00818869

Component

https://doi.org/10.3141/1766-02

http://scholar.google.com...Hesp&publication_year=2001

Results of low-temperature testing of Bow River asphalt binders and concrete mixtures, unmodified and modified with three commercially used polymers [diblock styrene-butadiene (SB), radial styrene-butadiene-styrene (SBS), and ethylene-vinyl acetate], are discussed. Thermal stress-restrained specimen tests, at a cooling rate of 10 deg C/h, were used to evaluate the performance of binders and mixtures. Binders were restrained as direct tension specimens with and without a sharp starter crack. Notching of the samples resulted in lower failure loads for all systems. But three of the four binders failed at warmer temperatures. The fourth binder, an exceptionally tough radial SBS-modified system, remained unaffected in this regard. Changes in failure temperatures ranged from 0 deg C (radial SBS) to +12 deg C (diblock SB). A comparison of binder results with those obtained for the mixture yields additional insights. It appears that there are differences between binder and mixture failure modes. The higher stress levels encountered in the mixture give rise to energy dissipating mechanisms that do not occur at the lower stress levels in the binder test. It is unlikely that a specification based on binder failure stress or strain will predict performance in polymer-modified systems. Three-point bend tests on notched asphalt binder or mastic beams may provide more realistic conditions for measuring materials properties. A compression test on the binder or mastic may be used to determine additional important parameters, such as Young's modulus and yield stress in compression, which along with the failure properties, will likely produce an improved fracture mechanics-based low-temperature failure criterion.

This paper appears in Transportation Research Record No. 1766, Asphalt Binders 2001.

English

p. 7-14

2001

Transportation Research Record

0309072271

Figures (3) ; References (42) ; Tables (3)

Asphalt mixtures; Bend tests; Bituminous binders; Compression tests; Dissipation; Low temperature tests; Performance; Polymers; Specifications; Stresses; Yield stress; Young's modulus

Energy; Highways; Materials; I31: Bituminous Binders and Materials

TRIS, TRB, ATRI

Oct 19 2001 12:00AM

• CORRELATIONS BETWEEN SUPERPAVE ASPHALT STIFFNESSES AND IN-SERVICE PAVEMENT PERFORMANCE
• EFFECT OF SILICONE RUBBER MOLDS ON LOW-TEMPERATURE BINDER GRADING PARAMETERS: BENDING BEAM RHEOMETER S(60) AND M-VALUE
• EVALUATION OF FATIGUE CRITERIA FOR ASPHALT BINDERS (WITH DISCUSSION AND CLOSURE)
• LOW-TEMPERATURE THERMAL CRACKING OF ASPHALT BINDERS AS RANKED BY STRENGTH AND FRACTURE PROPERTIES
• PROPOSED REFINEMENT OF SUPERPAVE HIGH-TEMPERATURE SPECIFICATION PARAMETER FOR PERFORMANCE-GRADED BINDERS (WITH DISCUSSION AND CLOSURE)
• SAMPLE PREPARATION FOR DIRECT TENSION TESTING: IMPROVING DETERMINATION OF ASPHALT BINDER FAILURE STRESS AND TEST REPEATABILITY
• TECHNIQUES FOR DETERMINING ERRORS IN ASPHALT BINDER RHEOLOGICAL DATA