EFFECT OF CALCIUM ON THE CONTINUITY OF ELECTROOSMOTIC FLOW RATE

THE BEARING CAPACITY OF A SUBGRADE IS A FUNCTION OF MOISTURE CONTENT. ONE POSSIBLE MEANS OF REMOVING EXCESS MOISTURE WHICH CAUSES PAVEMENT FAILURES APPEARS TO BE ELECTROOSMOSIS. A BRIEF REVIEW IS PRESENTED OF PREVIOUS INVESTIGATIONS IN ELECTROOSMOSIS OF SOILS. CLAYS AND SILTS WERE TESTED WITH A RADIAL FLOW APPARATUS. RELATIONSHIPS WERE DETERMINED BETWEEN ELECTROOSMOTIC FLOW RATES, ELECTRICAL POTENTIAL GRADIENT AND TIME. RESULTS SHOW THAT THE ELECTROOSMOTIC FLOW RATE FOR SOILS RELATIVELY HIGH IN CALCIUM IS CHARACTERIZED BY A RELATIVELY HIGH INITIAL FLOW RATE WHICH DROPS OFF RAPIDLY WITH TIME. THE REDUCTION IN FLOW IS GREATER FOR CLAYS THAN FOR SAND. ANALYSIS OF THE SOIL BETWEEN THE ANODE AND CATHODE AT THE COMPLETION OF A RUN SHOWS THAT THE PH HAS DECREASED AT THE ANODE AND INCREASED AT THE CATHODE. CONSIDERABLE AMOUNTS OF CALCIUM HYDROXIDE WERE DEPOSITED AT THE CATHODE. THIS CALCIUM HYDROXIDE COATS THE METALLIC CATHODE, CEMENTS THE SOIL PARTICLES, AND DENSIFIES THE SOIL ADJACENT TO THE CATHODE. THESE EFFECTS INCREASE THE ELECTRICAL RESISTANCE AND DECREASE THE CURRENT FLOWING IN THE SYSTEM. IT WAS SHOWN THAT THE REDUCTION IN FLOW OF WATER IS DIRECTLY PROPROTIONAL TO THE REDUCTION IN ELECTRICAL CURRENT.

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  • Supplemental Notes:
    • No 108, pp 120-128, 12 FIG, 4 TAB, 7 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
  • Authors:
    • Rollins, Ralph L
  • Publication Date: 1955

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; References; Tables;
  • Pagination: pp 120-128
  • Monograph Title: Soil and Soil-Aggregate Stabilization
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00231348
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 15 2004 2:41AM