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Title: ASPHALT AGING: DUAL OXIDATION MECHANISM AND ITS INTERRELATIONSHIPS WITH ASPHALT COMPOSITION AND OXIDATIVE AGE HARDENING
Accession Number: 00756179
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: The kinetic data and chemistry of asphalt oxidative age hardening suggested a sequential, dual mechanism for asphalt oxidation. The dual mechanism rationalizes conflicts between earlier mechanistic investigations and explains the hyperbolic-like, time-versus-property plots characteristic of asphalt oxidative aging. The oxidation kinetics provide further confirmation of the asphalt microstructural model. It is proposed that the rapid initial oxidation rate of asphalt results from reaction of oxygen with limited amounts of highly reactive hydrocarbons. Final oxidation products of this initial reaction are sulfoxides and, most likely, ring aromatization. During this initial reaction, a slower oxidation reaction of asphalt benzylic carbons is initiated; final products are ketones and sulfoxides. The ratio of ketones to sulfoxides formed and the rate of age hardening were found to be dependent on temperature and oxygen pressure. Low-temperature oxidative aging, as occurs in pavements, was found significantly more sensitive to variations in temperature and asphalt composition than 100 deg C pressure vessel aging.
Supplemental Notes: This paper appears in Transportation Research Record No. 1638, Asphalt Mixture Components.
Language: English
Corporate Authors: Transportation Research Board 500 Fifth Street, NW Authors: Petersen, J CHARNSBERGER, P MPagination: p. 47-55
Publication Date: 1998
Serial: ISBN: 0309065100
Features: Figures
(6)
; References
(30)
; Tables
(1)
TRT Terms: Old TRIS Terms: Subject Areas: Highways; Materials; I31: Bituminous Binders and Materials
Files: TRIS, TRB, ATRI
Created Date: Nov 12 1998 12:00AM
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