EXPERIENCE IN THE APPLICATION OF METHODS OF RESTORATION OF DAMAGED REINFORCED CONCRETE STRUCTURES IN TRANSPORT CONSTRUCTION

Evidence suggests that concrete self-healing can be achieved by introducing bacteria into the concrete matrix. Despite the fact that a number of researchers have conducted experiments with different types of bacteria, the ideal combination of factors such as bacterial species, types of mineral substrate, types of carrier materials and the amount of each of these components has yet to be identified to make a qualitative breakthrough in solving the problem of self-healing concrete and reinforced concrete structures. The paper presents the results of a study on the development of a technology for obtaining materials with bio-additives, the study of the process of crack repair in concrete, and the establishment of physical and technical properties of concrete modified with a microbiological additive and restored materials. The article analyses the processes of structure formation, physical and mechanical properties of concrete and other cement composites, ways to improve them, degradation processes, damage and defects that reduce the durability of reinforced concrete structures, as well as methods of their repair and restoration. Based on the analysis of existing approaches to the creation of concrete using biotechnology and self-healing processes of defective reinforced concrete structures, theoretical prerequisites for the development of technology for the creation of concrete modified with microbiological additives and self-healing structures are developed. It is concluded that it is potentially possible to heal cracks in concrete under the control of bacteria as a result of mineral sludge formation. However, some areas of this concept require further development. It is necessary to clarify how effectively the deposition of minerals produced by bacteria seals large cracks, i.e. how much the permeability of cracked concrete is reduced to prevent corrosion of embedded reinforcement and thus increase the service life of the building material. In addition, it is necessary to select bacterial species that remain viable when introduced into the concrete matrix for at least the expected service life of the structure. Despite the fact that no qualitative breakthrough has yet been achieved in the field of concrete self-healing, this is a very promising area of research.