NUCLEAR SOIL-MOISTURE CORRELATION
NUCLEAR SOIL-MOISTURE GAUGES ARE COMMONLY USED TO CONTROL THE COMPACTION OF SOIL. THE NUCLEAR MOISTURE TEST DEPENDS ON THE MODERATION, OR SLOWING DOWN, OF FAST NEUTRONS (EMITTED FROM A RADIOISOTOPE CONTAINED IN THE GAUGE) BY THE HYDROGEN IN THE SOIL WATER. THE FREE OR EASILY EVAPORABLE SOIL WATER MUST BE CONTROLLED IN EARTH CONSTRUCTION. HOWEVER, DIFFERENT SOILS HAVE VARYING AMOUNTS OF OTHER FORMS OF WATER SUCH AS HYDRATES, INTERLAYER WATER, AND HYDROXYL WATER. THOSE ARE NOT EASILY EVAPORABLE BUT ARE DETECTED BY THE GAUGE. ALSO, SOME SOILS CONTAIN ELEMENTS THAT ABSORB THE SLOW NEUTRONS. THIS REACTION MAY AFFECT THE NUCLEAR MOISTURE TEST. CONSEQUENTLY, A METHOD MUST BE FOUND OF ADJUSTING A GAUGE CALIBRATION DETERMINED IN THE LABORATORY SO THAT IS MAY BE USED WITH THE GAUGE IN THE FIELD TO TEST A VARIETY OF SOILS. THE EXPERIMENTAL DATA WERE OBTAINED BY TESTING (WITH 2 NUCLEAR MOISTURE GAUGES) 4 SOIL-WATER SYSTEMS COMPACTED IN LARGE MOLDS. THEY WERE PREPARED AT VARIOUS WATER CONTENTS AND INCLUDED A SILICA SAND, A KAOLIN CLAY, A CLAYEY FIELD SOIL, AND AN EXPANDED SHALE. THE RESULTS OF THIS RESEARCH INDICATE THAT IT IS SATISFACTORY TO ASSUME THAT THE FREE WATER CALIBRATION CURVES FOR VARIOUS SOILS DIFFER BY A CONSTANT THAT DEPENDS ON THE SUM OF THE EFFECTS OF STRUCTURAL WATER AND ABSORBING ELEMENTS PRESENT. THE SLOPE OF THE NUCLEAR MOISTURE CALIBRATION CURVES IS SATISFACTORILY ESTABLISHED BY TESTING ON REFERENCE STANDARDS OF SILICA SAND AND WATER.
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Availability:
- Find a library where document is available. Order URL: http://worldcat.org/isbn/0309021693
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Supplemental Notes:
- Sponsored by Committee on Compaction. Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved
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Authors:
- Smith, Robert E
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Conference:
- 52nd Annual Meeting of the Highway Research Board
- Location: Washington District of Columbia, United States
- Date: 1973-1-22 to 1973-1-26
- Publication Date: 1973
Media Info
- Media Type: Print
- Features: Figures; References; Tables;
- Pagination: pp 45-53
- Monograph Title: Soil compaction and corrugations
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Serial:
- Highway Research Record
- Issue Number: 438
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Calibration; Curves (Geometry); Moisture content; Nuclear tests; Soil compaction
- Subject Areas: Geotechnology; Highways; Materials;
Filing Info
- Accession Number: 00217343
- Record Type: Publication
- ISBN: 0309021693
- Files: TRIS, TRB
- Created Date: Dec 22 1973 12:00AM