PROGRESS WITH ADHESION-IMPROVING BITUMEN ADDITIVES

SOME THEORETICAL ASPECTS OF ADHESION ARE DISCUSSED AND THE TEST METHODS FOR TESTING ADHESIVENESS OF BITUMINOUS BINDERS ARE REVIEWED. AN ATTEMPT IS ALSO MADE TO SUMMARIZE AND COMPARE THE CURRENT PRACTICES WITH BITUMEN ADDITIVES IN THE UNITED STATES AND IN EUROPE. A COORDINATED LARGE-SCALE ROAD TEST PROGRAM IS SUGGESTED IN ORDER TO KEEP UP WITH THE RECENT EUROPEAN DEVELOPMENT. WHERE BITUMINOUS BINDERS ARE USED, MANY PROBLEMS AND FAILURES ARE CAUSED BY WATER. IT HAS BEEN DEMONSTRATED EXPERIMENTALLY THAT THE TENSILE STRENGTH OF A HOT-MIX PAVEMENT CAN BE LOWERED TO ONE-FOURTH OF ITS ORIGINAL VALUE BY SOAKING IN WATER FOR FOUR DAYS. ADHESION- IMPROVING BITUMEN ADDITIVES ARE USED TO ADVOID AND OVERCOME THESE FAILURES. GENERALLY THESE ADDITIVES CONSIST OF POLAR MOLECULES, WHICH TEND TO CONCENTRATE IN THE INTERFACES, ADHERE TO THE AGGREGATE SURFACES, AND STRONGLY IMPROVE THE BOND BETWEEN THE BINDER AND THE AGGREGATE. FOR COLD-MIXED PAVEMENTS AND SEAL COATS, AN ACTIVE ADHESION IS REQUIRED, THAT IS, THE ADDITIVE-IMPROVED BITUMEN MUST HAVE THE ABILITY TO ADHERE TO WET AGGREGATES AND TO REPLACE WATER ON WET SURFACES. RELIABLE TEST METHODS ARE OF PRIME IMPORTANCE FOR EVALUATION AND CLASSIFICATION OF ADHESION-IMPROVING ADDITIVES. THE TEST METHODS USED CAN BE DESCRIBED AS MEASUREMENT OF FUNDAMENTAL PHYSIO-CHEMICAL PROPERTIES, AND SIMULATION OF ROAD CONDITIONS. USAGE OF ADHESION-IMPROVING BITUMEN ADDITIVES IN SOME EUROPEAN COUNTRIES SEEMS TO BE FAR AHEAD OF THE CORRESPONDING USAGE IN THE UNITED STATES. IN WESTERN EUROPE ADDITIVES ARE USED MUCH MORE FREQUENTLY AND AT HIGHER LEVELS. EXTENSIVE TESTS IN SWEDEN AND ENGLAND HAVE RESULTED IN ACCEPTANCE OF AMINETYPE ADDITIVES. THE LATEST TREND IS ESSENTIALLY TOWARD NEW APPLICATIONS FOR IMPROVED BITUMINOUS MATERIALS. THE LIMITED HEAT STABILITY OF ADDITIVES KNOWN TO BE REALLY EFFICIENT AND ECONOMICAL DOES NOT ALLOW HEATING OF DOPED BITUMENS FOR PROLONGED PERIODS. EUROPEAN PRACTICE IS TO MIX ADDITIVES AND CUT-BACK ASPHALT DIRECTLY IN THE DISTRIBUTORS. ADDITIVES IN SOLID FORM ARE OFTEN PREFERRED, OWING TO EASIER AND SAFER HANDLING. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/192/192-003.pdf
• Supplemental Notes:
  • No 192, pp 26 - 32, 6 FIG, 7 REF Distribution, posting, or copying of this PDF is strictly prohibited without written permission of the Transportation Research Board of the National Academy of Sciences. Unless otherwise indicated, all materials in this PDF are copyrighted by the National Academy of Sciences. Copyright © National Academy of Sciences. All rights reserved.
• Authors:
  • Zvenjnieks, Andrejs
• Publication Date: 1958

Media Info

• Media Type: Digital/other
• Pagination: 8p
• Monograph Title: Rheological and Adhesion Characteristics of Asphalt
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 192
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Additives; Adhesion; Alternatives analysis; Binders; Bitumen; Bituminous materials; Cold mix paving mixtures; Highways; Hot mix asphalt; Improvements; Liquid asphalt; Physicochemical properties; Seal coats; Simulation; Tensile strength; Test procedures; Water
• Old TRIS Terms: Heat stability /additive/
• Subject Areas: Geotechnology; Highways; Materials;

Filing Info

• Accession Number: 00211335
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Sep 16 1994 12:00AM