EFFECTS OF AGGREGATE FACTORS ON PAVEMENT FRICTION
EVEN THOUGH THE SKIDDING RESISTANCE OF PAVEMENTS HAS BEEN STUDIED FOR MANY YEARS, MANY QUESTIONS CONCERNING THE TRUE NATURE OF THE INTERACTION OF RUBBER AND PAVEMENT SURFACE REMAIN UNANSWERED. FOR THIS REASON CERTAIN TESTS WERE CARRIED OUT BY THE AUTHORS ON LABORATORY SPECIMENS WHICH, WHILE NOT GREATLY RESEMBLING PAVEMENTS, WERE PLANNED TO ELIMINATE MANY VARIABLES AND THUS AID IN EVALUATING THOSE WHICH REMAIN. ACTUAL SURFACE RESISTANCE MEASUREMENTS WERE MADE IN A LABORATORY MACHINE. TESTS WERE CONDUCTED ON SURFACES PLANNED IN A MANNER TO MAINTAIN A CONSTANT AREA OF AGGREGATE WHILE VARYING THE NUMBER AND SHAPE OF EDGES. ALTHOUGH NOT EXHAUSTIVE, SEVERAL RADICALLY DIFFERENT SHAPES WERE INCLUDED. FOR SOME OF THE SPECIMENS, THE AGGREGATE SHAPES USED PERMITTED CONTROLLED VARIATION IN THE SHARPNESS OF AGGREGATE EDGES. A SERIES OF TESTS WAS PERFORMED IN WHICH THE NORMAL LOAD WAS MADE THE MAJOR VARIABLE. FOR ANY ONE SPECIMEN THE AGGREGATE AREA WAS CONSTANT. ADDITIONAL SPECIMENS WERE TESTED IN WHICH THE AREA OF AGGREGATE IN CONTACT WITH THE TEST SHOE WAS VARIED WHILE THE EDGES AND TEST LOAD WERE HELD CONSTANT. THE ROCK CORES USED WERE A SOFT LIMESTONE AND A DURABLE SANDSTONE. THE POLISHING RATES OF SEVERAL DIFFERENT ROCKS WERE INVESTIGATED. SKID- RESISTANCE TESTS WERE MADE ON CORES AFTER SUCCESSIVE POLISH CYCLES USING CRUSHED QUARTZ AS A POLISHING MEDIUM. THE SAME CORES ALSO WERE TESTED AFTER POLISHING WITH ABRASIVE DUST MADE FROM THE CORE MATERIAL. TESTS ON ROCK CORES, AS POLISHED BY DIFFERENT SIZES OF ABRASIVES, INDICATED THAT FOR A GIVEN RUBBER AN OPTIMUM SIZE OF ROUGHNESS EXISTED. GRADED SILICA SAND WAS USED TO MAKE SURFACES OF DIFFERENT DEGREES OF ROUGHNESS IN ORDER TO FIND THIS OPTIMUM SIZE OF ROUGHNESS OR TEXTURE FOR THE RUBBER TEST SHOES USED. /AUTHOR/
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Supplemental Notes:
- No 302, pp 1-17, 10 FIG, 6 TAB, 13 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.
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Authors:
- Stephens, Jack E
- Goetz, William H
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Conference:
- 40th Annual Meeting of the Highway Research Board
- Location: Washington DC, United States
- Date: 1961-1-9 to 1961-1-13
- Publication Date: 1961
Media Info
- Media Type: Digital/other
- Monograph Title: Skid testing 1961
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Serial:
- Highway Research Board Bulletin
- Issue Number: 302
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Aggregates; Aggregates by shape and surface texture; Laboratory tests; Limestone aggregates; Pavements; Polished aggregates; Sandstones; Skid resistance; Skidding; Texture; Tires
- Uncontrolled Terms: Aggregate shape
- Old TRIS Terms: Aggregate characteristics
- Subject Areas: Geotechnology; Highways; Pavements; Safety and Human Factors; Vehicles and Equipment;
Filing Info
- Accession Number: 00206916
- Record Type: Publication
- Files: TRIS, TRB
- Created Date: Sep 12 1994 12:00AM