Standardizing Lightweight Deflectometer Measurements for QA and Modulus Determination in Unbound Bases and Subgrades

The primary objective of this study is to provide State Departments of Transportation (DOTs) and local government engineers with a practical and theoretically sound methodology for the evaluation of in-place elastic modulus of unbound layers, subgrades, and other earthwork from Lightweight Deflectometer (LWD) field test data. This will require the development of techniques to fully account for: (1) the influence of moisture suction pressures on LWD measurements; (2) the differences in the LWD induced stress states/strain levels and the stress states/strain levels induced by construction equipment and long term traffic loads; and (3) the effects of layering on LWD measurements when testing on finite-thickness layers (e.g., base or subbase over subgrade) vs. half-space conditions (e.g., subgrade). The test standards and analysis methodologies developed in this study will enable agencies to: (a) use LWDs with confidence for construction quality assurance (QA); (b) develop catalogs of appropriate design modulus values for use in pavement structural design, specifically in the Mechanistic-Empirical Pavement Design Guide, (MEPDG) and its companion DARWin-ME software; and (c) reduce recurring annual costs associated with QA inspection of soils and unbound materials.


  • English


  • Status: Completed
  • Funding: $400000
  • Contract Numbers:


  • Sponsor Organizations:

    Maryland Department of Transportation

    707 N. Calvert Street
    Baltimore, MD  United States  21202

    Florida Department of Transportation

    605 Suwannee Street
    Tallahassee, FL  United States  32399-0450

    New York State Department of Transportation

    50 Wolf Road
    Albany, NY  United States  12232

    North Carolina Department of Transportation

    P.O. Box 25201
    1 South Wilmington Street
    Raleigh, NC  United States  27611

    South Carolina Department of Transportation

    955 Park Street
    P.O. Box 191
    Columbia, SC  United States  29202-0191

    Virginia Department of Transportation

    1401 East Broad Street
    Richmond, VA  United States  23219

    Missouri Department of Transportation

    1617 Missouri Boulevard
    P.O. Box 270
    Jefferson City, MO  United States  65102

    Michigan Department of Transportation

    Murray Van Wagoner Building
    425 West Ottawa, P.O. Box 30050
    Lansing, MI  United States  48909
  • Project Managers:

    Hardt, Allison

  • Start Date: 20130821
  • Expected Completion Date: 0
  • Actual Completion Date: 20161130
  • Source Data: RiP Project 41985

Subject/Index Terms

Filing Info

  • Accession Number: 01541241
  • Record Type: Research project
  • Source Agency: Federal Highway Administration
  • Contract Numbers: TPF-5(285)
  • Files: RiP, USDOT
  • Created Date: Oct 21 2014 1:01AM