EFFECT OF LIGHT AND WATER ON THE DEGRADATION OF ASPHALT

COATINGS PREPARED FROM TWO BLOWN PETROLEUM ASPHALTS IN A THICKNESS RANGE OF 0.002 TO 0.04 INCHES WERE EXPOSED TO ACCELERATED TEST CONDITIONS AND OUTDOORS. WHEN EXPOSED TO LIGHT ONLY, A SURFACE FILM, INSOLUBLE IN COMMON ASPHALT SOLVENTS, WAS FORMED. THE FORMATION OF THIS SURFACE FILM WAS ACCOMPANIED BY A GAIN IN WEIGHT OF THE COATINGS, APPARENTLY DUE TO AN OXYGEN PICKUP. THIS SURFACE FILM RETARDED FURTHER DEGRADATION OF THE MALTENES DURING THE EXPOSURES MADE TO LIGHT ONLY. WHEN THE COATINGS WERE IMMERSED IN WATER AFTER EXPOSURE, OR SPRAYED WITH WATER DURING EXPOSURE, OR EXPOSED OUTDOORS, THEY LOST WEIGHT. THESE DECREASES IN WEIGHT WERE FOUND TO BE IN PART DUE TO THE EXTRACTION OF WATER-SOLUBLE, LIGHT-DEGRADED MATERIAL. THEIR MAGNITUDES WERE DEPENDENT UPON THE ASPHALT EXPOSED, THE THICKNESS OF THE EXPOSED COATINGS, AND EXPOSURE CONDITIONS. THE RELATIONSHIP BETWEEN THE LOSSES IN WEIGHT AND WATER-SOLUBLE MATERIAL, WHEN CONSIDERED IN CONJUNCTION WITH THE OXYGEN CONTENT OF THE ASPHALTS AND THE WATER-SOLUBLE MATERIALS, INDICATED THAT VOLATILE DEGRADATION PRODUCTS WERE ALSO FORMED.

  • Supplemental Notes:
    • Vol 63c, P 31
  • Authors:
    • Kleinschmidt, L R
    • Snoke, H R
  • Publication Date: 1959

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  • Accession Number: 00210956
  • Record Type: Publication
  • Source Agency: Highway Research Board Bibliography
  • Files: TRIS
  • Created Date: Jun 10 1994 12:00AM