Mesoscopic Numerical Simulation Study On Mechanics Properties Of Triaxial Test Of Hydraulic Asphalt Concrete Based On DEM

The triaxial test of hydraulic asphalt concrete are simulated by the particle discrete element method and the particle flow code(PFC3D)to discuss the influence of the meso-parameters,the size of the specimen and the shape of the aggregate on the results of numerical simulation triaxial test of asphalt concrete.The results show that:(1)Using particle flow code,the numerical simulation triaxial test of asphalt concrete can be accomplished,and the development process of shear failure can be reproduced.In the process of test,according to the material composition and properties of asphalt concrete,the appropriate contact constitutive model and mesoscopic parameters between elements were selected.(2)The effects of mesoscopic parameters on numerical simulation results are as follows:The friction coefficient and the normal bond strength can only affect the peak strength and yield strength of the stress-strain curve,which is obtained from the numerical simulation test of asphalt concrete,but has little effect on the initial elastic modulus.Both of the peak strength and yield strength are increased with the increasing of the friction coefficient and the normal bond strength,but due to the different mechanism,the friction coefficient mainly affects the yield strength,and the normal bonding strength of the contact mainly affects the peak strength.The shear bond strength only affects the yield strength of the stress-strain curve.The elastic modulus between the particles only affects the initial elastic modulus.(3)The height-to-diameter ratio(H/D)of specimen has an influence on the stress-strain curve of the numerical simulation test.It is found that the smaller the ratio(H/D),the more stable the specimen macro-structure and the meso-structure,and the compressive strength of specimens increased slightly.(4)Using the clump particles to simulate the irregular shape of aggregate can improve the similarity of the particle shape and arrangement between the numerical sample and the actual sample,and can improve the compressive strength of numerical specimen.