## 2 Materials and Methods
### Production
#### 2.2.2 Kim Test  
The Kim test is a novel testing method developed in South Korea that aims to evaluate the asphalt mixture's deformation mechanism when subjected to wheel loading [20,25]. Typically, the Marshall test is used to assess the resistance of the asphalt mixture against plastic deformation. However, due to the inward squeezing pressure load application of the Marshall test, it was found that the load deformation mechanism of the Marshall test does not represent the wheel load application on the pavement, which is the main cause of plastic deformation [26]. Thus, a new testing method, the Kim test, was developed in South Korea, wherein the same type of specimen is still utilized, similar to the Marshall test, but the loading mechanism is modified to represent the application of the wheel load on the asphalt pavement more accurately. Since the development and standardization of the Kim test, it has been implemented in several studies [27, 28, 29] as an alternative testing method in measuring the asphalt mixture's resistance to plastic deformation.  
In accordance with the testing method standardized by the Ministry of Land, Infrastructure, and Transportation [20], the Kim test was conducted as shown in Figure 8. Marshall specimens with a diameter of 100 mm and thickness range of 60-65 mm were  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Volumetric Properties** & **Criteria**[18] & **Value** \\ \hline Asphal binder content (\%) & \textgreater{}6.2 & 6.8 \\ Air void content (\%) & 2.0–4.0 & 2.7 \\ Degree of saturation (\%) & \textgreater{}75 & 84.9 \\ VMA (\%) & \textgreater{}17 & 18.1 \\ \hline \hline \end{tabular}
\end{table}
Table 4: Standard for mix design of the SMA mixture with 13 mm NMAS.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Properties** & **Normal Binder** & **Binder with Pigment** \\ \hline Penetration (0.1 mm) & 48 & 51 \\ Softening Point (\({}^{\circ}\)C) & 71 & 73 \\ Solubility (\%wt) & 99.8 & 99.4 \\ Viscosity (Pa.s) & 1.65 & 1.78 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Comparison of the rheological properties of the normal binder and the binder with pigment.  
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Aggregate Property** & **Standards** & **Criteria**[18] \\ \hline Absolute dry density & KS F 2503 [19] & \textgreater{}2.5 \\ Absorption rate (\%) & KS F 2503 [19] & \textless{}3.0 \\ Coating rate after dynamic immersion test (\%) & MOLIT Anneuses and Appendices IV-A [20] & \textgreater{}50 \\ Flatness rate (\%) & KS F 2575 [21] & \textless{}10 \\ Abrasion rate (\%) & KS F 2508 [22] & \textless{}35 \\ Stability (\%) & KS F 2507 [23] & \textless{}12 \\ Percentage of fractured particles in coarse aggregate (\%) & ASTM D5821 [24] & \textgreater{}85 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Aggregate property test standards and criteria.  
fabricated and preconditioned in the water bath for 30 min at 60 \({}^{\circ}\)C. After preconditioning, each specimen was placed in a special mold for Kim test. The mold has a tube guide for the loading rod to ensure that the loading application is maintained at a right angle to the test specimen. The loading rod, having a circular cross-section with a diameter of 40 mm and a rounded corner with a radius of 10 mm at the loading surface of the rod, is geometrically designed to simulate circular tire imprints of a single-wheel loading. The Marshall tester was used to apply the static compressive load on the test specimen with a loading rate of 30 mm/min until it reached failure. For each material, three testing repetitions were performed on three test specimens to consider the repeatability and precision of the test results. From the stress-strain curve produced from the testing, the maximum load and vertical depth were obtained, and the deformation strength was computed using the following equation:  
\[S_{D}=\frac{0.32P}{(10+\sqrt{20y-y^{2}})^{2}} \tag{1}\]  
where \(S_{D}\) is the deformation strength in MPa; \(P\) is the maximum load in N; and \(y\) is the maximum vertical depth in mm.