In reinforced concrete design standards, the values of concrete strain are taken as average values, whereas the strength characteristics are adopted with a high level of reliability. In the ultimate force method for calculating reinforced concrete structures, the strains of concrete and reinforcement are not directly used in the governing equations. In calculations based on the nonlinear deformation model, the strain values are directly used in the analysis. Using average values of the ultimate strains of concrete reduces the reliability of the obtained results. This study examines the influence of the variability of deformation characteristics of concrete and reinforcement on the load-bearing capacity of eccentrically compressed reinforced concrete elements. It was found that the variability of the deformation characteristics of concrete and reinforcement significantly affects the load-bearing capacity of eccentrically compressed reinforced concrete elements. This influence increases with the reinforcement ratio and depends on the eccentricity of the applied axial force. The reliability and safety of eccentrically compressed reinforced concrete elements decrease significantly when average values of the deformation characteristics of concrete and reinforcement are used in calculations.

Keywords: eccentric compression, reinforced concrete, variability of deformation characteristics, concrete, load-bearing capacity, reinforcement, nonlinear deformation model

The paper presents a study of the resistance of connections of load-bearing laminated wood structures using domestic melamine-urea-formaldehyde adhesives (MMFC) to cyclic temperature and humidity influences. The method of cyclic tests is described. An assessment is made of the resistance of MMFC to temperature and humidity influences and the compliance of the selected adhesive with the requirements established for the production of long-span load-bearing structures.

Keywords: melamine-urea-formaldehyde adhesives, wooden structures, resistance of adhesive joints to cyclic temperature and humidity influences, strength