Quantification of Cohesive Healing of Asphalt Binder and its Impact Factors Based on Dissipated Energy Analysis

ABSTRACT The effect of healing on asphalt material fatigue performance has been accepted as an important property which is, at least partially, responsible for the significant difference between the laboratory and field fatigue behavior. Although some studies have been conducted to characterize the asphalt healing and its mechanism, very few researches have clearly identified how different loading and climate conditions can influence the effect of healing in a quantitative way. In addition, little suggestion has been provided on the integration healing into fatigue life prediction and pavement design. Therefore, this study develops a research based on the fundamental dissipated energy analysis to quantify the cohesive healing in asphalt binder. The key impact factors on healing are evaluated in a systematic way under different loading and environmental conditions. A healing rate predictive model and fatigue life prediction model based on binder rheological properties and visco-elastic energy dissipation is developed, which provides a promising way to integrate healing into a more mechanistic based pavement design procedure. The methodology used in this study can also be applied to investigate and quantify the adhesive healing at the aggregate-asphalt interface when aggregates are introduced into the experimental testing.