Comparison of Mechanical Responses of Asphalt Mixtures under Uniform and Non-Uniform Loads Using Microscale Finite Element Simulation

Abstract

Continuously increasing traffic volumes necessitate accurate design methods to ensure the optimal service life and efficient use of raw materials. Numerical simulations commonly pursue a simplified approach with homogeneous pavement materials and homogeneous loading. Neither the pavement geometry nor the loading is homogeneous in reality. In this study, the mechanical response of the asphalt mixtures due to homogeneous loads is compared with their mechanical response to inhomogeneous loads. A 3D finite element model was reconstructed with the aid of X-ray computed tomography. Sections of a real tire’s pressure distribution were used for the inhomogeneous loads. The evaluation of the material response analyzes the stress distribution within the samples. An inhomogeneous load evokes an increased proportion of high stresses within the sample in every case, particularly at low temperatures. When comparing the two types of loads, the average stresses on the interior (tension and compression) exhibit significant differences. The magnitude of the discrepancies shows that this approach yields results that differ significantly from the common practice of using homogeneous models and can be used to improve pavement design.

Asphalt Layer Cracking Behavior and Thickness Control of Continuously Reinforced Concrete and Asphalt Concrete Composite Pavement

“…qi (i = 1, 2, 3) was the transverse horizontal force perpendicular to the normal direction of the road, and fi (i=1, 2, 3) was the frictional force opposite to the driving direction on each wheel path. Under normal driving, according to the paper by [8], the distribution of the pressure values (P 1 , P 2 , P 3 ), transverse force (q 1 , q 2 , q 3 ), and frictional force (f 1 , f 2 , f 3 ) on the tread is shown in Table 5. Emergency braking in high-speed driving was considered an unfavorable working condition of the pavement structure.…”

“…Chen and Zhang [7] developed a tire-pavement finite element model to study the influence of different indexes on the dynamic behavior of flexible pavement, and the model was validated by a field test. Lu et al [8] compared the mechanical response of an asphalt mixture under homogeneous loads to that under inhomogeneous loads, and the average stresses on the interior were significantly different. The finite element method is already a well-established method for the study of pavement structures.…”