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J. Mirwald, S. Werkovits, I. Camargo, D. Maschauer, B. Hofko, H. Grothe:
"Impact of aging on polarity fractions of asphalt binders";
Talk: Petersen Asphalt Research Conference 2020, Laramie, Wyoming (invited); 2020-07-13 - 2020-07-14.

The service life of a road is determined by the aging behavior of the asphalt binder, as it is the only component of organic nature. Common chemo-mechanical analysis involving dynamic shear rheometer (DSR) and Fourier-Transformation Infrared (FTIR) spectroscopy are capable to capture these changes, but they are only analyzing the materials performance as a composite. By looking at binder´s polarity based molecular constituents and how they change during aging, we go one step further towards the molecular level and correlate it directly to the initial binder state.
In this study, various long-term aged (LTA) binders from the different crude oil sources were investigated with FTIR spectroscopy, DSR, separated into their four polarity based (SARA) fractions and measured with FTIR spectroscopy subsequently. The results show the same trends on the molecular and binder level. The fractions showed that the most notable changes upon aging occur in the aromatics, resins and asphaltenes with the formation of carbonyls. The formation of sulfoxides is only found in the resins and asphaltenes. By the outcome of this study, we intend to contribute to a better understanding on how bitumen ages and how we can translate that knowledge to realistically simulate field aging in the laboratory.