ASPHALT DURABILITY AND ITS RELATION TO PAVEMENT PERFORMANCE- ADHESION

A NEW TECHNIQUE WAS DEVELOPED FOR MEASURING ADHESION (AND COHESION) BETWEEN ASPHALT CEMENTS AND AGGREGATES. COMPARATIVE ASSESSMENTS ARE POSSIBLE BY MEASURING THE MATERIALS ELECTROKINETIC PROPERTIES. AN ASPHALT CEMENT IS CAUSED TO FLOW THROUGH THE AGGREGATE UNDER APPLIED PRESSURE GENERATING STREAMING POTENTIALS (OR STREAMING CURRENTS). ACTUALLY, THE MIXING OF AN ASPHALT CEMENT AND AN AGGREGATE BRINGS ABOUT TANGENTIAL MOVEMENT OF THESE PHASES AGAINST EACH OTHER AND THUS THE CREATION OF ELECTROKINETIC EFFECTS. THESE EFFECTS ARE EXPLAINED IN TERMS OF ELECTRICAL DOUBLE LAYERS WHICH SHEATH THE SURFACES OF THE AGGREGATE PARTICLES. THE DEVELOPED DATA-ACQUISITION SYSTEM IS ESSENTIALLY AN ANALOG-TO-DIGITAL SYSTEM. A PREREQUISITE FOR THIS SYSTEM WAS THE MEASUREMENT OF SMALL SIGNALS PRODUCED BY VERY HIGH IMPEDANCE, SUCH AS IS ENCOUNTERED IN ASPHALT CEMENT-AGGREGATE SYSTEMS. THIS DATA-ACQUISITION SYSTEM PROVED TO BE ACCURATE AND RELIABLE, PROVIDING QUANTITATIVE EVALUATION OF ADHESION BY MEASUREMENTS OF ELECTROKINETIC PROPERTIES. INDEED, THE ADHESIVE QUALITIES OF AN ASPHALT CEMENT AND AN AGGREGATE ARE INFLUENCED BY THE INHERENT AND DIVERSE PROPERTIES OF BOTH THESE MATERIALS. BOTH PHYSICAL AND CHEMICAL ADSORPTION OCCUR. THE INTERFACIAL REACTIVITY OF AN ASPHALT CEMENT DEPENDS ON THE CONTAINED ENTITIES, WHETHER IONIC, MOLECULAR, MICELLAR, POLAR OR NONPOLAR, OR COMPLEXES OF WHATEVER NATURE; THE REACTIVITY OF AGGREGATES DEPENDS ON THEIR VARIABLE PHYSICAL AND CHEMICAL PROPERTIES. IN THE EVALUATION OF A TEMPERATURE-CONTROLLED ASPHALT CEMENT-AGGRAGTE SYSTEM, STREAMING POTENTIAL-PRESSURE RATIOS AND ZETA POTENTIALS DEMONSTRATE THE ADHESIVE AND ADSORPTIVE QUALITIES OF A PARTICULAR ASPHALT CEMENT FOR A PARTICULAR AGGREGATE. /AUTHOR/

• Supplemental Notes:
  • PROJ NO 9-2
• Authors:
  • Mcglashan, D W
• Publication Date: 1972

Media Info

• Features: Figures; References;
• Pagination: p. 111-20
• Serial:
  • Highway Research Board NCHRP Summary

Subject/Index Terms

• TRT Terms: Adhesion; Aggregates; Asphalt cement; Electrokinetics; Measurement; Methodology; Quantitative analysis
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00211779
• Record Type: Publication
• Files: TRIS
• Created Date: Jan 3 1973 12:00AM