Investigating the effects of loading, mechanical properties and layers geometry on fatigue life of asphalt pavements

Abstract

In this paper, fatigue life, crack growth trajectory, and stress intensity factors of top‐down and bottom‐up cracks have been investigated in a multilayered asphalt pavement using numerical method. Finite element models, Paris law, and maximum tangential stress criteria were used to determine the effects of vehicle position, thickness, and stiffness of layers on fatigue life of pavements. The results show that the minimum fatigue life of pavements with top‐down crack occurs when the wheels are symmetrically located relative to the crack plane. On the other side, in pavements with bottom‐up crack, it occurs when the front tire located on top of the crack. Moreover, the result reveals that the top‐down crack grows slower than bottom‐up crack. Also, the surface layer's stiffness has the most effect on fatigue life of pavement.

Heterogeneity effect on fracture parameters of a multilayer asphalt pavement structure containing a top‐down crack and subjected to moving traffic loading

“…Based on the extensive numerical analyses performed in this research, it can be mentioned that a noticeable difference may exist between the fracture parameters of homogenous modeling of the pavement layers (often considered in most of the previous papers 4,9,14,15,17,55,56 ) and heterogeneous modeling of the HMA layer (investigated for the first time in this research). For example, the difference between the effective SIFs of homogenous and heterogeneous models for the investigated multilayer pavement system of current research is compared in Figure 15 for different I/L ratios.…”

“…The aggregates were distributed using the AGP algorithm within this two‐phase zone. Indeed, despite the previous similar works in this regard (e.g., previous works 4,14–17 ), which consider the whole layers as isotropic and homogenous body, a part of the HMA layer around the surface crack was modeled as heterogeneous material. This can result in more similarity and consistency with the stress and strain field for the TDC in a real pavement structure.…”

“…Most of the numerical studies in this regard have calculated the fracture parameters by assuming the asphalt mixture as a homogeneous material 5–13 . For example, Ziari et al 14 modeled a part of a cracked pavement layer containing both TDC and BUC by considering isotropic and homogeneous properties for all layers under the influence of traffic loading. Using the finite element method (FEM), they investigated the impact of vehicle wheel loading, mechanical properties (i.e., modulus of elasticity and Poisson's ratio), and geometry of the layers on the SIFs, the crack growth path and fatigue life of the asphalt pavement.…”

Heterogeneity effects on mixed‐mode I/II stress intensity factors and fracture path of laboratory asphalt mixtures in the shape of SCB specimen

“…[1][2][3] Cracking and rutting are the most important damages in asphalt pavements. Annually, a lot of money is spent for the design, construction, maintenance and rehabilitation of roads.…”

“…Annually, a lot of money is spent for the design, construction, maintenance and rehabilitation of roads. [1][2][3] Cracking and rutting are the most important damages in asphalt pavements. [4][5][6] Cracking mostly occurs in cold climates, where asphalt behaves as a linear elastic material.…”