Steel fittings or reinforcements are used in concrete to compensate for its tensile strength. The steel used in reinforced concrete structures for this purpose is in the form of wire or rebar and is called steel fittings.
Different types of steel fittings are produced in different countries with different standards, and in each governorate there is a definite classification in relation to the mechanical properties of steels. In Iran, the major part of the rebar steel produced by the Isfahan Iron and Steel Works complies with the Russian standard. The steel produced in Iran (according to the Russian standard) is divided into three groups:
A-1 steel, A-2 steel and A-3 steel
The steel A-1 is of a flat type, with a yield strength and tensile strength of 2400 and 3600 kg / cm2, respectively.
The A-2 steel is of a 3400-tiered ribbed type with a tensile strength of 5000 kg per square centimeter.
And the steel A-3 is also of a type with a tolerance of 4000 and a tensile strength of 6000 kg per square centimeter. In terms of the diameter of the bars, the standards of the manufacturers are different. In the Russian system used in Isfahan Steel Factories, the bars are made up to 40 mm in diameter.