Verification of Austroads concrete pavement design method using EverFE computer program

Verification of Austroads concrete pavement design method using EverFE computer program

The current Austroads concrete pavement design procedure is based on the PCA’s empirical design method originally developed in 1960’s, which may only be applicable for certain loading and environmental conditions. With the increased utilisation of larger and heavier commercial vehicles, eventually future pavements cannot be designed using this method. While this method is still considered adequate at present, this paper attempts to investigate whether there is a need to revise the design procedure in the future.

In the present study, pavement design was initially performed as per the Austroads procedure using the RMS pavement design spreadsheet for a comparison with the EverFE 3D Finite Element Analysis computer program. Traffic data from Pennant Hills Road in North Parramatta and the eastbound lanes of the M2 motorway in North Epping, Sydney were used.

The results of this study reveals that the equivalent stress values of standard vehicles obtained from Austroads method are lower than the maximum tensile stress obtained from EverFE for unbonded boundary condition by as little as 5.7% (for TRDT) to a maximum of 15.7% (for SAST). However, for the selected traffic compositions, it has been found that the difference in equivalent stress values does not influence allowable axle repetitions and the resulting pavement thickness.

EverFE was subsequently used to model the response of a rigid pavement configuration to hypothetical axle loadings for different wheel positions from pavement edge. It was found that under the assumed traffic loading the pavement stresses could increase threefold but temperature gradient in the pavement would still be the most significant factor in affecting pavement stresses. The overall results therefore suggest that the Austroads concrete pavement design method is presently adequate, but there may be a need to revise the current design method if the traffic loading increases significantly in the future.