01661634

Component

This study aims to identify binder aging mechanisms induced by varying thermal-oxidative aging conditions. Toward this end, long-term aging process simulated by the pressure aging vessel (PAV) was conducted at different combinations of aging duration-temperature. Experimentally, SARA analysis was conducted to acquire core information of chemical evolution occurred during the aging process, and FT-IR analysis was employed to investigate chemical bonding variations of the reactive system. The two experimental outcomes were then associated with kinetic models to identify the aging time – temperature dependency of aging indices during laboratory aging process. It was found that the Sulfoxide index is limited as a reliable indicator of oxidative binder aging. Gravimetric measurements of binder over different aging levels indicated that molecular/atomic rearrangements due to laboratory aging are the most likely physicochemical events. The kinetic analysis results integrated with PAV test results further implied that oxygen molecules diffused into binder were not actively reactive with existing binder molecules for oxidation. Furthermore, the proposed relationship between aging time – temperature and Carbonyl index can be used for the estimation of oxidation level of the asphalt binder at varying thermal-oxidative conditions.

This paper was sponsored by TRB committee AFK20 Standing Committee on Asphalt Binders.

18-02480

English

6p

2018

Transportation Research Board 97th Annual Meeting

Digital/other

Figures; References; Tables

Aging (Materials); Bituminous binders; Chemical bond; Kinetics; Laboratory tests; Oxidation; Thermal stresses

Pressure aging vessels

Highways; Materials; Pavements

Transportation Research Board Annual Meeting 2018 Paper #18-02480

TRIS, TRB, ATRI

Jan 8 2018 10:36AM