## 2 Materials and Methods  
In this study, asphalt binder with a penetration grade of Pen 60/80 (Hubei Guochuang Hi-tech Material Co., Ltd., Wuhan, China) was investigated as the substance to be removed, the fundamental properties are listed in Table 1. This bituminous binder is largely employed in heavy traffic roads. The used #92 gasoline was supplied by Sinopec (Sinopec, Beijing, China). The mineral powder adopted was made of limestone with an average size of 48 \(\upmu\)m, Table 2 shows its associated physical properties.  
In order to analyze the absorbing strength, the experiment added mineral powder into mixed asphalt and gasoline solution whose sediment was then investigated further. Figure 1 depicts the sample preparation processes. Firstly, 10 g asphalt binder was dissolved in 150 mL gasoline contained in an Erlenmeyer flask, the process was accelerated by shaking the flask for 10 min and letting it rest for 60 min. Successively, 20 g of mineral was added into the solution, which rested for 30 min; afterwards, the sediment was extracted with suction filtration. Due to the complex composition of gasoline and asphalt, the components of both mineral powder and sediment were investigated as research objects for their relatively stable components and structures. Corresponding to the actual situation for asphalt cleaning works, all procedures for sample preparation were implemented under room temperature and normal pressure conditions. Pure mineral powder was labelled as sample A, the sediment from gasoline and mineral powder was labelled as sample B and the sediment from mineral powder, asphalt and gasoline was marked as Sample C.  
There are three primary aims for this research: (1) verify the feasibility of using mineral powder to absorb asphalt; (2) explore the absorbance efficiency and mechanism of using mineral powder to absorb asphalt; (3) assess the environmental impacts and financial investment of using mineral powder. In order to address these problems, this study focused on the dissolving process and utilized XRD (BRUKER AXS GMBH, Karlsruhe, Germany) with D8 Advance specification to study samples' crystal compositions [27]. XRF (Malvern Panalytical, Almelo, Netherland) method with Zetium specification was adopted to integrate the contents and compositions of samples [28]. The specification of the FTIR instrument used in the experiment was Nicolet 6700 (Thermo Electron Scientific Instruments, Madison, WI, US), the conducted wavenumber range was 400-4000 cm\({}^{-1}\)[29]. The AAS employed was CONTRA-700 (Analytik Jena AG, Thuringia, Germany), and the samples were tested at 0.3 MPa under an argon atmosphere [30]. Additionally, a case study from Wuhan University of Technology was implemented to assess the cost and environmental impacts. Consulting the data from the China Energy  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Property** & **Result** & **Standard** \\ \hline Specific gravity & 1.034 & ASTM D70 \\ Penetration at 25 \({}^{\circ}\)C (0.1 mm) & 63 & ASTM D5 \\ Ductility, 5 cm/min, 5 \({}^{\circ}\)C (mm) & 37 & ASTM D113 \\ Softening point (\({}^{\circ}\)C) & 48 & ASTM D36 \\ Apparent viscosity, 135 \({}^{\circ}\)C (Pa-s) & 0.46 & ASTM D4402 \\ Loss on heating (wt.\%) & +0.09 & ASTM D6 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Fundamental properties of Pen60/80 asphalt binder.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Property** & **Result** & **Standard** \\ \hline Apparent density (t/m\({}^{3}\)) & \textgreater{}2.701 & T 0352-2000 \\ \hline Moisture content (\%) & \textless{}0.1 & T 0103-1993 \\ \hline Hydrophilic coefficient & 0.8 & T 0353-2000 \\ \hline Plasticity index (\%) & 3.4 & T 0354-2000 \\ \hline Passing rate (0.075 mm sieve, \%) & 86.7 & T 0351-2000 \\ \hline \hline \end{tabular}
\end{table}
Table 2: Physical properties of mineral powder.  
Statistical Yearbook 2013 [31] and published literature [32; 33; 34; 35; 36], the extraction processes of gasoline and mineral powder were considered, and their comprehensive benefits were calculated and compared.