The interfacial interaction between asphalt binder and mineral filler: a comprehensive review on mechanisms, evaluation methods and influence factors

Asphalt binder and mineral filler are mixed together to bond fine and coarse aggregates of asphalt mixture. The interaction between asphalt and filler plays an important role in deciding the rheological responses of asphalt mixture. Significant efforts have been devoted over the years to studying the asphalt-filler interaction in terms of mechanisms, evaluation methods and influence factors. The interaction mechanisms of filler particles to asphalt have been analysed from various perspectives, including rheological test, microstructural change and molecular dynamic simulation. This paper systematically reviews current evidence to thoroughly reflect the asphalt-filler interaction mechanism. Based on different theoretical models and rheological parameters, several evaluation indices have been proposed in recent decades. This paper also summarises the effectiveness and sensitiveness of these indices to measuring the asphalt-filler interaction ability. Additionally, the influences of internal and external factors on asphalt-filler interaction ability are comprehensively reviewed, aiming to shed light on its fundamental mechanisms to enhance asphalt mixture design. The internal factors refer to the characteristics of asphalt and filler particles, while the external factors include temperature, loading frequency, asphalt thermal oxidation and water.