DigiRoad Simulation of handling and compaction of unbound aggregates in road construction

Research Project, 2018 – 2021

The DigiRoad project aims at increasing the productivity, quality and service life of Swedish roads through simulation of crushed unbound rock material and its interaction with construction machinery. The application mainly targets the focus areas "New tools and calculation models for state assessment", as well as "Holistic design and dimensioning tools for transport infrastructure". Fraunhofer-Chalmers Center (FCC) conducts leading development of simulation software, including Discrete Element Method (DEM), which is the major method for particulate materials. Together with Chalmers Rock Processing research group, it has ten years of experience in research and utilization of DEM in mining and aggregate industry. Through the Chalmers strength area Building Futures, FCC has conducted a preliminary study aimed at modeling unbound aggregates in road production. The results show that significant segregation effects occur during loading, transportation and unloading. Furthermore, laboratory tests and simulation of compaction show that they lead to a significant difference in stiffness. The road´s future deformation and service life can be directly correlated to the stiffness and packing density of base and sub-base layers. The simulation technology shows great potential for evaluating and optimizing the handling and compacting of unbound aggregates, which is expected to provide increased packing quality with lower variance. The project plans extensive lab and full scale experiments to create input data for validation of the simulation technology. The project team has unique expertise in addressing the challenge and consists of researchers at FCC and Chalmers, as well as key people from NCC, Dynapac and Volvo CE.