00211682

Component

http://onlinepubs.trb.org...s/hrr/1971/350/350-002.pdf

EXPERIENCE IN ALBERTA WITH 150 TO 200 AND 200 TO 300 PENETRATION GRADE ASPHALT CEMENTS HAS SHOWN THAT THOSE ASPHALTS WITH LOW VISCOSITIES AT 140 F ARE PARTICULARLY SUSCEPTIBLE TO TRANSVERSE CRACKING AT LOW WINTER TEMPERATURES. THIS WAS VERIFIED IN A CAREFULLY CONDUCTED PAVING PROJECT WHEREIN THREE 200 TO 300 PENETRATION-GRADE ASPHALTS REPRESENTING LOW, INTERMEDIATE, AND HIGH VISCOSITIES AT 140 F WERE INCORPORATED IN THE SURFACING. THE LOW VISCOSITY SECTION CRACKED EARLIEST AND MOST EXTENSIVELY AND EXHIBITED THE MOST RAPID DENSIFICATION UNDER MODERATE TRAFFIC. DETAILS OF PHYSICAL CHANGES OF THE 3 ASPHALTS DURING A 34-MONTH SERVICE PERIOD ARE DISCUSSED.THE TENSILE SPLITTING TEST, CONDUCTED AT 0 F, DEMONSTRATES THE DIFFERENT STRAIN CAPABILITIES OF THE 3 ASPHALTS IN ORDER WITH THEIR RELATIVE VISCOSITIES AT 140 F. A GENERAL RELATIONSHIP AMONG PENETRATION AT 77 F, ABSOLUTE VISCOSITY AT 140 F, AND TENSILE STRAIN CAPABILITY AT 0 F IS PRESENTED. A SPECIFICATION INCORPORATING A MINIMUM PENETRATION OF 250 AT 77 F AND MINIMUM VISCOSITY OF 27K POISES AT 140 F WAS ADOPTED IN 1967. THIS HAS RESULTED IN A MORE UNIFORM PRODUCT FROM PROVINCIAL REFINERS, ELIMINATION OF TENDER MIXES, AND A REDUCTION IN EARLY TRANSVERSE CRACKING. /AUTHOR/

Sponsored by Committee on Characteristics of Bituminous Materials and presented at the 50th Annual Meeting. 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.

01410282

pp 15-25

1971

Highway Research Record

50th Annual Meeting of the Highway Research Board

0309019621

Digital/other

Figures (6) ; References (4) ; Tables (4)

Asphalt cement; Bituminous mixtures; Classification; Control; Densification; Laboratory tests; Low temperature; Low temperature tests; Performance; Soil penetration test; Specifications; Strain (Mechanics); Tensile properties; Tension tests; Transverse cracking; Viscosity

Field performance

Highways; Materials

TRIS, TRB

Oct 3 1971 12:00AM

• DEVELOPMENT OF SPECIFICATIONS FOR VISCOSITY-GRADED ASPHALTS
• GENERAL DISCUSSION OF VISCOSITY GRADING OF ASPHALTS
• PAVING ASPHALT PROPERTIES
• TEMPERATURE-SUSCEPTIBILITY CONTROL IN ASPHALT-CEMENT SPECIFICATIONS
• VISCOSITY GRADING FOR ASPHALT CEMENTS