THEORETICAL IMPLICATIONS OF THE AASHTO 1986 NONDESTRUCTIVE TESTING METHOD 2 FOR PAVEMENT EVALUATION

The conventional classification of pavement design procedures into "empirical" and "mechanistic" is reexamined. It is submitted that the term "mechanistic" originally denoted a data interpretation methodology based on the laws of engineering mechanics, proposed as an alternative to the statistical interpretation techniques used extensively in the interpretation of AASHO Road Test data. Current mechanistic design procedures retain statistical/empirical correlations, but this is a matter of practical expediency, pending improvements in analytical capabilities. On the other hand, incorporating mechanistic results into a statistical/empirical framework rarely leads to reliable conclusions. A case in point is provided by AASHTO 1986 Nondestructive Testing Method 2 (NDTM2), which combines the mechanistic layered elastic theory with the purely statistical/empirical structural number concept. The derivation of the NDTM2 equations is traced and simplified, and a number of theoretical shortcomings are highlighted. It is recommended that use of NDTM2 be discouraged and that efforts for the gradual elimination of statistical/empirical constructs (e.g., structural number, equivalents single-axle load, and Miner's fatigue concepts) be intensified. Attempts to define statistical/empirical parameters (e.g., layer coefficients, present serviceability index, and load equivalency factors) using mechanistic theoretical tools should be abandoned.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/trr/1991/1307/1307-024.pdf
• Record URL:
  https://scholar.google.com/scholar_lookup?title=THEORETICAL+IMPLICATIONS+OF+THE+AASHTO+1986+NONDESTRUCTIVE+TESTING+METHOD+2+FOR+PAVEMENT+EVALUATION&author=A.+Ioannides&publication_year=1991
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• Supplemental Notes:
  • This paper appears in Transportation Research Record No. 1307, Pavement Analysis, Design, Rehabilitation, and Environmental Factors 1991. 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:
  • Ioannides, Anastasios M
• Publication Date: 1991

Media Info

• Features: References; Tables;
• Pagination: p. 211-220
• Monograph Title: Pavement analysis, design, rehabilitation, and environmental factors, 1991
• Serial:
  • Transportation Research Record
  • Issue Number: 1307
  • Publisher: Transportation Research Board
  • ISSN: 0361-1981

Subject/Index Terms

• TRT Terms: Design; Elastic analysis; Empirical methods; Equations; Evaluation; Mechanical analysis; Mechanistic design; Nondestructive tests; Pavement performance; Pavements; Theory
• Identifier Terms: American Association of State Highway and Transportation Officials
• Uncontrolled Terms: Layered elastic analysis
• Subject Areas: Design; Highways; Pavements; I22: Design of Pavements, Railways and Guideways; I23: Properties of Road Surfaces;

Filing Info

• Accession Number: 00621599
• Record Type: Publication
• ISBN: 0309051177
• Files: TRIS, TRB, ATRI
• Created Date: Apr 30 1992 12:00AM