INTERNATIONAL STANDARD
HOT-ROLLED STEEL FOR REINFORCEMENT CONCRETE STRUCTURES
Specifications
GOST 5781-82
INTERNATIONAL STANDARD
This standard applies to hot-rolled round steel of smooth and periodic profile intended for the reinforcement of conventional and prestressed reinforced concrete structures (reinforcing steel).
Regarding the norms of the chemical composition of low-alloy steels, the standard also applies to ingots, blooms and billets.
(Modified edition, Rev. No. 4).
1. CLASSIFICATION AND VARIETY
1.1. Depending on the mechanical properties, reinforcing steel is subdivided into classes AI (A240), A-II (A300), A-III (A400), A-IV (A600), AV (A800), A-VI (A1000).
1.2. Reinforcing steel is produced in rods or coils. Reinforcing steel of class AI (A240) is made smooth, classes A-II (A300), A-III (A400), A-IV (A600), AV (A800) and A-VI (A1000) - periodic profile.
At the request of the consumer, steel of classes A-II (A300), A-III (A400), A-IV (A600) and A-V (A1000) is made smooth.
1.1, 1.2. (Modified edition, Rev. No. 5) .
1.3. Profile numbers, cross-sectional areas, mass of 1 m of length of reinforcing steel of smooth and periodic profile, as well as maximum deviations in mass for periodic profiles must correspond to those indicated in table. 1.
1.4. The nominal diameters of periodic profiles should correspond to the nominal diameters of smooth profiles of equal cross-sectional area.
Table 1
(Modified edition, Rev. No. 3).
1.5. The mass of 1 m of the profile is calculated according to the nominal dimensions with a steel density equal to 7.85 × 10 3 kg /m 3 . The probability of providing a mass of 1 m must be at least 0.9.
(Modified edition, Rev. No. 3).
1.6. Limit deviations of the diameter of smooth sections must comply with GOST 2590-88 for normal rolling accuracy.
1.7. Reinforcing steel of a periodic profile is a circular profile with two longitudinal ribs and transverse protrusions running along a three-start helical line. For profiles with a diameter of 6 mm, protrusions are allowed along a single-start helical line, with a diameter of 8 mm - along a two-start helical line.
1.8. Reinforcing steel of class A-II (A300), made in the usual version, with the profile shown in fig. 1 a , and special purpose Ac-II (Ac300) profile shown in fig. 2 a must have protrusions running along helical lines with the same approach on both sides of the profile.
Steel class A-III (A400), manufactured with the profile shown in fig. 1 b , and classes A-IV (A600), A-V (A800), A-VI (A1000) with the profile shown in fig. 1 b , 2 b , should have protrusions along the helical lines, having on one side of the profile right, and on the other - left approaches.
Damn. 1
Damn. 2
Reinforcing steel for special purposes of class Ac-II (Ac300) is made by the profiles shown in Fig. 1 a or 2 a .
Profile shown in fig. 2 a , special purpose is manufactured by agreement between the manufacturer and the consumer. The shape and dimensions of the profiles shown in Fig. 2 a and b , subject to change.
1.9. Dimensions and limit deviations of the dimensions of the reinforcing steel of the periodic profile, manufactured according to the drawing. 1 a and b must correspond to those given in table. 2, but damn. 2 a and b - given in table. 3.
Table 2
Dimensions , mm
Note. At the request of the consumer, the maximum deviations of the size d1 must not exceed the maximum deviations d plus twice the maximum deviations h .
Table 3
Dimensions , mm
