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The article introduces the comparative results of the deformability and fracture resistance of steel reinforced concrete beams with combined reinforcement obtained on the basis of laboratory tests with the results of computer-aided mathematical modelling of such structures. The results were compared for the purpose of mathematical model testing and its further usage in the study of the optimal reinforcement percentage in steel reinforced concrete beams with combined reinforcement. Results obtained on the basis of the proposed mathematical model show sufficient correlation with the experimental data up to the stage of structure strength exhaustion. As the result it enables to evaluate the features of destruction of the tested samples with the sufficient accuracy, namely, their load-carrying capacity, cracks formation, to analyze stresses in both steel bars and tapes, monitor deflections and deformations during the loading of the tested beams. Deviation of the experimental values for steel reinforced concrete beam with the combined reinforcement from the data obtained according to mathematical model: up to 5.0% for fracture resistance; up to 14.3% for deformability.

Nowadays, reducing the material content of not only buildings and structures in general, but also individual constructions is a topical task that can be realized through the use of high-strength concrete and reinforcement, as well as with the use of external reinforcement. The concentrated location of sheet reinforcement on the external the most tense facets of steel and concrete structures increases the operating height of the cross-section, makes it possible to more effectively use the strength properties of steel in comparison with conventional reinforced concrete, and with the same bearing capacity to economize on expenses. Composite and monolithic reinforced concrete structures with external reinforcement are used in various construction sectors around the world. This contributed to the expansion of the use of reinforced concrete for special buildings of power-engineering and hydrotechnical construction. The technical nd econom efficiency, as well as the possibility of using external rebar as formwork for monolithic concrete construction, have been proved. Therefore, there is a need for the study of structures with combined reinforcement, in which high rigidity of steel and concrete structures is combined with an effective use of high-strength reinforcing bars (rebar) without prior tension

This article presents the results of experimental researches of bearing capacity and deformability of reinforced masonry beams with combined reinforcement. This study was carried out in the zone of maximum bending moment. The reinforcement A400C and A1000 were used for experimental samples. The combined action of ceramic masonry and reinforcement was ensured at the expense of a cement-sand grout in the joints of masonry and vertical reinforcing meshes in support zones of beams, which were welded to angle bars. Besides that, there was carried out a comparison of the results of experimental researches with calculated values by the active standards of Ukraine. This comparison permits to determine the expediency of the use of the existing design procedure of bearing capacity of reinforced masonry structures with combined double reinforcement. Finally, this scientific work has also presented the conclusions about the possibility of the efficient design of reinforced masonry structures in the effective area of normal forces.