Long-Term Performance of Geotextile Separators, Bucoda Test Site--Phase III

This research was Phase III of field investigations carried out over 12 years at a test section in southwest Washington State in an effort to quantify the contribution of geotextile separators to the long-term performance of pavement sections. Five different geotextile separators, as well as a control (soil-only) section, were installed in a test section covering two lanes with different base course thicknesses on a low volume but heavily loaded rural highway west of Bucoda, Washington. Phase I evaluated the performance of the separators during construction. Phase II and III were conducted to evaluate the performance of the separators 5 and 12 years after construction, respectively. Field and laboratory tests were conducted on the subgrade, granular base materials, and the geotextiles as part of the effort to correlate the performance of the pavement section to the presence of the geotextile separators. Falling weight deflectometer (FWD) testing was also performed at the site as part of the effort to quantify the performance of the pavement section. The laboratory tests indicated that the geotextiles successfully performed their separation function over the 12-year period. However, the soil-only sections had a minimal amount of intermixing at the base course/subgrade interface, indicating that the separation benefits of geotextiles may not be realized under relatively thick pavement sections. The FWD tests showed that the most significant increase in the subgrade moduli occurred in the first few months following construction. However, the soil-only sections exhibited behavior similar to the sections with geotextiles during the FWD testing, suggesting that for the relatively thick pavement sections, incorporation of geotextiles may not have provided a significant contribution to the overall performance of the section over the 12-year period. Some of the FWD results did suggest that geotextiles might contribute to an increase in the base course modulus over time.

• Record URL:
  http://www.wsdot.wa.gov/research/reports/fullreports/595.1.pdf
• 
• 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:
  • Collins, Brian M
  • Holtz, Robert D
• Publication Date: 2005-10

Language

• English

Media Info

• Media Type: Print
• Edition: Research Report
• Features: Appendices; Bibliography; Figures; Photos; References; Tables;
• Pagination: v.p.

Subject/Index Terms

• TRT Terms: Base course (Pavements); Falling weight deflectometers; Field tests; Geotextiles; Laboratory tests; Modulus of resilience; Pavement layers; Pavement performance; Rural highways; Subgrade (Pavements); Test sections; Thickness
• Geographic Terms: Bucoda (Washington)
• Subject Areas: Design; Geotechnology; Highways; Materials; Pavements; I22: Design of Pavements, Railways and Guideways; I33: Other Materials used in Pavement Layers; I42: Soil Mechanics;

Filing Info

• Accession Number: 01015099
• Record Type: Publication
• Report/Paper Numbers: WA-RD 595.1
• Contract Numbers: Agreement T2695, Task 35
• Files: TRIS, USDOT, STATEDOT
• Created Date: Jan 6 2006 3:32PM