SEVEN YEARS' PERFORMANCE OF A BITUMINOUS SURFACE TREATMENT TEST ROAD

A PERFORMANCE SURVEY OF A BITUMINOUS SURFACE TREATMENT TEST ROAD SEVEN YEARS OLD HAS RECENTLY BEEN MADE. THE TEST ROAD IS 10 MILES LONG, IS LOCATED IN NORTHERN INDIANA ON THE STATE HIGHWAY SYSTEM, AND CONSISTS OF 51 EXPERIMNTAL SECTIONS CONSTRUCTED WITH THREE TYPES OF BITUMINOUS MATERIALS AND AGGREGATE FROM TWO SOURCES. OTHER VARIABLES INCLUDED THE AMOUNT AND METHOD OF APPLICATION OF BITUMINOUS MATERIAL AND SIZE OF AGGREGATE. FISUAL RATINGS WERE MADE OF EACH SECTION BY TWO DIFFERENT METHODS: OVER-ALL RATINGS AND ESTIMATING THE PERCENTAGE AREA OF FAILURE. SURFACE TEXTURE MEASUREMENTS WERE MADE OF EACH SECTION IN AT LEAST TWO LOCATIONS BY MEANS OF A TEXTURE PROFILOMETER. FOUR SPECIMENS WERE REMOVED FROM THE ROAD AND WERE TESTED FOR STABILITY ON A MINITRACK MACHINE. TWO SURFACE SAMPLES WERE TAKEN AT REPRESENTATIVE AREAS IN EACH SECTION, ONE IN THE WHEEL TRACK AREA AND ONE BETWEEN WHEEL TRACKS. THESE SAMPLES WERE ANALYZED IN THE LABORATORY FOR BITUMEN CONTENT AND GRADING OF THE BITUMEN-FREE AGGREGATES. SURFACE-AREA VALUES WERE CALCULATED FROM THE GRADING RESULTS. THE RESULTS OF THE SURVEY SHOW THAT THE AVERAGE SURFACE AREA OF THE AGGREGATES HAS INCREASED ABOUT 500 OR 600 PERCENT OVER THAT AT THE TIME OF CONSTRUCTION (BEFORE MIXING AND ROLLING). SINCE 1939, DUE TO TRAFFIC AND WEATHERING, THE AVERAGE SURFACE AREA OF THE AGGREGATES HAS INCREASED ABOUT 200 PERCENT OF THE LATE 1939 VALUE. LIKEWISE, THE BITUMEN CONTENT OF SOME SECTIONS HAS INCREASED AS MUCH AS 100 PERCENT OVER THAT AT THE TIME OF CONSTRUCTION. THE AVERAGE VALUES SHOW THAT THE PERCENTAGE OF BITUMEN BY WEIGHT IS NOW ABOUT 50 PERCENT GREATER THAN IT WAS IN LATE 1939. AGAIN REFERRING TO AVERAGE VALUES, THE RESULTS SHOW THAT THE TAR SECTIONS INCREASED MOST IN BITUMEN CONTENT, THE ASPHALT EMULSION SECTIONS LAST, WITH THE ASPHALT CUT- BACK SECTIONS OCCUPYING AN INTERMEDIATE POSTITION; ON THE CONTRARY, THE AVERAGE SURFACE AREA RESULTS SHOW THE SECTIONS CONSTRUCTED WITH TAR TO HAVE INCREASED LEAST IN SURFACE-AREA OF THE AGGREGATE, THE AES-3 SECTIONS TO HAVE INCREASED MOST, WITH THE RC-3 VALUES AGAIN OCCUPYING AN INTERMEDIATE POSITION. THE TEST ROAD HAS SHOWN RATHER REMARKABLE PERFORMANCE AND LONGEVITY WHICH IS ATTRIBUTED CHIEFLY TO GENERALLY GOOD SOIL CONDITIONS, HIGH-LEVEL PROFILE, ADEQUATE BASE, LOW TRAFFIC DENSITY, AND ESPECIALLY, CAREFUL WORKMANSHIP DURING CONSTRUCTION. HOWEVER, EVEN WITH VERY CAREFUL CONSTRUCTION BY EXPERIENCED PERSONNEL, THE BITUMEN CONTENT, SURFACE-AREA OF THE AGGREGATE, AND PERFORMANCE OF ROAD-MIX BITUMINOUS SURFACE TREATMENT MAY BE EXPECTED TO VARY MARKEDLY. SUCCESSFUL PERFORMANCE DEPENDS MORE UPON UNIFORMITY OF MIXTURE AND GRADING OF AGGREGATE THAN UPON TYPE OF BITUMINOUS MATERIAL OR SOURCE OF AGGREGATE. /AUTHOR/

  • Supplemental Notes:
    • Vol 26, pp 272-285, 7 FIG, 10 TAB
  • Authors:
    • Goetz, W H
  • Publication Date: 1947

Media Info

  • Monograph Title: Proceedings of the Twenty-Sixth Annual Meeting of the Highway Research Board Held at Washington, D.C. December 5-8, 1946
  • Serial:

Subject/Index Terms

Filing Info

  • Accession Number: 00207315
  • Record Type: Publication
  • Files: TRIS, TRB
  • Created Date: May 29 1972 12:00AM