MN/Road TDR Evaluation and Data Analysis

Water content measurement using time domain reflectometry (TDR) is an important integral component of the Minnesota Road Research Project (Mn/ROAD) program. However, erroneous and inaccurate water content values are frequently generated using current data collection and interpretation procedures. Whereas the erroneous and obviously unreasonable values are caused by limitations of the current waveguide/cable systems, inaccurate water content values are most likely caused by the inadequacy of the empirical calibration equations. Base, Subbase, and Subgrade materials are different from agricultural soils in composition, water retention characteristics, and more importantly in their dielectric properties in relation to water content and temperature regimes in the road pavement. This project was to develop a new composition-based calibration between water content and apparent dielectric constant of the pavement materials. Temperature effect on the dielectric constants of water and pavement components was also integrated in the new calibration. Results indicated that the new calibration was more theoretically sound and relatively simple to use. Additional tests and developments may be needed to further validate the reliability of the new approach.

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  • Record URL:
  • Corporate Authors:

    University of Minnesota, St Paul

    Department of Soil, Water and Climate, 1991 Upper Buford Circle
    St Paul, MN  United States  55108

    Minnesota Department of Transportation

    Research Services Section, 395 John Ireland Boulevard, Mail Stop 330
    St Paul, MN  United States  55155
  • Authors:
    • Wang, Dong
    • Baker, John
  • Publication Date: 2003-12


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 31p

Subject/Index Terms

Filing Info

  • Accession Number: 01851539
  • Record Type: Publication
  • Report/Paper Numbers: MN/RC – 2004-15
  • Contract Numbers: (c) 74708 (wo) 110
  • Files: NTL
  • Created Date: Jul 18 2022 9:25AM