Features of the Calculation of Bending Elements of Steel-Fiber-Concrete Structures According to Normal Sections

The issues of calculation and design of bending elements of steel-fiber-reinforced concrete structures with combined reinforcement are considered. The values of coefficients of minimum and maximum reinforcement by longitudinal tensile reinforcement are substantiated. The minimum and maximum coefficients of longitudinal tensile reinforcement were determined both using the diagrams of a rigid-plastic body for compressed and tensioned steel fiber concrete, and for the diagrams proposed in SP 360. It is shown that the value of the minimum reinforcement coefficient depends not only on the compressive strength of steel fiber concrete and residual strength tension, but also on the values of the limiting deformation of steel fiber concrete for compression (ε_fb0) and tension (ε_fbt3). The issues of assigning the filling coefficients of the diagram for compressed and tensioned steel fiber reinforced concrete and their influence on the bearing capacity of bending steel fiber reinforced concrete elements with different reinforcement coefficients of longitudinal tensile reinforcement are discussed. An engineering method for calculating the required cross-sectional area of longitudinal reinforcement is proposed.

V.M. POPOV, Candidate of Sciences (Engineering) (This email address is being protected from spambots. You need JavaScript enabled to view it.),
V.V. KONDRATYUK, post-graduate student (This email address is being protected from spambots. You need JavaScript enabled to view it.)

Saint-Petersburg State University of Architecture and Civil Engineering (4, Vtoraya Krasnoarmeiskaya Street, Saint-Petersburg, 190005, Russian Federation)

1. Morozov V.I., Opbul E.K. Calculation of bent steel-reinforced concrete elements according to a nonlinear deformation model using experimental diagrams of deformation of steel-reinforced concrete. Vestnik grazhdanskikh inzhenerov. 2016. No. 5 (58), pp. 51–55. (In Russian).
2. Opbul E.K., Dmitriev D.A., Vedernikova A.A. Nonlinear iterative strength calculation of steel-reinforced concrete elements using experimental diagrams of deformation of materials. Vestnik grazhdanskikh inzhenerov. 2017. No. 1 (60), pp. 79–91. (In Russian).
3. Opbul E.K., Dmitriev D.A. Calculation of the strength of prestressed structures based on a nonlinear deformation2 model on the example of a multi-hollow floor slab of non-formwork technology. Vestnik grazhdanskikh inzhenerov. 2019. No. 6 (77), pp. 93–110. (In Russian).
4. Aleksey Pavlov, Aleksey Khegay, Tatiana Khegay. Analysis of bending steel fiber reinforced concrete elements with a stress-strain model. Architecture and Engineering. 2020. Vol. 5. Iss. 3, pp. 14–19. (In Russian).
5. Mukhamediev T.A. Calculation of the strength of bendable fiber-concrete structures by the method of marginal forces. Stroitel’naya mekhanika i raschet sooruzhenii. 2016. No. 5, pp. 12–18. (In Russian).
6. Mukhamediev T.A., Sokolov B.S. New in the rationing of steel-fiber concrete and calculations of steel-fiber concrete structures. Stroitel’nye Materialy [Construction materials]. 2017. No. 4, pp. 59-64. (In Russian).
7. Mukhamediev T.A. On the issue of calculation of fibro-concrete structures. Promyshlennoe i grazhdanskoe stroitel’stvo. 2017. No. 1, pp. 16–20. (In Russian).
8. Popov V.M., Suvorov I.V. Some features of the calculation of bent elements made of steel-fiber concrete with combined reinforcement. Vestnik grazhdanskikh inzhenerov. 2014. No. 3 (44), pp. 88–91. (In Russian).
9. Popov V.M., Sapunova A.A. Investigation of the stress-strain state of fiber-reinforced concrete elements of a trapezoidal profile with combined reinforcement. Promyshlennoe i grazhdanskoe stroitel’stvo. 2015. No. 9, pp. 15–20. (In Russian).
10. Sokolov B.S., Mukhamediev T.A. Design of steel-fiber concrete structures in the manual for SP 360.1325800.2017. Vestnik NITs «Stroitel’stvo». 2020. No. 1 (24), pp. 98–107. (In Russian).