Polyphosphoric Acid

Asphalt modifiers are used in asphalt roads to increase the durability of roads over a broad range of temperature and traffic conditions.  Polyphosphoric Acid, a widely used modifier, significantly increases the high-temperature performance grade (PG) rating of asphalt pavement and delivers improved resistance to rutting and superior adhesion to moisture-sensitive compositions, with no loss of low-temperature properties and performance.  In asphalt paving, Polyphosphoric acid can be used alone or in conjunction with a variety of organic polymers.

Polyphosphoric Acid (PPA) is an inorganic water-free liquid, which allows total miscibility with asphalt.  The elementary composition of Polyphosphoric Acid is basically phosphorus, hydrogen and oxygen, derived from phosphate mineral deposits.

Click here to access the March 2012 Federal Highway Administration (FHWA) Tech Brief The Use and Performance of Asphalt Binder Modified with Polyphosphoric Acid (PPA).

Click here to access the article “Why Does FHWA Have a Chemistry Lab,” which was published in the January/February 2012 edition of the FHWA’s magazine Public Roads.

Click the links below to view parts of the white paper "Use of Polyphosphoric Acid in Asphalt Binders":

To view the full version of "Use of Polyphosphoric Acid in Asphalt Binders," as well as other resources including "Best Practices for PPA Modification of Asphalt," and information from the 2009 PPA Workshop, please provide the following: