Multiscale heterogeneous numerical simulation of asphalt mixture

Abstract

A multiscale heterogeneous numerical finite element (FE) model is a method used in order to prognosticate the asphalt mixture's mechanical behaviour at various scales (bitumen and mortar mastic). Thus, the aim of this research paper is to evaluate its accuracy. A biphasic approach was adopted to model the bituminous composite. The latter is made of elastic aggregates and viscoelastic matrix. In this developed multiscale method, the biphasic composite's properties are shifted from an initial scale to a greater one. The parameters inputted into the FE model consisted of the dynamic modulus and the elastic properties of the matrix at several scales. A software developed in our laboratory was used to obtain randomly generated aggregates. These inclusions have different sizes and shapes. Therefore, this program generates the bituminous composites' aggregate skeletons. Values of the complex modulus and phase angle obtained from numerical simulations were compared with those obtained by an analytical method based on the Generalized Self Consistent Scheme (GSCS) model and to experimental ones. The results confirm the accuracy of the global mechanical behaviour obtained from the generated heterogeneous numerical model. Lastly, at local scale, the asphalt mixture's mechanical behaviour was examined regarding the influence of the heterogeneous microstructures.

The Influence of Mortar’s Poisson Ratio and Viscous Properties on Effective Stiffness and Anisotropy of Asphalt Mixture

“…For this purpose, research works have been conducted, based mainly on laboratory test methods, and attempts are made to model the viscoelastic properties of the asphalt mixture using the finite element method. Currently, numerical methods are mainly focused on heterogeneous multi-level modelling, which allows the transfer of bitumen properties to the properties of the final material, i.e., asphalt mixture [4][5][6]. The proper separation of the composite structure components is very important and affects the proper selection of meshes for FEM modelling.…”

The Effect of Mineral Powder on the Surface/Interface of Aggregates and Asphalt

“…The surface energy theory evaluates the wetting level of asphalt on the surface of crushed stone flakes by measuring the wetting angle [13][14][15]. The surface structure theory analyzes the adhesion between aggregates and asphalt by studying the surface topographic features such as the angularity, contour, and shape of the aggregates [16,17]. The electrostatic attraction theory believes that when asphalt is in contact with aggregates, two layers of electrostatic attraction will be formed, and the adhesive force between the interfaces is the action force between the two layers; the asphalt mixtures can be regarded as a capacitor, which can be charged by the contact between asphalt and aggregates [18].…”