文摘
This paper is attempted to establish a practical shear rate for optimum compaction temperature determination of modified asphalt binders in asphalt mixture design. Viscosity of seven modified asphalt binders was measured, optimum compaction temperatures of eight asphalt mixtures were obtained and the shear rate range during roller compaction was estimated. Results showed that in the shear rate measuring range of commonly used Brookfield viscometer (0.3–25 s−1), viscosity characteristics at 25 s−1 showed the best similarity to viscosity characteristics during roller compaction in the shear rate range of 10–130 s−1. Also, viscosity at the shear rate of 25 s−1 exhibited the best correlation with the minimum compaction energy index of asphalt mixtures at optimum compaction temperatures. Based on the results above, 25 s−1 was suggested as the practical shear rate, providing a direct viscosity measurement for optimum compaction temperature determination of modified asphalt binders in asphalt mixture design.KeywordsModified asphalt binderOptimum compaction temperatureShear rateViscosityCompaction energy index