Environmental changes and construction activities tend to adversely affect the fabric of shales, causing disintegration which causes increases in plasticity, and reduction of stability. It is necessary to establish methods of testing and criteria which will permit the material characterization of shales so their engineering performance can be predicted more accurately. Oklahoma shales were tested for index and strength related properties, mineralogical and chemical properties; ultrasonic disaggregation, durability, fabric identification and factor and cluster analyses were employed to categorize them. When the combined amount of silt and clay is less than 40%, shale can be classified as "no problem" shale, but when this combined amount is equal to or in excess of 40%, it should be characterized as "problem" shale. The problem shale requires supplementary testing and design precedures. First, the shale should be subjected to one hour ultrasonic treatment, which disaggregates it in a manner simulating the time dependent changes occurring in its fabric due to environmental disturbances in the field. Second, the index properties are determined on the ultrasonically treated shale, and design parameters are based on the changing properties of the material. It should be noted that ultrasonic treatment does not alter the mineralogical character of shales. The durability index test accompanied by the sand equivalent test appear to show promise as diagnostic tests for shales. However, criteria for these two tests have not been established. Ultrasonic methods of disaggregation of clay forming materials for use in Atterberg limit and grain size distribution determinations are appended to the report.

  • Availability:
  • Supplemental Notes:
    • Prepared in cooperation with FHWA and Oklahoma State Department of Highways.
  • Corporate Authors:

    University of Oklahoma, Norman

    Research Institute
    Norman, OK  United States  73019
  • Authors:
    • Laguros, J G
  • Publication Date: 1972-8

Media Info

  • Pagination: 194 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00098975
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • ISBN: 86-03-2
  • Report/Paper Numbers: Final Rpt.
  • Files: TRIS, USDOT
  • Created Date: Oct 18 1975 12:00AM