PHYSICO-CHEMICAL ASPECT OF ASPHALTS

THE THREE MAIN CONSTITUENTS OF ASPHALTS ARE ASPHALTENES, ASPHALTIC RESINS AND OILY CONSTITUENTS. THE ASPHALTENES ARE SOLUBLE IN ASPHALTIC RESINS. THEIR SOLUBILITIES IN THE OILY CONSTITUENTS, HOWEVER, DEPEND UPON THE CHEMICAL PROPERTIES OF THE LATTER. OILY CONSTITUENTS RICH IN SULFUR OR AROMATIC IN CHARACTER ARE SOLVENTS FOR THE ASPHALTENES. THE ASPHALTENES HAVE A RELATIVELY LOW MOLECULAR WEIGHT. THEY DIALYZE AND DIFFUSE. THEY ARE CLASSIFIED AS SEMI-COLLOIDS. SOLS OF ASPHALTENES FROM DIFFERENT SOURCES IN PETROLENES WHOSE OILY CONSTITUENTS ARE SOLVENTS FOR ASPHALTENES ARE VISCUOUS LIQUIDS OF HIGH VISCOSITY. ASPHALTENE SOLS IN PETROLENES WHOSE OILY CONSTITUENTS DO NOT DISSOLVE ASPHALTENES SHOW PLASTIC FLOW. IN PLASTIC ASPHALTS THE ASPHALTENES ARE DISPERSED IN A LESSER DEGREE THAN IN VISCOUS ASPHALTS. THE LARGER ASPHALTENE PARTICLES IN PLASTIC CEMENTS HAVE BEEN ATTRIBUTED TO A REDUCTION OF THEIR TRUE SOLUBILITY. PLASTIC ASPHALTS ARE TRULY COLLOIDAL SYSTEMS OF THE LYOPHILIC TYPE, VISCOUS ASPHALTS BELONG TO A SYSTEM FALLING BETWEEN TRUE AND COLLOIDAL SOLUTIONS. THE SUSCEPTIBILITIES OF ASPHALTS DEPEND MAINLY ON THE TYPES OF OILY CONSTITUENTS AND THEIR VISCOSITY-TEMPERATURE RELATIONSHIPS.

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Filing Info

  • Accession Number: 00210906
  • Record Type: Publication
  • Source Agency: Highway Research Board Bibliography
  • Report/Paper Numbers: No 40
  • Files: TRIS
  • Created Date: May 13 1994 12:00AM