STABILIZATION OF LATERITE SOILS

MICROSCOPIC EXAMINATION OF LATERITES DERIVED FROM THE ALTERNATION OF ROCKS IN PLACE SHOW THAT THESE MATERIALS ARE COMPOSED OF PURE SILICA FROM EOLIAN SANDS AND HYDROUS OXIDES OF ALUMINUM AND OF IRON. MINERALOGIC EXAMINATION SHOWS THAT THE NORMAL WEATHERING OF FELDSPARS LEADS TO THE FORMATION OF CLAYS. ON THE OTHER HAND, THE SPECIFIC LATERITIC ALTERATION LEADS FIRST TO HYDRATES AND THEN TO OXIDES. THIS LATERITIC ALTERATION IS A CONSEQUENCE OF THE HYDROLYSIS OF THE FELDSPARS AND OF THE ELUTRIATION OF THE ALKALIS AND OF PART OF THE IRON IN THE FORM OF THE BICARBONATE. THIS ELIMINATION IS FAVORED BY PURITY OF THE WATERS AND BY AN ELEVATED TEMPERATURE (ABOUT 86 F). THE HYDRATES TEND TO TRANSFORM INTO OXIDES UNDER THE EFFECT OF SOLAR RADIATION AND POSSIBLY ALSO UNDER THE ACTION OF IRON BACTERIA. ALL LATERITES POSSESS PECULIAR MECHANICAL PROPERTIES: THE NODULES ARE ALWAYS FRIABLE AND OF POROUS STRUCTURE, AND THE FINE PARTICLES ARE ALWAYS FLOCCULATED. TEST METHODS MUST THEREFORE BE MODIFIED. THE FRAGILITY OF THE LATERITE NODULES IS SUCH THAT IT IS NECESSARY TO USE NEW MATERIAL FOR EACH POINT OF THE PROCTOR CURVE. UTILIZATION OF LATERITES FOR NONPAVED AND PAVED HIGHWAYS ARE DISCUSSED. IT IS CONCLUDED THAT UNPAVED HIGHWAYS EXPECTED TO BE MAINTAINED BY MOTOR GRADER MUST BE CONSTITUTED OF LIVE LATERITES, WHOSE FINES ARE STILL RICH IN HYDRATES. IN REGARD TO PAVED HIGHWAYS, EXPERIENCE HAS PROVED THAT EVEN IN THE CASE OF LATERITES HAVING A HIGH PLASTIC INDEX, PENETRATION IS SATISFACTORY IF THE SURFACE IS THOROUGHLY MOISTENED.

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  • Supplemental Notes:
    • No 108, pp 96-101, 7 FIG, 1 TAB 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:
    • Remillon, A
  • Publication Date: 1955

Language

  • English

Media Info

  • Media Type: Print
  • Features: Figures; Tables;
  • Pagination: pp 96-101
  • Monograph Title: Soil and Soil-Aggregate Stabilization
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00231345
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: Aug 15 2004 2:41AM