ISSN: 0090-3973
Published Online: 16 February 2007
Page Count: 8

Characterization of Thermal Degradation ofqa Liquid Amine Anti-Strip Additives in Asphaltqa Binders Due to RTFO and PAV-Aging
Wasiuddin, Nazimuddin M.
Doctoral Candidate, School of Civil Engineering and Environmental Science, University of Oklahoma, OK

Fogle, Chris M.
Graduate Student, School of Chemical, Biological and Materials Engineering, University of Oklahoma, OK

Zaman, Musharraf M.
David Ross Boyd Professor and Aaron Alexander Professor, Associate Dean for Research, College of Engineering, University of Oklahoma, OK

O’Rear, Edgar A.
Francis W. Winn Professor, University of Oklahoma, OK

(Received 24 May 2006; accepted 12 December 2006)

Abstract

In this study, thermal degradation of amine-based liquid anti-strip additives was evaluated due to RTFO-aging and PAV-aging according to AASHTO T 240 and AASHTO R 28 test methods, respectively. The surface free energy (SFE) characteristics of asphalt binders before and after aging were used as a tool for this evaluation. Two asphalt binders, namely PG 64-22 and PG 70-28, and two anti-strip additives, namely AD-Here HP Plus and Redicote E-6, were evaluated. It was observed for 0.75 % AD-Here HP Plus in PG 64-22, mixing at 163°C is more effective than mixing at 145°C with respect to increase in SFE. Also, both RTFO and PAV-aging decrease the total SFE of asphalt binders; both the aging processes are more effective in PG 64-22. In addition, the beneficial effect of anti-strip additives in acid-base characteristics of asphalt binders is severely reduced by RTFO and PAV-aging. Finally, the chemical model of asphalt binder, proposed by Wasiuddin , was expanded to include the SFE characteristics of asphalt binders due to aging.

Keywords:
asphalt binder, anti-strip additives, thermal degradation, RTFO-aging, PAV-aging, surface free energy, dynamic Wilhelmy plate method, contact angle, acid, base

Paper ID: JTE100660
DOI: 10.1520/JTE100660
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