Introduction of Flat Ribbon Cable (FRC) Sensor for In Situ Moisture and Density Measurement of Road Materials Using Spatial Time Domain Reflectometry (STDR): Laboratory Experiment and Field Assessment

Moisture content and density of unbound granular pavement materials are significant properties for compaction control providing a large effect on pavement performance. Time domain reflectometry (TDR) usually uses rod probe sensors, which can provide pointwise readings of moisture and density. However, pointwise readings might not be representative enough for a complete road section. This paper introduces the application of flat ribbon cable (FRC) sensor that can be extended up to 6 meter to measure moisture and density of road materials. Soil specific calibration is done in the laboratory considering the variation of moisture and density of materials where sensors of three different lengths are considered to enable the development of length-normalized calibration. The electric parameter used to derive soil density is the voltage drop, which occurs after the passage of an electromagnetic wave along the sensor embedded in the soil. Soil moisture is related to the permittivity of the soil sample, which is obtained from the travel time of the Spatial Time domain reflectometry (STDR) signal. Laboratory results indicate that calibration functions are independent of moisture and density. These soil specific calibration functions are useful in measuring long-term pavement performance and managing road deformations.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFP20 Standing Committee on Geotechnical Site Characterization.
• Authors:
  • Bhuyan, Md Habibullah
  • Scheuermann, Alexander
  • Bodin, Didier
  • Becker, Rolf
• Conference:
  • Transportation Research Board 97th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2018-1-7 to 2018-1-11
• Date: 2018

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; Photos; References; Tables;
• Pagination: 20p

Subject/Index Terms

• TRT Terms: Density; Field tests; Instruments for measuring density; Laboratory tests; Moisture content; Moisture meters; Road materials; Sensors; Time domain reflectometers
• Subject Areas: Geotechnology; Highways; Materials; Pavements;

Filing Info

• Accession Number: 01657878
• Record Type: Publication
• Report/Paper Numbers: 18-03743
• Files: TRIS, TRB, ATRI
• Created Date: Jan 25 2018 9:33AM