15. Multiscale modelling of creep of asphalt – performance-based optimization of flexible pavements.
The rapid degradation of the road infrastructure was the reason for founding the Christian-Doppler Laboratory for “Performance-based optimization of flexible pavements” at Vienna University of Technology in which the IMWS is scientific partner. The Christian-Doppler Laboratory is chaired by Prof. Ronald Blab (Institute for Transportation (E320). Currently, a multiscale model for asphalt is being developed, allowing identification of fundamental mechanisms of behavior of asphalt at several observation scales. By means of application of advanced upscaling methods, the gain in knowledge at the finer scales is translated to the structural scale and finally used for the design of new pavement structures and the assessment of existing ones.
Upscaling of rheological properties of bitumen-aggregate composites is performed in the framework of continuum micromechanics, utilizing the Mori-Tanaka scheme in the Laplace-Carson space.
The elastic-viscoelastic correspondence principle gives access to the effective (homogenized) creep compliance of a matrix/inclusion-composite. Finally, by means of the inverse Laplace-Carson transformation the time-dependent effective behavior of the composite material and, hence, the macroscopic viscous properties of asphalt can be quantified as a function of the asphalt mix design.