THE FABRIC OF SOIL CEMENT AND ITS FORMATION

THE ELECTRON MICROSCOPE HAS BEEN USED TO STUDY CHANGES IN PARTICLE SIZE, SHAPE AND ARRANGEMENT THAT OCCUR DURING THE HYDRATION OF CLAY IN SOIL-CEMENT. SAMPLES OF KAOLINITE, OF A MIXTURE OF SILICA FLOUR AND MONTMORILLONITE, AND OF A NATURAL SILTY CLAY WERE MIXED WITH SUFFICIENT PORTLAND CEMENT TO PRODUCE SOIL-CEMENT. SPECIMENS WERE CURED AT CONSTANT MOISTURE CONTENT FOR PERIODS UP TO 32 WEEKS AFTER COMPACTION AT OPTIMUM MOISTURE CONTENT FOR THE MIXTURE. AT THE END OF THE CURING PERIOD, SURFACES OF FRESH FRACTURES WERE REPLICATED, AND THE REPLICAS WERE STUDIED USING THE ELECTRON MICROSCOPE. ALL THREE MIXTURES SHOWED SIMILAR BEHAVIOR. INITIALLY THE FABRIC IS ONE OF SEPARATE PORTLAND CEMENT GRAINS DISTRIBUTED THROUGHOUT THE CLAY SOIL. AS HYDRATION OF THE CEMENT PROCEEDS, CEMENT HYDRATE GEL FORMS ALONG THE EDGES OF GROUPS OF CLAY PARTICLES. REACTION BETWEEN THE SOIL AND THE CEMENT IS OBSERVED EARLY IN THE HYDRATION PERIOD. AS HYDRATION CONTINUES, THE SOIL GRAINS ARE MORE AND MORE BROKEN DOWN AND THE CEMENT GEL DIFFUSES MORE EXTENSIVELY THROUGHOUT THE MASS. EVENTUALLY, THE BREAKDOWN OF THE SOIL MINERALS AND THE FORMATION OF HYDRATION PRODUCTS REACHES A POINT WHERE THE SOIL AND CEMENT CAN NO LONGER BE DISTINGUISHED AS SEPARATE PHASES. /AUTHOR/

  • Corporate Authors:

    Nat Conf Clays Clay Minerals Proc

    ,    
  • Authors:
    • Mitchell, J K
    • El, JACK SA
  • Publication Date: 1966

Subject/Index Terms

Filing Info

  • Accession Number: 00212356
  • Record Type: Publication
  • Report/Paper Numbers: pp 297-305
  • Files: TRIS
  • Created Date: Apr 27 1994 12:00AM