Effect of PCC Joint Skew on Reflective Cracking in HMA Overlays

TL;DR

This study uses advanced 3D finite element modeling to examine how skewed transverse joints in rigid pavements influence the development of reflective cracking in asphalt overlays, revealing that skewing increases cracking risk.

Contribution

It provides the first detailed finite element analysis of the impact of skewed joints on reflective cracking in HMA overlays, incorporating complex material and contact behaviors.

Findings

Skewed joints increase reflective cracking potential.

Finite element models accurately predict stress concentrations.

Fracture mechanics parameters correlate with cracking development.

Abstract

Reflective cracking is a relatively premature distress that occurs in HMA materials overlaying cracked and jointed underlying pavements. The high concentration of stresses and strains in the vicinity of the discontinuity of the old pavement causes the cracks to reflect into the newly placed HMA overlay. While it is a common practice to use skewed transverse joints in rigid pavements to improve the latter's performance, the impact of such a practice on the cracking of a potential HMA overlay has not been examined so far. In this context, this study investigates the effect of using skewed transverse joints in rigid pavements on reflective cracking development in the HMA overlay. Advanced three-dimensional Finite Element models including viscoelastic material properties for the HMA overlay, 3D beam modeling of dowel bars, non-uniform tire-pavement contact stresses, friction interfaces, and infinite boundary elements were constructed for both normal and skewed transverse joints using ABAQUS v-6.11. The potential for reflective cracking was monitored through the fracture mechanics J-integral parameter. Results obtained show, among other things, that the practice of skewing transverse joints increases the potential for reflective cracking development in the asphalt concrete overlay.