Turkish Journal of Engineering and Environmental Sciences

Calculation of Shear Rate on Asphalt Binder in The Superpave Gyratory Compactor
Yetkin YILDIRIM
The University of Texas at Austin ECJ 6.100, Austin, TX 78712
e-mail: yetkin@mail.utexas.edu
Thomas W. KENNEDY
The University of Texas at Austin ECJ 6.100, Austin, TX 78712

Abstract: Most modified asphalt binders show pseudoplastic characteristics and their viscosity values depend on shear rate. The calculation of compaction temperatures for Superpave gyratory compactors (SGCs) depends on viscosity measurements. Therefore, for modified asphalt binders, it is not possible to calculate the compaction temperatures without including the effect of shear rate in the SGC during viscosity measurements. Prior to this study, no experimental study on the calculation of shear rate in the SGC had been performed. The calculation of the shear rate in the SGC will make it possible to include the effect of shear rate during viscosity measurements. In this study, the shear rate inside the SGC was approximately 490 1/s. Standard error (SE) values of the estimates of shear rate values were calculated by the propagation of error method. The average value for SE was approximately 53 1/s.

Key Words: Asphalt, Superpave, Superpave gyratory compactor, Viscosity, Mixing, Compaction, Shear rate.

Turkish J. Eng. Env. Sci., 27, (2003), 375-382.
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Other articles published in the same issue: Turkish J. Eng. Env. Sci.,vol.27,iss.6.