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Title: DISCUSSION AND REVIEW OF SYMPOSIUM PAPERS
Accession Number: 00235354
Record Type: Component
Abstract: EXPERIMENTAL WORK AND FINDINGS ARE REPORTED ON THERMALLY ACTIVATED DIFFUSION IN POROUS MEDIA. DISAGREEMENT IS OBSERVED WITH REGARD TO THE MAGNITUDE OF OBSERVED RATES OF MOISTURE FLOW. IT IS AGREED THAT THE DIRECT TEMPERATURE EFFECT ON THE SURFACE IS SMALL AND DOES NOT ACCOUNT FOR INCREASED TRANSFER OF MOISTURE NORMALLY OBSERVED UNDER TEMPERATURE GRADIENTS. IT IS BELIEVED THAT THERMALLY ACTIVIATED DIFFUSION RESULTS FROM A POTENTIAL CREATED BY A TEMPERATURE GRADIENT ACROSS THE VAPOR FACE GIVING RISE TO VAPOR FLOW IN THE DIRECTION OF DECREASING VAPOR PRESSURE GRADIENTS WHICH MAY BE COMBINED WITH SERIES FLOW IN THE LIQUID PHASE. IN AN OPEN SYSTEM THE NET FLOW IS IN THE DIRECTION OF DECREASING VAPOR PRESSURE GRADIENTS. ISOTHERMAL FLOW IN POROUS MEDIA IS DISCUSSED. PREDICTING THE MOISTURE CONTENT CHANGES THAT OCCUR WHEN THE SOIL IS COVERED AND EVAPORATION IS INTERFERED WITH IS OF GREAT INTEREST FOR HIGHWAY AND AIRPORT CONSTRUCTION. AN EQUATION IS GIVEN FOR THE CALCULATION OF MOISTURE CONTENT DISTRIBUTION. FROST-INDUCED MOSITURE FLOW IS DISCUSSED, RECOGNIZING THAT SOME VAPOR MOVEMENT FREQUENTLY ACCOMPANIES THE PROCESS. A GROUND MOVEMENTS DISCUSSION BRINGS OUT MANY USEFUL FACTS ON THE EFFECT OF WATER MOVEMENT ON SOIL FOR THE PRACTICING ENGINEER. THE EFFECT OF RATE OF LOADING INFLUENCES THE AMOUNT OF CONSOLIDATION IN A CONSOLIDATION TEST. THIS GENERALIZATION SHOULD BE VIEWED WITH CAUTION ACCORDING TO THE AUTHOR. THE PROBLEM OF AVOIDING FROST HEAVE UNDER COLD STORAGE STRUCTURES IS BRIEFLY DISCUSSED. THE MACRO STRUCTURES DEVELOPED IN SOILS UNDER FREEZING CONDITIONS ARE DISCUSSED. THE VERTICAL AND HORIZONTAL ICE FORMS ARE SHOWN AS BELONGING TO CLAY SOILS AND THE CURVED ICE FORMS TO LOESS SOILS. REFERENCES: HIGHWAY RESEARCH BOARD SPECIAL REPORT 40, 238 PP, 1958.
Supplemental Notes: No 287, pp 2-6, 2 PHOT, 20 REF. 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.
Monograph Title: Monograph Accession #: 01500267
Authors: Penner, EPagination: 5p
Publication Date: 1961
Serial: Conference:
40th Annual Meeting of the Highway Research Board
Location:
Washington DC, United States Media Type: Digital/other
TRT Terms: Uncontrolled Terms: Old TRIS Terms: Subject Areas: Geotechnology; Highways; Hydraulics and Hydrology
Files: TRIS, TRB, ATRI
Created Date: Sep 16 1994 12:00AM
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