FEM SEAL-3D: development of 3D finite element chip seal models

ABSTRACT

FEM SEAL-3D is a software development designed to produce finite element models of chip seals. This paper introduces the principles behind FEM SEAL-3D by explaining the ongoing model developments and demonstrating the relevance of preliminary results. The models were developed to investigate stress and strain conditions in the binder film subject to rolling wheel traffic. The rolling wheel attribute sets this paper apart from previous works, which assigned loading signals to aggregate nodes in the models to simulate traffic. Aggregates are randomly generated 3D polyhedral structures which are stored in virtual stockpiles. Aggregate spread rates are adjustable such that the chip seal models can vary from very open to tightly interlocked structures. The amount and type of binder can be selected, enabling FEM SEAL-3D to be utilised as an evaluation tool, cognisant of chip seal volumetrics. The results in this paper present an increase in the stress distribution with the advent of traction wheel loads compared to free-rolling wheel loads. Stress and strain responses were translated to dissipated energy parameters. The dissipated energy parameter was specifically selected with the intent to be utilised in future fatigue analyses of chip seal crack initiation models. The magnitude of this condition is indicative of the expected chip seal performance.

KEYWORDS:

• Abaqus
• chip seal
• finite element modelling
• bituminous binder
• dissipated energy

Acknowledgements

The authors would like to express their sincere thanks to the South African Bitumen Association (SABITA) for the opportunity to carry out this investigation.