In article on the basis of the hypothesis of plane cross-sections, non-linear deformation curve of concrete, reinforcement composed and solved equations to describe the stress-strain state of the normal sections of flexible concrete elements at all stages of work and the show features a deformation structure in stages of exploitation and destruction.

Keywords: Flexible reinforced concrete element, the change in the height of the compressed zone, the levels of the deformation of the reinforcement at failure of the compressed concrete.

The article considers the problem of determining the moment of cracking in flexible reinforced concrete structures. It is shown that the stress at which cracks, significantly depend on the modulus of elasticity of concrete under tension, equal to the ratio of the elastic part of the deformation to the limit of elasticity of concrete.

Keywords: diversification of management, production diversification, financial and economic purposes of a diversification, technological purposes of ensuring flexibility of production