SOME NOTES ON PAVEMENT STRUCTURAL DESIGN

THE EMPIRICALLY DERIVED DESIGN EQUATION RESULTING FROM THE ANALYSIS OF LOAD TEST DATA OBTAINED BY THE CANADIAN DEPARTMENT OF TRANSPORT ON AIRPORT PAVEMENTS IN CANADA BY MEANS OF PLATE BEARING TESTS, IS REVIEWED AND SHOWN TO BE AN ELASTIC EQUATION, AND IS FOUND TO BE RELATED MATHEMATICALLY TO THE ELASTIC EQUATIONS DEVELOPED BY BURMISTER FOR HIS LAYERED SYSTEM APPROACH TO PAVEMENT DESIGN. ANALYSIS OF THE HYBLA VALLEY LOAD TEST DATA SHOWS THAT FOR ANY GIVEN SIZE OF LOADED AREA, THE PAVEMENT FACTOR VARIES WITH PAVEMENT THICKNESS AND HAS A MINIMUM VALUE AT SOME THICKNESS ROUGHLY BETWEEN THE RADIUS AND THE DIAMETER OF THE LOADED AREA. ON THE BASIS OF HYBLA VALLEY LOAD TEST DATA, THE INFLUENCE OF VARIABLES SUCH AS SIZE OF LOADED AREA , PAVEMENT THICKNESS, AND DEFLECTION, ON VALUES OF THE PAVEMENT ELASTIC MODULUS AND SUBGRADE ELASTIC MODULUS IS INVESTIGATED, AND THE NEED FOR A RAPID, SIMPLE, PRECISE METHOD FOR EVALUATING THE ELASTIC MODULI FOR BOTH DYNAMIC AND STATIC LOADING CONDITIONS IS EMPHASIZED. DATA PRESENTED SUGGEST THAT THE CONVENTIONAL METHOD OF FLEXIBLE PAVEMENT DESIGN, WHICH CALLS FOR GREAT THICKNESSES OF GRANULAR SUBBASE AND BASE COURSE MATERIALS OVER POORER SOILS, TENDS BE WASTEFUL OF THE DIMINISHING AGGREGATE RESOURCES. THE TECHNICAL UTILITY OF THIS SOLUTION TO THE PROBLEM OF ACHIEVING GREATER BEARING CAPACITY IS QUESTIONED AND IT IS SHOWN THAT THE ADDED THICKNESS IS OFTEN WELL DOWN ON THE CURVE OF DIMINISHING RETURNS WITH REGARD TO STRENGTH INCREASE. THE QUALITY OF INFERIOR GRANULAR MATERIALS COULD BE ACHIEVED BY TREATMENT OF THE ENTIRE DEPTH OF PAVEMENT MATERIAL ABOVE THE SUBGRADE TO INCREASE THE ELASTIC MODULUS SO THAT A PAVEMENT STRUCTURE OF MUCH SMALLER THICKNESS WOULD HAVE THE NECESSARY OVERALL STRENGTH. INCREASING THE ELASTIC MODULUS OF THE PAVEMENT COMPONENT REQUIRES UPGRADING THE STRENGTH CHARACTERISTICS OF GRANULAR OR SOIL MATERIALS BY THE APPLICATION OF STABILIZATION PROCEDURES, AND THE INCORPORATION OF BITUMINOUS BINDERS.

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1963/13/13-004.pdf
• Supplemental Notes:
  • No 13, pp 66-141, 12 TAB, 55 FIG, 1 APP, 23 REF 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:
  • McLeod, Norman W
• Publication Date: 1963

Media Info

• Media Type: Digital/other
• Features: Appendices; Figures; References; Tables;
• Pagination: pp 66-141
• Monograph Title: Flexible pavement design
• Serial:
  • Highway Research Record
  • Issue Number: 13
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Analysis; Areas; Binders; Bituminous materials; Deflection; Design; Elasticity (Mechanics); Equations; Flexible pavements; Load tests; Loads; Modulus of elasticity; Pavement design; Pavements; Plate bearing test; Size; Soil stabilization; Structural design; Subgrade (Pavements); Thickness
• Uncontrolled Terms: Data; Increase; Pavement thickness; Stabilization
• Geographic Terms: Canada
• Old TRIS Terms: Elastic theory; Pavement deflection
• Subject Areas: Design; Geotechnology; Highways; Pavements;

Filing Info

• Accession Number: 00205291
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Jan 23 1994 12:00AM