A VACUUM EXTRACTOR FOR BITUMINOUS MIXES

QUALITY CONTROL TESTS OF HOT BITUMINOUS MIXTURES IN THE FIELD SHOULD BE SPEEDED UP BY THIS NEW METHOD DEVELOPED BY COLORADO DEPARTMENT OF HIGHWAYS. THE VACUUM EXTRACTION TEST PROCEDURE AND APPARATUS HAVE THE FOLLOWING DISADVANTAGES' /1/ MORE SOLVENT IS REQUIRED THAN FOR THE REFLUX METHOD, BUT ABOUT THE SAME AS FOR THE CENTRIFUGE, FOR THE SAME TEST SPECIMEN SIZE, /2/ THE METHYLENE CHLORIDE MUST BE STORED IN A COOL PLACE BECAUSE OF ITS LOW BOILING POINT, AND /3/ HOT BITUMINOUS MIXTURES MUST BE COOLED TO 130F BEFORE TESTING. THE ADVANTAGES OF THIS PROCEDURE ARE' /1/ THE 12-IN.- DIAMETER FILTER IS LARGE ENOUGH FOR TESTING SPECIMENS WEIGHING UP TO 3000 G, /2/ THE VACUUM REDUCES FILTERING TIME TO LESS THAN 15 MIN, /3/ THE FILTER IS SEALED TO PREVENT SIGNIFICANT LOSS OF FINES, AND NO CORRECTION NEED BE MADE FOR SUCH LOSS WHEN DOING ROUTINE CONTROL TESTING, /4/ THE USE OF DIATOMACEOUS SILICA SPEEDS FILTERING ON CERTAIN FINE- GRAINED MIXTURES, /5/ EIGHT TESTS OR MORE, PER SHIFT, CAN BE MADE WITH A SINGLE APPARATUS, /6/ FOR MIXTURES CONTAINING LESS THAN 0.6 PER CENT MOISTURE, NO MOISTURE TEST NEED BE MADE, /7/ IT IS AT LEAST AS ACCURATE AS CONVENTIONAL METHODS, AND /8/ THE COST PER TEST IS REASONABLE. THE MERIT OF THE 20 VACUUM EXTRACTION PROCESS HAS LED TO ITS ADOPTION BY THE COLORADO DEPARTMENT OF HIGHWAYS AS ONE OF THREE STANDARD PROCEDURES. /AUTHOR/

  • Supplemental Notes:
    • Vol 5, No 12, PP 622-629
  • Authors:
    • Brakey, B A
  • Publication Date: 1965-12

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  • Accession Number: 00210633
  • Record Type: Publication
  • Files: TRIS
  • Created Date: May 4 1994 12:00AM