Using Linear Viscoelastic Modeling to Evaluate the Low Temperature Properties of Asphalt Mixtures Prepared With Aggregates of Different Sizes

This paper evaluates the low temperature properties of asphalt mixtures prepared with aggregates of different sizes using a linear viscoelastic analysis method. Three nominal maximum aggregate size (NMAS) asphalt mixtures (i.e., 12.5 mm, 9.5 mm, and 4.7 5mm) were produced and trimmed into small asphalt mixture beams to be tested using a bending beam rheometer (BBR). Creep compliance data were obtained from the BBR at three different temperatures (-18°C, -24°C, and -30°C). Linear viscoelastic modeling associated with Laplace transform methods was performed to determine the relaxation modulus curves and thermal stresses of three NMAS mixture specimens. The results indicate that even though the maximum aggregate sizes were different, the behavior was essentially the same, suggesting that the effect of aggregate size on the low temperature behavior of asphalt mixtures is minimal. The low temperature properties of asphalt mixtures are not affected by spatial distributions within an asphalt mixture beam.