00820074

Component

https://doi.org/10.3141/1767-03

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

The use of crumb rubber modifiers (CRMs) to change asphalt binders was evaluated. Blending two base asphalt binders of performance grade 70-22 and 64-22 with three sizes of a CRM at two rubber contents resulted in varying grades of asphalt binders. In addition to these binders, two binders modified with reacted crumb rubber using a patented process were included in the study. Testing was conducted at different temperatures, testing frequencies, and strain conditions, using methods recently developed as part of the NCHRP 9-10 project (Superpave Protocols for Modified Asphalt Binders) for complex binders. The new testing includes the particulate additives test (PAT), which determines the volume of particulate material greater than 75 microns in asphalt, and the laboratory asphalt stability test (LAST), which measures the potential for separation and degradation of additives in asphalt. Strain sweeps, fatigue testing, and low-temperature failure and creep properties were also measured. The results indicate that the concentration and size of crumb rubber affect the viscosity of the resulting modified binders significantly and influence the volume of residue collected in PAT. It was observed that concentration and size of rubber are, however, not important compared with other factors in LAST and that keeping the binders agitated during storage can reduce separation significantly. On the basis of the rheological testing, it was found that both fatigue and strain dependencies are highly sensitive to asphalt binder type, rubber size, and rubber content. The failure properties of CRMs measured using the direct tension test indicate that failure stress and strain are reduced by increasing rubber size and concentration.

This paper appears in Transportation Research Record No. 1767, Asphalt Mixtures 2001.

English

p. 15-24

2001

Transportation Research Record

030907228X

Figures (6) ; References (10) ; Tables (5)

Asphalt tests; Bituminous binders; Cargo handling equipment; Crumb rubber; Failure; Laboratory tests; Particulates; Rheological properties; Strain (Mechanics); Stresses; Tension tests; Viscosity; Volume

Asphalt modifiers; Asphalt stability; Particle size (Materials); Rubber content

Highways; Materials; I31: Bituminous Binders and Materials

TRIS, TRB, ATRI

Nov 29 2001 12:00AM

• ASPHALT PERMEABILITY TESTING: SPECIMEN PREPARATION AND TESTING VARIABILITY
• CHARACTERISTICS OF COLD PROCESSED ASPHALT MILLINGS AND CEMENT-EMULSION MIX
• COMPARISON OF FOUR BRANDS OF SUPERPAVE GYRATORY COMPACTORS
• CONSTITUTIVE RELATIONS FOR ASPHALT CONCRETE UNDER HIGH RATES OF LOADING
• DESIGN, CONSTRUCTION, AND EARLY PERFORMANCE OF VIRGINIA'S HOT-MIX ASPHALT STABILIZER AND MODIFIER TEST SECTIONS
• DEVELOPMENT OF VOID PATHWAY TEST FOR INVESTIGATING VOID INTERCONNECTIVITY IN COMPACTED HOT-MIX ASPHALT CONCRETE
• EFFECT OF MIX GRADATION ON RUTTING POTENTIAL OF DENSE-GRADED ASPHALT MIXTURES
• EVALUATION OF LABORATORY-MEASURED CRACK GROWTH RATE FOR ASPHALT MIXTURES
• EVALUATION OF MICRODAMAGE, HEALING, AND HEAT DISSIPATION OF ASPHALT MIXTURES, USING A DYNAMIC MECHANICAL ANALYZER
• FATIGUE AND PERMANENT DEFORMATION MODELS FOR POLYMER-MODIFIED ASPHALT MIXTURES
• FIELD AGING EFFECTS ON FATIGUE OF ASPHALT CONCRETE AND ASPHALT-RUBBER CONCRETE
• GRADATION EFFECTS ON HOT-MIX ASPHALT PERFORMANCE
• HYDRAULIC CONDUCTIVITY (PERMEABILITY) OF LABORATORY-COMPACTED ASPHALT MIXTURES
• IMPACT OF GRADATION RELATIVE TO SUPERPAVE RESTRICTED ZONE ON HOT-MIX ASPHALT PERFORMANCE
• MECHANISTIC ANALYSIS OF ASPHALT PAVEMENTS, USING SUPERPAVE SHEAR TESTER AND HAMBURG WHEEL-TRACKING DEVICE
• MICROSTRUCTURE STUDY OF WESTRACK MIXES FROM X-RAY TOMOGRAPHY IMAGES
• QUANTITATIVE EVALUATION OF STRIPPING POTENTIAL IN HOT-MIX ASPHALT, USING ULTRASONIC ENERGY FOR MOISTURE-ACCELERATED CONDITIONING
• REPEATED TRIAXIAL TESTING DURING MIX DESIGN FOR PERFORMANCE CHARACTERIZATION
• SOME CHARACTERISTICS OF FOAMED BITUMEN MIXES
• VARIABILITY OF ASPHALT MIXTURE TESTS USING SUPERPAVE SHEAR TESTER REPEATED SHEAR AT CONSTANT HEIGHT TEST