Multiple Shear Step Approach to Determine Rotational Viscosity of Asphalt Emulsions and Its Correlation with Water Content of Original and Diluted Emulsions

Viscosity determination of thixotropic emulsions with good repeatability has always been a major challenge. Currently Saybolt Furol viscometer (SVF) is used to determine the viscosity of the emulsion, but the main drawback of the SFV is that, it cannot simulate the behavior of emulsion under different shear rate. Rotational viscometer (RV) can measure viscosity at different shear rates. Due to the thixotropic behavior of the emulsions, getting repeatable results by following the hot binder specification is a problematic task. In this study, a new multiple shear step approach is used to determine the viscosity of the asphalt emulsions using rotational viscometer. Three low viscous (SS-1, SS-1H and SS-1L) and two high viscous (CRS-2 and CRS-2P) emulsions were used in this study. Shear stress is gradually stepped up to different levels after certain time interval to determine the viscosity. In this manner, emulsion undergoes a known shear state and each reading is preceded by a certain repeatable shear history. It was observed that with the progression of time and simultaneous increase of shear rate, the viscosity results are much more stable and repeatable with less than 5% coefficient of variance. The Final specifications proposed are 220-730 cP and 5-90 cP at 50 rpm and 30°C for high and low viscous emulsions, respectively, which is based on 98% probability. Viscosity measured by this approach also showed strong correlation with water content (R² >0.94). The correlation between viscosity and water content is even stronger after dilution. With different dilution water content, viscosity of CRS-2 and CRS-2P exhibited R^2 values of 0.97 and 0.98, respectively.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK20 Characteristics of Asphalt Materials.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Islam, Readul Mohammad
  • Abadie, Christopher
  • Wasiuddin, Nazimuddin M
• Conference:
  • Transportation Research Board 94th Annual Meeting
  • Location: Washington DC, United States
  • Date: 2015-1-11 to 2015-1-15
• Date: 2015

Language

• English

Media Info

• Media Type: Digital/other
• Features: Figures; References; Tables;
• Pagination: 18p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Asphalt emulsions; Dilution; Moisture content; Shear stress; Viscosity; Water
• Subject Areas: Highways; Pavements; I30: Materials; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01555547
• Record Type: Publication
• Report/Paper Numbers: 15-5508
• Files: TRIS, TRB, ATRI
• Created Date: Feb 27 2015 10:03AM