## 2 Materials and Methods
### Methods  
The aerated concrete was prepared in the following sequence: cement, sand, lime, gypsum, and additives were mixed in full in a dry state for 30 s, then 50% of the water necessary for mixing was introduced into the resulting homogeneous mixture of dry components and mixed for 1.5 min, then aluminum powder was introduced into the resulting mixture along with the rest of the mixing water. The resulting mixture was kept at rest for 1 min. After holding the aerated concrete mixture, its mixing continued for 2 min until a homogeneous mixture without lumps was obtained. The samples were cast in one layer and compacted manually using a steel rod. The crust (surplus) was removed after 4 h of exposure with a scraper. Next, the samples were wrapped in a film and kept indoors at a temperature of 24 \(\pm\) 2 \({}^{\circ}\)C for 24 h. After holding for a day, the samples were removed from the formwork and placed in a normal hardening chamber, in which they were kept for 27 days. To determine the proportions of the mixture that will provide the best \"physical and mechanical properties of non-autoclaved aerated concrete, with partial replacement of part of the cement with ground blast furnace slag (GBFS)\" and microsilica (MS), the following replacement levels were chosen: 4%, 8%, 12%, 16%, and 20% of these mineral components by weight of cement. All samples were prepared at a ratio of water and binder component W/B = 0.5, lime was introduced in an amount of 10%, gypsum in an amount of 5%, and aluminum powder in an amount of 1% by weight of the binder. Table 8 shows the formulation of the experimental compositions. \begin{table}
\begin{tabular}{c c} \hline
**Property** & **Value** \\ \hline Bulk density, kg/m\({}^{3}\) & 658 \\ gypsum mortar pH & 7 \\ Water absorption, \% & 38 \\ Fineness of grinding, residue on a sieve with a mesh size of 0.2 mm, \% & 0.9 \\ Setting time, min & \\ Start & 7 \\ the end & 18 \\ \hline \end{tabular}
\end{table} 
Table 7: Characteristics of lime. \begin{table}
\begin{tabular}{c c} \hline
**Property** & **Value** \\ \hline Appearance & Easy-to-smear, silver-gray product. Aluminum particles in the powder are plate-shaped and covered with a thin oxide and fatty film. \\ \hline Average particle thickness, \(\mu\)m & 0.25–0.50 \\ \hline Average linear size of particles, microns & 20–30 \\ \hline Bulk density of powder, g/cm\({}^{3}\) & 0.23 \\ \hline Content of active aluminum, \% & 92 \\ \hline \end{tabular}
\end{table} 
Table 5: Characteristics of aluminum powder PAP-1. \begin{table}
\begin{tabular}{c c} \hline
**Property** & **Value** \\ \hline Content of active CaO and MgO, \% & 88.5 \\ The content of unquenched grains, \% & 11 \\ Extinguishing speed, min & 20 \\ Hydration water content, \% & 3 \\ \hline \end{tabular}
\end{table} 
Table 5: Characteristics of aluminum powder PAP-1. A total of 96 sample cubes were made for testing the average density and compressive strength and 80 sample plates for testing the thermal conductivity (Figure 1). The average density of the manufactured samples of non-autoclaved aerated concrete was determined according to GOST 12730.1 \"Concretes. Methods of determination of density\". The samples were dried to constant weight for 24 h in a laboratory oven at a temperature of 110 \(\pm\) 5 \({}^{\circ}\)C. The weight of the samples was determined by weighing with an error of no more than 0.1%. The density of samples of non-autoclaved aerated concrete sample \(\rho\)w, kg/m\({}^{3}\), was calculated with an error of up to 1 kg/m\({}^{3}\) according to the formula:  
\[\rho_{w}=\frac{m}{V}\cdot 1000, \tag{1}\]  
where \(m\) is the mass of the sample, g; \(V\) is the sample volume, cm\({}^{3}\). The compressive strength was determined according to GOST 10180 \"Concretes. Methods for strength determination using reference specimens\". After installing the prototype on the support plates of the press, its upper plate was combined with the face of the prototype, such that their planes completely adjoined one to the other.