The value of regulatory acts and classifications in industrial production is very great, this is especially acute at the junction of construction and metallurgy.
The range of fittings is a classification of the most used hot-rolled and cold-drawn steel rods or composite materials, which are represented in a particular country by an assortment of a metallurgical or other production enterprise. The assortment is usually compiled according to the current regulatory and technical documentation, which determines the gradation and optimal characteristics of the sections of the rods. It is intended for the rational selection of reinforcement according to the strength characteristics and minimize waste during construction and installation works. This is due to the fact that even carbon steel of ordinary quality St3, St5 is a rather expensive material, and its overrun is unacceptable.
The origin of the term and features of its application
The term "assortment of fittings" is common only in the professional environment of design engineers, technologists and other technical workers in the construction industry and industrial enterprises producing this structural material. It is uncommon in widespread use. The origin of the expression is due to the borrowing of the French word assortiment, which in the course of adaptation to the Russian language acquired specific features inherent only in phrases used in the professional environment.
Key features and differences between assortments
The structure of all assortments can be divided into dimensional and profile, in the first embodiment, the basic sizes of one type of reinforcement with details of its features are indicated, while in the second embodiment, the rods are classified according to the purpose of their application (welded, heat-strengthened reinforcement, and so on). Classical for the Russian Federation assortment of fittings (GOST 5781-82 its source) combines all the above features and displays the necessary indicators in the most convenient form. This state standard considers the principles of conformity of steel reinforcement (wire and bar) with the requirements for it, and permissible deviations of material losses are determined. In comparison with the conditional ideal of the assortment, which would contain the entire numerical set of cross-sections of various profiles and the length of the rods, only rationally selected standard sizes are displayed in GOST. They do not allow both excessive load on structural elements due to excessive sections and their own weight, and a significant excess of material consumption and provide only minimal irretrievable losses during technological processes of construction. At the same time, various industrial enterprises can produce products according to the technical conditions developed by them, taking into account its purpose. First of all, this applies to rod and wire products made of composite materials and the corresponding application recommendations.
Data from GOST 5781-82
Range of fittings a400, a300, a500| Ø | Estimated cross-sectional area of the rod | Weight 1 m running |
| 4 mm | 0.12 cm 2 | 0.098 kg |
| 5 mm | 0.2 cm 2 | 0.154 kg |
| 6 mm | 0.28 cm 2 | 0.222 kg |
| 7 mm | 0.39 cm 2 | 0.302 kg |
| 10 mm | 0.79 cm 2 | 0.617 kg |
| 12 mm | 1.13 cm 2 | 0.888 kg |
| 14 mm | 1.54 cm 2 | 1,208 kg |
| 16 mm | 2.01 cm 2 | 1,578 kg |
| 18 mm | 2.55 cm 2 | 1,998 kg |
| 20 mm | 3.14 cm 2 | 2,466 kg |
| 22 mm | 3.80 cm 2 | 2,984 kg |
| 25 mm | 4.91 cm 2 | 3.853 kg |
| 28 mm | 6.16 cm 2 | 4.834 kg |
| 32 mm | 8.04 cm 2 | 6.313 kg |
| 36 mm | 10.2 cm 2 | 7,990 kg |
| 40 mm | 12.6 cm 2 | 9.805 kg |
Features of the use of fittings and assortment in multi-storey construction
Despite the fact that the scope of application of steel reinforcement is not too extensive (unlike other metallurgy products), it is practically irreplaceable in the construction industry of reinforced concrete monolithic structures. After all, this type of construction of multi-storey and high-rise buildings involves the arrangement of a continuous knitted or welded frame and its monolithic. It perceives all the critical values of the stresses arising in the structures: tensile, compression, bending, wind vibrations, and, if necessary, seismic effects, also prevents the unacceptable opening of cracks in the reinforced concrete elements of the building. Such an important element of any structure is delivered to the construction site in bays or in bundles with rods (depending on the diameter of the reinforcement), each of which has its own marking. At the place of unloading the material, it is received, the accompanying document for which is the invoices of the manufacturer or supplier, where the assortment of reinforcement is indicated.
The importance of product regulation in the field of metallurgy and construction
Factory complexes for the production of reinforced concrete products, which produce structures with steel embedded parts using methods of steaming and vibrating, sell their products to companies building buildings from prefabricated reinforced concrete elements. The functioning of manufacturers and contractors engaged in this field is impossible without a sufficient range of steel materials, and the assortment of fittings is the basis for their production. In the field of regulatory regulation, standardization and unification of such products, such technical documentation assumes the role of a unifying factor, due to which normal interaction between non-adjacent areas of production is carried out.