THE OPTIMIZATION STRENGTH THEORY OF RC ELEMENTS AND SOLUTION OF SHEAR PROBLEM

1
Center for Advanced Design Methods of Concrete Structures
2
Poltava National Technical Yuri Kondratuyk University

The shear strength designs recommended by the MC 2010 are analyzed. It is noted that despite the multiformity of shear failure types observed in experiments, the MC 2010 takes into account only two types: on the Critical Inclined Crack (CIC) and on the web concrete crushing. It is shown the nonvalidity of opinion concerning exclusive great importance of interlock forces in the crack for shear bearing capacity. It is emphasized the need to reveal the cause of considered problem complication, i.e. missing information which must be included into model. Such missing information is complete system of possible shear failure types which is offered in the form of the elements classification depending on quantity of longitudinal and shear reinforcement, respective behavior under loading and failure type. This classification was assumed as a basis of the Optimization Strength Theory of Concrete Elements (OSTCE) under joint action of bending moment, shear and axial forces. The offered classification shows the great variety of possible shear failure types and allows to select the elements group with optimal practical features: minimum steel expense, plastic failure on the CIC and comparatively simple design. The fundamentals of OSTCE, its merits, practical application and well agreement with various test data are stated.

Beck, A. & Kaufmann, W. (2017), Paradigms of Shear in Structural Concrete – Review and Experimental Verification. Book of Abstracts for 2017 fib Symposium, Hordijk, D.A.; Lukovic, M. (Eds), Maastricht, The
Netherlands, p. 344.
CADMCS (2016): Center for Advanced Design Methods of Concrete Structures, http://www.cadmcs.org (Oct. 2016).
fib Bulletin 57 (2010), Shear and punching shear in RC and FRC elements. Technical report, Proceedings of a workshop held on 15-16 October 2010, in Salo, Lake Garda, Italy.
Kotlyarov, V.A. (1992), Strength of reinforced concrete elements under joint action of the bending moments, longitudinal compressive and shear forces. Ph.D. thesis. Poltava Eng. Build. Inst., Poltava. (in Russian).
Mikitenko, S.M. (1995), Strength under bending of reinforced concrete elements with complete resistance of shear and high-strength longitudinal reinforcement. Ph.D. thesis, Poltava TU, Poltava. (in Ukrainian).
Mitrofanov, V.P. (1982), The stress-strain state, strength and cracking of the RC elements under cross bending. Ph.D. thesis, VZISI, Moscow (in Russian).
Mitrofanov, V.P. (1999), Investigation of destruction zone resistance of HSC of beams under shear forces action.Proceedings of the 5th International Symposium on Utilization of HS/HP Concrete, Holland,I., Sellevold, E.J.,(Eds), Sandefjord, Norway, vol. 1, pp. 461–468.
Mitrofanov, V.P. (2000), Optimization strength theory of reinforced concrete bar elements and structures with practical aspects of its use. Bygningsstatiske Meddelelser. Danish Society for Structural Science and
Engineering, 71, Dec. 2000, pp. 71–125.
Mitrofanov, V.P. & Artsev, S.I.(2007), Experimental verification of the Optimization Strength Theory of Reinforced Concrete Elements by the beams with changing height of section. Building Structures, Kiev NIISK, 67, 244–253. (in Russian).
Mitrofanov, V.P. (2008), Investigation of cracks surface roughness and shear transfer strength of cracked HSC. Proceedings of the International fib Symposium 2008, Walraven, J.C.; Stoelhorst, D. (Eds), Amsterdam, The Netherlands, CRC Press/Balkema, p. 134.
Mitrofanov, V.P. & Pinchuk, N.M. & Mitrofanov, P.B. (2014), The primary design conceptions of concrete and reinforced concrete structures in the ADM Model Code. Proceedings of the 4th International fib Congress 2014, Mumbai, India, Short paper 73, pp. 259 – 261.
Mitrofanov, V. & Pinchuk, N. (2017), Aspects of Implementation into practice of Optimization Strength Theory of RC Elements. Book of Abstracts for 2017 fib Symposium, Hordijk, D.A.; Lukovic,M. (Eds), Maastricht, The Netherlands, p. 352.
Peregudov, F.I. & Tarasenko, F.P. (1989), Introduction to System Analysis. Higher School, Moscow (in Russian).
Voskoboynik, P.P. (1985), Complex stress state of concrete failure zone and taking into account of the one in the strength designs of RC elements cross sections. Ph. D. Thesis, OISI, Odessa, 1985 (in Russian)
Walraven, J. & Stroband J. (1999) Shear Capacity of High Strength Concrete beams with Shear Reinforcement. Proceedings of 5th International Symposium on Utilization of HS/HP Concrete, Holand, I.; Sellevold, E. J. (Eds), Sandefjord, Norway, v.1, pp. 693 – 700.