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.

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