ADDITIVES FOR BITUMINOUS MATERIALS

TESTS WERE CONDUCTED ON A NUMBER OF CHEMICAL AGENTS OFFERED COMMERCIALLY AS AIDS IN COATING WET AGGREGATE WITH BITUMENS AND IN RETAINING BITUMINOUS COATING ON AGGREGATES THAT OTHERWISE MIGHT BE ADVERSELY AFFECTED BY MOISTURE. THE TESTS WERE MADE TO OBTAIN DEFINITE INFORMATION ON THE FOLLOWING: (1) EFFECT OF ADDITIVES IN COATING WET AGGREGATES WITH BITUMEN, (2) EFFECT OF ADDITIVES IN REDUCING FILM STRIPPING, (3) EFFECT OF VARYING PERCENTAGES OF ADDITIVES, (4) EFFECT OF ADDITIVES ON THE CHARACTERISTICS OF BITUMINOUS MATERIALS WITH WHICH THEY ARE USED, (5) EFFECT OF ADDITIVES WHEN USED WITH DIFFERENT BITUMINOUS MATERIALS, (6) EFFECT OF ADDITIVES IN REDUCING LOSS OF STRENGTH OF BITUMINOUS MIXTURES DUE TO WATER ACTION, AND (7) PERMANENCY OF BENEFIT OBTAINED BY THE USE OF ADDITIVES. SEVEN ADDITIVES WERE STUDIED AND THE FOLLOWING THREE DIFFERENT TESTS USED TO MEASURE THE EFFECT OF THE ADDITIVES; (1) A STATIC-IMMERSION STRIPPING TEST, (2) A MODIFICATION OF THE NICHOLSON STRIPPING TEST, AND (3) THE IMMERSION-COMPRESSION TEST. IT IS CONCLUDED THAT: (1) ADDITIVES ARE AVAILABLE THAT FACILITATE THE COATING OF WET AGGREGATE WITH LIQUID BITUMINOUS MATERIALS, (2) ADDITIVES ARE AVAILABLE THAT GREATLY INCREASE THE RESISTANCE OF BITUMINOUS FILMS TO STRIPPING IN THE PRESENCE OF MOISTURE, (3) THE USE OF ADDITIVES WITH TAR DOES NOT APPEAR TO BE WARRANTED EXCEPT POSSIBLY WHEN MIXING MUST BE DONE UNDER PARTICULARLY ADVERSE CONDITIONS, SUCH AS DURING A RAIN OR IMMEDIATELY PRIOR THERETO, (4) ADDITIVES APPEAR TO HAVE NO DETRIMENTAL EFFECT UPON THE BITUMINOUS MATERIAL WITH WHICH THEY ARE USED, (5) ADDITIVES APPEAR TO HAVE NO MATERIAL EFFECT ON THE ORIGINAL COMPRESSIVE STRENGTH OF BITUMINOUS MIXTURES, (6) ADDITIVES ARE AVAILABLE THAT WILL REDUCE THE LOSS OF STABILITY OF BITUMINOUS MIXTURES DUE TO THE DETRIMENTAL ACTION OF WATER, (7) THE BENEFITS AFFORDED BY ADDITIVES APPEAR TO HAVE CONSIDERABLE PERMANENCE BUT THE DEGREE OF PERMANENCE WAS NOT DISCLOSED BY THESE TESTS, AND (8) THE IMMERSION-COMPRESSION TEST PROVIDES A USEFUL MEASURE OF THE BENEFITS TO BE DERIVED FROM THE USE OF ADDITIVES.

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  • Supplemental Notes:
    • Vol 24, No 5, PP 131-142
  • Authors:
    • Critz, P F
    • Goode, J F
  • Publication Date: 1945-9

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  • Accession Number: 00210905
  • Record Type: Publication
  • Source Agency: Highway Research Board Bibliography
  • Files: TRIS
  • Created Date: May 1 1994 12:00AM