## 2 Materials and Experiment
### Anti-Icing Asphalt Mixture
#### 2.2.4 Transverse Distribution Evaluation  
Likewise, in the transverse direction, the specimen was scanned with Computed Tomography (CT) at an interval of 13.5 mm. Each image was divided into 12 segments for the evaluation of distribution uniformity. After Image 1 was segmented, anti-icing filler points were marked, as illustrated in Figures 5 and 6.  
Figure 4: Extract scatter.  
Figure 3: Image partition.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Number**} & \multicolumn{11}{c}{**Region**} \\ \cline{2-13}  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **Variance** & **Uniformity** \\ \hline
1 & 7 & 6 & 6 & 6 & 1 & 10 & 9 & 5 & 3 & 10 & 8 & 4 & 7.02 & \(-0.85\) \\
3 & 23 & 22 & 16 & 17 & 27 & 13 & 18 & 19 & 29 & 19 & 10 & 20 & 26.58 & \(-1.42\) \\
4 & 21 & 23 & 15 & 16 & 28 & 16 & 14 & 16 & 25 & 21 & 16 & 12 & 22.08 & \(-1.34\) \\
5 & 23 & 23 & 17 & 18 & 24 & 21 & 18 & 18 & 21 & 25 & 16 & 19 & 8.19 & \(-0.91\) \\
6 & 22 & 23 & 18 & 17 & 17 & 24 & 19 & 20 & 21 & 22 & 21 & 16 & 6.17 & \(-0.79\) \\
7 & 21 & 22 & 18 & 17 & 25 & 15 & 17 & 21 & 26 & 19 & 13 & 20 & 13.42 & \(-1.13\) \\
8 & 17 & 15 & 11 & 17 & 16 & 17 & 12 & 15 & 18 & 11 & 13 & 18 & 6.33 & \(-0.80\) \\
9 & 14 & 8 & 8 & 11 & 12 & 6 & 11 & 12 & 13 & 11 & 7 & 10 & 5.69 & \(-0.75\) \\ \hline \hline \end{tabular}
\end{table}
Table 8: Calculation results of longitudinal uniformity.  
In Figure 6, the numbers of anti-icing filler points in Segments 1-12 are 22, 29, 19, 14, 28, 21, 15, 20, 26, 25, 20, and 13, respectively. The variance \(S\) is 25.83. The \(U\) value is equal to \(-1.41\) (more than \(-2\)), indicating a great uniformity in the transverse direction. The results of the other five images are shown in Table 9.  
The average longitudinal and transverse uniformity values are \(-0.999\) and \(-1.094\), respectively. Both are more than \(-2\), indicating that the anti-icing filler was uniformly distributed in the asphalt mixture.  
When the anti-icing filler is uniformly distributed inside of the asphalt mixture, the salting-out is uniform, so the snow melt effect of every part of the pavement is consistent and the asphalt mixture performances are less affected. Because of the uniform salting-out, the void volume will not increase sharply in certain parts. As a result, uniform changes of pavement performances can be guaranteed.  
Figure 5: Image partition.  
Figure 6: Extract scatter.  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Number**} & \multicolumn{11}{c}{**Region**} \\ \cline{2-13}  & **1** & **2** & **3** & **4** & **5** & **6** & **7** & **8** & **9** & **10** & **11** & **12** & **Variance** & **Uniformity** \\ \hline
2 & 23 & 25 & 18 & 24 & 20 & 19 & 13 & 19 & 25 & 16 & 19 & 22 & 12.52 & \(-1.10\) \\
3 & 22 & 22 & 27 & 24 & 19 & 25 & 27 & 29 & 28 & 16 & 17 & 21 & 17.08 & \(-1.23\) \\
4 & 24 & 28 & 20 & 16 & 25 & 22 & 27 & 18 & 24 & 24 & 19 & 23 & 12.08 & \(-1.08\) \\
5 & 19 & 15 & 22 & 25 & 20 & 21 & 20 & 24 & 23 & 22 & 20 & 25 & 7.39 & \(-0.87\) \\
6 & 18 & 25 & 20 & 26 & 19 & 20 & 25 & 24 & 21 & 26 & 21 & 21 & 7.47 & \(-0.87\) \\ \hline \hline \end{tabular}
\end{table}
Table 9: Calculation results of horizontal uniformity.