Model for forecasting ruts in rutting tester

The results of research on the rheological parameters of mineral-asphalt mixes subjected to the creep test in the Nottingham Asphalt Tester (NAT) are presented. The rheological parameters were determined through the approximation of the experimental creep curves by the theoretical curves for three viscoelastic models: the Maxwell model, the Burgers model and the Zerner model. This was done after the 1st, 2nd and 3rd ucycle of loading of the same specimen. It was found that the approximation error in the 3rd loading cycle was the smallest for the Burgers model. The obtained rheological parameters were used for forecasting ruts in the French Pavement Rutting Tester (FPRT). For this purpose, a theoretical model for forecasting ruts was developed using a finite element method (FEM). The model was validated by comparing the rut depths calculated for the rheological parameters determined from creep tests with the rut depths measured in the rutting tester, in which the considered mineral-asphalt mixes were tested. The best agreement between the rut depth measurements and the model calculation results was obtained for the Burgers model and the Maxwell model. For the covering abstract see ITRD E117423.