## 3 Results and Discussion
Figure 9: Homogeneity coefficient of foam concrete mixture vs. inclination angle \(\alpha_{cone}\) of the conical part of turbulent mixer at fixed mixing time \(t\) = 180 s (experimental data). Effect of the Number of Activator Blades on Mixture Homogeneity and Power Consumed for Mixing the Foam Concrete Mixture (Stage 4)  
At this stage, the influence of the number of activator blades on the homogeneity of the foam concrete mixture was investigated. For this, the following actions were performed: the samples were made from the working version of the mixture composition in series of \(n_{smp}\)= 10 pieces for each version of the blades. The number of variations in the mixture composition was nine pieces. The recipe was selected for testing with an average density of mixtures from 400 to 1200 kg/m\({}^{3}\) with a step of 100 kg/m\({}^{3}\). The experimental composition of the mixtures is shown in Table 1. Mixing took place for 360 s. After the mixing, a finished mixture was taken from the mixer and poured into test forms in the form of a cube. The size of the test pieces was \(100\times 100\times 100\) mm\({}^{3}\). The density of foam concrete was determined by testing samples dried to constant weight under normal conditions. The sample density values were obtained for each batch test for each mixture and paddle option. For each sample from the working version of the mixture composition, three extreme terms were selected to estimate the maximum and minimum density values. The calculation of the averaged maximum \(\overline{\rho}_{max}\) and averaged minimum \(\overline{\rho}_{min}\) values of the density of the finished samples took place. The mean density value was estimated as \(\overline{\rho}=\sum\rho_{i}/n_{smp}\). Then, the coefficient of homogeneity of the foam concrete mixture \(K_{chm}\) was calculated. The test results and estimates of variations in the homogeneity coefficient of the foam concrete mixture \(K_{chm}\) are shown in Table 2.  
\begin{table}
\begin{tabular}{c c c c c} \hline \multirow{2}{*}{**No. **} & \multirow{2}{*}{**Number of Blades, pcs**} & \multicolumn{2}{c}{**Coefficient of Homogeneity of Foam Concrete Mixture \(K_{chm}\)=\(\overline{\rho}_{min}\)/\(\overline{\rho}_{max}\)**} \\ \cline{3-5}  & & \multicolumn{3}{c}{**Activator Rotation Speed, rpm**} \\ \cline{3-5}  & & **200** & **500** & **800** \\ \hline
1 & 2 & 0.52 \(\pm\) 0.03 & 0.59 \(\pm\) 0.03 & 0.63 \(\pm\) 0.03 \\
2 & 3 & 0.63 \(\pm\) 0.03 & 0.96 \(\pm\) 0.04 & 0  
The initial analysis of the results showed that the homogeneity coefficient of the foam concrete mixture \(K_{clm}\) at a rotational speed of 200 rpm did not exceed 0.7 for all variants of the mixture compositions. The average spread of values \(K_{clm}\) did not exceed 5%. This analysis showed that the effect of the number of blades of the activator (\(Z_{m}\)) on the homogeneity degree of mixed foam concrete was insignificant if \(Z_{m}\geq 3\) pcs. This was shown by our measurements of the density of foam concrete mixture in mixer after its preparation. Analyzing these results, we found that increasing the number of blades from two to three significantly increased the homogeneity of the mixture being prepared. A further increase in the number of blades did not lead to a significant improvement in the quality of foam concrete mixture. Thus, both from the viewpoint of the homogeneity of the prepared foam concrete mixture and from the viewpoint of the design of the activator, the optimal number of blades was \(Z_{m}=3\) pcs. As a result of our studies, it turned out that, with an increase in the number of activator blades, the power spent on mixing the mixture increased. Figure 11 shows the dependence of the power consumption factor \(k_{N4}\) on the number of revolutions of the activator \(n\) and the number of blades \(Z_{m}\) at activator diameter \(d_{a}=const\) for an activator with straight blades. The studies were carried out for \(Z_{m}\) = 2-8 blades.