STATISTICAL ANALYSIS OF REINFORCING BARS CHARACTERISTICS FROM MODERN METALLURGICAL PLANTS FOR REINFORCED CONCRETE CIVIL PROTECTION FRAMES

Abstract

Modern construction in Ukraine currently includes both new and urgently needed restorative, war-caused, and repair works in civil, residential, and industrial buildings and structures. It is advisable to use reinforced concrete and composite steel and concrete structures for the implementation of these works, which allow ensuring a high level of reliability, durability and maintainability of buildings. For the manufacture of the mentioned structures, metal products are necessary, the production of which in Ukraine has been significantly decreased due to the occupation and military operations. Considering the above, existing metallurgical enterprises on the territory of Ukraine should increase the number and expand the nomenclature of manufactured products. The production of new types of rolled metal requires the establishment of quality control, in particular control of physical and mechanical characteristics. For this purpose, 48 samples of reinforcing bars made of A400C steel grade with nominal diameters from 10 to 25 mm have been tensile tested. The values of yield strength, ultimate strength and relative elongation after rupture were determined. It was found that the yield strength and temporary resistance determined with the assurance of p = 0.95 exceed the minimum standardized values by 8.5... 19.4% and 10.4...18.2%, respectively. The obtained accurate test results of steel bars make it possible to use them in the manufacture of reinforced concrete structures. Stress increase in the reinforcement on the branch of its elastic-plastic work  may be taken into account at the design of reinforced concrete members.