00803833

Component

https://doi.org/10.3141/1728-08

http://scholar.google.com...Hesp&publication_year=2000

Results from the low-temperature performance evaluation of a new class of reactive polymer modifiers designed to improve binder-aggregate adhesion in asphalt concrete are discussed. A living free radical polymerization process was used to prepare polyisoprene (PI) with short blocks of reactive silane-functional monomer at one end of the polymer chain. Performance was evaluated with the thermal stress restrained specimen test at a cooling rate of -10 deg C/h. The results obtained were compared with those for unmodified and styrene-butadiene (SB)-modified mixes. When added at 3 and 6% by weight of the binder, SB reduced the fracture temperature of the asphalt concrete by 6 deg C and 9 deg C, respectively. Similar results were obtained with the reactive polymers. However, although all the SB-modified samples failed in a catastrophic mode, none of the samples containing the silane-functional PI did. It is hypothesized that these polymers toughened the asphalt to an extent that cracks were only able to grow in a stable mode as opposed to an unstable mode or that localized yielding occurred. The method for obtaining the desired toughening effect is flexible; lower-cost monomers, such as butadiene, and more common polymerization methods, such as emulsion or anionic polymerization techniques, could be used equally well to produce polymers with similar or better performance characteristics. An added benefit is that the tested polymers were able to improve the stripping resistance of the mix significantly.

This paper appears in Transportation Research Record No. 1728, Asphalt Binders 2000.

English

p. 68-74

2000

Transportation Research Record

0309067316

Figures (4) ; References (23) ; Tables (3)

Adhesion; Asphalt concrete; Bituminous binders; Low temperature; Pavement cracking; Performance evaluations; Polymerization; Polymers; Silane; Stripping (Pavements); Styrene butadiene rubber

Polyisoprene

Highways; Materials; I31: Bituminous Binders and Materials

TRIS, TRB, ATRI

Dec 7 2001 12:00AM

• CRACK PINNING IN ASPHALT MASTIC AND CONCRETE: REGULAR FATIGUE STUDIES
• DAMPING OF SHEAR VIBRATIONS IN ASPHALT MODIFIED WITH STYRENE-BUTADIENE-STYRENE POLYMER
• DISTRIBUTION OF STRAINS WITHIN HOT-MIX ASPHALT BINDERS: APPLYING IMAGING AND FINITE-ELEMENT TECHNIQUES
• EFFECT OF FILM THICKNESS ON RHEOLOGICAL BEHAVIOR OF ASPHALT BINDERS
• ESTABLISHING LINEAR VISCOELASTIC CONDITIONS FOR ASPHALT BINDERS
• EVALUATION OF MOISTURE SUSCEPTIBILITY OF ASPHALT MIXTURES: CONVENTIONAL AND NEW METHODS
• FACTORS AFFECTING VARIABILITY IN STRATEGIC HIGHWAY RESEARCH PROGRAM BINDER TESTS
• FIELD VALIDATION OF NEW SUPERPAVE LOW-TEMPERATURE BINDER SPECIFICATION PROCEDURE: PERFORMANCE DATA FROM PENNSYLVANIA TEST SECTIONS
• LOW-TEMPERATURE FRACTURE TESTING OF ASPHALT BINDERS: REGULAR AND MODIFIED SYSTEMS
• NEW CLASS OF REACTIVE POLYMER MODIFIERS FOR ASPHALT: MITIGATION OF MOISTURE DAMAGE