RESISTANCE OF COMPOSITE BUILDING MATERIALS UNDER THE INFLUENCE OF THE ENVIRONMENT

The article provides a detailed analysis of the impact of climatic conditions on the physical and mechanical properties of building materials, particularly concrete, which is a key material for construction structures. The study examines the complex effects of temperature and humidity fluctuations, freeze-thaw cycles, and wetting-drying processes, which cause irreversible structural changes in the material. These factors are identified as the main reasons for the reduction in durability and stability of composite building materials under operating conditions. The analysis revealed that the climatic conditions of southern Ukraine, characterized by significant daily and seasonal temperature variations, high precipitation levels during the autumn-winter period, and elevated summer temperatures, exert a complex impact on concrete. These climatic factors contribute to the development of internal defects, such as microcracks, degradation of the porous structure, and a decrease in adhesion between the material's components. The role of not only freeze-thaw cycles, which cause stress in the structure of concrete, but also wetting-drying processes and the overall complex influence of climatic factors, is emphasized. The article substantiates the importance of considering climatic impacts during the design stage of concrete composition. Based on experimental research, it has been established that cyclical climatic influences cause changes in characteristics such as compressive strength, flexural strength, ultrasonic wave velocity, water absorption, and carbonation depth. The findings highlight the necessity of developing compositional and technological solutions to enhance the resistance of building materials to climatic factors. The article proposes recommendations for the development of concretes with improved operational characteristics, which will extend the service life of structures and ensure their safety.