A CRITICAL REVIEW OF PRESENT KNOWLEDGE OF THE PROBLEM OF RATIONAL THICKNESS DESIGN OF FLEXIBLE PAVEMENTS

THE HYPOTHESIS THAT FLEXIBLE PAVEMENTS ARE PERFECTLY ELASTIC APPEARS TO BE VALID FOR LIMITED NUMBERS OF SAFE LEADS OF SHORT DURATION. HOWEVER, FOR SLOW-MOVING OR STATIC LEADS LARGE ENOUGH NEARLY TO OVERSTRESS THE PAVEMENT, A RHEOLOGICAL MODEL IS MORE APPLICABLE. PAVEMENT LAYERS LACKING TENSILE STRENGTH MAY ACCOUNT FOR A LARGE PART OF THE DIFFERENCE BETWEEN CALCULATED AND MEASURED DEFLECTIONS AND STRESSES. THERE MAY BE MERIT IN USING AN EQUIVALENT MODULUS OF ELASTICITY FOR THE SYSTEM. ALTHOUGH POISSONS RATIO HAS LITTLE EFFECT ON CALCULATED STRESSES, A VALUE OF 0.5 SEEMS TO BE APPROPRIATE FOR SOILS AND PAVEMENTS. THE DEFLECTION FACTOR IS IMPORTANT IN RELATION TO THE EFFECT OF PAVEMENT RIGIDITY ON PAVEMENT DEFLECTIONS. THE LAYERED SYSTEM MODEL OF FLEXIBLE PAVEMENTS SHOULD INCLUDE THE CONDITION OF ZERO TENSILE MODULUS OF THE COMPONENT MATERIALS. /RRL/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrr/1965/71/71-006.pdf
• Supplemental Notes:
  • 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:
  • De Barros, S Thenn
• Publication Date: 1965

Media Info

• Media Type: Print
• Features: Figures; References; Tables;
• Pagination: pp 105-128
• Monograph Title: Flexible pavement design; 1963 and 1964
• Serial:
  • Highway Research Record
  • Issue Number: 71
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Deflection; Elasticity (Mechanics); Flexibility; Flexible pavements; Mathematical models; Modulus of elasticity; Pavement design; Pavement layers; Pavements; Poisson distributions; Poisson ratio; Reviews; Rheology; Static loads; Stiffness; Stresses; Studies; Systems; Tensile properties; Thickness
• Uncontrolled Terms: Flexible; Models
• Old TRIS Terms: Layered system mechanics; Pavement deflection; Poissons ratio; Rheological studies; Thickness design
• Subject Areas: Highways; Pavements;

Filing Info

• Accession Number: 00205423
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 12 1994 12:00AM