DOMINANT EFFECT OF FINE AGGREGATE ON STRENGTH OF DENSE-GRADED ASPHALT MIXES
TESTS WERE CONDUCTED ON A SAND-ASPHALT MIX AND ON MIXES MADE WITH TWO DIFFERENT COARSE AGGREGATES AND THE SAME FINE AGGREGATE USED IN THE SAND ASPHALT, IN TWO TEST SECTIONS AT THE U.S. ARMY ENGINEERS WATERWAYS EXPERIMENT STATION. ALTHOUGH THE OPTIMUM ASPHALT CONTENT VARIED WITH THE DIFFERENT MIXES, ALL MIXES AT OPTIMUM SHOWED ESSENTIALLY EQUAL PERFORMANCE IN RESISTING THE STRESSES INDUCED BY TRAFFIC. THESE TESTS SHOWED THAT THE FINE AGGREGATE DOMINATES THE STRENGTH CHARACTERISTICS OF DENSE-GRADED MIXES. THE DATA ARE REVIEWED FROM THESE TESTS. OBSERVATION IS MADE THAT THE MARSHALL STABILITY NUMBER DID NOT RATE MIXES ON THEIR CAPABILITY TO WITHSTAND STRESSES INDUCED WITHIN THE MIX. AN ASPHALT MIX MUST BE CAPABLE OF SPREADING THE STRESSES SO THAT THE UNDERLYING LAYER IS NOT OVERSTRESSED. THESE TESTS DID NOT INCLUDE THE VARIABLES NECESSARY TO ESTABLISH THE EFFECT OF AGGREGATE TYPE ON THIS FEATURE. HOWEVER, THE TESTS DID SHOW, THAT ASPHALT OVER HIGH-QUALITY BASE COURSES NEED HAVE VERY FEW STRESS-DISTRIBUTING QUALITIES. STRESS-DISTRIBUTING CAPABILITIES RELATE TO THE MODULUS OF ELASTICITY AT STRAINS. IT IS OBSERVED THAT A MIX WITH COARSE AGGREGATE WOULD NORMALLY HAVE STRESS-DISTRIBUTING CAPABILITIES BETTER THAN THOSE OF A FINE MIX, AND A MIX WITH CRUSHED COARSE AGGREGATE WOULD HAVE CAPABILITIES BETTER THAN THOSE OF A MIX WITH UNCRUSHED AGGREGATES.
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Supplemental Notes:
- 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:
- Foster, Charles R
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Conference:
- 47th Annual Meeting of the Highway Research Board
- Location: Washington District of Columbia, United States
- Date: 1968-1-15 to 1968-1-19
- Publication Date: 1970
Media Info
- Media Type: Print
- Features: Figures; References;
- Pagination: pp 1-3
- Monograph Title: EFFECTS OF AGGREGATE SIZE, SHAPE, AND SURFACE TEXTURE ON PROPERTIES OF BITUMINOUS MIXTURES
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Serial:
- Highway Research Board Special Report
- Issue Number: 109
- Publisher: Highway Research Board
Subject/Index Terms
- TRT Terms: Asphalt; Asphalt content; Asphaltic sand; Bituminous mixtures; Bituminous pavements; Coarse aggregates; Crushed aggregates; Deformation curve; Fine aggregates; Marshall test; Modulus of elasticity; Pavement performance; Physical properties; Strength of materials
- Old TRIS Terms: Marshall stability marshall stability & flow test flow
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 00211482
- Record Type: Publication
- Files: TRIS, TRB, ATRI
- Created Date: Jul 21 1970 12:00AM