GOST 7348-81

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  ГОСТ 7348-81

GOST 7348−81 (ST SEV 5728−86) carbon steel Wire for reinforcement of prestressed concrete structures. Specifications (with Amendments No. 1, 3, 4)

GOST 7348−81
(ST CMEA 5728−86)
Group V72

INTERSTATE STANDARD

CARBON STEEL WIRE FOR REINFORCEMENT
PRESTRESSED CONCRETE STRUCTURES

Specifications

Carbon steel wire for reinforcement of prestressed
concrete constructions. Specifications

OKP 12 2400

Date of introduction 1983−01−01

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Ministry of ferrous metallurgy of the USSR

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 21.01.81 N 138

3. The standard contains all the requirements of ST CMEA 5728−86

4. INSTEAD 7348−63 GOST, GOST 8480−63

5. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

6. Limitation of actions taken by Protocol No. 4−93 of the Interstate Council for standardization, Metrology and certification (ICS 4−93)

7. EDITION with Amendments No. 1, 3, 4, approved in February 1986, December 1987, January 1990 (IUS 5−86, 3−88, 5−90)


This standard applies to cold drawn carbon steel wire for reinforcement of prestressed concrete structures.

1. BASIC PARAMETERS AND DIMENSIONS

1.1. The wire is divided into:

mind:

round — To,

periodic profile — BP;

as built:

with the release

with the release energised (stable) — R;

for precision manufacturing to groups: 1, 2, 3.

Stabilized wire is produced only round. Wire depending on the diameter and magnitude of the conditional yield strength produced strength classes: 1500, 1400, 1300, 1200, 1100, 1000.

Note. Wire strength classes 1100 and 1000 is made until 01.01.93.


(Changed edition, Rev. N 3, 4).

1.2. Nominal diameter limit deviation, depth of dents, the pitch of nicks and the limit deviation shall be as specified in table. 1.

Designation of sizes of wire periodic profile is given in Fig.

Table 1

mm

Note. Nominal diameter of wire periodic profile corresponds to the nominal diameter of round wire before applying to its surface profile.

1.3. The radius of the cylindrical surface nicks to the wire diameters of the VR should be equal to (8±0,5) mm.

Allowed relative offset is diametrically opposite indentations up to 2 mm.

1.4. The circular round wire shall not exceed the limit deviations of the diameter.

Examples of callouts

Wire dia 5 mm, strength class 1400, round, stable, precision band 1:

Wire 5В1400-R1 GOST 7348−81

The same, 3 mm diameter, strength class 1500, periodic profile, precision band 1, with the release:

Wire 3Вр1500−1 GOST 7348−81.

1.2.-1.4. (Changed edition, Rev. N 3).

1.5. The calculated sectional area and theoretical weight of 1000 m of wire is given in Annex 2.

(Added, Rev. N 3).

2. TECHNICAL REQUIREMENTS

2.1. Wire shall be manufactured from carbon steel grades 65, 70, 75, 80, 85 churchyard 14959 or according to normative-technical documentation in accordance with the requirements of this standard.

2.2. Mechanical properties of the wire shall be as specified in table.2.

Table 2

Notes:

1. Rules on nominal ultimate strength are reference values.

2. The modulus of elasticity E is equal to (200±20) GPA.

3. Standards for mechanical properties wire diameter 6.0 and 8.0 mm are 01.01.93.


Until 01.01.93 mechanical properties wire diameter 6,0; 7,0; 8,0 mm shall be as specified in table.2A.

Table 2A

(Changed edition, Rev. N 3, 4).

2.3. Wire with a diameter of 6.0 mm and above shall withstand a bend test of 180°. It should be free of tears and cracks visible without using the magnifying means.

(Changed edition, Rev. N 3).

2.4. On the surface of wire should be no holes, cracks, delaminations, and captured. Permitted risks and the dent depth is not more than the maximum deviations of the diameter, and rust.

2.5. The wire should be folded into skeins separatornyi rows. Each skein must consist of one segment.

The mass of a coil shall be not less than 100 kg for wire diameters up to 6.0 mm and not less than 120 kg to a wire diameter of 6.0 mm or more.

Allowed up to 10% of the coils of low weight, but not less than 30 kg.

Customer’s request wire is allowed to produce bars of standard length.

The presence of welded joints in the finished wire is not allowed.

(Changed edition, Rev. N 1, 3, 4).

2.6. Wire produced with a normalized value of the straightness.

Wire consider a straight, if free cast cut wire on a plane it forms a segment with a base of 1 m and a maximum height of 90 mm for a wire of 3.0 and 4.0 mm and height 60 mm — for wire diameter from 5.0 to 8.0 mm. At the customer’s request the height of the segment should not be more than 30 mm.

(Changed edition, Rev. N 3).

2.7. (Deleted, Rev. N 1).

2.8. Loss of stress relaxation in stable wire on initial load of 0.7 from the actual breaking strength should not exceed 2.5% after 1000 hours of exposure under stress at normal temperatures. Requirements for relaxation are 01.01.90.

(Added, Rev. N 3).

