Rutting Resistance of Asphalt Pavement Mixes by Finite Element Modelling and Optimisation

Asphalt pavement rutting is a major safety concern and is one of the main distress modes of asphalt pavement. Research into asphalt pavement mixes that provide strong resistance for rutting is considered of great significance as it can help provide extended pavement life and significant cost savings in pavement maintenance and rehabilitation. The objectives of this study are to develop numerical models to investigate the rutting of asphalt concrete pavements and to find optimal design of asphalt pavement mix for rutting resistance. Three-dimensional Finite Element models were first developed to simulate both the axial compression and wheel track testing in which a visco-elastic-plastic material model was used to predict the rutting of the asphalt concrete pavements. A strain hardening creep model with the material parameters developed from experimental testing was employed to model the time-dependent characteristics of the asphalt concrete pavements. The results were validated against the previous experimental wheel track test results of different pavement mixes. Finally, optimisation techniques using the Design Of Experiments method were applied to the simulation rutting results by varying creep parameters to identify their effects on rutting resistance in order to obtain an optimal asphalt pavements mixes. The results of this paper clearly demonstrate an efficient and effective experimental-numerical method and tool set towards optimal design for asphalt concrete pavements for rutting resistance.