THE THERMAL CONDUCTIVITY OF KAOLINITE CLAY AS A FUNCTION OF TYPE OF EXCHANGE ION, DENSITY AND MOISTURE CONTENT

THE THERMAL CONDUCTIVITY OF SOILS IS OF MAJOR IMPORTANCE IN HIGHWAY ENGINEERING, AGRICULTURE AND THE ELECTRIC POWER INDUSTRY. WHILE A GREAT DEAL OF WORK HAS BEEN DONE IN THIS FIELD, THERE IS A REMARKABLE LACK OF DEPENDABLE EXPERIMENTAL DATA WITH RESPECT TO PURE CLAY SYSTEMS. A SYSTEMATIC ATTEMPT IS BEING MADE TO REMEDY THIS SITUATION. THIS PAPER REPORTS ON DATA OBTAINED WITH A NATURAL KAOLINITE CLAY AND ITS NA-, CA-, AND AL-MODIFICATIONS. THE CLAY SAMPLE USED WAS FROM A SEDIMENTARY GEORGIA KAOLIN AND HAD A SURFACE AREA OF ABOUT 21.4 M SQUARED G. X-RAY DIFFRACTION SHOWED IT TO BE WELL CRYSTALLIZED WITH SOME DISORDER ALONG THE B-AXIS. THE HOMOIONIC MODIFICATIONS WERE PREPARED BY LEACHING WITH SOLUBLE SALTS OF THE RESPECTIVE CATIONS AND SUBSEQUENT WASHING WITH DISTILLED WATER. THE THERMAL CONDUCTIVITIES WERE DETERMINED BY AN ADAPTATION OF THE STALHANE-PYK METHOD PREVIOUSLY DESCRIBED BY VAN ROOYEN AND WINTERKORN. TESTS WERE PERFORMED ON EACH OF THE MODIFICATIONS IN THE MOISTURE PERCENTAGE RANGES 1.24-1.44: 5.24-5.76: 11.01-12.62: 15.81- 17.9: AND 30.56-34.78, AND IN THE POROSITY RANGE OF ABOUT 58-68 PERCENT. WITH ALL THE SAMPLES AND MOISTURE CONTENTS, THE LOG OF THE THERMAL CONDUCTIVITY INCREASED LINEARLY WITH DECREASING POROSITY WHILE AT CONSTANT POROSITY IT INCREASED WITH INCREASING MOISTURE CONTENT BUT AT A DECREASING RATE. AT THE LOW MOISTURE CONTENTS AND HIGHER DENSITIES, THE ORDER OF THE IONIC EFFECT WAS NA GREATER THAN CA, CA GREATER THAN AL. THE DIFFERENCES BECAME LESS PRONOUNCED AT HIGHER MOISTURE CONTENTS AND GREATER POROSITIES. THE ORDER OF MAGNITUDE OF THE THERMAL CONDUCTIVITIES AT A POROSITY OF 60 PERCENT IN MILLIWATTS/DEG C CM WAS ABOUT 1.4-1.8: 3.4-3.7: 5-58: 6.4-7.4: AND 9.5-13.9, FOR THE AFOREMENTIONED MOISTURE RANGES. THE THEORETICAL AND PRACTICAL IMPLICATIONS OF THE TEST RESULTS ARE DISCUSSED. /AUTHOR/

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  • Supplemental Notes:
    • Paper sponsored by Committee on Physico-Chemical Phenomena in Soils and presented at the 46th Annual Meeting. 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
  • Authors:
    • Reno, W H
    • Winterkorn, Hans F
  • Publication Date: 1967

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 79-85
  • Monograph Title: Physicochemical properties of soils
  • Serial:

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Filing Info

  • Accession Number: 00237321
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Feb 2 1994 12:00AM