## 2 Materials and Methodology
### Testing Program  
Disintegration of the soils was achieved by using a laboratory mixer with mixing speed of 107 rpm. Disintegration time (T) is defined as the time required to homogenize and separate the agglomerated soil particles into smaller sizes, which represents the mixing duration in seconds. The disintegration (mixing) times were increased in several steps from 6 to 120 s for various soil types, to investigate the behavior of soil particles. The disintegration times were chosen depending on the soil type, plasticity index and water content.  
After mixing the soil with its natural water content for a specified time (Table 4), two specimens were prepared. The first specimen was prepared directly after mixing of soil and evaluated. While the second specimen was left to air dry at a controlled room temperature of about 20 \({}^{\circ}\)C for two days and evaluated. The air-dried specimen was prepared in order to avoid any concerns about clogging of sieve openings due to the wet specimen's moisture content.  
A visual observation and standard dry sieving tests using a sieving machine were used to optimize the ideal (proper) disintegration time for wet and air-dried specimens based on obtaining a smaller size of soil particles. The sieves used ranged in size from 16 to 0.063 mm. To find a suitable sieving time, six wet soil specimens from Soil 3 were prepared and sieved at different sieving times from 10 to 60 mins (Figure 2).  
\begin{table}
\begin{tabular}{c c c c c c c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Soil Types**} & **Water** & **Specimen** & \multicolumn{6}{c}{**Disintegration Time (T) (Second)**} & \multicolumn{6}{c}{**Number of**} & \multirow{2}{*}{**Sieving Time (Minutes)**} \\  & **Content \%** & & & **Type** & & & & & & & & & & & & \\ \hline Soil 1 (Silty) & 27–30 & Wet & 0 & 10 & 16 & 30 & 45 & 60 & 75 & 90 & 120 & 15 & 10 & 15 & 30 & 50 & 60 \\ clay PI - 185v) & 27–30 & Air dry & 17 & 30 & 60 & & & & & & & & & & & & \\ Soil 2 (Silty) & 50 & Wet & 0 & 10 & 13 & 16 & & & & & & & & & & \\ clay, PI - 585 & & Air dry & & 10 & 13 & & & & & & & & & & & \\ Soil 3 (Silty) & 47 & Wet & 0 & 6 & 12 & 22 & & & & & & & & & & \\ clay, PI - 16\%) & 47 & Air dry & & 6 & 13 & & & & & & & & & & & & \\ Soil 4 (Silt, PI = 11\%) & 40–50 & Wet & 0 & 7 & 15 & 30 & & & & & & & & & & \\ \hline \hline \end{tabular}
\end{table}
Table 4: The test program for homogenizing and disintegrating the natural soil.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Soil** & **Soil 1** & **Soil 2** & **Soil 3** & **Soil 4** \\ \hline Soil location & Gothenburg & \multicolumn{2}{c}{Sunderbyn, Lulééà} & Umeà \\ Soil conditions & Aerobic & Anaerobic (N) & Aerobic & Anaerobic \\ Silicon oxide (SiO\({}_{2}\)) \% & 65.7 & 54.7 & 54.1 & 63.3 \\ Aluminum oxide (Al\({}_{2}\))O \% & 12.3 & 12.8 & 11.3 & 10.8 \\ Calcium oxide (CaO) \% & 2.4 & 2.11 & 1.88 & 1.9 \\ Iron oxide (Fe\({}_{2}\)O\({}_{3}\)) & 3.42 & 4.33 & 4.93 & 3.7 \\ Potassium oxide (K\({}_{2}\)O) \% & 2.84 & 2.77 & 2.67 & 2.29 \\ Magnesium oxide (MgO) \% & 1.31 & 2.25 & 1.4 & 1.29 \\ MnO \% & 0.15 & 0.217 & 0.0482 & 0.0644 \\ Sodium oxide (Na\({}_{2}\)O) \% & 0.55 & 2.56 & 2.68 & 2.47 \\ P\({}_{2}\)O\% & 0.15 & 0.182 & 0.16 & 0.176 \\ TiO\({}_{2}\) \% & 0.55 & 0.677 & 0.615 & 0.603 \\ Sulfate content, mg/kg TS & & 24800 & 3400 & 2800 \\ \hline \hline \end{tabular}
\end{table}
Table 3: Chemical composition of tested soils.  
Figure 2: Laboratory mixer and sieving test for wet soil specimen.