Development of a Quality Control Test for Asphalt Binders

摘要

An innovative, simple, and easy-to-use test method for quality assurance testing of asphalt binders at the mix plant was developed. This new method, the Binder Quality Control Test (QCT), uses an air jet to produce indentation and a laser deflectometer to measure the resulting deflection. The QCT is conducted under constant stress and temperature similar to the traditional Penetration test (ASTM D5) except instead of the penetration needle, an air jet is used with a loading time of 20 s and recovery time of 60 s under no load. Unlike the Penetration test, the QCT measures both the loading and recovery characteristics of a binder. The complete creep-recovery curve is measured and stored. The measurement of recovery properties allows for successful discrimination of both unmodified and polymer modified binders. Several performance-graded and penetration-graded asphalt binders were tested with and without modifiers, which included polymers as well as Recycled Engine Oil Bottoms (REOB). At this time the QCT has the potential to be implemented as a control test, an informational test that would trigger more complex acceptance testing. Possible applications of the QCT method include an alternative to traditional Penetration testing, quick and easy determination of asphalt tank contamination issues, assistance in value engineering projects, and with formulation of polymer modified binders. This paper describes the development, and implications of using the QCT developed in this research.