DENSITY AND MOISTURE CONTENT MEASUREMENTS BY NUCLEAR METHODS INTERIM REPORT

DATA IS PROVIDED FROM AN EVALUATION OF THE ACCURACY OF THE NUCLEAR GAGES IN COMPARISON WITH THE CURRENTLY USED NON- NUCLEAR METHODS OF DETERMINING SOIL DENSITY AND MOISTURE CONTENT. THE RESEARCH STUDY WAS PRINCIPALLY THEORETICAL IN NATURE AND WAS CONDUCTED IN TWO PARTS WITH EACH PART RESPECTIVELY CONSIDERING DENSITY AND MOISTURE CONTENT. TWO EXISTING COMMERCIAL GAGES WERE EVALUATED, AND A NOMINAL EXPERIMENTAL PROGRAM EMPLOYING NON-SOIL STANDARDS OF KNOWN DENSITY AND COMPOSITION WAS CONDUCTED TO VERIFY THE DENSITY RESULTS. THE RESULTS OF THE MOISTURE CONTENT STUDY WERE CHECKED AGAINST DATA IN THE LITERATURE. THEORIES WERE FORMULATED REGARDING REPRODUCIBILITY AND THE PRIMARY AND SECONDARY SOURCES OF ERROR AFFECTING THE ACCURACY OF DENSITY AND MOISTURE CONTENT GAGES. RECOMMENDATIONS ARE MADE FOR EITHER MINIMIZING OR ELIMINATING ALL CLASSES OF ERRORS, AND IT IS CONCLUDED THAT WHEN THIS HAS BEEN ACCOMPLISHED THE NUCLEAR GAGES PROVIDE ACCURACY AT LEAST EQUAL TO THAT OF ANY NON-NUCLEAR TECHNIQUE. DETAILED MATHEMATICAL MODELS WERE DEVELOPED TO EXPRESS THE GAGE RESPONSE TO CHANGES IN SEVERAL GAGE PARAMETERS. THE MODELS INDICATED THAT THE TWO MOST SERIOUS SOURCES OF ERROR IN DENSITY AND MOISTURE MEASUREMENTS ARE ATTRIBUTABLE TO ELEMENTAL COMPOSITION OF THE SOIL MASS AND TO A LACK OF SUITABLE CALIBRATION STANDARDS OF EITHER SOIL OR SYNTHETIC MATERIALS. THE APPROACH RECOMMENDED FOR THE SOLUTION OF THESE PROBLEMS IS TO CALIBRATE THE GAGES ON NON-SOIL LABORATORY STANDARDS THAT CAN BE MADE HOMOGENEOUS. IT IS PROPOSED THAT THIS CAN BE ACCOMPLISHED BY USING AN ANALYTICAL, MATHEMATICAL MODEL FOR CALIBRATION THAT INCLUDES SUITABLE COMPOSITION AND DENSITY TERMS.

  • Availability:
  • Supplemental Notes:
    • No 14, 32 PP, 15 FIG, 11 TAB, 89, REF, 1 APP
  • Authors:
    • Ballard, L F
    • Gardner, R P
  • Publication Date: 1965

Media Info

  • Serial:
    • NCHRP Report
    • Issue Number: 14
    • Publisher: Transportation Research Board
    • ISSN: 0077-5614

Subject/Index Terms

Filing Info

  • Accession Number: 00214667
  • Record Type: Publication
  • Files: TRIS, ATRI
  • Created Date: Dec 16 1994 12:00AM