3. ACCEPTANCE RULES

3.1. Wire take parties. The party should consist of wire of the same strength class, one of type and condition of manufacture, the same precision and the same diameter and decorated with a single document about quality that contains:

trademark or the name and trademark of manufacturer;

batch number;

symbol wire;

the number of coils;

the weight of the party.

(Changed edition, Rev. N 3).

3.2. The diameter of the round wire and its surface quality check on each reel (rod).

3.3. To test breaking strength, elongation, number of bends, depth, and bend test from each lot shall be selected 10% of the coils (bars), but not less than 5.

To check the efforts of the respective conditional yield strength and straightness, from each lot should be sampled 3% of the coils (bars), but not less than 3.

Check relaxation resistance is carried out periodically at least once in 6 months for 3 rolls from the party that passed acceptance tests.

(Changed edition, Rev. N 1, 4).

3.4. If unsatisfactory test results of at least one indicator thereon, a second test sample from twice the number of coils does not pass the test. The results of repeated tests apply to the entire party.

(Changed edition, Rev. N 3).

4. TEST METHODS

4.1. For each test selected from a coil (bar) cut off one sample.

4.2. The surface quality of the wire is checked visually.

4.3. Diameter and ovality of wire To measure with a micrometer according to GOST 6507 in two mutually perpendicular directions of the cross section of the wire and wire class BP before applying to its surface profile with an accuracy of at least 0,01 mm.

The depth of the dents wire class BP measured with a micrometer according to GOST 6507 with special heel (Annex 1), on the measurement methods, certified according to GOST 8.010*. Allowed the use of a micrometer according to GOST 4380.
________________
* On the territory of the Russian Federation GOST R 8.563−96.

The settings of the profile wire class BP determined as the average of three measurements.

(Changed edition, Rev. N …*).
_________________
* Consistent with the original. — Note the CODE.

4.4. Test wire tensile is carried out according to GOST 12004.

4.5. Test the wire on the bend is carried out according to GOST 1579. The bend test is carried out at a temperature of (20) degrees to parallel sides by means of the pressure mandrel of diameter equal to five diameters of the test wire.

When testing wire class BP, the samples are installed so that the dents were facing the clamping jaws or the mandrel.

(Changed edition, Rev. N 3).

4.6. To control the straightness of the sample is placed on a flat surface. To loose the pattern of the wire strap is supplied with a length of 1 m, in the middle of which is installed at a right angle ruler with a scale division of 1 mm. With the help of this line is measured the height of the segment formed by the wire and strap.

4.7. The radius of the cylindrical surface nicks and dents, is a step reference values for design and manufacture of the profiling tool and the wire are not checked.

(Changed edition, Rev. N 2).

4.8. The estimated cross-sectional area of wire is given in Appendix 2.

4.9. Test wire on the relaxation is carried out according to GOST 28334.

(Added, Rev. N 4).

5. PACKING, MARKING, TRANSPORTATION AND STORAGE

5.1. Each coil should be evenly bandaged on the circumference of the soft wire of no less than three places. The ends of the rolls should be neatly arranged and easy to find.

Bars shall be Packed in bundles, tied in two places.

5.1. Rolls of barbed wire weighing 30−120 kg contact in coils weighing not more than 1500 kg.

Weight of cargo must not exceed 1500 kg.

The formation of transport packets is carried out according to GOST 21650, GOST 24597.

(Added, Rev. N 3).

5.2. Wire transporterowych without lubrication and packaging. At the customer’s request coils can be packaged to protect the wire from moisture and corrosive environments.

(Changed edition, Rev. N 3).

5.3. To each coils (the beam) must be attached to the label, which indicate:

trademark or the name and trademark of manufacturer;

batch number;

symbol wire;

stamp of technical control.

5.4. Wire is transported by all kinds of transport in accordance with cargo carriage regulations applicable to transport of this species. Stowage and securing of cargo on vehicles transported by rail, must comply with the technical conditions of loading and fastening of cargoes, approved by the Ministry of Railways of the USSR. Transportation by rail is carriages, light-duty or small shipments.

Allowed the transport of wire in universal containers according to GOST 15102,20435 GOST, GOST 22225.

5.5. Storage of wire — under the terms of 5 GOST 15150.

5.3.-5.5. (Changed edition, Rev. N 3).

5.6. Wire that is sent to the far North and remote areas, packaged and transported according to GOST 15846.

5.7. Transport marking under GOST 14192.

5.6, 5.7. (Added, Rev. N 3).

ANNEX 1 (mandatory). The special heel-to-micrometer MK-type according to GOST 6507

ANNEX 1
Mandatory

Material — steel SHKH15, U10A, U12A. Hardness — HRC 48 to 50.

ANNEX 2 (informative). The calculated sectional area and theoretical weight of 1000 m of wire

ANNEX 2
Reference

Table 2

Notes:

1. The calculated sectional area and theoretical weight of 1000 m of wire is calculated based on nominal diameter.

2. The density of steel is taken equal to 7,85 kg/DM.


Appendix 2. (Changed edition, Rev. N 3).



The text of the document is verified by:
the official publication of the
Wire metal. Part 1: Sat.Standards. -
M.: IPK Publishing house of standards, 2003