Study on reinforced concrete elements of buildings and structures with cracks, reinforced with composite polymer materials

Abstract

With the rapid development of modern construction practice around the world, serious problems arise in the application and subsequent operation of reinforced concrete structures. Today, the problem of reconstruction and restoration of buildings and structures requires an urgent solution. The deterioration of the environmental situation threatens the reliability of buildings and structures, a sharp deterioration in their condition is observed in almost all countries and climatic zones. In our case, the trend towards wear is developing due to the imperfection of regulatory documents and the need for proper maintenance of objects. The development of the construction industry and the use of innovative composite polymer materials in construction and the strengthening of existing buildings and structures with modern methods are relevant. Often very rare, expensive, historically significant structures require reliable operation, and their dismantling or replacement is more expensive than repair, or even impossible. Reinforcement of building structures using composite polymer materials (CPM) is by far the most “cautious” measure for their restoration and improvement of performance. In our research, the main attention is paid to the technology of external reinforcement of reinforced concrete beams using CFRP to increase their load-bearing capacity at shear. To reduce material consumption when strengthening the structure, it is more efficient to use CFRP in the form of strips, however, this practice has not been practically studied. Previous researchers have concentrated their attention mainly on external reinforcement, generally ignoring the effect of internal reinforcement. However, it is known that internal and external reinforcement complement each other and the destruction during shearing of reinforced concrete elements is mainly influenced by such factors as steel clamps, longitudinal reinforcement and the ratio of the shear span to the working height of the section. Therefore, in our studies, special attention was paid to considering the influence of these factors on the overall bearing capacity of beams. In addition, the work studied the ability to transfer shear stresses through cracks in reinforced concrete beams reinforced with external reinforcement from CFRP compared to the same unreinforced ones.