## 2 Materials and Methods  
### Materials  
When conducting research in the framework of this work, potassium hydroxide KOH produced by OOO Soda-Chlorate (Bereznik, Perm Region, Russia) [30] and sodium liquid glass Na\({}_{2}\)O (SiO\({}_{2}\))\({}_{n}\) produced by JSC Kubanzheldormash (Armavir, Russia) were used according to [31]. Quartz sand was used as a fine aggregate, the physical characteristics of which are presented in Table 1.  
Metakaolin produced by OOO RossPolymer (Noginsk, Moscow Region, Russia) was used as the main component of the geopolymer binder. The chemical composition of metakaolin and its physical characteristics are presented in Tables 2 and 3. Water for laboratory research was used tap water that fully meets the requirements [32]. Additionally, in this study, two types of stone flour were used--namely, potassium feldspar, grade FK-100, produced by Malyshevskoye Ore Administration JSC (Malyshev settlement, Sverdlovsk Region, Russia) and micro calcite, grade Km-2, produced by Koelgamramor (Koelg village, Chelyabinskaya Region, Russia) according to [33]. The chemical composition and physical properties of potassium feldspar and its granulometric characteristics following the manufacturer's specification are presented in Tables 4 and 5 and Figure 2. These data are provided by the manufacturer. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multicolumn{6}{c}{**Grain Composition**} \\ \hline  & \multicolumn{3}{c}{**Sieve Hole Sizes, mm**} & \multicolumn{3}{c}{**Pass-Through a**} & \multicolumn{3}{c}{**Size With**} & \multicolumn{3}{c}{**Content of**} & \multicolumn{1}{c}{**True**} & \multicolumn{1}{c}{**Bulk**} \\ \hline
**Sieve** & \multicolumn{3}{c}{**Private and Total Sieve Residual, \%**} & \multicolumn{3}{c}{**Mesh No. 0.16, wt \%**} & \multicolumn{3}{c}{**Module**} & \multicolumn{1}{c}{**Dust and Clay**} & \multicolumn{1}{c}{**Density**} & \multicolumn{1}{c}{**Density**} \\
**Residual** & \multicolumn{3}{c}{**Private and Total Sieve Residual, \%**} & \multicolumn{3}{c}{**wt \%**} & \multicolumn{3}{c}{**Particles, \%**} & \multicolumn{1}{c}{**kg/m\({}^{3}\)**} & \multicolumn{1}{c}{**kg/m\({}^{3}\)**} \\ \hline
**10** & **5** & **2.5** & **1.25** & **0.63** & **0.315** & **0.16** & & & & \\ \hline
0 & 0.17 & 1.39 & 8.86 & 45.80 & 41.03 & 2.49 & & & & \\
0 & 0.17 & 1.56 & 10.42 & 56.21 & 97.25 & 99.74 & 1.66 & 1.1 & 2650 & 1438 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Physical characteristics of dense fine aggregate. \begin{table}
\begin{tabular}{c c} \hline
**Title** & **Value** \\ \hline Aluminium oxide Al\({}_{2}\)O\({}_{3}\), wt \% & 42 \\ Silicon oxide SiO\({}_{2}\), wt \% & 51 \\ Iron oxide Fe\({}_{2}\)O\({}_{3}\), wt \% & 0.5 \\ Loss on ignition, \% & 1 \\ pH in 10\% aqueous suspension & 5.5 \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Chemical composition of metakaolin RossPolymer “MetaKaolin 1400”. \begin{table}
\begin{tabular}{c c} \hline
**Title** & **Value** \\ \hline Sieve residue No. 0063, wt \% & 0.2 \\ Average particle size (D50), no more, \(\mu\)m & 10 \\ Specific surface, m\({}^{2}\)/g & 18 \\ Bulk density, kg/m\({}^{3}\) & 265 \\ \hline \hline \end{tabular}
\end{table} 
Table 3: Physical characteristics of metakaolin. \begin{table}
\begin{tabular}{c c} \hline
**Chemical** \\
**Composition, \%** & **SiO\({}_{2}\)** & **Al\({}_{2}\)O\({}_{3}\)** & **K\({}_{2}\)O** & **Na\({}_{2}\)O** & **CaO** & **Fe\({}_{2}\)O\({}_{3}\)** & **TiO\({}_{2}\)** & **MgO** & **L.O.J** \\ \hline  & 68.60 & 17.00 & 11.20 & 2.15 & 0.45 & 0.09 & 0.02 & 0.04 & 0.45 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Chemical composition of FK-100 potassium feldspar. The chemical composition and physical properties of Km-2 grade micro calcite and its granulometric characteristics in accordance with the manufacturer's specification are presented in Table 6 and Figure 3.