DETERMINATION OF THE SURFACE CHARGES OF CERTAIN HIGHWAY AGGREGATES BY STREAMING POTENTIAL METHODS

EXPERIMENTATION WAS CONDUCTED TO MEASURE THE SURFACE CHARGE AND ZETA POTENTIAL ON A WIDE RANGE OF AGGREGATE TYPES OCCURRING IN VIRGINIA BY STREAMING POTENTIAL METHODS, AND TO INVESTIGATE THE QUALITY OF THE ASPHALT-AGGREGATE BONDS FORMED WITH THESE SAME AGGREGATES AND THREE DISTINCT TYPES OF ASPHALTS. AN EFFORT WAS MADE TO CORRELATE BY USE OF STATISTICAL METHODS THE SURFACE CHARGE DATA WITH BOND QUALITY OR STRIPPING RESULTS. THE EFFECTS ON BOND QUALITY OR STRIPPING RESULTS. THE EFFECTS ON BOND QUALITY OF AGGREGATE TYPE AND ASPHALT TYPE WERE EVALUATED. THE ASPHALT- AGGREGATE BOND WAS INVESTIGATED USING A STRIPPING OR BOILING TEST. ANALYSIS OF VARIANCE, CORRELATION COEFFICIENTS, AND EVALUATION OF ROCK TYPE-ASPHALT TYPE INTERACTION WERE CONDUCTED USING CONVENTIONAL STATISTICAL METHODS. DATA OBTAINED PERMIT THE FOLLOWING OBSERVATIONS: (1) ALL OF THE AGGREGATES UNDER STUDY WERE FOUND TO HAVE NEGATIVE SURFACE CHARGE, (2) THE NEGATIVE ZETA POTENTIALS RANGE FROM -8.23 TO -62.50, WITH EACH AGGREGATE TYPE EXHIBITING CONSIDERABLE SPREAD WITHIN THE INTERVAL, (3) CARBONATE AGGREGATES FORMED A DISTINCT PH GROUP, EXHIBITING PH VALUES CONSIDERABLY HIGHER THAN THE QUARTZ AND SILICATE AGGREGATES, (4) THE SILICATES SHOW A TREND TOWARD HIGHER NEGATIVE ZETA POTENTIALS AT LOWER PH VALUES, (5) THE SILICATES EXHIBIT A DECREASE IN ZETA POTENTIAL WITH AN INCREASE OF BASIC ELEMENTS, (6) CARBONATE AGGREGATES SHOW INCREASED NEGATIVE ZETA POTENTIAL AND INCREASED PH WITH INCREASED CALCIUM CONTENT, (7) THE STRIPPING AND VISUAL INSPECTION TEST UTILIZED IS THOUGHT TO BE PRECISE ENOUGH TO BE UTILIZED IN EVALUATING BOND QUALITY, (8) THE RELATIONSHIP BETWEEN SURFACE CHARGE AND STRIPPING RESULTS WAS FOUND TO BE POOR, (9) NEUTRAL EMULSION WITH AN ADHESION ADDITIVE WAS FOUND TO PERFORM SIGNIFICANTLY POORER IN THE STRIPPING TESTS THAN CATIONIC AND NEUTRAL EMULSIONS FROM THE SAME SUPPLIER, AND (10) A STATISTICALLY SIGNIFICANT INTERACTION BETWEEN AGGREGATE AND ASPHALT TYPE WAS NOTED. SIGNIFICANT CONCLUSIONS ARE: (1) THE BOILING TESTS FOR EVALUATION FOR THE ASPHALT-AGGREGATE BOND DEVELOPED IN THE STUDY YIELDS DATA OF SUFFICIENT PRECISION TO MAKE THIS A USEFUL TEST, (2) THE RELATIONSHIP BETWEEN AGGREGATE SURFACE CHARGE AND THE QUALITY OF THE ASPHALT-AGGREGATE BOND IS POOR AND INCONCLUSIVE, AND (3) A STATISTICALLY SIGNIFICANT INTERACTION RELATIONSHIP EXISTS WHICH INDICATES THAT DIFFERENTLY DISCHARGED ASPHALT EMULSIONS BOND SIGNIFICANTLY BETTER WITH DIFFERENT TYPES OF AGGREGATES. IT WAS FOUND THAT CATIONIC EMULSION-LIMESTONE MIXES AND NEUTRAL EMULSION- QUARTZ MIXES WERE MORE STABLE UNDER TESTS THAN THE NEUTRAL EMULSION-LIMESTONE AND THE CATIONIC EMULSION-QUARTZ MIXES.

• Supplemental Notes:
  • 53 Pp, 15 FIG, 1 TAB, 26 REF
• Corporate Authors:

  Virginia Highway Research Council

  Charlottesville, VA  United States 
• Authors:
  • Sherwood, W C
• Publication Date: 1967-4

Subject/Index Terms

• TRT Terms: Aggregates; Analysis of variance; Asphalt; Bituminous aggregates; Boiling; Bonds; Carbonate rocks; Cationic emulsified asphalt; Electric potential; Electrical properties; Emulsified asphalt; Limestone; pH value; Silicates; Statistical analysis; Stripping (Pavements); Test procedures
• Uncontrolled Terms: Streaming potential (Electricity); Zeta potential
• Old TRIS Terms: Negative charges; Surface charge
• Subject Areas: Data and Information Technology; Geotechnology; Highways;

Filing Info

• Accession Number: 00217790
• Record Type: Publication
• Files: TRIS
• Created Date: Sep 22 1994 12:00AM