3D Finite Element Analysis of HMA Overlay Mix Design to Control Reflective Cracking

TL;DR

This paper uses 3D finite element modeling to evaluate how different asphalt overlay mixes affect the development of reflective cracking in pavements, highlighting the benefits of polymer-modified binders in the leveling course.

Contribution

It introduces a detailed 3D FE model to analyze the impact of various asphalt mixtures on reflective cracking control in pavement overlays.

Findings

Polymer-Modified asphalt reduces tensile stress by 30% in the leveling course.

No significant benefit of polymer-modified or dense-graded mixes in surface or intermediate courses.

Using PM binder in the leveling course effectively mitigates reflective cracking.

Abstract

This study examines the effectiveness of HMA overlay design strategies for the purpose of controlling the development of reflective cracking. A parametric study was conducted using a 3D Finite Element (FE) model of a rigid pavement section including Linear Viscoelastic (LVE) material properties for the Hot Mix Asphalt (HMA) overlay and non-uniform tire-pavement contact stresses. Several asphalt mixtures were tested in the surface, intermediate, and leveling course of the HMA overlay. Results obtained show that no benefits can be anticipated by using either Polymer-Modified (PM) or Dense-Graded (DG) mixtures instead of Standard Binder (SB) mixtures in the surface or intermediate course. For the leveling course, the use of a PM asphalt binder was found beneficial in terms of mitigating reflective cracking. As compared to the SB mix, the use of PM asphalt mixture in the leveling course reduced the level of longitudinal tensile stress at the bottom of the HMA overlay above the PCC joint by approximately 30%.