Generalized self-consistent scheme for upscaling of viscoelastic properties of highly-filled matrix-inclusion composites - Application in the context of multiscale modeling of bituminous mixtures

In this paper, a multiscale material model for the prediction of viscous properties of bituminous mixtures is presented. The multiscale model is based on the mix design, i.e., volume fractions of different material phases and the intrinsic viscoelastic material behavior of the latter, making goal-oriented optimization of bituminous mixtures feasible. Previous developments for upscaling of viscoelastic properties of a bitumen/filler-composite (mastic) [Lackner, et al. J Mater Civil Eng 2005; 17 (5): 485-91] and of asphalt [Aigner, et al. J Mater Civil Eng 2009; 21: 771-80] are improved with regards to (i) the employed mode of upscaling, i.e., the way information is transferred from one scale of observation to the next higher scale of observation, and (ii) the underlying micromechanical concept. As regards the latter, the use of the so-called generalized self-consistent scheme, suitable for highly-filled matrix/inclusion-type morphologies, as is the case for asphalt, is proposed. The assessment of the proposed upscaling scheme with respective experimental results indicates the improved suitability of the generalized self-consistent scheme versus the commonly employed (at least for modeling of matrix-inclusion materials) Mori-Tanaka scheme, resulting in a sound representation of test data.