DISCUSSION OF TECHNIQUE FOR STUDY OF GRANULAR MATERIALS

THE WRITER, IN STUDYING THE DEVELOPMENTS IN SHEARED TRIAXIAL TEST SPECIMENS TO OBSERVE THE PHENOMENOLOGICAL BEHAVIOR OF PARTICULATE MATERIALS, HAS DEVELOPED A TECHNIQUE OF INJECTING GROUT INTO A SHEARED TRIAXIAL TEST SPECIMEN THROUGH AN ARRANGEMENT SHOWN IN A FIGURE, FITTED WITHIN THE CELL. THE SUCTION AND GROUT LEADS ARE TAKEN OUT THROUGH THE CELL CAP AND CONNECTED TO A SUCTION PRESSURE AND GROUT RESERVOIR, RESPECTIVELY. THE INGREDIENTS OF THE GROUT USED BY THE WRITER WERE: POLYESTER RESIN, MONOMERIC STYRENE THINNER, BAKELITE ACCELERATOR, AND BAKELITE CATALYST. THE VISCOSITY OF THE POLYESTER RESIN IS LOW ENOUGH TO PERMIT EASY FLOW THROUGH A COARSE SAND WITHOUT THE USE OF THINNER. THE POLYESTER RESIN AND BAKELITE ACCELERATOR WERE MIXED TOGETHER THOROUGHLY IN THE SPECIFIED PROPORTIONS. JUST BEFORE USE, THE BAKE-LITE CATALYST WAS ADDED AND MIXED THOROUGHLY. THE GROUT WAS DYED BY ADDING PIGMENT TO THE RESIN BEFORE ADDING THE ACCELERATOR AND CATALYST. THE WRITER HAS INJECTED THE GROUT DIRECTLY INTO THE SPECIMEN FOR FIXING THE SOIL PARTICLES, WITHOUT USING DIFFERENT GELS FOR THE STAGES OF STABILIZATION AND IMPREGNATION AS DESCRIBED BY THE AUTHORS. THE WRITER ELIMINATED THE ELABORATE PROCEDURE OF MOUNTING, GRINDING, AND PREPARING THIN SECTIONS FOR MICROSCOPIC STUDIES AS DESCRIBED BY ROSS AND BY SCHAFFER AND HIRST BY USING APPROXIMATELY 2 MM SAND PARTICLES AND OBTAINING ABOUT 2 MM THICK SECTIONS WHICH WERE DIRECTLY PHOTOGRAPHED USING A CLOSE-UP LENS. THIS TECHNIQUE ENABLES QUICKER STUDY OF THE PARTICLE ORIENTATION AND DISTRIBUTION. THE AUTHORS SUGGESTED THAT THE GRADATION AND POROSITY OF THE SPECIMEN COULD BE REASONABLY PREDICTED FROM THE STUDY OF THIN SECTIONS. IT HAS BEEN THE EXPERIENCE OF THE WRITER THAT WHEN SECTIONS OF A MASS OF UNIFORM SPHERICAL PARTICLES WERE PREPARED, THEY INDICATE DISCS OF VARYING SIZES AS THOUGH THE MASS HAD NONUNIFORM SPHERES. FOR DETERMINING THE POROSITY OF A REGION, THE WRITER ADOPTED AN APPROACH UNLIKE THE AUTHORS' METHOD OF ESTIMATING POROSITY ALONG A LINE. THE POROSITY WAS ESTIMATED FROM THE UNOBSCURED AREA (VOID AREA) WITHIN A CIRCULAR AREA. THE TWO DIMENSIONAL POROSITY WITHIN A LOCAL REGION IS EXTREMELY ERRATIC AND VARIES WITH THE SELECTION OF THE CENTER OF AN AREA IN A VOID OR ON A PARTICLE. THE POROSITY TENDS TO BE CONSTANT BEYOND A RADIAL DISTANCE OF 5 TIMES THE DIAMETER OF THE PARTICLES. WHEN IT IS DESIRED TO KNOW WHETHER A REGION IS DENSER OR LOOSER THAN THE OTHER WITHOUT ACTUALLY FINDING OUT THE POROSITY OF THE REGION, THE NUMBER OF CONTACTS OR THE NUMBER OF PARTICLE CENTERS LYING WITHIN THE REGION COULD SERVE THE SAME PURPOSE. /DISCUSSER/

  • Supplemental Notes:
    • Vol 97, No SM4, PP 686-690, 3 FIG, 5 REF, APP
  • Discussers:
    • Ramamurthy, T
  • Publication Date: 1971-4

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Filing Info

  • Accession Number: 00235967
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Aug 1 1971 12:00AM