Influence of Cooling Medium on Low-Temperature Strength of Asphalt Binders

Asphalt binder strength significantly affects the durability of asphalt pavements at low temperature. Currently, binder strength is obtained from uniaxial tension tests performed with the Direct Tension Tester (DTT). An alternative bending strength test performed with a modified Bending Beam Rheometer (TE-BBR Pro) that can break small binder beams under load control is presented in this paper. Two factors that can significantly affect results are investigated: the cooling medium in which binder specimens are conditioned and tested, and the specimen size. In the first part, three different cooling media, ethanol, potassium acetate and air, are investigated using the TE-BBR Pro. Similar strength values are obtained in air and potassium acetate and significantly lower values are obtained in ethanol. Preliminary investigation in which both ethanol and potassium acetate solutions were tinted with sodium fluorescein indicated that the fluorescing marker diffused in asphalt during conditioning and measurement when ethanol was used, and did not diffuse when potassium acetate solution was used as a BBR cooling medium. BBR strength in air was then compared with strength values obtained from Direct Tension Tester (DTT) in potassium acetate. Based on histogram testing and size effect theory for quasibrittle materials, it is demonstrated that BBR and DTT strength measurements are similar. Preliminary results on the effect of cooling medium on fracture properties of asphalt binder obtained on notched specimens are also presented.

• Supplemental Notes:
  • This paper was sponsored by TRB committee AFK20 Characteristics of Asphalt Materials. Alternate title: Influence of Cooling Medium on Low Temperature Strength of Asphalt Binders.
• Corporate Authors:

  Transportation Research Board

  500 Fifth Street, NW
  Washington, DC  United States  20001
• Authors:
  • Falchetto, Augusto Cannone
  • Marasteanu, Mihai
  • 0000-0001-8331-4504
  • Balamurugan, Sreelatha
  • Negulescu, Ioan
• 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: 16p
• Monograph Title: TRB 94th Annual Meeting Compendium of Papers

Subject/Index Terms

• TRT Terms: Bituminous binders; Cooling; Ethanol; Low temperature; Rheometers; Strength of materials
• Uncontrolled Terms: Indirect tension tester; Potassium acetate
• Subject Areas: Highways; Materials; Pavements; I31: Bituminous Binders and Materials;

Filing Info

• Accession Number: 01550199
• Record Type: Publication
• Report/Paper Numbers: 15-3332
• Files: TRIS, TRB, ATRI
• Created Date: Jan 17 2015 5:28PM