Features of strengthening metal structures with composite materials under the influence of an aggressive environment

Introduction. This article is devoted to the issues of reinforcing metal building structures with external reinforcement systems with composite materials. The application of these strengthening methods in domestic literature and in practice has not been fully studied. As a result, it is relevant to study the characteristics of strengthening under the action of an external aggressive environment, namely when exposed to galvanic corrosion, elevated ambient temperatures and extreme temperatures from firing. The purpose of the study is to establish the effectiveness of reinforcing metal structures with composite materials under the influence of various force factors, including cyclic loads, and under the action of an external aggressive environment. Materials and methods. The methodological basis of scientific research was the analysis of publications of domestic and foreign scientists on the theoretical and practical experience of using composite materials to strengthen metal structures. During the study, when describing the dependences of physical quantities on external and internal force and non-force factors, scientific methods of induction, deduction, generalization and comparison were used. Results. Performed a comprehensive study of the effectiveness of the use of composite materials to enhance the metal structures in hostile environments. The dependence of the increase in strength of reinforced steel samples on the length of the adhesive joint of external reinforcement is analyzed, the possibility of applying reinforcement at fatigue stresses is investigated. Recommendations on the use of protective insulating systems and materials that prevent the reduction of the bearing capacity of structures from external non-force factors are given. Conclusions. The effectiveness of reinforcing metal structures using composite carbon fiber materials is revealed. The bearing capacity of reinforced structures may be increased by 59 %. When the glass transition temperature of carbon fiber materials is reached, the increase in the bearing capacity from external amplification systems decreases by 50 %, and when the temperature is increased to 60 °C, the external amplification systems are ineffective and do not increase the bearing capacity. To achieve the required fire resistance of the amplification systems, equal to at least one hour, it is necessary to use external fire insulation.