ABSTRACT
ABSTRACT: This paper investigates the use of Discrete Element Modelling (DEM) to simulate the behavior of a highly heterogeneous nature under triaxial compressive test. The laboratory triaxial compressive test is conducted to capture the dilation of asphalt mixture. Dilative mechanism is analyzed through the microstructure using DEM. Digital specimens are prepared with random generator algorithm that would generate an irregular closed space to incorporate the balls inside of the space for each clump according to the graded mixture. Statistical regression method is developed to capture varying air void distributions along pavement depth. Based on this method, the air void phase of virtual specimen was built, which is close to the real asphalt pavement. Results show that the virtual specimen is similar to the actual triaxial compression test specimen and has the correct volumetric proportions. The dilatancy behavior and shear resistance are simulated by using DEM to investigate the variance of aggregate-binder-aggregate contact under triaxial compressive tests. The results of laboratory triaxial compressive test were in agreement with the result of DEM simulation. Both of these methods show that there was obvious dilation when the specimen was loaded. At the same time, the aggregate-binder-aggregate contact was fractured and formed a shear band.
