The effect of microbial and chemical corrosion on concrete structures operated in the conditions of chemical enterprises has been established that makes it possible to reliably predict the timing of their decommissioning in order to prevent industrial disasters. Even though the construction complies with all building codes, concrete structures eventually undergo chemical and biological corrosion.
The innovation proposed in this study implies investigating the depth and degree of damage to concrete at the microscopic level by the method of raster electron microscopy. In addition, the TPD-MS method has been suggested for determining the quantitative and qualitative state of the carbonate components of concrete and sulfur compounds.
This study has found that in concrete samples from the titanium dioxide production plant, the amount of carbon dioxide release is twice less than in control samples at t=600 °C while the level of sulfur dioxide, on the contrary, increases. This is due to the ability of thionic bacteria to accumulate sulfate acid that destroys the cementing component in concrete. The reported results confirm the impact of products of the activity of Acidithiobacillus thiooxidans microorganisms on corrosion processes in concrete.
In addition, when using the TPD-MS method, it was established in the storage room of the finished product that heating the control sample of concrete leads to a release of the significant amount of СО2 at t=580–600 °C. However, the experimental samples of concrete are almost lacking carbon compounds because the acid metabolites of microfungi interfere with its formation. Microscopic and REM studies revealed the localization of Acidithiobacillus thiooxidans and Aspergillus fumigatus in concrete.
This study has established patterns related to the mechanism that forms chemical compounds in concrete and the metabolism of microorganisms
The article analyzes the concepts to determine the essence of the investment project. The theoretical and methodical approach to the definition of an investment project, which will provide the possibility for a clear identification of the essential features, ensure an effective interaction with internal and external dynamic environment is offered. The most common classification features of investment projects are singled out. The main features of the definition of the functions of investment management as a management system and a special area of enterprise management are determined.It was emphasized that for the steady positive development of industrial enterprises in a competitive and rapidly changing environment, effective management of investment activity of enterprises is a necessary condition for functioning. In addition, it is proved that in the context of the limited financial and other types of resources, the use of an integrated approach to investing is one more major area for improving the efficiency of management of investment processes at the macro level, and an integrated investment design is a system-integrated process of management of a set of investment projects that are subordinated to a single strategic plan focused on the successful implementation of the enterprise investment program. The necessity of further, more profound research of investment management in conditions of uncertainty and risk is substantiated. The next stage of the research should be the construction of a system for making investment decisions in conditions of uncertainty and risk.