A refined method for designing the strength of normal cross-sections of eccentrically compressed concrete elements with composite polymer reinforcement

Introduction. The operating standards for the design of concrete structures with composite reinforcement SP 295.1325800.2017 do not consider the work of compressed reinforcement when calculating eccentrically compressed elements. The previous studies proposed a method for calculating the strength of normal cross-sections of eccentrically compressed elements. Though this method has shown a reasonably high agreement with the experimental data, it has also indicated some underestimation of the load-bearing capacity of such elements. In this paper, a further analysis of the developed method is performed and suggestions for its refinement are formulated in order to identify additional reserves of strength of concrete elements reinforced with composite reinforcement. Aim. To refine the method for designing the strength of normal cross-sections of eccentrically compressed concrete elements with composite reinforcement, to compare the refined method with experimental and theoretical data, as well as to assess its reliability. Materials and methods. Theoretical studies are based on the results of the tests that included the experimental examination of concrete samples reinforced with composite reinforcement under the action of eccentrically applied static compressive load consisting of four series of specimens with a total of 12 specimens. Results. The suggestions were formulated for specifying the value of the height of the compressed zone, as well as the value of tensile stresses in composite reinforcement for designing the strength of normal cross-sections of eccentrically compressed concrete elements with composite reinforcement. Conclusions. Based on the analysis of experimental data, a refined methodology for designing the strength of normal cross-sections of eccentrically compressed concrete elements reinforced with composite reinforcement is proposed. In addition, the assessment of the proposed refined method is carried out, which proved to have the required level of reliability, while providing the best convergence with the experimental data.