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Polyphosphoric Acid Modification of Asphalt

A study titled Performance Of Asphalt Mixtures Containing Polyphosphoric Acid was completed September, 2014 by Harold Von Quintus of Applied Research Associates. The study was sponsored by the Asphalt Institute, Federal Highway Administration, Association of Modified Asphalt Producers, ICL Performance Products LP and Innophos, Inc. The purpose of the investigation was compare the long-term field performance of PPA-modified mixtures to non-PPA-modified mixtures that were placed under the same conditions. A total of 15 paired sections (PPA-modified to non-PPA-modified) from across the United States in a wide variety of climatic and traffic conditions were analyzed by comparing rut-depth, fatigue cracking, transverse cracking and raveling. In summary, no significant or consistent difference in performance was identified between the PPA-modified and non-PPA-modified mixtures.

Workshop on PPA Modification of Asphalt Binders

A national workshop on Polyphosphoric Acid Modification of Asphalt Binders was conducted in Minneapolis, MN on April 7-8, 2009. The workshop was jointly sponsored by the Transportation Research Board (TRB), Federal Highway Administration, Minnesota Department of Transportation, TERRA, Association of Modified Asphalt Producers, Innophos, ICL Performance Products, and the Asphalt Institute.

The Asphalt has a publication on polymer modification of asphalt: PPA Modification of Asphalt (IS-220).The TRB also plans on publishing a circular of papers from the Workshop.

  • Overview of the Asphalt Institute publication, PPA Modification of Asphalt – IS-220 (PDF 172KB)
  • Important Note When Recovering Binders Containing PPA (PDF 32KB)
  • Rutting and Moisture Resistance of Asphalt Mixtures Containing Polymer and Polyphosphoric Acid Modified Bitumen (PDF 202KB)
  • Moisture Sensitivity of Acid Modified Asphalt & Mixtures With & Without Anti-Stripping Agents (PDF 4.2MB)

Moisture Sensitivity

  • Chemistry of Asphalt Aggregate Interaction (PDF 1.1MB)
  • The Effects of Dusty Aggregates Towards Stipping in Asphalt Pavements (PDF 158KB)
  • Influence of Mix Design Towards Stripping Potential of Asphalt Pavements (PDF 200KB)
  • Moisture Damage and the Environmental Conditioning System (PDF 1.2MB)
  • Test to Assess the Potential for Moisture Damage In Asphalt Mixtures (PDF 460KB)


  • (2.1MB) Crumb Rubber Bituminous Mixes from Waste Tires from Asphalt magazine