The Virginia Department of Highways and Transportation frequently utilizes induction loops in its vehicle detector systems. Although not documented, there have been many instances of loop failures; therefore, the practices and materials used by the Department in installing loop detectors were investigated. Two field tests were initially undertaken--the encasement of the loop wires by PVC conduit and vinyl tubing and the performance of different types of loop sealants, to determine the type and quantity of sand to expoxy sealants, and to derive the expansion factor of the resulting mixture. Finally, a third field test was undertaken to evaluate several of the laboratory findings. This report provides the status of the first two demonstrations and documents the findings and conclusions of the laboratory tests and the third field test. Several recommendations concerning the expansion factor, the current sealant specifications, and the required width of saw cut are made.

  • Record URL:
  • Corporate Authors:

    Virginia Highway and Transportation Research Council

    Charlottesville, VA  United States 

    Virginia Department of Highways

    Traffic and Planning Division, 1221 East Broad Street
    Richmond, VA  United States  23219
  • Authors:
    • Arnold Jr, E D
    • Steele, R E
    • Munn, G L
  • Publication Date: 1985-1

Media Info

  • Pagination: 23 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00454803
  • Record Type: Publication
  • Report/Paper Numbers: VHTRC 85-R21
  • Created Date: Jul 31 1986 12:00AM