## 2 Analysis and Experimental Methods of Correlating Toughness and Hydraulic Resistance
### Comparison of 2 mm and 10 mm Thickness  
Table 5 shows the average values of cohesive strength and elongation toughness for each type of SPRG viscosity and thickness of 2 mm and 10 mm specimens for each temperature condition. Figure 9: Cohesive strength and toughness comparison of viscosity types based on temperature condition (10 mm thickness); (**a**) toughness and cohesion strength comparison based on viscosity type, (**b**) toughness and cohesion strength comparison based on temperature condition. (1) _Comparison of cohesive strength_  
Figure 10 shows the results of comparison of the cohesive strength of the 2 mm and 10 mm thick specimens. Comparison of cohesive strength according to the thickness of the SPRG sample shows that the cohesive strength of 2 mm thickness is greater than that of 10 mm thickness in types A, B, and C viscosities. In a comparison of the cohesive strength according to the viscosity, it was found that the cohesive strength deviation was large according to the thickness difference in the low viscosity (Type A) or the medium viscosity (Type B), but the deviation was not large in the high viscosity (Type C). In a comparison of cohesive strength according to temperature conditions, it was found that in the low viscosity (Type A) or medium viscosity (Type B), the cohesive strength deviation was large according to the thickness difference at all temperatures, but the deviation was not large in high viscosity (Type C). Figure 10: Cohesive strength comparison with sample thickness and temperature. \begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Specimen** & **Thickness** & **Temperature** & \begin{tabular}{c} **Avg.** \\ **Cohesive** \\ **Strength** \\ **[N/mm\({}^{2}\)]** \\ \end{tabular} & \
\begin{tabular}{c} **Average** \\ **Elongation** \\ **[\%]** \\ \end{tabular} &
\begin{tabular}{c} **Average** \\ **Toughness** \\ **[N/mm\({}^{2}\)]** \\ \end{tabular} \\ \hline \multirow{4}{*}{Type A} & \multirow{4}{*}{2 mm} & 5 \({}^{\circ}\)C & 0.0195 & 1141 & 0.0123 \\  & & 10 \({}^{\circ}\)C & 0.0115 & 1400 & 0.0117 \\  & & 20 \({}^{\circ}\)C & 0.0136 & 695 & 0.0033 \\ \cline{2-6}  & \multirow{4}{*}{10 mm} & 5 \({}^{\circ}\)C & 0.0046 & 3075 & 0.0192 \\  & & 10 \({}^{\circ}\)C & 0.003 & 3076 & 0.0071 \\  & & 20 \({}^{\circ}\)C & 0.0031 & 2920 & 0.0067 \\ \hline \multirow{4}{*}{Type B} & \multirow{4}{*}{2 mm} & 5 \({}^{\circ}\)C & 0.0213 & 1409 & 0.0294 \\  & & 10 \({}^{\circ}\)C & 0.0251 & 1369 & 0.027 \\  & & 20 \({}^{\circ}\)C & 0.0186 & 811 & 0.0057 \\ \cline{2-6}  & \multirow{4}{*}{10 mm} & 5 \({}^{\circ}\)C & 0.0092 & 2127 & 0.1229 \\  & & 10 \({}^{\circ}\)C & 0.008 & 2412 & 0.0747 \\  & & 20 \({}^{\circ}\)C & 0.0071 & 2147 & 0.0352 \\ \hline \multirow{4}{*}{Type C} & \multirow{4}{*}{2 mm} & 5 \({}^{\circ}\)C & 0.0296 & 806 & 0.0309 \\  & & 10 \({}^{\circ}\)C & 0.0342 & 583 & 0.0295 \\ \cline{1-1}  & & 20 \({}^{\circ}\)C & 0.0216 & 1667 & 0.0368 \\ \cline{1-1} \cline{2-6}  & \multirow{4}{*}{10 mm} & 5 \({}^{\circ}\)C & 0.0289 & 1465 & 0.2062 \\ \cline{1-1}  & & 10 \({}^{\circ}\)C & 0.0286 & 5254 & 0.322 \\ \cline{1-1}  & & 20 \({}^{\circ}\)C & 0.0161 & 9490 & 0.2703 \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Comprehensive measurement results for each sample. (2) _Comparison of elongation rates_  
Figure 11 shows the comparison results of elongation rates of 2 mm and 10 mm thick specimens. Comparison of the elongation according to the thickness of the SPRG sample showed that the 10 mm thickness showed a greater elongation than the 2 mm thickness in types A, B, and C viscosities and temperature conditions. Comparing the elongation rate according to the difference in viscosity, it can be seen that the elongation rate is greater at high viscosity (Type C) than at low viscosity (Type A) or medium viscosity (Type B). Comparison of elongation rates according to temperature conditions shows that, at low viscosity (Type A) or medium viscosity (Type B), the elongation deviation is not large at all temperatures of 2 mm and 10 mm, but at high viscosity (Type C) there is a large deviation.