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.

Mechanical reinforcement by plant roots increases the soil shearing strength. The geometric and distribution characteristics of plant roots affect the soil shearing strength. Current research on the shear strength of rooted‐soil is mostly based on direct shear tests with a fixed shear surface and thus cannot reflect the actual failure state of the rooted‐soil. In this study, Golden Vicary Privet was used to create a rooted‐soil, and a triaxial test method was used for soil mechanical property analysis. The influence of the root geometry (root diameter and individual root length) and distribution characteristics (root density and root distribution angle) on the rooted‐soil shearing strength was studied by controlling the root morphology in the specimens. According to the results, both the root geometry and distribution characteristics affect the rooted‐soil shearing strength. For a fixed total length of the roots, the longer the individual root length is, the better the soil shearing strength is. In addition, the reinforcement effect of the root system increases as the angle between the root and the potential failure surface increases. The results also show that the root system significantly enhances the soil cohesion while only minimally affecting the internal friction angle. The maximum rooted‐soil cohesion is 2.39 times that of the plain soil cohesion, and the maximum internal friction angle of rooted‐soil is 1.24 times that of plain soil. This paper provides an approach for the determination of the rooted‐soil strength and a rationale for vegetation selection in ecological slope reinforcement applications.