## 1 Introduction  
The amount of construction trash produced each year has increased significantly as a result of the fast urbanization and infrastructural development. However, the utilization rate of solid waste during construction is still very low [1; 2; 3; 4]. On the other hand, mining natural aggregates can lead to irreversible ecological damage in mountainous areas, while the processing and transportation processes result in high carbon emissions, highlighting the increasingly prominent environmental and social issues [5; 6; 7]. In the context of global efforts to promote energy conservation and emission reduction, the transformation of resource utilization in the construction industry, which involves replacing natural sand and stone with construction solid waste, emerges as the path for the industry to achieve carbon reduction goals and upgrade development [8; 9; 10]. With the continuous improvement of construction solid waste particle-size crushing and component-sorting technology, a large amount of uniformly shaped, clean, and high-purity recycled concrete aggregate (RCA) can be obtained, and the cost of using RCA is lower than that of natural aggregates [11; 12; 13; 14]. Therefore, the application of RCA in asphalt pavement has significant environmental value and economic benefits [15]. The primary distinction between RCA and natural aggregates is that the surface absorbs a lot of cement mortar [16; 17]. According to studies, the main factor that contributes to the inadequate adhesion of asphalt and aggregates is the existence of cement mortar on the surface of RCA [18; 19]. The calcium silicate hydrate (C-S-H) in the cement mortar accounts for approximately 60-70% of the hydration products, and it is the principal component and strength source of cement hydration products [20]. However, the chemical bonding between C-S-H and asphalt is weak, which can easily lead to inadequate bond strength between the mortar and asphalt. On the other hand, the mortar pores and microcracks on the surface of RCA are plentiful, and water adsorbed by capillary action is difficult to discharge under natural conditions. Because asphalt is hydrophobic, the existence of water might cause damage to the RCA/asphal interface [21]. Therefore, in order to add the amount of RCA blending and improve the performance of hot-mix asphalt mixtures, it is necessary to address the problem of inadequate chemical bonding between RCA and asphalt, as well as water damage to the interface. For enhancing the basic properties of materials, many scholars have chosen different modification methods [22; 23; 24; 25; 26]. The addition of anti-spalling chemicals into asphalt mixtures is an efficient technique to boost binding strength and improve resistance to water damage at the asphalt/aggregate interface [27; 28; 29]. At the moment, the most popular anti-spalling agent is silane coupling agent (SCA), which is widely applied to enhance the interface binding strength of organic and inorganic materials [30]. This is due mainly to the fact that its organic functional groups and hydrolyzed groups can be chemically linked with organic and inorganic materials, respectively, which helps to improve the interfacial binding strength of organic and inorganic interface materials [31]. Due to the unique nature of SCA, its application in asphalt mixtures has attracted extensive attention from researchers. [PERSON] et al. [32] investigated the effect of SCA (KHE50) on the adhesion properties between acidic aggregates and asphalt. They found that SCA can act as a molecular bridge to enhance the bond strength between asphalt and acidic aggregates. [PERSON] et al. [33] conducted an analysis on the water stability of SCA-modified asphalt with aggregates, comparing it to SBS-modified asphalt and rock-modified asphalt. The study revealed that SCA-modified asphalt exhibited superior water stability when combined with aggregates. [PERSON] et al.