Rate-dependent fracture modeling of bituminous media using nonlinear viscoelastic cohesive zone with Gaussian damage function

Cracking of bituminous materials is one of the main distresses that results in roadway failure. As bituminous media are highly rate-dependent at intermediate temperatures due to the viscoelastic nature of the binding materials, cracking is also highly rate-dependent viscoelastic. This presents a clear need to address the phenomenon in the modeling-analysis process for a more accurate design of mixtures and pavements. This study proposes an advanced computational modeling method to predict complex rate-dependent cracking in bituminous materials and pavements. In particular, we explored an extrinsic nonlinear viscoelastic cohesive zone (NVCZ) integrated with Gaussian damage evolution. To examine the modeling method and its validity, two modeling efforts in multiple length scales were made: mm-scale material-level modeling and cm-m scale hierarchical modeling that linked the mixture with pavement structure. The NVCZ modeling with Gaussian damage evolution successfully predicted material cracking and damage at different loading rates by using a single set of fracture parameters. This implies that the complex cracking behavior of bituminous materials can be characterized by material-specific fracture parameters that can be identified by a simple fracture test. The pavement modeling through a parametric analysis demonstrated the sensitivity and capability of the modeling to effectively capture the interrelated influence of several core design variables, such as traffic, material properties, and layer configurations, all of which affect pavement responses and damage evolution. The computational modeling presented in this study has the scientific rigor to predict nonlinear rate-dependent viscoelastic fracture of bituminous materials and pavements with a good modeling efficiency by significantly reducing laboratory tests.

Automated summary

This study proposes an advanced computational modeling method to predict complex rate-dependent cracking in bituminous materials and pavements, with good modeling efficiency by significantly reducing laboratory tests. The modeling successfully predicted material cracking and damage at different loading rates, demonstrating the sensitivity and capability of the modeling to capture the interrelated influence of several core design variables.