In later years the development of pavement design has gone towards more and more analytically based methods. Future design will probably be based on incremental deterioration models. The objective of this study was to evaluate different types of rut depth prediction models for an incremental design process. Two models of different kinds were chosen for further studies: One model that calculates the plastic strain through the whole pavement, and one model that is based on a critical response at one location in the pavement. The models were calibrated to accelerated pavement tests and then validated to both theoretical sections and to two in-service roads. The model based on critical response can probably be used for normal flexible pavements. Two different studies have resulted in almost identical values for the most important model parameter, which indicates that that value is probably close to the best possible value. To get a good calibration of the plastic strain model, measurements of permanent deformations of each layer should be used.
Abstract