RELATION BETWEEN ASPHALT COMPOSITION AND HARDENING BY VOLATILIZATION AND OXIDATION

INVESTIGATIONS OF THE SERVICE DURABILITY AND CHEMICAL PROPERTIES OF ASPHALTIC CEMENTS ARE REVIEWED. ASPHALTS HARDEN TO VARYING DEGREES UPON AGING, AND WHEN SUBJECTED TO HEAT, OXYGEN, OR ACTINIC LIGHT. A CONSIDERATION VARIATION IN SUSCEPTIBILITY TO HARDENING EXISTS AMONG COMMERCIAL ASPHALTS. IT IS AGREED THAT ASPHALTS ARE COLLOIDAL SYSTEMS COMPOSED OF HIGH MOLECULAR WEIGHT COMPOUNDS DISPERSED IN AN OILY MEDIUM. INVESTIGATION OF RHEOLOGICAL AND COLLOIDAL PROPERTIES HAVE INDICATED THAT THE AMOUNT OF DISPERSED MATERIALS (ASPHALTENES, WHICH ARE THE N-PENTANE INSOLUBLE COMPONENT OF THE ASPHALT) AND THE CHEMICAL COMPOSITION OF THE PETROLENES (N-PENEANE SOLUBLE COMPONENT) CONTROL THE PROPERTIES OF AN ASPHALT. IF THE PETROLENES POSSESS A HIGH CONTENT OF UNSATURATED OR CYCLIC COMPOUNDS THE HEAVY ASPHALTIC BODIES ARE WELL DISPERSED. LARGE AMOUNTS OF SATURATED COMPOUNDS WILL CAUSE FLOCULATION OF THE HEAVIER BODIES AND THE APPEARANCE OF INTERNAL STRUCTURE IN THE ASPHALT. STUDIES IN THE AREA OF CRACKING OF ASPHALT HAVE PROVEN THAT ITS MAJOR CAUSE, IS THE HARDENING OF THE ASPHALT, GENERALLY WITH TIME. VOLATILIZATION AND OXIDATION INCREASE THE HARDNESS IN THE DEVELOPMENT OF INSOLUBLE MATTER IN THE ASPHALT. ANOTHER CAUSE OF THE HARDENING AND LOSS OF DURABILITY IN PAVING ASPHALTS IS THE ABSORPTION OR ADSORPTION OF CERTAIN COMPONENTS BY THE AGGREGATE USED IN BUILDING THE ROAD.

• Supplemental Notes:
  • Vol 30, pp 359-372
• Authors:
  • Traxler, R N
• Conference:
  • Assoc Asphalt Paving Technol Proc
• Publication Date: 1961

Subject/Index Terms

• TRT Terms: Absorption; Adsorption; Aggregates; Asphalt; Asphalt cement; Asphaltene; Chemical properties; Colloids; Concrete hardening; Durability; Flocculating agents; Hardness; Malthene; Oxidation; Pavement cracking; Pavements; Photochemistry; Rheological properties; Volatilization
• Old TRIS Terms: Aging; Flocculating; Petrolene component /asphalt/; Vaporizing
• Subject Areas: Geotechnology; Highways; Materials; Pavements;

Filing Info

• Accession Number: 00210850
• Record Type: Publication
• Files: TRIS
• Created Date: May 6 1994 12:00AM