MnROAD Field Investigation of Polyphosphoric Acid Modified Asphalt 
This MnROAD study built upon the findings of previous Federal Highway Administration research to conduct a field trial assessing the performance of Polyphosphoric Acid (PPA) over a 5-year period. PPA has been used for 30 years to stiffen asphalt pavement. Recent research by the FHWA and MnROAD hope to establish mutual cost- effectiveness and asphalt strength to provide a better utilization method for PPA.
Work Plans:
Reports and Publications:
- March 2012 FHWA TechBrief
"The Use and Performance of Asphalt Binder Modified with Polyphosphoric Acid (PPA)"
- January 2012 Transportation Research Circular
"Polyphosphoric Acid Modification of Asphalt Binders: A Workshop"
- August 2010 Phosophorous-31 NMR Studies of MnROAD Test Track Cells
- March 2010 MnROAD PPA Interim Report
- Laboratory Evaluation of Asphalt Binders and Mixtures Containing Polyphosphoric Acid
- Low Temperature Fracture Properties of Poly-Phosphoric Acid Modified Asphalt Mixtures
- Fracture Properties and Fatigue Cracking Resistance of Asphalt Binders
- Fatigue Characterization Test for MnROAD PPA Modified Mixtures
Presentations:
- July 2008 Petersen Conference
Polyphosphoric Acid Modified Asphalt in Conjunction with Lime as an Antistripping Agency