- STRUCTURAL MECHANICS
- On the Theory of Strength of Reinforced Concrete Elements along Oblique Sections
- UDC 624.072.2

**Aleksei N. MOROZOV**, e-mail: aleksei.morozofff@gmail.com

St. Umera, 7, apt 25, 13816 Tallinn, Republic of Estonia

**Abstract**. The studies were carried out using aerated concrete with low workability and in the absence of a large aggregate, which allows more accurate evaluation of stresses and the use of small base sensors. Calculations of strength of reinforced concrete structures by normal and oblique sections have significant difference in terms of strength criteria. If in the first case the strength criterion is an actual compression strength determined by standard methods, in the second case the strength criterion is a rather vague shear strength, which has different values relative to the tensile strength and is a function of the shape of the normal stress distribution diagram in the vertical section passing through the top of the oblique crack and attributed to the value of the relative shear span. Because of this, taking into account the cutout of the indicated diagram, the formula was derived at the end of the oblique crack, which brings about change in the value of shearing stresses, and in some cases results in their maximum spot. The value of shearing stresses was determined on the basis of aerated concrete strength criterion and experimental values of its strengths derived for this condition, with said value used to determine the effective value of these stresses subject to the coefficient m, which is equal to the axial tension strength. It is shown that the strength of the normal section passing through the top of the critical oblique crack reflects well the actual bearing capacity of the oblique section, on which basis the equilibrium condition for the moments by normal and oblique sections was derived. A comparison of the experimental values of transverse load with their calculated values according to the given methodology shows good coincidence. An analysis of the experimental data on the strength of oblique sections of heavy concrete beams given in the literature also produces positive results.

**Key words**: oblique and normal section passing through the top of oblique crack, shear stresses, transverse force. - REFERENCES

1. Zalesov A. S., Il'in O. F. Soprotivlenie zhelezobetonnykh balok deystviyu poperechnykh sil [Shear force resistance of reinforced concrete beams]. Moscow, Stroyizdat Publ., 1977, pp. 115-140. (In Russian).

2. Gusakov V. N., Fortuchenko Yu. A. Investigation of deformed state of shear reinforcement in heavy silicate concrete structures. Sb. tr. VNIISTROM. Moscow, 1966, no. 6, pp. 171-207. (In Russian).

3. Morozov A. N. Aerated concrete structure shear strength calculation. Beton i zhelezobeton, 1991, no. 5, pp. 13-14. (In Russian).

4. Morozov A. N. Aerated concrete structure strength calculation by normal sections. Beton i zhelezobeton, 1988, no. 7, pp. 18-19. (In Russian).

5. Morozov A. N. Cinder-shale aerated concrete structure strength calculation by oblique sections. Tallinn, NII stroitel'stva Gosstroya ESSR Publ., 1985. 80 p. (In Russian).

6. Morozov A. N. On new approaches and theory of calculating the strength of aerated concrete elements by oblique sections. Tallinn, NII stroitel'stva Estonii Publ., 1992, pp. 10-25. (In Russian).

7. Geniev G. A., Kissyuk V. N., Levin N. I., Nikonova G. A. Prochnost' legkikh i yacheistykh betonov pri slozhnykh napryazhennykh sostoyaniyakh [Strength of light and cellular concretes in a combined stress state]. Moscow, Stroyizdat Publ., 1978, pp. 32-74. (In Russian).

8. Kani G. N. I. Basic facts concerning shear failure. Journal of ACI, 1966, vol. 63, no. 6, pp. 675-692.

9. Morozov A. N. Refining the procedure for calculating the strength of cinder-shale aerated concrete structures. Tallinn, NII stroitel'stva Gosstroya ESSR Publ., 1986, pp. 1-17. (In Russian).

10. Morozov A. N. On some concepts for shear strength calculating the strength of reinforced concrete elements by oblique sections. Problemy sovremennoy nauki i obrazovaniya, 2015, no. 4(34), pp. 48-58. (In Russian).

11. Zalesov A. S., Klimov Yu. A. Prochnost' zhelezobetonnykh konstruktsiy pri deystvii poperechnykh sil [Shear Strength of Reinforced Concrete Structures]. Kishinev, Budivel'nyk Publ., 1989. 104 p. (In Russian).

12. Silant'ev A. S. Strength of bent ferro-concrete elements without clamps by oblique sections subject to parameters of longitudinal reinforcement. Vestnik MGSU, 2012, no. 2, vol. 1, pp. 163-169. (In Russian). **For citation**: Morozov A. N. On the Theory of Strength of Reinforced Concrete Elements along Oblique Sections.*Promyshlennoe i grazhdanskoe stroitel'stvo*[Industrial and Civil Engineering], 2018, no. 2, pp. 53-59. (In Russian).

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