Macroscopic constitutive law for Mastic Asphalt Mixtures from multiscale modeling

TL;DR

This paper develops a multiscale modeling framework to predict the macroscopic behavior of Mastic Asphalt mixtures using a hierarchical approach and a statistically equivalent periodic unit cell, improving understanding of their thermal and mechanical properties.

Contribution

It introduces a multiscale modeling approach with a two-step homogenization scheme for Mastic Asphalt mixtures, incorporating a statistically equivalent periodic unit cell to better reflect real microstructures.

Findings

Effective material properties for mortar phase derived from experiments.

Model parameters estimated through virtual numerical experiments.

Comparison reveals limitations of classical micromechanical models.

Abstract

A well established framework of an uncoupled hierarchical modeling approach is adopted here for the prediction of macroscopic material parameters of the Generalized Leonov (GL) constitutive model intended for the analysis of flexible pavements at both moderate and elevated temperature regimes. To that end, a recently introduced concept of a statistically equivalent periodic unit cell (SEPUC) is addressed to reflect a real microstructure of Mastic Asphalt mixtures (MAm). While mastic properties are derived from an extensive experimental program, the macroscopic properties of MAm are fitted to virtual numerical experiments performed on the basis of first order homogenization scheme. To enhance feasibility of the solution of the underlying nonlinear problem a two-step homogenization procedure is proposed. Here, the effective material properties are first found for a mortar phase, a composite consisting of a mastic matrix and a fraction of small aggregates. These properties are then introduced in place of the matrix in actual unit cells to give estimates of the model parameters on macroscale. Comparison with the Mori-Tanaka predictions is also provided suggesting limitations of classical micromechanical models.