00669042

Component

http://onlinepubs.trb.org...trr/1994/1436/1436-010.pdf

https://scholar.google.co...Hesp&publication_year=1994

The low-temperature fracture toughness was determined for rubber-modified asphalt binders. Crumb rubber tire, both plain and surface modified, and devulcanized rubber tire were investigated for their effectiveness in improving low-temperature asphalt binder performance in a notched, three-point bending beam fracture test. The increases in low-temperature fracture toughness for unmodified crumb rubber-asphalt mixtures were highest for fine ground rubber. At loading levels of 4 to 10 wt percent on the binder, the fracture toughness for 10- and 20-mesh ground rubber tire-modified samples was not significantly different from that of the unmodified binders. Reasonable increases in toughness were found for binder modification with 4 to 10 wt percent 30-, 40-, and 80-mesh rubber samples. An in situ sulfur grafting reaction of low-molecular-weight polybutadiene onto the crumb rubber dramatically increases the fracture performance for both coarse and fine crumb rubber-modified binders. A 9- and 15-fold increase in added fracture toughness was observed for binders containing 7 wt percent of 10- and 20-mesh cryogenically ground rubber tire. Whether these improvements will translate into a reduction in transverse thermal stress cracking remains to be investigated in further tests on binder-aggregate mixes and in field trials. The fracture toughness for a devulcanized rubber-modified asphalt was also investigated. The homogeneous sample contained as much as 10 wt percent devulcanized rubber tire but performed only marginally better than an 85-100 penetration control sample. Reaction of the devulcanized rubber-modified binder with sulfur increases its fracture toughness by 18 percent.

This paper appears in Transportation Research Record No. 1436, Asphalt Concrete Mix Materials. 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

01401249

English

p. 83-87

1994-10

Transportation Research Record

030905513X

Figures (1) ; References (31) ; Tables (6)

Asphalt rubber; Binders; Crumb rubber; Fracture properties; Fracture tests; Low temperature; Performance evaluations; Sulfur

Highways; Materials; I31: Bituminous Binders and Materials

TRIS, TRB

Nov 23 1994 12:00AM

• DESIGNING ASPHALT PAVEMENTS FOR EXTREME CLIMATES
• EFFECT OF ANTISTRIP ADDITIVES ON THE PROPERTIES OF POLYMER-MODIFIED ASPHALT BINDERS AND MIXTURES
• EFFECT OF COMPOSITION ON ASPHALT RECYCLING AGENT PERFORMANCE
• EMPIRICAL EVALUATION OF OLIVE HUSK IN ASPHALT CEMENT BINDER AND BITUMINOUS CONCRETE
• EVALUATION AND CHARACTERIZATION OF A RUBBER-MODIFIED HOT MIX ASPHALT PAVEMENT
• EVALUATION AND FIELD VALIDATION OF PROPOSED STRATEGIC HIGHWAY RESEARCH PROGRAM BINDER SPECIFICATION FOR THERMAL CRACKING
• EVALUATION OF NATURAL SANDS USED IN ASPHALT MIXTURES
• INVESTIGATION OF LABORATORY AGING PROCESSES OF ASPHALT BINDERS USED IN FLORIDA
• INVESTIGATION OF RUTTING OF ASPHALT SURFACE LAYERS: INFLUENCE OF BINDER AND AXLE LOADING CONFIGURATION
• LOW-TEMPERATURE FRACTURE TOUGHNESS OF POLYETHYLENE-MODIFIED ASPHALT BINDERS
• RHEOLOGICAL AND RHEO-OPTICAL CHARACTERIZATION OF ASPHALT CEMENT AND EVALUATION OF RELAXATION PROPERTIES
• SOFTENING OF ASPHALTS IN DILUTE SOLUTIONS AT PRIMARY DISTILLATION CONDITIONS
• STUDY OF THE FATIGUE OF ASPHALT MIXES USING THE CIRCULAR TEST TRACK OF THE LABORATOIRE CENTRAL DES PONTS ET CHAUSSEES IN NANTES, FRANCE
• USE OF RUBBER IN ASPHALT PAVEMENTS: KANSAS EXPERIENCE