Investigation on triaxial numerical test method and dilatancy behavior of asphalt mixture

Abstract To investigate factors affecting the dilatancy behavior of asphalt mixture, more accurate prediction and reduction of rutting are required. The dilatancy law of asphalt mixture was studied using an indoor triaxial test. Based on the triaxial numerical test, the effect of meso-model parameters on the test results was studied, and relevant model parameters were determined. Then, the effects of the loading speed, confining pressure levels, and pore and aggregate characteristics on the dilatancy performance of asphalt mixture were studied. The results show that the constructed triaxial numerical simulation method correlates well with the indoor triaxial test. Increasing the loading speed and confining pressure levels can improve the dilatancy resistance of the asphalt mixture numerical model. When pores are uniformly distributed, the dilatancy deformation of the numerical model decreases as the porosity increases; the dilatancy angle increases with the increase of aggregate content; and the rougher the surface of the coarse aggregate, the larger the dilatancy angle of the specimen; when the aggregate distribution characteristics are different, the corresponding dilatancy characteristics are also different.