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Title: EXTENDING THE LIFE OF THIN ASPHALT SURFACINGS
Accession Number: 00646154
Record Type: Component
Availability: Find a library where document is available Abstract: The scope for extending the life of asphalt surfacings in the United States is examined by comparing the durabilities of Australian and North American asphaltic cements. A model is used to estimate the effect of durability on surfacing life at a number of sites in the United States. Two approaches to reducing asphalt oxidative hardening are presented. In the first, a road trial of a gap-graded mix designed for surfacing lightly trafficked residential streets is described. After 10 years of service, the gap-graded mix had hardened much less than conventional ones. Sectioning of cores from the trial showed that all the hardening in the gap-graded mix had occurred at the surface; the interior of the mix had not hardened since construction. This is attributed to the low air void content initially obtained as a result of the ease of compaction of the mix. The second approach is reduction of the hardening rate of asphalt binders by addition of an antioxidant. The antioxidant lead diamyldithiocarbamate (LDADC) is being evaluated in two chip seal road trials in Australia. Binder hardening is well advanced at the trial in a tropical environment, and the results of sampling and testing 6 years after construction are presented. These results show that, for LDADC concentrations greater than 4%, a substantial reduction in binder hardening has occurred. LDADC has acted sacrificially and none now remains in any of the trial sections. Further observation of the trial will reveal whether the observed improvement continues to be maintained.
Supplemental Notes: This paper appears in Transportation Research Record No. 1427, Pavement Surface Courses, Stone Mastic Asphalt Pavements, and Asphalt Concrete Recycling. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
Monograph Title: Pavement surface courses, stone mastic asphalt pavements, and asphalt concrete recycling Monograph Accession #: 01403263
Language: English
Authors: Oliver, John W HPagination: p. 22-29
Publication Date: 1993
Serial: ISBN: 0309055008
Features: Figures
(6)
; References
(15)
; Tables
(6)
TRT Terms: Uncontrolled Terms: Old TRIS Terms: Subject Areas: Design; Highways; Materials; Pavements; I23: Properties of Road Surfaces; I31: Bituminous Binders and Materials
Files: TRIS, TRB, ATRI
Created Date: Apr 22 1994 12:00AM
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