ASPHALT HARDENING IN SPRAYED SEALS

A low-cost pavement that consists of a sprayed surface seal over a thin granular base is widely used in Australia on low-volume roads. The average life before a reseal is required is of the order of 10 to 15 years. The main reasons for such long service lives are considered to be (a) the design procedures used in Australia, (b) the selection of materials, particularly the durability of the asphaltic cement (asphalt), and (c) the high degree of control of the construction operation. Information on each of these factors is given. The Australian Road Research Board (ARRB) Asphalt Durability Test is described. Full-scale road trials that were placed in a range of climatic conditions and observed for up to 10 years have shown the test to be a good indicator of the resistance of an asphalt to hardening in sprayed seals. Road trials in which additives were evaluated to improve asphalt durability, such as hydrated lime and lead diamyldithiocarbamate (LDADC), are also being monitored. A simple predictive model of asphalt hardening has been developed. Only the following inputs are needed to calculate asphalt viscosity at a particular site: (a) the average temperature at the site, which can be obtained from the closest weather station, (b) the ARRB Asphalt Durability Test result for the fresh asphalt, and (c) the age of the seal. The model can be used to test the effects of asphalt durability on field hardening at particular sites and to identify climatic areas in which asphalt hardening will be particularly rapid. If it is further developed, the model could be usefully incorporated into pavement management systems.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1987/1106v1/1106v1-025.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=ASPHALT+HARDENING+IN+SPRAYED+SEALS&author=J.+Oliver&publication_year=1987
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/isbn/0309044545
• Supplemental Notes:
  • This paper appeared in Transportation Research Record N1106, Fourth International Conference on Low-Volume Roads, Volume 1. 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
• Authors:
  • Oliver, John W H
• Conference:
  • International Conference on Low Volume Roads, 4th, 1987, Ithaca, New York, USA
• Publication Date: 1987-8

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 196-201
• Monograph Title: FOURTH INTERNATIONAL CONFERENCE ON LOW-VOLUME ROADS. VOLUME 2
• Serial:
  • Transportation Research Record
  • Issue Number: 1106
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Additives; Asphalt concrete; Asphalt hardening; Asphalt tests; Climate; Construction management; Design methods; Durability; Low volume roads; Materials selection; Mathematical models; Pavement management systems; Pavements; Sealing compounds; Service life; Sprays (Materials); Viscosity
• Uncontrolled Terms: Low cost roads
• Geographic Terms: Australia
• Old TRIS Terms: Construction control; Materials evaluation; Pavement life
• Subject Areas: Construction; Design; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 00473114
• Record Type: Publication
• ISBN: 0309044545
• Files: TRIS, TRB
• Created Date: Sep 30 1987 12:00AM