Analytical models to characterise crack growth in asphaltic materials and healing in asphalt binders

Abstract

Cracking is a prevalent form of distress in flexible pavements. A thorough understanding of the mechanisms that lead to fatigue cracking and self-healing in bituminous materials is the essential and first step towards improving the performance of pavements and the bituminous materials used to construct these pavements. During the last two decades, several researchers have addressed the problem of understanding and modelling fracture and self-healing in bituminous materials at several different length scales. The first part of this paper presents a comprehensive review of the development of an energy-based fracture mechanics model to characterise the crack growth in bituminous materials. A few other approaches to model crack growth in viscoelastic materials that have not been widely used with bituminous materials are also briefly discussed. The second part of this paper presents a comprehensive review of an analytical model that can be used to represent self-healing in asphalt binders. The advantages, limitations and approximations associated with the implementation of the fracture and self-healing models are also discussed.

Keywords:

• asphalt binder
• bituminous mixtures
• J-integral
• fracture
• fatigue
• self-healing

Acknowledgements

The authors wish to acknowledge the many valuable discussions with Profs Dallas Little, Eyad Masad and Richard Kim related to the topics covered in this paper.