RATIONAL ANALYSIS OF KENTUCKY FLEXIBLE PAVEMENT DESIGN CRITERION

COMPARISONS BETWEEN THEORETICALLY COMPUTED STRAINS, DISPLACEMENTS AND CURRENT AND PROPOSED DESIGN CURVES ARE MADE BY SUPERPOSING THE THEORETICAL CURVES ON THE CURRENT IN-USE DESIGN CURVES. THE THEORETICAL CURVES WERE OBTAINED USING THE CHEVRON ELASTIC LAYERED COMPUTER PROGRAM FOR DETERMINATION OF RADIAL STRAIN ON THE UNDERSIDE OF THE FIRST LAYER (ASPHALT CONCRETE), VERTICAL STRAIN ON THE TOP OF THE THIRD LAYER (SUBGRADE), AND VERTICAL DISPLACEMENT ON THE SURFACE. ALL VALUES WERE COMPUTED FOR POINTS DIRECTLY UNDER A 9000 POUND WHEEL LOAD OF 112.5 SQ. IN. CIRCULAR AREA. THE THEORETICAL CURVES SUPERPOSED ON THE DESIGN CURVES CONSISTED OF ISO-STRAIN AND ISO-DEFLECTION FOR SURFACING TEMPERATURE, AND RATIO OF SURFACE THICKNESS TO BASE THICKNESS. AN ASSUMED CONSTANT ELASTIC MODULUS OF GRANULAR BASE MATERIAL IS USED, SUBGRADE MODULUS IS OBTAINED FROM CBR, AND ASPHALT MODULUS IS OBTAINED FROM AASHO DATA. CONCLUSIONS ARE THAT THE DESIGN CURVES ARE VERY NEARLY PARALLEL THE THEORETICALLY COMPUTED ISO-SUBGRADE STRAIN LINES AND DO NOT PARALLEL THE ISO- DEFLECTION LINES, THUS SUGGESTING THAT DESIGN CURVES BE BASED ON LIMITING STRAINS RATHER THAN ON LIMITING DEFLECTION DEFLECTIONS. /BPR/

  • Record URL:
  • Supplemental Notes:
    • Hpr-1 (4), BPR ITEM 15, STATE NO 64-20
  • Corporate Authors:

    Kentucky Department Highways

    ,    

    Bureau of Public Roads /US

    400 7th Street, SW
    Washington, DC  United States  20590
  • Authors:
    • Southgate, H F
    • Deen, R C
    • Havens, J H
  • Publication Date: 1968-11

Subject/Index Terms

Filing Info

  • Accession Number: 00205357
  • Record Type: Publication
  • Source Agency: Bureau of Public Roads /US
  • Files: TRIS, STATEDOT
  • Created Date: Mar 18 1994 12:00AM