THE EFFECT OF VISCOSITY OF ASPHALT ON PROPERTIES OF BITUMINOUS WEARING SURFACE MIXTURES
TWENTY-FOUR, 600 FOOT TEST STRIPS OF A 1-INCH BITUMINOUS CONCRETE WEARING SURFACE WERE LAID IN WHICH MIXING VISCOSITIES OF THE APHALTIC BINDER WERE VARIED FROM APPROXIMATELY 900 TO 40 SAYBOLT FUROL SECONDS. TWELVE STRIPS HAD CRUSHED GRANITE AS THE COARSE AGGREGATE AND TWELVE OTHER STRIPS HAD A SILICIOUS GRAVEL AS COARSE AGGREGATE. FOR EACH SET OF TWELVE STRIPS, THREE REPLICATIONS OF MIX TEMPERATURE WERE USED TO GIVE THE DESIRED RANGE OF MIX VISCOSITIES. THE 85 TO 100 PENETRATION ASPHALT SOURCE REMAINED CONSTANT FOR ALL STRIPS. MODIFIED ROSS COUNTS WERE MADE ON THE MIXES, LAYING CHARACTERISTICS WERE OBSERVED, AND DENSITY SAMPLES WERE CUT FROM THE FINISHED PAVEMENTS. WHILE THE PAVEMENT WAS COMPACTED, TEMPERATURES WERE MEASURED AT FOUR DIFFERENT ELEVATIONS IN THE PAVEMENT LAYER. CORES WERE CUT FROM THE PAVEMENTS AT 4, 9, AND 21 MONTHS AND PENETRATIONS AND VISCOSITIES DETERMINED ON THE RECOVERED ASPHALT. THERE APPEARED TO BE NO MARKED DIFFERENCES IN THE MIXING AND LAYING CHARACTERISTICS OF THE MIXES MADE AT THE WIDE RANGE IN VISCOSITY. THE AVERAGE COMPACTION OBTAINED WAS THE LOWEST ON THE 225 F. MIXES AND HIGHEST ON THE 287 F. MIXES. THE MIXES MADE AT LOW MIX TEMPERATURES SHOWED A LARGER RETAINED PENETRATION IMMEDIATELY AFTER MIXING THAN THOSE MADE AT THE HIGHER MIX TEMPERATURES. MIXES MADE AT 225 F. HARDENED FASTER IN THE PAVEMENT THAN THOSE MADE AT OTHER TEMPERATURES AND THOSE MADE AT 287 F. HARDENED THE LEAST. THIS IS PROBABLY CAUSED BY LARGER PERCENT VOIDS IN MIXES MADE AT 225 F. AFTER 21 MONTHS THE ADVANTAGES OF MIXING AT LOW TEMPERATURES HAD DISAPPEARED AND PENETRATION VALUES FOR STRIPS MIXED AT 225 F. WERE LOWER THAN STRIPS MIXED AT HIGHER TEMPERATURES. /AUTHOR/
-
Supplemental Notes:
- Vol 35, pp 164-206, 13 FIG, 20 TAB, 17 REF, 1 APP
-
Authors:
- BRIGHT, R
- Steed, B
- Steele, J
- Justice, A
- Conference:
- Publication Date: 1966-2
Subject/Index Terms
- TRT Terms: Asphalt; Asphalt concrete; Binders; Bituminous materials; Bituminous pavements; Coarse aggregates; Compaction; Concrete hardening; Core samples; Hardness; Low temperature; Mix design; Pendulum tests; Surface treating; Temperature; Temperature measurement; Viscosity; Wearing course (Pavements)
- Old TRIS Terms: Bituminous surfacing; Cores
- Subject Areas: Highways; Materials;
Filing Info
- Accession Number: 00210789
- Record Type: Publication
- Files: TRIS
- Created Date: May 6 1994 12:00AM