# Study on Components Determination and Performance Evaluation of LS Pre-Maintenance Agent
## 1 Introduction  
Asphalt pavement is affected by traffic load and other environmental factors during its service period. Its performance gradually declines, as shown in Figure 1, and therefore taking active pre-maintenance before significant damage can occur effectively prevents the early disease of asphalt pavement and improves road conditions [1; 2]. How to choose the targeted maintenance schedule means understanding the right time, and has been the focus of maintenance engineering research overmany years. Specifically, high altitude areas, strong ultraviolet (UV) radiation, and thin asphalt surface cause serious damage and can significantly age asphalt. The UV aging range typically reaches 20-25% thickness of the surface layer, which means higher requirements for maintenance materials and technology [3]. Although some progress has been made, such as micro-surfacing and fog sealing, the application effect of existing technology is limited. Research into asphalt pavement pre-maintenance materials in strong UV radiation areas is relatively scarce [4; 5]. Thus this study explores existing scarce research and develops a novel treatment schedule. Existing studies have conducted research on aging and regenerating of asphalt. [PERSON] used the thin film oven test (TFOT) and rolling thin film oven test (RTFOT) tests to simulate the aging process of asphalt. They studied the chemical and rheological properties of aging asphalt by infrared spectroscopy, chromatography, and dynamic mechanical analysis, then compared the effects of the different aging methods [6]. [PERSON] compared the effects of the RTFOT and UV aging tests on the thermal stability and adhesion of aged asphalt, using kinetic information to predict the service life of modified asphalt [7]. [PERSON] used X-ray diffraction to analyze the micro-structural changes in UV aging of SBS by adding organic montmorillonite (OMMT), analyzing the light aging resistance of the OMMT/SBS asphalt [8]. [PERSON] used a dynamic shear rheometer (DSR) and FTIR (Fourier transform infrared spectroscopy) to analyze the temperature effect on the asphalt UV aging process, comparing the significance of temperature in an aging test [9]. [PERSON] combined component tests, combined with conventional and Superpave indicators to analyze asphalt change as a result of the RTFOT and pressure aging vessel (PAV) tests, comparing asphalt composition changes and anti-aging properties during the aging process [10]. The above research provides a multi-angle analysis on asphalt rheological properties and chemical changes in thermal oxygen aging and UV aging methods. The research outlined above of asphalt UV aging is closely related to this study. For asphalt regeneration, the essence is to add new asphalt and an aromatics reducing agent into the aged asphalt to restore its original performance. [PERSON] simulated a long-term light and heat aging process of an asphalt pavement, establishing a standard aging test model that analyzed the anti-aging and storage stability of antioxidants and UV absorbers [11]. [PERSON] evaluated the restorative effects of different reducing agents on aged asphalt by bending beam rheometer (BBR) and DSR, especially on asphalt viscoelastic and low temperature performance [12]. [PERSON] used AFM (Atomic Force Microscopy) to study the mechanism of asphalt aging and regeneration, analyzing the change in asphalt composition from the micro-structure [13]. The above research above provides a solid theoretical basis and the experimental ideas guiding this study. From the viewpoint of maintenance time, scientifically determining the maintenance time can effectively reduce the cost, prolong road life, and improve surface conditions; however, this requires a matched monitoring, data collecting, and analyzing system [14]. [PERSON] summarized the effectiveness and applicability of common pre-maintenance measures, such as fog seal, slurry seal,  
Figure 1: Road conditions under taking/not taking pre-maintenance work. thin cover and micro-surfacing.