DEVELOPMENT OF AN IMPROVED OVERLAY DESIGN PROCEDURE FOR ALASKA

Alaska is currently developing a pavement management system for their road system. An important input to the system is the determination of flexible overlays based on the structural adequacy of the existing pavement. The current overlay procedure (Asphalt Institute method) does not always show a need for overlays, despite the poor surface condition of the pavement and high traffic volumes. Therefore, an improved procedure that considers not only traffic but also surface distress, structural properties of the pavement, and effects of a freezing and thawing of the base, subbase, and subgrade layers is needed. This report recommends two such methods: a simplified mechanistic method using equations developed in Pennsylvania, and a mechanistic procedure using a back-calculation computer program known as ELSDEF. A comparison of these methods showed that the Asphalt Institute procedure was inappropriate and underdesigned the overlay for the road sections. The Pennsylvania equations were slightly more conservative than the mechanistic method using ELSDEF, except for cases where the pavement fatigue life had been utilized completely by past traffic loads. It is recommended that Alaska utilize the mechanistic approach to design overlays and ELSDEF as the back-calculation procedure. The Pennsylvania equations can be used in cases not requiring considerable accuracy.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1988/1207/1207-008.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=DEVELOPMENT+OF+AN+IMPROVED+OVERLAY+DESIGN+PROCEDURE+FOR+ALASKA&author=M.+Yapp&author=R.+Hicks&author=B.+Connor&publication_year=1988
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1207, Pavement Design. 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:
  • Yapp, Margot
  • Hicks, R G
  • Connor, Billy
• Publication Date: 1988

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 76-87
• Monograph Title: Pavement design
• Serial:
  • Transportation Research Record
  • Issue Number: 1207
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Accuracy; Backcalculation; Computer programs; Design; Design methods; Equations; Mechanical analysis; Mechanistic design; Overlays (Pavements); Pavement management systems
• Geographic Terms: Alaska
• Subject Areas: Data and Information Technology; Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00490203
• Record Type: Publication
• ISBN: 03090477730
• Files: TRIS, TRB, ATRI
• Created Date: Dec 31 1989 12:00AM