Fatigue of asphalt binder,mastic and mixture at low temperature

The fatigue damage is one of the most common distresses observed on the asphalt concrete pavement.To thoroughly understand the fatigue of asphalt concrete,the behaviors of the major components of asphalt concrete under cyclic loading are investigated respectively in this study.A new experiment method is developed to evaluate the performances of asphalt binder,mastic and fine aggregates mixture under cyclic tensile loading.The fatigue test results of asphalt binder show that the fatigue performance of asphalt binder is closely related with loading magnitude,temperature and loading rate.Mastic specimens with different filler content are tested and the results indicate that mastic specimens with 30%filler content show better fatigue resistance and higher permanent strain.The micro-structure analysis of mastic and mixture indicates that the fatigue resistance is closely related with the air void content of specimen.3D digital specimens are developed to model the fatigue of the asphalt binder,mastic and mixture specimens based on the finite element method(FEM).Fatigue damage of asphalt concrete is simplified by a damage model.With proper selection of damage parameters,the simulation results agree well with laboratory test results and can be used as a basis for future fatigue research.