## 1 Introduction  
Asphalt mixtures are composite materials consisting of mineral aggregates and asphalt binders [1]. Asphalt pavement, in the long-term use of the process, is vulnerable to environmental factors and vehicle loading continuous action, during which the asphalt binder aging is deepened, resulting in a reduction in the comprehensive application of asphalt mixture performance [2; 3; 4]. To conserve natural resources, reduce economic costs, and protect the environment, aged asphalt mixtures are rejuvenated to replace some of the virgin material [5; 6]. Owing to the aging process, asphalt binders will occur a series of physical and chemical reactions, which will lead to asphalt binder road performance degradation. Asphalt pavement rejuvenation technology, through the addition of an asphalt binder rejuvenator to regulate the aging asphalt binder component, changes to restore its road performance [7; 8; 9]. At present, more precise experimental instruments are needed to study the microstructure and performance changes during the aging and rejuvenation process of asphalt binders. Atomic force microscopy (AFM) provides a promising method for researchers to study asphalt binders on a micro scale from different perspectives [10]. The first application of AFM in asphalt binders was made by [PERSON], who discovered the bee structure in asphalt binders [11]. Waves in asphalt binders can occur as bee structures [12]. The bee structure of asphalt binders is of interest because of its unique morphology, and the microstructure has three distinct phases: the catana phase, the peri phase, and the para phase (the terms 'bee phase', 'bee casing', and 'interstitial phase' are used in this article, which refer to the 'catana phase' or the 'peri phase' and 'para phase', respectively) [13]. [PERSON] et al. [14] linked the appearance of the bee structure to the presence of wax, while [PERSON] et al. [15] discovered a connection among asphaltene and the bee structure. [PERSON] et al. [16] found that the formation of the bee structure was observed in asphalt binders during cooling, and the disappearance of the bee structure was observed during heating. Several studies have analyzed the surface properties of recycled asphalt binders after the addition of rejuvenators. For example, the addition of rejuvenators resulted in dramatic changes in the asphalt binder morphology [17; 18]. In a study by [PERSON] et al. [1], in order to better understand the variations in the microstructures of aged asphalt binders after the addition of rejuvenators, or the variations in the microstructures of asphalt binders before and after aging, the modulus of elasticity of the surfaces of all asphalt binders before and after aging was measured using an AFM, and a comparative analysis of the modulus of elasticity of the surface of the bee structure with the bulk modulus of elasticity of the unaged asphalt binder was also performed. [PERSON] et al. [11] used AFM quantitative nanomechanical property maps to demonstrate the morphology of an asphalt binder and its relationship with the local mechanical properties. Some special structures on the surfaces of asphalt binders, including the bee structure, can adversely affect the micromechanical properties of asphalt binders [19]. [PERSON] et al. [19] studied the microstructures and micromechanical properties of four types of asphalt and SARA (saturated hydrocarbons, aromatics, resins, and asphaltenes) components in the temperature range of 25 \({}^{\circ}\)C to 65 \({}^{\circ}\)C using quantitative nanomechanical performance maps equipped in AFM. The morphology of the bee structure changed significantly at temperatures between 50 \({}^{\circ}\)C and 56 \({}^{\circ}\)C, and the bee structure disappeared completely at temperatures above 57 \({}^{\circ}\)C [20]. A comparison of unaged and aged asphalt binders via AFM testing confirms that the lightweight component content is greatly reduced during the aging process.