experiencing considerable alligator cracking and was scheduled to be re-paved. After some site investigation, it was determined that more serious patching would be required due to the unexpected pumping that was observed in some areas of the pavement surface.

THE DESIGN

After excavating a couple of test pits, everyone involved on the project realized that just a standard overlay would not be adequate. The majority view was that the appropriate repair would require full depth removal and replacement of the pavement cross section, over a wider area than originally planned. Due to the costs and time associated with this type of construction repair, everyone agreed that other options needed to be assessed. The decision, made by committee that included the contractors involved with input from the sitting President of NAPA, was to incorporate Mirafi® MPV500 to significantly reduce the surface water infiltration into the pavement, and to provide some stress relief between the existing surfaces/patches and the new overlay. While this was not thought to be the perfect fix, it was understood that this solution would significantly increase the longevity of the new overlay.

THE CONSTRUCTION

After the edge milling and patching was completed, American Paving Fabrics, placed PG64/22 at a rate of approximately 0.25 gallons/SY over the prepared surface and placed the Mirafi® MPV500. The paving overlay machines followed right behind them with their HMA overlay.

THE PERFORMANCE

The finished pavement looks great and will be inspected going forward to determine the increase in service life that the interlayer system provided. Each of the contractors involved in the pavement rehabilitation project were given a NAPA Recognition Award at their February 2008 conference.