Rolled metal used for reinforcement of concrete products. It is often called reinforcing wire. The characteristic difference is an annular (not spiral-shaped) periodic profile. Made of wire rod. It is important to know that the nominal diameter of the wire BP corresponds to the nominal diameter of the rod from which it is made. The wire of BP happens two types:

• BPI cold-drawn wire, made of low carbon steel for reinforcement of concrete products (GOST 6727-80).
• ВРІІ - cold-drawn wire made of carbon steel, designed for the reinforcement of prestressed concrete products (GOST 7348-81).

A prestressed concrete product is a structure in which the reinforcing steel frame is pre-stretched by a certain amount, and only then is it poured with concrete. After the concrete hardens, the frame releases and he, trying to return to a relaxed state, compresses the concrete. During operation, if a tensile force is applied to the concrete (bending force), it is actually unloaded - the tensile stresses are compensated by the compressive stresses existing in it. This allows:

• increase the bearing capacity of a concrete product or reduce the consumption of concrete on it (up to 30%) to achieve a given bearing capacity;
• reduce the likelihood of cracks in it.

The main advantage is low price compared to other types of reinforcing metal. At the same time, due to the presence of the grooved surface, the BP wire sets better to the concrete than ordinary smooth wire of the same diameter. We have already said about the main area of ​​use - reinforcement of reinforced concrete products. Besides this metal rolling can be used, as an independent power element for creation of various designs. Wire BPI is used to create a lightweight masonry mesh.

Steel wire classification

Wire ВPІІ has 6 strength classes (1000, 1100, 1200, 1300, 1400, 1500) and 3 accuracy groups (1,2,3). The table below shows data on compliance with the nominal diameter of the wire BPII and strength class.