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Asphalt Modification with Phosphoric Acid

Project Information

Project ID: 
Project Status: 
Start Date: 
Wednesday, December 6, 2006
End Date: 
Thursday, February 20, 2014
FHWA Program: 
FHWA Subprogram: 
Pavement and Materials
FHWA Topics: 
Research/Technologies--Turner-Fairbank Highway Research Center (TFHRC); Roads and Bridges--Pavement and Materials
TRT Terms: 
Asphalt Modification; Phosphoric Acid; Infrastructure Asphalt; Pavements; Binders; Styrene Butadiene Styrene; Research
FHWA Discipline: 
Pavement and Materials
TRB Subject Area: 

Contact Information

First Name: 
Last Name: 
(202) 493-3305
Email Address: 
Infrastructure Materials Team
Office of Infrastructure Research and Development
Office Code: 

Project Details

Project Description: 

This project continues ongoing research activity that will provide guidance to State agencies and industry partners on the appropriate use of phosphoric acid as an asphalt modifier. Issues still not clearly resolved are the reaction of phosphoric acid with asphalt from different crude sources, reaction with lime and limestone aggregates, and the effect on rutting and fatigue. The comparison of phosphoric acid modification with polymer modification needs to be augmented. There are also unresolved forensic issues in New York State concerning phosphoric acid and premature pavement failures. Until this is resolved, other State agencies will likely reject the use of this potentially cost-saving additive.


Deliverable Name: 
Guidance on use of polyphosphoric acid as an asphalt modifier
Deliverable Type: 
Research report or guidelines
Deliverable Description: 
Final report providing best practice guidelines for the use of phosphoric acid to modify asphalt