In this paper, time series of rut data from 109 in-service pavement sections in LTPP, SPS-1 experiment were used to predict the permanent deformation parameters for the VESYS mechanistic-empirical rut model. This was accomplished by matching the rut performance curves versus time for each section using a commercially available iterative solver. To insure uniqueness of the Permanent Deformation Parameters (PDPs) for a given section, the transverse surface profiles were used to match the most likely contributions by layer according to the criteria proposed in NCHRP report 468. On average, the contribution to the total surface rutting from the various pavement layers was as follows: 57 % from the AC layer, 27 % from the base layer, and 16 % from the subgrade. These results confirm that the contribution to the total rutting from AC and base layers are important and need to be included in any mechanistic-empirical design procedure.
Abstract