This report investigates the peculiarities of stress-strain state at the top crack area in reinforced-concrete elements by means of the complex potentials method. Solid items structural failure is caused by macroscopic cracks formation and development. The question to determine “local” tensioning near considerable changes of body surface form is marked in a separate problem: the problem of tensioning concentration. The complex potential method is suitable only for plane problems evaluation but it is distinguished by high efficiency and that’s why it was described in this article. An integral transformation method can be used for the analysis of three-dimensional static and dynamic tasks of a line mechanics destruction, however, it demands to know complex mathematical methods. The investigation of solid items resistibility and rack problems is an important aim either theoretically or experimental. This report gives an asymptotical analysis of of stress-strain state at the top crack in a normal separation. It is estimated the importance of next items: two – dimensional tensioning and motion allocation near the top crack always has a constant structure i.e. the same functional dependence in polar coordinates r, Ɵ, with its beginning at the top crack not depending on the a body form, a crack shape and outer forces.
