Pavement drainage layers have been proved to be highly effective in the efficient and quick dissipation of subsurface water from a pavement structure. The Ministry of Transportation of Ontario requires a 100-mm lift of open-graded drainage layer (OGDL) directly beneath the concrete slab as part of the rigid pavement design for expressway facilities. The gradation of the OGDL consists almost entirely of coarse aggregates retained on the 4.75-mm sieve, which provides a highly permeable drainage layer. Because of this uniformly graded coarse aggregate, the drainage layer has proved difficult to construct by conventional means. In order to alleviate this problem, the OGDL is treated with 1.8% asphalt cement to increase the stability of the material during construction. The addition of an asphalt cement binder has been used successfully on numerous contracts. In 1990, the Ministry initiated a demonstration project to evaluate alternative methods of increasing the constructability of the OGDL. The three types of OGDL placed on this project were (a) a 1-km section of portland cement-treated OGDL with various cement contents [cement-treated permeable base (CTPB)], (b) a 1-km section where no binder was used but the amount of fine aggregate passing the 4.75 mm was increased to improve the stability [untreated permeable base (UTPB)], and (c) the asphalt cement-treated permeable base (ATPB) as just mentioned. The design and construction details are elaborated on in this paper, and the OGDL sections are evaluated in terms of permeability, gradation, constructability, and stability on the basis of falling weight deflectometer test results.


  • English

Media Info

  • Features: Figures; References; Tables;
  • Pagination: p. 29-36
  • Monograph Title: Subsurface drainage, soil-fluid interface phenomena, and management of unpaved surfaces
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00666227
  • Record Type: Publication
  • ISBN: 0309055113
  • Files: TRIS, TRB
  • Created Date: Sep 16 1994 12:00AM