Effect of Oxidative Aging on Binder Fatigue Performance

• Autores: CASSIE HINTZ, RAUL VELASQUEZ, Zhijun Li, HUSSAIN BAHIA
• Localización: Asphalt paving technology, ISSN 0270-2932, Vol. 80, 2011, págs. 527-548
• Idioma: inglés
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• Resumen

  • Oxidative aging in asphalt binders is generally accepted to be the cause of hardening of the asphalt over time. To adequately predict long-term pavement performance, it is necessary to understand how aging affects binder properties.

    In this paper, the effect of age hardening on fatigue damage resistance is investigated. Six asphalt binders used in construction of sections that are part of the Strategic Highway Research Program Long-Term Pavement Performance (LTPP) study were tested by means of the recently developed Linear Amplitude Sweep (LAS) test. The LAS test is an accelerated cyclic fatigue test that uses incrementally increasing load amplitudes to generate damage in the binder. The framework of viscoelastic continuum damage (VECD) was used to analyze the LAS results in order to develop fatigue laws for each LTPP binder. The LTPP asphalt binders were tested at five different age levels: un-aged, rolling thin film oven (RTFO) aged, pressure aging vessel (PAV) aged, double PAV aged, and quadruple PAV aged. Results indicate that laboratory aging changes the relationship between fatigue life and strain applied significantly and systematically. The changes are such that aging appears to improve binder fatigue resistance at low strain levels but deteriorates fatigue resistance at high strain levels. The changes are highly asphalt specific; for some binders the changes are less than for others. These trends were verified by conducting time sweep tests and are fairly repeatable.

    Keywords: age, fatigue, asphalt binder, viscoelastic continuum damage ___________________________________________________ 1Graduate Research Assistant, University of Wisconsin, Madison, WI 2Research Associate, University of Wisconsin, Madison, WI 3Senior Engineer, Fushun Research Institute of Petroleum & Petrochemicals, Sinopec 4Professor, University of Wisconsin, Madison, WI The oral presentation was made by Ms. Hintz.