The landscape indication, based on the automated analysis of remote sensing data, is one of the key methods of research and mapping of lithohydrogene geosystems. The article describes a set of methods for effective detection of types of lithohydrogene systems, including a set of modules for identifying dynamic and invariant descriptors of the territory; assessment of geophysical diversity of landscapes; analysis of the geophysical shell through the calculation of the descriptors of the neighborhood; ensemble-analysis of remote sensing data for monitoring the state of geosystems and forecasting of natural processes. The system of methods for detecting types of landscapes made it possible to conduct geodiagnostics of lithohydrogene systems of the Privolzhskaya Upland and the marginal part of the Oka-Don lowland reservoir within the boundaries of the Republic of Mordovia in order to predict the development of exogeodynamic processes.

The article describes the chemical processes of biogenesis of calcium carbonate for self-healing of concrete, taking into account four main factors: the concentration of calcium, the concentration of soluble inorganic carbon, the pH value, the presence of the crystallization center. A number of bacteria that can be found in soil, sand and natural minerals have the ability to release calcium carbonate, both in natural and laboratory conditions. In the laboratory, calcium lactate (CaC6H10O6) was used as a starting material for the formation of calcium carbonate. In addition, urea necessary for bacteria as a source of urease enzyme and yeast extract as a source of carbon and nitrogen were added. The resulting pH was brought to 9 to avoid possible chemical deposition of calcium carbonate. To improve the production technology of biological concrete, specially selected bacteria of the genus Bacillus with a combination of nutrients were used to create a reducing agent in concrete. With the help of such self-healing concrete by means of bacteria, cracks more than 100 µm wide can be compacted. With this approach, the bacteria in the alkaline medium convert CO2 into carbonate ions, which then interact with the Ca ions from the concrete matrix. This leads to the formation of calcium carbonate crystals. In addition, CO2 directly reacts with the calcium hydroxide matrix, which leads to the formation of calcite precipitate. The appearance of calcium carbonate crystals of large size with the participation of bacteria incorporated into the self-healing concrete provides an excellent ability to self-healing compared to traditional or developed environmentally unsafe self-healing cement materials. That is why this area of research is a promising alternative to environmentally hazardous methods of repair using cement.

Self-healing concrete is a product in which, with the help of microorganisms, limestone will be produced to fill cracks appearing on the surface of concrete structures. The author presents that specially selected types of bacteria of the genus Bacillus, a calcium-based nutrient known as calcium lactate, as well as nitrogen and phosphorus, are added to the ingredients of concrete when mixing it. These self-healing agents can be at rest inside the concrete for up to 200 years. Self-healing materials are a special type of materials that regenerate their strength properties after minor destruction caused to the material during its service life. Self-healing technology is particularly useful in the case of composite materials, as composites have low damage detection capacity and are susceptible to sudden and brittle fracture. Modern artificial materials have excellent mechanical properties. However, they lack the ability to self-repair. Therefore, in case of damage, there is a possibility of loss of mechanical strength, and over time, a gradual loss of functional strength in the absence of human intervention. Different types of bacteria, along with abiotic factors such as mineralization, pH value of the surrounding area, temperature, availability of nutrients and habitat composition, play a significant role in the deposition of calcium carbonate in a wide range of different media. There are four key factors that determine the MICP process: (i) calcium concentration, (ii) dissolved inorganic carbon concentration, (iii) pH value and (iv) presence of nucleation centers.

Introduction: the article is dedicated to assessing the condition with respect to use for traffic methods of bridges as part of hydraulic structures (dams, hydroelectric power stations, locks). The main factors affecting the structural element’s durability included in the composition of the hydraulic structures are dynamic loads (applied repeatedly and repeated) affecting the bay due to the hydrodynamic effect; temporary, moving loads from passing highway transportation, along the top of the structure (along the roadway); harmful chemical impurities contained in the water passing through the structure. Under the influence of the above-mentioned factors, defects and damage occur in the hydraulic facilities’ structural elements. Methods: the authors assessed the actual state of the material of the operating structure. To assess structures and materials actual state during the bridge structure inspection work, the following instrumental measurements were performed on as-built structural elements: leveling the top of the sidewalks and the roadway; materials strength determination of the main supporting structures by nondestructive methods; thickness measuring the asphalt concrete pavement of the roadway; determination of the degree of carbonation of concrete; identification of defects in the elements of the bridge. The actual structure’s concrete strength was determined by nondestructive testing methods: (1) by the method of the elastic rebound; (2) by the shock pulse monitoring method; (3) an indirect method of concrete strength ultrasonic testing based on the revealed relationship between the method of separation with shear test and methods – shock pulse and elastic rebound. Results: technical condition and bridge safety indicators calculation as a hydraulic structure element was executed. Discussion: technical examination results of the bridge structural elements and instrumental studies confirm the conclusion about the repair measures need with high-strength concretes and protective coatings based on polymer composite materials. Final report: following the emergency scenarios a numerical estimate table for the quantitative and qualitative parameters list was made, parameters corresponding to a particular structure state. Thus, according to the scenario related to the 3rd accident group, the bridge technical condition is assessed as limited operable, and the safety level is reduced.

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