CALIFORNIA STUDY OF ASPHALT CONCRETE DENSITY MEASUREMENT--NUCLEAR VERSUS CORE DENSITY

The lack of a fast, reliable method for accurately determining in-situ density has been the major obstacle in the California Department of Transportation's (Caltrans) effort to develop an end-result compaction requirement for asphalt concrete pavement. Although the nuclear gage provides a rapid method of determining inplace densities, the results have not proven consistent with the densities determined by the generally accepted water displacement method of testing core specimens. This paper discusses factors contributing to these inconsistencies. It is concluded that the water displacement method is incorrectly described as a measure of bulk density and is not measuring the sample properties as the nuclear method. It is also concluded that the Caltrans procedure for calibrating backscatter nuclear gages is introducing inconsistencies into the nuclear density determinations. Several procedures for measuring the density of thin layers (less than 50 mm) of asphalt concrete have been examined. These procedures are described and their weaknesses discussed. (Author)

  • Supplemental Notes:
    • The ASTM, STP829 Placement and Compaction of Asphalt Mixtures, papers from the symposium of the same name presented in Phoenix, Arizona, December 8, 1982. Sponsored by ASTM Committee D-4 on Road and Paving Materials.
  • Corporate Authors:

    ASTM Special Technical Publications

    1916 Race Street
    Philadelphia, PA  United States  19103
  • Authors:
    • Alexander, M L
    • Doty, R N
  • Publication Date: 1984-1

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Filing Info

  • Accession Number: 00390779
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Nov 30 1984 12:00AM