Maliovana O. Strength of high-strength concrete elements under the shear action.

Object: the shear of concrete and reinforced concrete elements of high-strength concrete. Purpose: taking into account the specifics of work and improving the strength calculation of concrete and reinforced concrete elements of high-strength concrete, which are destroyed under the shear action. Methods: analytical review of the literature, variational method in the theory of concrete plasticity using the principle of virtual velocities, experimental studies, comparative analysis of theoretical and experimental data. Novelty: new experimental data are obtained on the deformed state, failure character and ultimate load of high-strength concrete elements, which are destroyed under the shear action: Gvozdev samples, rectangular reinforced concrete keys and truncated concrete wedges; new experimental data are obtained on the deformed state, failure character and ultimate load of the inclined section and the ultimate load of high-strength concrete beams; the calculation method of elements under the shear action by a variational method has found further development in the direction of area expansion of its application for calculations of high-strength concrete elements; the methods realization limit of strength calculation according to the truss analogy and disk model is established; the normative method of strength calculation of bending reinforced concrete elements by inclined sections on the action of transverse forces has been improved. Results: the obtained results create the possibility of effective use of high-strength concrete in the design of reinforced concrete elements and their joints, that work on the perception of shear forces; the constructive decision of the keyed joint of the increased durability and plasticity is offered; practical recommendations are provided for distinguishing methods for calculating bending elements in inclined sections, which allows to reasonably assess their strength. The field of application is construction.