Application of plateau value to predict fatigue life

Abstract

Fatigue resistance of asphalt mixtures represents an important parameter for pavement design. This fatigue resistance is calculated through laboratory tests which require some time depending on the strain level applied to the specimen. For very low strain levels, identical to the one installed in the pavement, one test may last more than one week depending on the testing frequency. The time needed for the development of the fatigue law may last long-er. Recent developments introduced an energy approach, based on the ratio of dissipated energy change, which leads to a plateau value that requires short testing to predict the specimen failure. This paper presents the implementation of this approach to evaluate the fatigue resistance of Portuguese asphalt mixtures. Three asphalt mixtures were studied. The first mixture was tested using two strain levels and three specimens for strain level. The second mixture was tested using three strain levels and three specimens per strain level, whereas the last mixture was tested with 18 specimens, 6 per strain level. The approach seems to have potential to be used for fast evalu-ation of the fatigue response of asphalt mixtures.