Guofang Zhao, Yadong Liu, Xiaoyong Wu, Zhanyou Yan and
Xiangyang Lv
Vol. 20 (2025), No. 3, 269–288
DOI: 10.2140/jomms.2025.20.269
Abstract
Asphalt concrete is the main type of pavement used on expressways. After long-term
use, fine cracks inevitably occur inside the pavement, significantly impacting its
performance and service life. To investigate the mechanical response of asphalt
concrete pavements with initial defects under vehicle-road coupling, a microscale,
multilayer subgrade pavement model was constructed using the discrete element
method. After comparing the uniaxial compression experiment data for each
structural layer in the model with actual experimental data under the same working
conditions, the mesoscopic parameters for each pavement structural layer
were obtained through continuous iterative calculations. These parameters
were used to create a discrete element model of the multilayer subgrade
and pavement. In the discrete element model, a constant load travelling
at a constant speed was used for the calculation, and a discrete fracture
network (DFN) was used to characterize the initial defects in the pavement.
The response of initial defects to the structural layers of asphalt pavements
was studied by altering the number of microcracks in the upper and lower
layers.
Summary of results: The number of microcracks in the pavement significantly
influenced the peak stress value. Compared to pavements without cracks,
the vertical stress of each structural layer was reduced by 8% to 10%, the
horizontal stress by 9% to 12% and the tangential stress by 5% to 8%. The
greater the number of microcracks in the upper layer when mobile loads
are applied, the smaller the vertical/horizontal stress response of the lower
layer would be. When there were 200–400 microcracks in the upper layer
(positioned at 1,000 microcracks in the lower layer), the horizontal stress in the
upper layer decreased by 26%, as did the shear stress by 9.5%. Microcracks
significantly impacted the response of asphalt concrete pavements to vehicle-road
coupling.
Keywords
microcracks, mechanical response, discrete element model,
vehicle-road interaction, stress