# Mechanical Properties of Cement-Treated Soil Mixed with Cellulose Nanofibre
## 2 Materials and the Mixture Method
### Mixture Procedure of Soil, Cement, and CNF
#### 2.3.2 Method 2  
As mentioned above, CNF in gel form was used in Method 1 with the aim of ensuring uniform mixing. However, water in the gel is added to the soil to increase the amount of CNF, and consequently, more cement is required to solidify the soil. To overcome this problem, dry powdered CNF was added to wet clay in Method 2 instead of the gel form of CNF. This is a more practical method for addition in the field. It is also practical to use high concentrations of CNF, even if it is difficult to produce powdered CNF. Figure 3 shows the mixture procedure for specimen preparation using Method 2. Powdered CNF (TEMPO-CNF) and cement (blast-furnace cement type B or high-early-strength cement) were mixed well in advance. Separately, Kawasaki clay was water-adjusted to obtain a liquid limit ratio of 1.55 or 1.95; then, they were mixed and stirred. For the specimens used in the permeability tests, ACC-CNF-S mixed with high-early-strength cement was also prepared, because the powdered ACC-CNF-S was not available. The gel form was used in this type of specimen. \begin{table}
\begin{tabular}{c c c c c c c c c c c c} \hline \hline \multirow{2}{*}{**(a)**} & \multicolumn{3}{c}{**Soil (Kasaoka Clay)**} & \multicolumn{3}{c}{**Amounts of Component**} & \multirow{2}{*}{**CNF -No Addition-**} & \multirow{2}{*}{**Total**} & \multirow{2}{*}{**Addition**} & \multirow{2}{*}{**Addition**} \\ \cline{2-2} \cline{6-11}  & \multicolumn{2}{c}{**Total**} & & & & & **(Ordinary** & & & **Portal)** & & **Total** \\ \hline \(\beta\) & 769 & 725 & 45 & 655 & 100 & 0 & 0 & 0 & 1525 & & \\ \(\text{g}/\text{cm}^{3}\) & - & 2.70 & 1.00 & 1.00 & 3.16 & - & 1.5 & 1.0 & 1.52 & 0.0 & 100.0 \\ \(\text{cm}^{3}\) & 313 & 268 & 45 & 655 & 32 & 0 & 0 & 0 & 1000 & & \\ \hline \hline \multicolumn{11}{c}{**Amounts of Component**} & \multirow{2}{*}{**Total**} & \multirow{2}{*}{**CNF (TEMPO-CNF)**} & \multirow{2}{*}{**Content**} \\ \cline{2-2} \cline{6-11}  & \multicolumn{2}{c}{**Soil (Kasaoka Clay)**} & & & & & **(Centim)** & & **(CNF & **Condition** & **Addition** & **Addition** \\ \cline{2-2} \cline{6-11}  & \multicolumn{2}{c}{**Total**} & \multirow{2}{*}{**Serial**} & \multirow{2}{*}{**Water**} & \multirow{2}{*}{**Portland)**} & \multirow{2}{*}{**Total**} & \multirow{2}{*}{**Total**} & \multirow{2}{*}{**Total**} & \multirow{2}{*}{**Water**} & \multirow{2}{*}{**Rate (\%)**} & \multirow{2}{*}{**Rate (\%)**} & \multirow{2}{*}{**Rate (\%)**} \\ \hline \(\beta\) & 769 & 725 & 45 & 300 & 100 & 363 & 7.25 & 355 & 1532 & & \\ \(\text{g}/\text{cm}^{3}\) & - & 2.70 & 1.00 & 1.00 & 3.16 & - & 1.5 & 1.0 & 1.52 & 1.0 & 99.5 \\ \(\text{cm}^{3}\) & 313 & 268 & 45 & 300 & 32 & 360 & 5 & 355 & 1005 & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Mix proportion of cement, CNF, water, and soil in Method 1: (**a**) Treated soil without CNF; (**b**) Treated soil with TEMPO-CNF (Gel); (**c**) Treated soil with ACC-CNF-S; (**d**) Treated soil with ACC-CNF-B. Figure 3: Mixture procedure for preparing specimens (Method 2). The soil mixer used for mixing was the same as that used in Method 1, and the mixing time was set to 1 or 5 min. A 5 min agitation makes the cement-treated soil uniform both with and without CNF. For this reason, the mixing time was shortened to 1 min for some specimens, which deliberately created a condition of insufficient mixing. It was easy to predict that without CNF mixing, stirring would be inadequate, and this test series was used to investigate whether the addition of CNF would promote uniform mixing of the cement. The specimens used in the permeability tests required uniformly treated soil. This was why a sufficient mixing time of 5 min was provided. Figure 4 shows the immediate aftermath of a short mixing time of 1 min for the specimen. In the figure, it was easily possible to visually distinguish between cemented and uncomented areas in the soil without the CNF mixture. On the other hand, in the soil mixed with CNF, there was no unevenness of mixing as far as could be visually observed, indicating the effect of the addition of CNF.