Coupled thermo-hydraulic modelling of pavement under frost

Abstract

Frost action is a major factor causing deteriorations of pavements in cold regions. The resultant temperature and moisture redistributions play an important role in determining the mechanical responses of pavement. This paper develops a multi-physical model to analyse the coupled thermo-hydraulic field under pavements, especially those in the unsaturated base and subgrade. This model integrates the Fourier's laws for heat transfer, Richards' equation for fluid transfer and poroelastic constitutive relationships. Various coupled parameters were utilised to transfer information between field variables. Additional relationships, such as the similarity between drying and freezing processes and the Clapeyron equation for ice–water balance, were incorporated to allow for the effects of frost action. The coupled nonlinear partial differential equation system was solved on a multi-physical platform. Two instrumented pavement sections (one asphalt pavement and one concrete pavement) were used to validate the results of the model simulations. The simulation results match reasonably well with the field-monitored data.

Keywords::

• multi-physics model
• coupled hydro-thermal field
• frost action
• temperature and moisture redistribution
• rigid and flexible pavement

Acknowledgements

The authors gratefully acknowledge the help from Roger Green, a pavement engineer of the Ohio Department of Transportation (USA). The financial support of this study is partially from NSF project CMMI 0856407.

Notes

^1. Email: [email protected]