This research involved field investigations and laboratory testing to evaluate the properties and overall performance of geotextile separators exhumed from the roadway at 8 sites in eastern and central Washington (Phase I), and 14 sites in western Washington (Phase II). Both nonwoven and woven geotextile separators of different in-service ages were examined in detail, and specimens were tested in the laboratory for strength and hydraulic characteristics. The subgrade condition and geotechnical properties of the base course aggregate and subgrade soils were also evaluated. Although all of the geotextile separators performed their intended separation function adequately, the geotextiles experienced very different levels of damage during construction. Base aggregate type, rather than initial aggregate lift thickness, appeared to have the most influence on the level of damage. Test results indicated that the permittivity of the woven slit-films and the needle-punched nonwovens both increased by similar percentages after being washed. The unwashed (i.e., undisturbed) permittivity results also indicated that most woven slit-film geotextile permeabilities fell well below the Washington State Department of Transportation's required value. All of the pavements examined were in good condition, and damage to the geotextile separators did not appear to have had any negative impact on the pavements' long-term performance.

  • Record URL:
  • Corporate Authors:

    Washington State Transportation Center

    University of Washington, 1107 NE 45th Street, Suite 535
    Seattle, WA  United States  98105

    Washington State Department of Transportation

    Transportation Building, 310 Maple Park Avenue SE, P.O. Box 47300
    Olympia, WA  United States  98504-7300

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Holtz, R D
  • Publication Date: 1996-1


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: 65 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00720095
  • Record Type: Publication
  • Report/Paper Numbers: WA-RD 321.2,, Proj T9233, Task 13,, Geotextile Separators II
  • Created Date: Apr 9 2000 12:00AM