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Title: Wetting Characteristics of Asphalt Binders at Mixing Temperatures
Accession Number: 01587432
Record Type: Component
Record URL: Availability: Transportation Research Board Business Office 500 Fifth Street, NW Find a library where document is available Abstract: Conventional hot-mix asphalt is produced by heating the aggregate and the asphalt binder to elevated temperatures, typically within the range of 140°C to 170°C. These temperatures ensure that the viscosity of the asphalt binder is low enough to coat the aggregate particles effectively. During the past decade, warm-mix asphalt (WMA) technology has been introduced to reduce the mixing temperatures by approximately 30°C compared with hot-mix asphalt. Workability at these reduced temperatures typically is achieved by the use of chemical additives in the asphalt binder or through the foaming of the asphalt binder with small percentages of water. In either case (i.e., WMA or hot-mix asphalt), one of the important physical properties that dictates the quality of coating and concomitant aggregate–binder bonding is the surface tension of the asphalt binder at mixing temperatures. In this study, the surface tension of different liquid asphalt binders was measured at typical mixing temperatures. The influence on the surface tension of binder type, temperature, and chemical additives used to produce WMA was evaluated. The results showed that the surface tension of asphalt binder depended on the rate of surface formation, temperature, and the source of the asphalt binder. The dynamic surface tension of the asphalt binders suggested that inherently they behaved similarly to surfactants. This observation lent indirect support to the theory that different molecular species tended to agglomerate within the binder, which rendered the binder microstructurally heterogeneous. Only one of the chemical additives resulted in a significant reduction in the surface tension of the binder compared with the control.
Monograph Title: Monograph Accession #: 01587029
Report/Paper Numbers: 15-3271
Language: English
Authors: Osmari, Patricia HennigArega, ZelalemBhasin, AmitPagination: pp 66-75
Publication Date: 2015
ISBN: 9780309369312
Media Type: Print
Features: Figures; Photos; References; Tables
TRT Terms: Subject Areas: Highways; Materials; I31: Bituminous Binders and Materials
Files: TRIS, TRB, ATRI
Created Date: Jan 27 2016 8:00AM
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