The performance of two layer asphalt stabilized drainage systems is reported. The two layer drainage system consists of a filter layer of sand-gravel blend filter material, aggregate base or similar material which will satisfy the filter criteria overlain by an open graded drainage layer stabilized with 1.5 to 2 percent paving grade asphalt. The low asphalt content bonds the open graded material into a stable mass without reducing permeability. Asphalt treated permeable material has a drainage capacity up to 100 times greater than a California standard Class 2 permeable material. One installation after six winter seasons had an efficiency 12 times greater than a single layer system under the same service conditions. The two layer system is no more difficult to construct than normal permeable blankets and normal construction equipment and methods can be used. Direct cost comparisons indicate that two layer drainage systems can be constructed at a cost competitive with or lower than conventional single layer drainage systems.

  • Availability:
  • Supplemental Notes:
    • Study was sponsored by California DOT and conducted in cooperation with FHWA under title: Open Graded Asphalt Treated Drainage Blanket.
  • Corporate Authors:

    Transportation Laboratory

    5900 Folsom Boulevard
    Sacramento, CA  United States  95819
  • Authors:
    • Gray, W C
    • HANNON, J B
    • Forsyth, R A
  • Publication Date: 1974-6

Media Info

  • Pagination: 34 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00081300
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • ISBN: 19201-762503-632618
  • Report/Paper Numbers: Final Rpt.
  • Contract Numbers: D-2-1
  • Files: TRIS, ATRI, USDOT
  • Created Date: Mar 26 1975 12:00AM