RHEOLOGICAL MODELLING OF FLEXIBLE PAVEMENT MATERIALS USING ADVANCED FINITE ELEMENT METHODS FOR THE DEVELOPMENT OF A MECHANISTIC-EMPIRICAL DESIGN APPROACH

Abstract

Flexible pavements are composed of layered materials, including an asphalt concrete surface, unbound granular base and subbase, and a subgrade. Each layer has distinct mechanical characteristics, making the structural response to traffic loading highly complex. Accurate modelling of these materials is essential for reliable pavement performance predictions. The Mechanistic-Empirical (ME) design method addresses this complexity by combining mechanical analysis with empirical performance models. Constitutive models are used to simulate stresses, strains, and displacements, which are then linked to pavement deterioration through transfer functions. This article critically reviews current pavement design methodologies, emphasizing differences across international standards. Modelling approaches are classified into analytical, experimental, and numerical categories, with a particular focus on finite element modelling of unbound granular materials (UGMs). The finite element method (FEM) is applied as a numerical tool for simulating pavement behavior. The main objective is to develop a refined modelling approach using FEM, supported by advanced rheological characterization of flexible pavement materials.