The Stress Relaxation Of Modified Bitumens

Pavel Coufalík 1 , Ondřej Dašek 2 , Jiří Kachtík 3 , Jan Kudrna 4  and Svatopluk Stoklásek 5
  • 1 Brno University of Technology, Faculty of Civil Engineering, Czech Republic
  • 2 Brno University of Technology, Faculty of Civil Engineering, Czech Republic
  • 3 Brno University of Technology, Faculty of Civil Engineering, Czech Republic
  • 4 Brno University of Technology, Faculty of Civil Engineering, Czech Republic
  • 5 Independent consultant, Czech Republic


The Asphalt pavements in Central and Eastern Europe have to be resistant to high and very low temperatures and climatic changes. Especially emphasize influence of low temperatures seems to be critical parameter. That is why the modified bitumens with low temperature susceptibility and with high resistance to low temperature cracking are searched for. Dynamic Shear Rheometer (DSR) can be used as a quick method that can evaluate the modification system of bituminous binders. The advantage of DSR testing is also related to possibility of comparison of unaged and aged bitumen.

The relaxations of shear stress of several asphalt rubber binders (containing 11 %, 13 %, 15 % and 17 % of crumb rubber) and paving bitumen were determined in DSR at the temperature of 0 °C and −10 °C. Relaxation tests were performed in the controlled strain regime. Total shear strain (rotation of upper geometry) was set to 1 % of the sample thickness and stress was applied for 60 s. Relaxation time was set to a period of 15 minutes. The shear stress relaxation behaviour of unaged bitumens and bitumens aged after 75 minutes and 225 minutes in Rolling Thin Film Oven Test (RTFOT) is presented and discussed.

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  • Bahia, H. U., Anderson, D. A. (1995). “The Pressure Aging Vessel (PAV): a Test to Simulate Rheological Changes Due to Field Aging,” Physical Properties of Asphalt Cement Binders, pp. 67-88.

  • Bahia, H. U., Hislop, W. P., Zhai, H., Rangel, A. (1998). “Classification of Asphalt Binders into Simple and Complex Binders,” Journal of the Association of Asphalt Paving Technologists, pp. 67.

  • Brown, S.F., Scholz, T.V. (2000). “Development of Laboratory Protocols for the Ageing of Asphalt Mixtures,” 2nd Eurasphalt & Eurobitume Congress Barcelona.

  • Carlson, D.D., Zhu, H. (1999). “Asphalt-Rubber an Anchor to Crumb Rubber Markets,” Third Joint UNCAD/IRSG Workshop on Rubber and the Environment, International Rubber Forum, Veracruz.

  • European Standard (2007). “EN 12607-1 Bitumen and bituminous binders – Determination of the resistance to hardening under the influence of heat and air – Part 1: RTFOT method.”

  • European Standard (2007). “EN 1426 Bitumen and bituminous binders – Determination of needle penetration.”

  • European Standard (2007). “EN 1427 Bitumen and bituminous binders – Determination of the softening point – Ring and Ball method.”

  • European Standard (2010). “EN 13302 Bitumen and bituminous binders – Determination of dynamic viscosity of bituminous binder using a rotating spindle apparatus.”

  • European Standard (2010). “EN 13398 Bitumen and bituminous binders – Determination of the elastic recovery of modified bitumen.”

  • European Standard (2010). “EN 13880-3 Hot applied joints sealants – Part 3: Test method for the determination of penetration and recovery (resilience).”

  • European Standard (2010). “EN 14770 Bitumen and bituminous binders – Determination of complex shear modulus and phase angle – Dynamic Shear Rheometer (DSR).”

  • European Standard (2012). “EN 12697-46 Bituminous mixtures – Test methods for hot mix asphalt – Part 46: Low temperature cracking and properties by uniaxial tension tests.”

  • Gauer, P. (1996). “Relaxationsverhalten von Asphalt bei tiefen Temperaturen,” Eurasphalt & Eurobitume Congress, Strasbourg.

  • Heitzman, M. A. (1992). “State of the Practice – Design and Construction of Asphalt Paving Materials with Crumb Rubber Modifier,” FHWA-SA-92-022, Federal Highway Administration.

  • Isacsson, U., Zeng, H. (1998). “Low-temperature Cracking of Polymer-modified Asphalt, Materials and Structures,” p. 58-63.

  • Kudrna, J., Dasek, O. (2012). “European Approach to Asphalt Rubber,” Asphalt Rubber Conference 2012, Munich.

  • McGennis, R.B., Shuler, S., Bahia, H.U. (1994). “Background of Superpave Asphalt Binder Test Methods,” FHWA-SA-94-069, National Asphalt Training Center, Demonstration Project 101, Washington, DC.

  • Mezger, T.G. (2011). “The Rheology Handbook. For users of rotational and oscillatory rheometers. 3rd revised edition,” ISBN 978-3-86630-864-0, Germany.

  • Mturi, G.A.J., O’Connell, J. (2012). “Monitoring Ageing of Bituminous Binders,” 31st Annual Southern African Transport Conference, Pretoria.

  • Muller, J., Jenkins, K.J. (2011). “The Use of an Extended Rolling Thin Film Ageing Method as an Alternative to the Pressurised Ageing Vessel Method in the Determination of Bitumen Durability, 10th Conference on Asphalt Pavements for Suothern Africa, KwaZulu-Natal.

  • Sebaaly, P.E., Lake, A., Epps, J. (2001). “Evaluation of Low Temperature properties of HMA Mixtures,” ASCE Journal of Transportation Engineering.

  • Spiegl, M. (2009). “Entwicklungen von gebrauchsverhaltensorientierten Bitumenspezifikationen,” Bauseminar Gestrata.

  • Sui, Ch., Farrar, M.J, Harnsberger, P.M., Tuminello, W.H., Turner, T.F. (2011). “New Low-Temperature Performance-Grading Method,” Transportation Research Record 2207, p. 43-48.

  • Technical Recommendation (2010). “TP 151 High stiffness mixtures. Ministry of Transport.”

  • Zalman, L. (2011). “Dynamic viscosity of bituminous binders and additives,” Conference Asphalt Pavements, p. 4. Czech Republic.


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