Advances in the research of interfacial properties of reclaimed asphalt mixture: A comprehensive review☆

Recycling of reclaimed asphalt pavement (RAP) faces significant challenges due to interfacial interaction problems within reclaimed asphalt mixtures (RAM). This review focuses on two critical interfaces within RAM: the interface between fresh and aged asphalt, and the interface between aged asphalt and aggregate. These interfaces exert a profound influence on the performance of RAM, impacting key pavement attributes such as rutting resistance, fatigue life, and moisture damage resistance. Consequently, a comprehensive understanding and enhancement of these interfacial interactions are essential for optimizing RAP utilization and elevating the overall performance of RAM. The review commences with systematic analysis of two pivotal interface properties within RAM. It delves into the definition of these interfaces, elucidates the factors influencing their performance, and meticulously examines the methodologies employed to evaluate their characteristics. Subsequently, the review investigates the impact of rejuvenating agents, including petroleum-based oils, bio-based oils, and chemical modifiers, on enhancing interfacial properties. Additionally, the role of surface treatment techniques, such as chemical treatments and mechanical grinding, in augmenting interfacial adhesion between asphalt and aggregates is discussed. While progress has been made in interfacial study, several challenges persist. Consequently, the review concludes by providing some recommendations for future research endeavors. These recommendations aim to overcome the existing challenges and advance the field of RAM interfacial property enhancement.