A nuclear cement content gage designed to measure the cement content of plastic concrete has been evaluated under routine testing and field conditions on three projects by the Georgia Department of Transportation. The evaluation was performed by establishing and verifying calibration curves and by field testing to determine the accuracy, reliability, and maintainability of the gage under routine use. The gage, which uses low energy gamma-rays from an Americium-241 radioactive source, was found to be very sensitive to changes in the aggregate proportions in the design mix. As a result, it was necessary to establish more than one calibration line on two of the three projects, due to changes made in the mix design during the testing phase. All the projects monitored used siliceous aggregates. The test results indicated that the nuclear gage will indicate the cement content of the plastic concrete within FHWA's previously established error margins for the device (36 lbs/cu yd (21 kg/cu m) for a single sample, siliceous aggregate, 90 percent confidence level).

  • Corporate Authors:

    Georgia Department of Transportation

    One Georgia Center
    600 West Peachtree Street, NW
    Atlanta, GA  United States  30308

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Gulden, W
  • Publication Date: 1975-5

Media Info

  • Pagination: 78 p.

Subject/Index Terms

Filing Info

  • Accession Number: 00130559
  • Record Type: Publication
  • Source Agency: Federal Highway Administration
  • Report/Paper Numbers: FHWA-RD-75-525 Final Rpt., FCP 36B1-064
  • Contract Numbers: PO 5-1-0106
  • Created Date: Mar 29 1976 12:00AM