Results from neutron activation analysis of in-place and plastic concrete samples are presented. Data were obtained by equipment suitable for and operated under field conditions. The system described for determination of cement content of in-place concrete includes a 35-microgram Cf-252 source, portable activation/shield assembly with remote operating cable, and commercially available detector and electronics. An analysis of in-place concrete is accomplished in 22 minutes. Results for plastic concrete were obtained with a system designed for soil-cement mixtures. Using a 140-microgram Cf-252 source, an analysis could be completed in 9 minutes with an accuracy of plus or minus 5 percent of the amount of cement for normal cement contents. A system for analysis of samples of plastic concrete, cores, and soil-cement is described that can be moved to field sites in a trailer. Most existing methods for determination of cement content of concrete suffer because they are too slow, use too small a sample to be representative, and must be done in a laboratory. The other field measurement technique being studied utilizes low-energy photon scatter. This technique uses only a thin layer of the available sample and fails to achieve necessary accuracy when aggregate varies in size distribution or heavy element content. Neutron activation analysis offers a rapid, simple, field-operational procedure for measurement of cement content. Besides these advantages, activation analysis allows the use of large, representative samples and offers considerable freedom from interferences.

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 20-26
  • Monograph Title: Corrosion, concrete, quality control and paint beads
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00126829
  • Record Type: Publication
  • ISBN: 0309023904
  • Files: TRIS, TRB
  • Created Date: Dec 16 1975 12:00AM