## 5 Results and Discussion
#### 5.1.1 Research Results of the Integral Characteristics of Concrete  
When analyzing the experimental results obtained, we paid especial attention to the influence of manufacturing technology. The results of experimental studies of the averaged integral characteristics of test concrete samples are shown in Table 2 and Figures 10-18. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Characteristics of Concrete**} & \multirow{2}{*}{**Age, Days**} & \multicolumn{3}{c}{**Manufacturing Technology**} & \multicolumn{3}{c}{**Deviations, \%**} \\ \cline{3-7}  & & **V** & **C** & **VC** & \(\Delta_{1}\) & \(\Delta_{2}\) & \(\Delta_{3}\) \\ \hline \multirow{3}{*}{Density, kg/m\({}^{3}\)} & 7 & 2395 & 2439 & 2445 & & \\ \cline{2-7}  & 28 & 2385 & 2428 & 2434 & 1.8 & 2.1 & 0.2 \\ \cline{1-1} \cline{2-7}  & 180 & 2365 & 2406 & 2421 & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of experimental studies of the averaged integral characteristics of vibrated (V), centrifuged (C) and vibro-centrifuged (VC) test concrete samples. Figure 9: Test modes of experimental small-size samples: (**a**) in stages, with a constant loading rate; (**b**) in stages, with a constant rate of deformation. Figure 10: Dependence of the concrete density on the manufacturing technology. Figure 11: Dependence of the cubic compression strength of concrete on the manufacturing technology. Figure 12: Dependence of the prismatic strength of concrete at axial compression on the manufacturing technology. Figure 13: Dependence of the tension strength of concrete in bending on the manufacturing technology. Figure 16: Dependence of the limiting strains of concrete at axial tension on the manufacturing technology. Figure 14: Dependence of the axial tension strength of concrete on the manufacturing technology. Figure 15: Dependence of the limiting strains of concrete at axial compression on the manufacturing technology. 1.2 Analysis of Integral Density, Strength, Limiting Deformations, Elasticity Modulus and Deformation Diagrams of Concrete in Compression and Tension  
Analysis of the obtained experimental results shown in Table 2 and Figures 10-18 allowed us to draw the following conclusions. The density (Table 1 and Figure 10) practically did not depend much (within 2%) on the technology of their manufacture at all values of age; therefore, the technology can be ignored when calculating the density assessment. The compression and tension strength of vibro-centrifuged concretes at any age was noticeably higher compared to centrifuged and vibrated concretes. This is applied to both cubic and prismatic compression strength (up to 22.0%, see Table 2, Figures 11 and 12), and axial tension and flexural tension strength (up to 26.6%, see Table 2, Figures 13 and 14). The excess of the compression and tension strength of the vibro-centrifuged concretes in comparison with the vibrated and centrifuged concretes grows with the age of concrete and is approximately in the same range at all values of age of concrete, namely from 7 to 180 days, which is explained by the ordering of the continuing processes of hydration in the cement stone during this entire period. Figure 17: Dependence of the elasticity modulus of concrete on the manufacturing technology. Figure 9:0 Principal dependences of the “\(\sigma\)-\(\epsilon\)” diagrams of concrete on the technology of their manufacture. The values of limiting strains under axial compression and tension (corresponding to the maximum strength of concrete) showed the opposite picture, namely they decreased at all ages in vibro-centrifuged concretes, compared with centrifuged and vibrated concretes, although these reductions were, in general, insignificant and were within 6% (see Table 2, Figures 15 and 16). We only noted that all values of limiting strains in the vibro-centrifuged concretes both as at axial compression as axial tension were lesser at any age compared with corresponding values for centrifuged and vibrated concretes.