## 3 Research Results and Discussion
They evidence a relative decrease in strength at accumulated values of \(10^{5}\) and \(10^{7}\) Gy [74], and in general, this decrease did not depend on the radiation dose (at relatively low (31 Gy/h) and higher (\(3.8\cdot 10^{3}\) Gy/h) exposure rates [70]. In turn, higher intensity values translated into an increase in strength at a total absorbed dose of 10 MGy [60]. The study [71] has a similar reference to the research conducted by [PERSON] and [PERSON] in 2001. This work reports a 15% decrease in compressive strength of cement stone at an absorbed dose of 22 MGy. However, [PERSON] and [PERSON] report that the mechanism of this strength decrease is still unclear [71]. Results of experimental studies conducted by [PERSON] et al. in 2019 using the isotope Co\({}^{60}\) with a gamma irradiation dose in the range of 3.9 to 4.71 kGy/h [79], and a total absorbed dose of 12.0 to 15.0 MGy, show that gamma radiation greatly reduces the compressive strength of cement mortar specimens (by 20% on average) whose composition is close to that of the structural concrete mix that has no coarse aggregate at the age of 72 days of hardening. The study [126] provides information that a decrease in compressive strength was detected at lower dose rates (1.36 kGy/h) for \"older\" concrete specimens (which were older before exposure to gamma radiation). However, this effect was not observed at ionizing irradiation of 2-8 Gy/h. This conclusion is also confirmed by the study [74], which reports its experimentally derived conclusion that if a dose is up to 10 Gy/h, the age of concrete before irradiation does not have any effect on the decrease in strength. A similar dependence was identified at a rate of 1 kGy/h and described in the work of [PERSON] et al. [126], that is, the older the concrete before irradiation, the greater its loss of strength [74]. In addition, amorphization of the cement phase under the effect of high accumulated doses (130 MGy) of gamma radiation was reported in [126]. Other authors report prognostic (based on calculated assumptions) anticipations of the greatest radiation-induced changes in silicate minerals and rocks of concrete fillers under the effect of gamma radiation of 5 MeV and an accumulated dose of 10\({}^{10}\)-10\({}^{11}\) Gy at a temperature of 30 \({}^{\circ}\)C [121]. Authors of [59] provide information about the oxygen-induced dislocation of groups of silicon oxides as a result of exposure of silicon atoms to gamma radiation if the accumulated dose is 10 kGy [59]. Although such changes were discussed above in the context of neutron-induced radiation with a density of 10\({}^{19}\) neutrons/cm\({}^{2}\)[117]. Obviously, independent studies are needed to detect changes in the physical and mechanical properties of silicate minerals used as additives in concrete composites subjected to gamma radiation. At this stage, processes of reinforcement corrosion in concrete can be comprehensively taken into account by discussing the research and engineering information, namely, the concrete specimens testing results considered in this work. Summarized results are provided in Table 1.  
\begin{table}
\begin{tabular}{c c c c c} \hline \hline
**Research,** & **Composition of the Mixtures** & **Accumulated Dose** & **Gamma** & **Research Results** \\
**Year** & **of the Studied Specimens** & **of Gamma Radiation** & **Radiation Rate** & **Research Results** \\ \hline  & cement (CEM 142.5R)—33.5\%; & & & \\ Khmurovska & water—12.7\%; & 12.0–15.0 MGy & & Gamma irradiation \\ [PERSON] et al., 2019 & sand (0–4 mm)—53.5\%; & (accelerated tests & 3.9–4.71 kGy/h & greatly reduces \\
[79] & superplasticizer (Glenium & isotope Co\({}^{60}\)) & & & \\  & ACE 442)—0.3\% & & 10 MGy, which corresponds to the shelter-type protective structure during & & \\ Anopko D.V.