Class A400 Reinforcement is a steel bar with a periodic profile, widely used for reinforcing reinforced concrete structures. It features an optimal balance of strength and plasticity, making it one of the most in-demand materials in construction.
Production Technology

The manufacturing process includes the following stages:
1.    Steel Billet Preparation: Carbon steel of the required chemical composition is used.
2.    Heating: The billet is heated in furnaces to a temperature of 1100-1200°C.
3.    Hot Rolling: In rolling mills, a bar of the specified diameter with transverse ribs is formed.
4.    Controlled Cooling: The reinforcement undergoes a stage of natural or accelerated cooling.
5.    Cutting and Straightening: Cutting to measured lengths and straightening to eliminate bends.
6.    Marking and Packaging: Application of identification information and packaging for shipment.

Characteristics and Assortment
•    Nominal Diameters: 6, 8, 10, 12, 14, 16, 18, 20, 22, 25, 28, 32, 36, 40 mm.
•    Strength Characteristics:
o    Yield strength: ≥ 400 MPa.
o    Tensile strength: ≥ 600 MPa.
o    Elongation: ≥ 14%.
•    Mass per 1 meter: from 0.222 kg (Ø6 mm) to 9.87 kg (Ø40 mm).
•    Bar Length: 11.7 m (measured) or 6-12 m (non-measured).

Advantages
•    High Strength and reliable bond with concrete.
•    Resistance to static and dynamic loads.
•    Good Plasticity and resistance to fracture.
•    Affordable Cost compared to higher classes.
•    Versatile Application in various types of structures.
•    Proven Reliability through years of application experience.

Areas of Application
•    Monolithic Construction: foundations, columns, floor slabs.
•    Precast Concrete: production of slabs, beams, girders.
•    Road Construction: reinforcement of road slabs and pavements.
•    Civil Construction: residential and public buildings.
•    Industrial Construction: workshops, warehouses, industrial premises.
•    Construction of reinforced concrete structures for special purposes.

Normative Documentation (GOST Standards)
Main standards regulating the production of Class A400 reinforcement:
GOST 5781-82 – "Hot-rolled steel for reinforcing reinforced concrete structures. Technical specifications"
•    Defines technical requirements for A400 class reinforcement.
•    Establishes mechanical properties and test methods.
•    Regulates acceptance rules and assortment.
GOST 34028-2016 – "Reinforcing rolled products for reinforced concrete structures. Technical specifications"
•    A modern standard including requirements for A400 reinforcement.
•    Establishes improved quality parameters.
•    Defines marking and packaging requirements.
Additional Normative Documents:
•    SP 63.13330.2018 – Concrete and reinforced concrete structures.
•    GOST 10884-94 – Thermomechanically strengthened reinforcing steel.
•    GOST 18105-2010 – Rules for controlling concrete strength.
Marking Features:
•    A400 – strength class designation.
•    Ribbed surface – to improve bond with concrete.
•    Manufacturer's stamp on each bar.