Methodology of Mixing and Compaction Temperatures for Modified Asphalt Mixture

To study methodology of determining mixing and compaction temperature for modified asphalt mixture, the Superpave gyratory compaction tests are adopted to study the volumetric parameters of several modified asphalt mixtures. First, the rational compaction temperature is obtained based on the optimal compaction effect, and according to the relationship of viscosity with temperature and shear rate considerations, a shear rate of 60(1·s^–1) is proposed to measure the viscosity of modified asphalt. At this shear rate, the viscosity of modified asphalt at different temperatures can be obtained and the viscosity-temperature curve can be achieved. As a result, the mixing and compaction temperature for modified asphalt can be determined to deliver 0.17±0.02Pa·s and 0.28±0.03Pa·s for HMA mixing and compaction, respectively. The difference between temperatures obtained with the methodology and temperatures at which optimal compaction effect can be obtained is less than 5°C. The proposed temperatures are also kept in good accordance with paving practice.