## 1 Introduction  
Asphalt pavements offer several advantages, such as enhanced driving comfort, reduced noise levels, minimal dust, and ease of maintenance. Consequently, asphalt mixturesare widely used as the primary material for highway pavement construction [1; 2]. However, asphalt pavements are susceptible to various forms of distress, including cracking, loosening, and particle loss. These issues not only shorten the service life, but also pose significant challenges in achieving the designed lifespan of pavements [3; 4]. Therefore, improving the performance and extending the service life of asphalt pavements has become a central focus of research. The service life of asphalt pavements is closely related to the performance of asphalt mixtures. Asphalt mixtures are multiphase composites composed of asphalt, aggregates, and mineral fillers blended in specific proportions. The asphalt mastic, consisting of asphalt and mineral fillers, serves as a binder in asphalt mixtures. Previous studies have identified asphalt mastic as the most vulnerable component in asphalt mixtures [5]. The properties of asphalt mastic significantly influence the high-temperature stability, low-temperature crack resistance, and water resistance of asphalt mixtures [6; 7]. The performance of asphalt mastic is primarily determined by the interaction between asphalt and mineral filler. Therefore, the characterization of the interactions between asphalt and mineral fillers, along with the exploration of their influencing factors, is critical for enhancing the performance of asphalt mastic. The rheological properties of asphalt mastic are significantly influenced by the addition of mineral fillers. Early studies assessed the effects of mineral fillers on asphalt properties using indicators such as softening point, penetration, ductility, and viscosity. While these methods provide a clear understanding of how mineral fillers affect asphalt properties, they do not adequately characterize or evaluate the interaction between asphalt and mineral filler [8; 9]. In recent years, the assessment of this interaction has increasingly relied on a series of interaction indices based on rheological properties, which are primarily categorized into three types. Phase-Angle-Based Indices: The [PERSON]-\(A\) index evaluates the interaction between asphalt and mineral fillers by measuring energy dissipation at the interface through the loss factor (tan\(\delta\)) [10]. [PERSON] et al. proposed that mineral filler adsorbs free asphalt, forming an interfacial layer that enhances its effective volume fraction. The Ziegel-\(B\) index quantifies this interaction by adjusting the filler volume fraction based on the phase angle [11]. Viscosity-Based Indices: [PERSON]'s model describes a linear relationship between spherical particle volume fraction and solution viscosity, applicable only for fractions below 0.1 and neglecting particle-solution interactions [12]. [PERSON] et al. developed a semi-empirical viscosity equation that incorporates interaction effects [13]. [PERSON] et al. introduced the composite viscosity coefficient \(\Delta\eta^{\star}\), which reflects asphalt-filler interactions but is also influenced by filler particle size and shape [14]. Complex Shear-Modulus-Based Indices: [PERSON] et al. proposed the complex shear modulus coefficient \(\Delta G^{\star}\) to characterize asphalt-filler interactions [15]. [PERSON] and [PERSON] further developed a coefficient, denoted as \(C\), to assess the interaction between asphalt and mineral fillers. This coefficient is referred to as the Palierne-\(C\) index [11]. [PERSON] et al. concluded that the Ziegel-\(B\) index is more sensitive and physically significant than the [PERSON]-\(A\), \(\Delta G^{\star}\), and \(\Delta\eta^{\star}\) indices [14]. [PERSON] et al. found that \(\Delta G^{\star}\) and the Palierne-\(C\) index better reflect interaction capability than the Einstein coefficient but show lower sensitivity to changes in asphalt properties [16].