## 1 Introduction
[PERSON]'s analysis indicated that all three indices are influenced by filler volume fraction, with the Palierne-\(C\) index exhibiting the least dependence [17]. From the above analysis, it is clear that the applicability of interaction evaluation methods based on rheological properties varies under different conditions. Moreover, these methods also exhibit dependence on the volume fraction of the mineral filler. [PERSON] analyzedthe variations in three indicators--Luis Ibarrara-_A_, Ziegel-_B_, and Palierne-C--relative to the volume fraction of mineral filler. The results indicated that all three indicators are influenced by the volume fraction of mineral filler, with the Palierne-_C_ index showing the least dependence [17]. Since these interaction indicators are calculated at a single volume fraction of mineral filler, this dependency affects the accuracy of the interaction evaluation. In addition to rheology-based evaluation indices, relevant standards have also established parameters for assessing the interaction between bitumen and mineral fillers, such as the Bitumen Capacity Index (BCI). The BCI is a key parameter for quantifying the interaction between bitumen and mineral fillers, as defined in the European Standard EN 13179-2 [18]. The calculation of BCI typically involves determining the bitumen adsorption, viscosity, and specific surface area of the filler, as well as its chemical reactivity. However, these standard methods have certain limitations. They require multiple steps and sophisticated equipment, which can be time-consuming and resource-intensive [19]. Moreover, these methods primarily focus on adsorption and chemical reactivity but may not completely capture the full range of physical and mechanical interactions between bitumen and fillers under operational conditions. According to the research of [PERSON] on the interaction between asphalt and mineral filler, physicochemical interactions occur between asphalt and mineral filler during high-temperature mixing. Asphalt undergoes a rearrangement of its chemical components on the surface of the mineral filler, forming a structural asphalt layer [20]. The thickness of this layer is referred to as the adsorbed asphalt film thickness. The thickness of the adsorbed asphalt film is directly proportional to the intensity of the physicochemical interaction between the asphalt and the mineral filler. Therefore, compared to rheological property-based evaluation indicators, the adsorbed asphalt film thickness provides a more accurate representation of the interaction capability between asphalt and mineral fillers. To measure the thickness of the adsorbed asphalt film on mineral filler, [PERSON] et al. employed Differential Scanning Calorimetry (DSC) to determine the glass transition temperature of asphaltastic. The thickness of the adsorbed asphalt film was calculated based on changes in specific heat capacity during the glass transition process. Using this method, the calculated thickness ranged from 0.02 to 5.28 nm [20]. However, DSC is typically applicable to homogeneous materials, where thermal properties such as specific heat capacity and thermal conductivity are uniform throughout the sample. For asphalt mastic, which is a heterogeneous material, the results obtained from DSC may not accurately reflect the true thermal behavior of the material. Wide-Angle X-ray Diffraction (WAXD) offers several advantages over DSC for analyzing the crystalline structure of asphalt mastic. WAXD can directly observe the presence and arrangement of crystalline domains, providing detailed information on the crystalline phases and molecular orientation within the material. This technique is particularly suitable for heterogeneous materials like asphalt mastic, as it can provide spatially resolved information on the crystalline structure. Recent studies, such as the work by [PERSON] et al.