A micromechanical model to create digital microstructures of asphalt mastics and crumb rubber-modified binders

This paper presents a micromechanical model to develop digital microstructures of asphalt mastics and crumb rubber-modified binders. The micromechanical model was based on the dissipative particle dynamics (DPD) model that is typically used for modelling suspensions. This paper utilises X-ray tomography images of particles to create microstructures. First, a database of 3D images of crumb rubber particles were generated by scanning specimens using X-ray computed tomography and X-ray microtomography. Once the 3D images were generated for individual particle shapes, a series of spherical harmonic (SH) functions were fitted to the surface of the particles and SH coefficients were determined. Utilisation of SH coefficients for each particle (rather than the actual 3D image voxels) allowed efficient numerical DPD simulations performed to generate microstructures. Example simulations were performed to generate microstructures and used to generate finite element meshes and exported to ABAQUS. The linear viscoelastic responses of the microstructures were simulated using ABAQUS and compared to the measured values.