This work package has two purposes. The first one is to create a reliable model for rolling resistance in the tire-road contact zone in close interaction with the results from the down-scaled laboratory for rolling resistance and skid resistance model validation described in WP1. This includes model and predict the rolling resistance for a given texture and how to scale the WP1-laboratory results to realistic conditions.
The second purpose is to simulate molecular models of bitumen that can be used to predict the durability of the new asphalt pavement. This includes investigating the molecular mechanics controlling the aging and durability in bitumen mixtures.
Mathematical modeling of rolling resistance have been investigated for several years, one approach is molecular bitumen models which have been introduced for molecular dynamics computer simulations, but only phenomena on the nanosecond time scale can be investigated in such models because these are all-atoms models. Recently much faster methods than have been developed in the project COOEE, and in ROSE project this work will be continued with initial focus on reproducing the results from the WP1 laboratory with a solid rubber tire. Subsequently, pneumatic tires will be modelled. Once the experimental setup of WP1 has been properly modelled, existing models for rolling resistance are tested and improved by comparing predictions to WP1 measurements. When a model for the setup has been validated, it will be real-life tested at the IFSTTAR test-track facilities in Nantes (France).
For the second half of WP2 we will use the united-atom, molecular ”COOEE bitumen model” based on the SARA classification. The simulations are performed on the Graphical-Processor-Unit (GPU) based software package RUMD, which provides the ROSE project access to one of the world’s fastest molecular-dynamics codes. The computer cluster is hosted at Roskilde University.