Valve classes: general information

Armature is an important part of reinforced concrete structures, designed to take large loads. It can be said that the reliability and performance characteristics of the structures largely depend on the strength and endurance of these steel rods. Valve classes reflect mechanical, chemical and physical properties, rolling technology, post-rolling processing methods, corrosion resistance, and a number of other parameters of these load-bearing elements of any modern structure.

It is known that the construction of the building constantly experiences various types of loads: the weight of the equipment, machines or furniture in the building and up to the total weight of people and structural elements of the building itself. And all kinds of loads have a different effect on the bearing elements. They can compress them, stretch or bend them. The force of these loads is also different.

All classes of reinforcement, having individual qualities, are designed to take different efforts. For example, working armature perfectly withstands even the most unfavorable for the building load - tensile forces created by external factors and own weight of reinforced concrete structures. In such building elements as columns and supports, this kind of reinforcement perceives the basic compressive forces. However, only this type of steel rods is not enough to give the structure the necessary strength.

Therefore, along with the working armature in the construction of most modern buildings, a distribution is used, designed to distribute the force between the rods evenly, and an assembly one, which performs the function of combining individual steel elements into a single rigid frame. To prevent the formation of oblique cracks in the structure of the structure, additional high-strength rods, figured clamps and hooks are introduced.

All classes of reinforcement are indicated by an alphanumeric index from A-1 to A-6. The higher this designation, the stronger the bars themselves. The sphere of application of these elements of building structures also depends on this. For example, valves of class A1 are hot rolled smooth steel rods. It is used mainly in buildings that are not subject to heavy loads and stress. The armature of this class serves as mounting, structural and transverse elements. It has good weldability.

Other classes of reinforcement, starting with A-2 and above, are hot-rolled rod elements of a periodic profile. As a rule, such rods are subjected to thermochemical treatment after rolling, which increases their strength. The use of class A-2 is almost the same as A-1. With the exception of rods made of St 5 steel and having a diameter of more than 32 mm, since when welding such rods they do not provide a sufficiently reliable weld joint.

Armature class A3 is widely used in the manufacture of standard reinforced concrete structures, where it serves as a working component. It also has good weldability. Class A-4 has much greater strength than the previous ones, and, accordingly, is used as a tensile (bearing) element. The weldability of such reinforcement is considered satisfactory, although slightly inferior to the previous classes. Therefore, the rods of this category are joined in a manner known as a crimped cage. Reinforcing rods of classes A-5 and A-6 are extremely strong structural elements. They are used in long building structures with a span of at least twelve meters. Such fittings are capable of withstanding very heavy loads and forces.