Generalizations have been made as to (re) using shingles in HMA and WMA pavements.  The engineering opimization of RAS has only been touched upon as to setting limits of RAS replacement.  Grade bumping of virgin AC, mixing times, storage, and production temperatures are only a few of the areas to be optimized for pavement performance in various cold and warm weather climates.

Related Work (Added by TERI Administrator 3/2011)
A Strategy to Select the Combination of Innovative Sustainable Materials for Asphalt Mixtures – Michigan Technological University, Houghton, Active

Use of Recycled Asphalt Shingles in HMA; Texas Department of Transportation, 2010, Active

Evaluation of Waste Recycled Materials Applications in Highway Pavement in California: An Overview of Research; California Polytechnic State University, 2010, 44p

Incorporation of Recycled Asphalt Shingles in Hot-Mixed Asphalt Pavement Mixtures; Minnesota Department of Transportation, 2010, 83p

Utilization of Post Consumer Recycled Asphalt Shingles and Fractionated Recycled Asphalt Pavement in Hot Mix Asphalt; 2010 Green Streets and Highways Conference, 2010, pp 349-359

Performance of Recycled Asphalt Shingles in Hot Mix Asphalt; Missouri Department of Transportation, $765000.00, 2009, Active