EFFECT OF CHLORINATION ON OXIDIZABILITY OF ROAD ASPHALTS

OXIDATION OF THE ASPHALTIC BINDER IN BITUMINOUS PAVEMENTS IS A FREQUENT CAUSE OF PAVEMENT FAILURE. THE HARDENING, OR LOSS OF PENETRATION OF THE ASPHALT, WHICH RESULTS FROM OXIDATION OCCURS GRADUALLY OVER THE LIFE SPAN OF THE PAVE- MENT. IT CAN ALSO TAKE PLACE FAIRLY RAPIDLY AT THE ELEVATED TEMPERATURES USED DURING MIXING OPERATIONS. THIS PAPER DESCRIBES SOME OF THE PHYSICAL AND CHEMICAL EFFECTS OF DIRECT CHLORINATION ON ROAD BUILDING ASPHALTS. IN THE LABORATORY, EXPERIMENTAL DATA HAVE BEEN OBTAINED WHICH INDICATE THAT THE OXIDIZABILITY OF THE ASPHALT MAY BE MATERIALLY REDUCED BY TREATMENT WITH CHLORINE. THE ACTION OF CHLORINE ON ASPHALT IS IN MANY RESPECTS SIMILAR TO THAT OF OXYGEN. HOWEVER, IT IS TO BE EXPECTED THAT THE LOSS OF PENETRATION RESULTING FROM TREATMENT WITH LIMITED AMOUNTS OF CHLORINE WILL BE LESS THAN THAT RESULTING FROM A CHEMICALLY COMPARABLE AMOUNT OF OXIDATION. BECAUSE OF THE FACT THAT CHLORINE IS IN GENERAL MORE ACTIVE CHEMICALLY THAN OXYGEN, IT IS ALSO TO BE EXPECTED THAT THE COMPOUNDS FORMED IN ASPHALT BY TREATMENT WITH CHLORINE WILL BE RELATIVELY STABLE AND THAT THE RESISTANCE OF THE ASPHALT TO OXIDATION WILL BE INCREASED. IN THE LABORATORY, EIGHT SAMPLES OF ASPHALT CEMENT WERE SUBJECTED TO DIRECT CHLORINATION. TESTS PERFORMED ON THE SAMPLES BEFORE AND AFTER CHLORINATION, INCLUDING THE ANDERSON-STROSS-ELLINGS TESTS, INDICATE THAT ALTHOUGH THE PENETRATION OF THE ASPHALT CEMENTS TESTED IS DECREASED BY CHLORINATION, THE RESISTANCE TO HARDENING IS GREATLY INCREASED. /AUTHOR/

• Record URL:
  http://onlinepubs.trb.org/Onlinepubs/hrbbulletin/118/118-001.pdf
• Supplemental Notes:
  • No 118, Pp1-12, 1 FIG, 3 TAB, 15 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:
  • Sanderson, Frederick C
• Publication Date: 1956

Media Info

• Monograph Title: Effects of chlorination and microorganisms and constituents of asphalts
• Serial:
  • Highway Research Board Bulletin
  • Issue Number: 118
  • Publisher: Highway Research Board

Subject/Index Terms

• TRT Terms: Asphalt; Asphalt cement; Asphalt hardening; Before and after studies; Binders; Bituminous pavements; Chlorination; Oxidation; Pendulum tests
• Old TRIS Terms: Resistance
• Subject Areas: Highways; Materials;

Filing Info

• Accession Number: 00211340
• Record Type: Publication
• Files: TRIS, TRB
• Created Date: Dec 9 1994 12:00AM