VANE SHEAR METHOD OF CONTROLLING COMPACTION OF BITUMEN-SAND MIXTURES

TRIALS WERE CARRIED OUT TO TEST TECHNIQUES OF MIXING, AERATION AND COMPACTION OF A BITUMINOUS STABILIZED SAND. A PROCEDURE WAS DEVELOPED TO DETERMINE WHEN AERATION WAS CARRIED OUT SUFFICIENTLY TO ALLOW COMPACTION TO COMMENCE. THE PROCEDURE IS AS FOLLOWS: (1) A SAMPLE OF THE FIELD MIXTURE IS SUBJECTED TO ACCELERATED AERATION BY DRYING IT IN SHALLOW PANS IN THE SUN, (2) DURING THE ACCELERATED AERATION PROCESS SAMPLES ARE COMPACTED IN A CBR MOULD UNDER MODIFIED AASHO COMPACTION AND THE DENSITY, VANE SHEAR STRENGTH AND FLUID CONTENT DETERMINED TO ENABLE THE PLOTTING OF CURVES OF DENSITY AND SHEAR STRENGTH AGAINST FLUID CONTENT, AND (3) THE SAME TESTS ARE CARRIED OUT AT INTERVALS ON SAMPLES TAKEN FROM THE NATURALLY AERATING MIXTURE ON THE ROAD. THE CURVES OBTAINED FOR THESE SAMPLES SHOW PROGRESSIVE DEVELOPMENT OF THE DENSITY AND SHEAR STRENGTH AGAINST FLUID CONTENT. TESTS WITH THE VANE SHEAR APPARATUS INDICATED THAT A HIGH INITIAL FLUID CONTENT RESULTING FROM A RELATIVELY HIGH CONTENT OF MIXING MOISTURE GIVES RISE TO A HIGHER VALUE OF SHEAR STRENGTH THAN IS OBTAINED BY STARTING WITH A LOWER INITIAL FLUID CONTENT. IF MEASUREMENTS ARE CARRIED OUT IN SITU, THE VANE SHEAR APPARATUS CAN ALSO BE USED TO PROVIDE INFORMATION ON THE SETTING-UP BEHAVIOR OF MIXTURES AFTER COMPACTION.

  • Supplemental Notes:
    • Annual Rept 1965, SPECIAL REPT PAD 14, PP 8-9
  • Corporate Authors:

    Cncl Scient & Indus Res /S Africa

    /Nat Inst Road Res
    ,   USA 
  • Publication Date: 1966

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Filing Info

  • Accession Number: 00214765
  • Record Type: Publication
  • Files: TRIS
  • Created Date: Jul 29 2004 6:25PM