EFFECTIVE STRUCTURAL NUMBER ALGORITHM ENHANCEMENTS TO ROADHOG

ROADHOG is a deflection-based flexible pavement overlay design procedure used by the Arkansas Highway and Transportation Department. It uses a structural deficiency approach to overlay design modeled after the guidelines given in the 1986 AASHTO "Guide for Design of Pavement Structures". The effective structural capacity of the existing pavement (SN sub eff) is calculated as a function of the difference in the maximum pavement deflection and a deflection at some radial distance from the point of loading. This deflection difference is termed delta-D. As originally developed ROADHOG is limited to the structural thickness design of asphalt concrete (AC) overlays for existing conventional flexible pavements (AC surface, granular base, subgrade). Research has enhanced ROADHOG by adding capabilities to determine the SN sub eff for full-depth asphalt (FDA) pavements and surface-treated pavements (STPs). These enhancements allow the use of ROADHOG for any flexible pavement. The SN sub eff algorithm for FDA pavements uses a delta-D approach similar to the algorithm currently used in ROADHOG for conventional flexible payments. SN sub eff is determined for STPs by using a deflection ratio, delta-D/D0, in which D0 is the maximum pavement deflection under load. The algorithms are developed by using a comprehensive deflection basin data base generated by the finite-element pavement model ILLI-PAVE, varying surface and base course thickness and stiffness and subgrade stiffness. In both the FDA and STP algorithms the subgrade stiffness is not considered explicitly for estimating SN sub eff. SN sub eff estimates for surface-treated pavements also do not explicitly include the granular layer thickness of the STP. Comparisons of the new SN sub eff algorithms with the current procedures in ROADHOG indicate that the new algorithms give more consistent and accurate estimates of the effective structural number of the existing pavement.

• Record URL:
  • http://onlinepubs.trb.org/Onlinepubs/trr/1995/1473/1473-014.pdf
• Record URL:
  • https://scholar.google.com/scholar_lookup?title=EFFECTIVE+STRUCTURAL+NUMBER+ALGORITHM+ENHANCEMENTS+TO+ROADHOG&author=K.+Hall&author=Q.+Watkins&publication_year=1995
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1473, Strength and Deformation Characteristics of Pavement Sections and Pavement Rehabilitation. 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:
  • Hall, Kevin D
  • Watkins, Quintin B
• Publication Date: 1995

Language

• English

Media Info

• Features: Figures; References; Tables;
• Pagination: p. 115-119
• Monograph Title: Strength and deformation characteristics of pavement sections and pavement rehabilitation
• Serial:
  • Transportation Research Record
  • Issue Number: 1473
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Accuracy; Algorithms; Asphalt concrete; Asphalt pavements; Computer programs; Design; Flexible pavements; Full-depth asphalt pavements; Overlays (Pavements); Pavement structural numbers
• Old TRIS Terms: Effective structural number; Surface treated pavements
• Subject Areas: Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways;

Filing Info

• Accession Number: 00682846
• Record Type: Publication
• ISBN: 0309061121
• Files: TRIS, TRB, ATRI
• Created Date: Aug 24 1995 12:00AM