FATIGUE-BASED CRITERIA FOR SEASONAL LOAD LIMIT SELECTION

During spring thaw, restrictions on allowable axle weights (load limits) are often applied to flexible pavement sections in seasonal frost areas to prevent premature failure of thaw-weakened pavements. Currently, load limits are selected on the basis of experience. An approach to load limits that is based on controlling seasonal rates of fatigue consumption is described. Fatigue consumption can be determined from fatigue curves that relate critical tensile strains in the pavement section to the number of load repetitions causing fatigue failure. By using a layered-elastic computer program, strain is determined for the traffic loads applied to the pavement while it is in various seasonal states. Seasonal values for elastic-response parameters (resilient modulus and Poisson's ratio) are determined in laboratory tests on appropriately conditioned specimens. By relating the fatigue damage produced to the number and magnitude of loads applied during each of the seasonal pavement conditions, the effects of alternative load limit policies on remaining pavement life can be compared. In an application of the method to an existing pavement it was decided that the maximum axle load permitted during the spring-thaw period should be one that produced the same rate of fatigue consumption as the normal-summer-fall legal maximum of 18.9 kips. Using this criterion, the maximum spring-thaw load for the pavement would be 11.5 kips. Comparisons indicated that the remaining service life under the posted 14-kip load limit would be 80 percent of the life remaining if the 11.5-kip load limit were imposed. If no special spring-thaw period load limit is imposed, the remaining service life of the pavement will be reduced to 40 percent of the life remaining under the 11.5-kip limitation. (Author)

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1983/918/918-004.pdf
• Summary URL:
  https://scholar.google.com/scholar_lookup?title=FATIGUE-BASED+CRITERIA+FOR+SEASONAL+LOAD+LIMIT+SELECTION&author=J.+Hardcastle&author=R.+Lottman&author=T.+Buu&publication_year=1983
• Availability:
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• Supplemental Notes:
  • Publication of this paper sponsored by Committee on Frost Action. 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.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Hardcastle, James H
  • Lottman, Robert P
  • Buu, Tri
• Conference:
  • 62nd Annual Meeting of the Transportation Research Board
  • Location: Washington District of Columbia, United States
  • Date: 1983-1-17 to 1983-1-21
• Publication Date: 1983

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 22-30
• Monograph Title: FROST ACTION ON TRANSPORTATION FACILITIES
• Serial:
  • Transportation Research Record
  • Issue Number: 918
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Axle load force; Fatigue (Mechanics); Flexible pavements; Modulus of resilience; Poisson ratio; Seasons; Service life; Tension; Thaw; Ultimate load design
• Uncontrolled Terms: Criteria; Seasonal variations
• Old TRIS Terms: Limits; Poissons ratio
• Subject Areas: Design; Geotechnology; Highways; Pavements; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00381783
• Record Type: Publication
• ISBN: 030903561
• Files: TRIS, TRB
• Created Date: Mar 30 1984 12:00AM