Multiscale Modeling of Asphaltic Pavements: Comparison with Field Performance and Parametric Analysis of Design Variables

Abstract

This study presents a multiscale model that concurrently links mixture-level component properties to the structural performance of asphaltic pavements. Two scales (the global scale of the pavement and the local scale of mixtures) were two-way linked in the model framework based on a thermomechanical finite-element formulation. Global and local scales were systemically represented in the model by a homogeneous pavement structure and a heterogeneous asphalt concrete mixture, respectively. A four-layer pavement structure on I-8 in Nebraska was used as an example to demonstrate the modeling. A comparison of the rutting field measurements and model predictions shows relatively good agreement. Parametric analysis of the model was then conducted to investigate the effect of the component properties (viscoelastic stiffness and fracture) and mixture microstructures on two primary pavement distresses: rutting and fatigue cracking. Because mixture heterogeneity, elastic-viscoelastic deformation, and fracture damage in mixture microstructures (local scale) are considered in predicting pavement performance with damage (global scale), typical distress types in asphaltic pavements can be directly examined as a function of the core design-related variables, such as mixture component properties, mixture designs, pavement layer configurations, and traffic loading conditions. Furthermore, the model is expected to significantly reduce the experimental costs and time required to design pavement structures because it uses only the properties of mixture components, not the test results of entire mixtures. Although the modeling approach is in an early stage and requires further improvements before practical implementation, its simulation results show that it has great potential for advancing materials selection, mixture design, and mechanistic pavement analysis/design.