SOME LABORATORY EVALUATIONS OF BITUMINOUS COATINGS

THE EFFECTIVENESS OF BITUMINOUS COATINGS IS BASED LARGELY ON THEIR RESISTANCE TO MOISTURE AND CHEMICAL ATTACK. THE CRITERIA GOVERNING COATINGS DEVELOPMENT ARE: WATER ABSORPTION, WATER PENETRATION, WATER SATURATION, VALUE OF THE ELECTRICAL INSULATION, AND PERFORMANCE IN GALVANIC ENVIRONMENT. A REVIEW IS PRESENTED OF LABORATORY EVALUATION OF PERFORMANCE OF BITUMINOUS COATINGS. WATER IS ABSORBED BY OSMOTIC AND ELECTRO-OSMOTIC EFFECTS. THE ABSORPTION MAY BE MEASURED GRAVIMETRICALLY AND RELATED TO QUANTITY PER UNIT AREA. BY THIS METHOD, ALSO, THE SOLUBILITY OR LEACHING CHARACTERISTICS OF CERTAIN BITUMENS MAY BE TESTED BY MEANS OF DRYING AND WEIGHING AFTER WATER IMMERSION EXPOSURES. COLD TARS TYPES WERE FOUND TO BE MORE SUSCEPTIBLE THAN ASPHALTS. IN GRAVIMETRIC ABSORPTION TESTS CARRIED OUT AT 160 DEGREES F, THIS FACT WAS ACCENTUATED. AT THIS TEMPERATURE ALL OF THE BITUMINOUS MATERIALS TESTED SHOWED MULTIFOLD ABSORPTION INCREASES. ELECTRICAL PROPERTIES WERE STUDIED IN RELATION TO WATER ABSORPTION CHARACTERISTICS AND TO PERFORMANCE OF BITUMINOUS MATERIALS AS INSULTATIVE COATINGS. VOLUME RESISTIVITY MEASUREMENTS WERE OBTAINED ON THE BITUMINOUS COATINGS. A NEW METHOD WAS DEVELOPED TO DERIVE MEASUREMENTS OF DEPTH OF WATER PENETRATION BY ELECTRICAL CAPACITANCE. THIS METHOD PERMITS EVALUATION OF BITUMINOUS COMPOUNDS OF KNOWN PERFORMANCE AGAINST NEWER COMPOUNDS. WATER PENETRATION VALUES CAN BE CO-RELATED TO GRAVIMETRIC ABSORPTION. WITH A MODERATE VERSION OF THE CATH- ODIC CURRENT DISBONDING PROCEDURE, A NUMBER OF BITUMINOUS MATERIALS WERE EVALUATED AND FOUND TO BE SUPERIOR TO MANY OTHER COATING TYPES.

• Supplemental Notes:
  • Vol 58, No 6, PP 45-54, 21 FIG, 5 TAB, 17 REF
• Authors:
  • O'brien, H C
• Publication Date: 1966-6

Media Info

• Serial:
  • Industrial & Engineering Chemistry

Subject/Index Terms

• TRT Terms: Absorption; Bituminous materials; Coatings; Electric insulating materials; Electrical resistivity; Electroosmosis; Gravimetric analysis; Laboratory studies; Osmosis; Pendulum tests; Percent saturation; Protective coatings; Reviews; Water
• Old TRIS Terms: Electrical insulation; Gravimetric analyses; Resistivity
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00211532
• Record Type: Publication
• Files: TRIS
• Created Date: Aug 26 1970 12:00AM