Tensile fracture simulation of random heterogeneous asphalt mixture with cohesive crack model

A heterogeneous fracture modeling technology is presented to simulate complex two-dimensional crack propagation in asphalt mixture which is treated as composites consisting of randomly distributed coarse aggregates and asphalt mastic. In this technology, the random aggregate generation and packing algorithm is utilized to create numerical asphalt mixture samples with heterogeneous mesostructures, and cohesive elements with the bilinear softening law are inserted into both the mastic and the interfaces between the mastic and aggregates to simulate crack initiation and propagation. After mesh-dependence of computational results is discussed, a series of virtual uniaxial tensile fracture tests are performed at −10 °C to study nucleation and coalescence of microcracks, and gestation and propagation of main macrocracks. The effects of aggregate distribution and main parameters of the cohesive crack model on the performance of asphalt mixture are also evaluated. Some important conclusions are given.

► Propose a heterogeneous fracture modeling technology.
► Aggregate generation and packing algorithm is for creating a mesostructural model.
► Characterize microcrack initiation and coalescence and macrocrack gestation.
► Effects of aggregate distribution and fracture parameters on fracture behavior are evaluated.