Comparing finite element and constitutive modelling techniques for predicting rutting of asphalt pavements

Abstract

This paper focuses on a comprehensive evaluation of the effects of different finite element (FE) modelling techniques and material constitutive models on predicting rutting in asphalt pavements under repeated loading conditions. Different simplified 2D and more realistic 3D loading techniques are simulated and compared for predicting asphalt rutting. This study also evaluates and compares the rutting performance predictions using different material constitutive behaviours such as viscoelastic–viscoplastic, elasto-viscoplastic and coupled viscoelastic, viscoplastic and viscodamage behaviours. The simulations show that the assumption of the equivalency between a pulse loading and an equivalent loading, which are commonly used as simplified loading assumptions for predicting rutting, is reasonable for viscoelastic–viscoplastic and elasto-viscoplastic constitutive behaviours. However, these loading assumptions and material constitutive models overestimate rutting as damage grows. Results show that the 2D plane strain FE simulations significantly overestimate rutting as compared with the rutting performance predictions from more realistic 3D FE simulations.

Keywords:

• rutting
• viscoelasticity
• viscoplasticity
• damage
• finite element simulations
• wheel loading

Acknowledgements

The authors acknowledge the financial support provided by the Federal Highway Administration through the Asphalt Research Consortium, and the partial financial support by the Qatar National Research Fund. Also, the authors acknowledge the helpful comments by the anonymous reviewers who helped in making the paper more complete.