Chip Seal Finite Element Model

Abstract

This paper describes the preliminary development of a 3-D finite element model of a chip seal road surfacing. A 3-D chip matrix was constructed using X-ray tomography scans of multiple layer seal samples removed from a highway in New Zealand. Care was taken to minimize smoothing of the chip surfaces and to obtain accurate rendering of chip to chip contact points. The model was implemented using the ABAQUS finite element package. Aggregate par¬ticles were modeled as rigid bodies; the bitumen was modeled using a viscoelastic constitutive model. Constants for the bitumen model were determined by back- calculation from experi¬mental measurements made using a dynamically loaded ball bearing assembly simulating a chip seal. Results from the equivalent geometry implemented in ABAQUS, were compared to the experimental data using an iterative process to optimize the model constants. The model will be used to study the effect of bitumen type and seal design on seal cohesion and stability.