A critical review of fatigue cracking in asphalt concrete pavement: a challenge to pavement durability

Fatigue cracking in asphalt pavements is a pervasive problem that undermines pavement longevity and performance, leading to costly repairs and disruptions. Despite significant advancements in pavement design and materials, fatigue failure remains a critical challenge, particularly in the context of increased traffic loads and the growing use of recycled materials. Existing studies have explored various aspects of fatigue, yet gaps persist in accurately predicting field performance and optimizing fatigue resistance. This review provides a comprehensive analysis of fatigue mechanisms, influencing factors, and the current state of laboratory testing and modeling techniques. It highlights that fatigue failure in asphalt pavements manifests primarily as top-down or bottom-up cracking, with each mode influenced by factors such as traffic loads, pavement structure, and environmental conditions. Although mechanistic models have advanced the understanding of these failures, practical challenges remain, particularly in the calibration of models to real-world conditions. The study recommends that future research prioritize the refinement of mechanistic models, such as integrating viscoelastic properties into fatigue life predictions, and enhancing testing protocols by adopting more representative tests like the Indirect Tensile Creep Compliance and Strength (IDT). Validation of predictive tools like AASHTOWare Pavement ME against long-term pavement performance data is also crucial. Additionally, employing high-quality materials, such as polymer-modified asphalts, optimizing mix designs through methods like Superpave validated by laboratory and field performance, and implementing proactive maintenance practices like timely crack sealing can significantly improve fatigue resistance. These integrated strategies are essential for extending pavement service life, reducing maintenance costs, and promoting sustainable pavement management.