A part of the multilayer pavement structure containing top‐down crack in the hot mix asphalt (HMA) layer and subjected to loading of a moving vehicle is simulated using the finite element method. Aggregate distribution and packing algorithm was used for modeling the HMA layer around the top‐down crack as a heterogeneous two‐phase (aggregate/fine aggregate matrix [FAM]) medium. By considering the heterogeneity aspects of the asphalt mixture, the influence of traffic loading location, aggregate distribution, crack length, thickness layer, and mechanical properties of layers and components were investigated on the fracture parameters. The results showed that for different locations of vehicle wheels relative to the top‐down crack, the magnitude and sign of the fracture parameters in heterogeneous modeling were significantly different from the similar values of the homogeneous simulation. The stress intensity factors and especially the T‐stress were significantly sensitive to the crack tip location that can be placed either inside the stiffer aggregate or the softer FAM part.

Using aggregate generation and packing algorithm technique coupled with finite element method, a part of reconstructed asphalt pavement structure with five layers and containing a bottom-up crack was simulated. For more realistic modeling and more accurate analyzing the cracking behavior of pavement, a region surrounding the initial crack (and bottom-up crack) region and its neighborhood was modeled as a heterogeneous two-phase (aggregate/mastic) mixture. The results of numerical analyses showed that a significant difference exists between the crack tip fracture parameters (i.e., K I , K II , K eff , T-stress, and Biaxiality ratio) of the homogenous and heterogeneous models. The heterogeneous simulation (in this case study) leads to approximately 70% reduction in the effective stress intensity factor. Furthermore, it was shown that the fracture trajectory of a simulative reflective cracking (SRC) test conducted on a real bilayer asphalt beam sample can be predicted well by modeling the beam layers as a heterogeneous two-phase mixture. K E Y W O R D Saggregate generation and packing algorithms, bottom-up crack, finite element method, fracture parameters, reflective cracking trajectory, two-phase heterogeneous asphalt modeling