Asphalt is an important road paving material. Besides an acceptable price, durability, surface conditions (likeroughening and evenness), age-, weather- and traffic-induced failures and degradation are relevant aspects. In theprofessional road-engineering branch empirical models are used to describe the mechanical behaviour of the materialand to address large-scale problems for road distress phenomena like rutting, ravelling, cracking and roughness. Themesoscopic granular nature of asphalt and the mechanics of the bitumen layer between the particles are only partlyinvolved in this kind of approach. The discrete particle method is a modern tool that allows for arbitrary (self-)organization of the asphalt meso-structure and for rearrangements due to compaction and cyclic loading. This is ofutmost importance for asphalt during the construction phase and the usage period, in forecasting the relevant distressphenomena and understand their origin on the grain-, contact-, or molecular scales. Contact models that involve viscoelasticity,plasticity, friction and roughness are state-of-the art in fields like particle technology and can now bemodified for asphalt and validated experimentally on small samples. The ultimate goal is then to derive micro- andmeso-based constitutive models that can be applied to model behaviour of asphalt pavements on the larger macroscale.Using the new contact models, damage and crack formation in asphalt and their propagation can be modelled, aswell as compaction. Furthermore, the possibility to trigger self-healing in the material can be investigated from amicro-mechanical point of view.
展开▼
