GOST 8478-81

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  ГОСТ 8478-81

GOST 8478−81 welded meshes for reinforced concrete structures. Specifications (with Change No. 1)

GOST 8478−81

Group В76

INTERSTATE STANDARD

WELDED MESHES FOR REINFORCED CONCRETE STRUCTURES

Specifications

Welded meshes for reinforced concrete structures.
Specifications

ISS 77.140.65
OKP 12 7600

Date of introduction 1983−01−0

INFORMATION DATA

1. DESIGNED AND MADE with the USSR State Committee for construction

2. APPROVED AND put INTO EFFECT by Decision of the USSR State Committee for standards from 18.05.81 N 2426

3. REPLACE GOST 8478−66

4. REFERENCE NORMATIVE AND TECHNICAL DOCUMENTS

5. Limitation of actions taken by Protocol No. 3−93 Interstate Council for standardization, Metrology and certification (ICS 5−6-93)

6. EDITION with Change No. 1, approved in June 1988 (IUS 11−88)


This standard applies to welded roll mesh, made from reinforcing wire, located in two mutually perpendicular directions connected at the intersection of resistance spot welding, and is intended for reinforcement of concrete structures.

The standard does not apply to welded mesh for reinforcement of ferroconcrete structures.

(Changed edition, Rev. N 1).

1. BASIC PARAMETERS AND DIMENSIONS

1.1 a. Grid dimensional accuracy produce:

— normal accuracy;

— high accuracy — P.

(Added, Rev. N 1).

1.1. Width of meshes , diameter of longitudinal bars diameter of transverse rods , the main step of the longitudinal bars , the main step of transverse rods , the extending step, the longitudinal rods , the free ends of the longitudinal bars and the free ends of the cross rods shall be as specified in the drawing and table.1 and 2.

Table 1

Table 2

The location of the longitudinal bars across the width of the grid

Note. The tolerance on width for meshes of high accuracy should not be more than mm.


(Changed edition, Rev. N 1).

1.2, 1.3. (Deleted, Rev. N 1).

1.4. Mesh are made with transverse studs for their entire width (see drawing).

(Changed edition, Rev. N 1).

1.5, 1.6. (Deleted, Rev. N 1).

Examples of symbols

Mesh roll with normal fabrication precision of the cell width 2350 mm, with longitudinal and transverse rods of the wire class BP-I, with a diameter of 5 mm, step 200 mm and editions of longitudinal rods , cross rods =25 mm:

5ВрІ2350 GOST 8478−81

The same, high manufacturing precision of the cell width 2350 mm? with longitudinal and transverse rods of the wire class BP-I, with a diameter of 5 mm, step 200 mm and editions of longitudinal rods , cross rods =25 mm:

5ПВрІ2350 GOST 8478−81

2. TECHNICAL REQUIREMENTS

2.1. Mesh shall be manufactured in accordance with the requirements of this standard for technological regulations approved in the prescribed manner, of low carbon wire class BP-I with a diameter of 5 mm according to GOST 6727.

2.2. The rods in the grids should be straightforward. The permissible deviations from straightness of the rods to the length of the grid equal to their step, with the exception of the plane of folding of the mesh in the roll, should not be more than:

4% of the cell size for the grids of high accuracy of manufacture;

5% «""""normal «"

The permissible deviations of the distances between extreme longitudinal bars should not be more than:

±5 mm for meshes manufacturing high precision;

±10 mm «"normal «"

The allowable deviation of the cell size should not be more than ±5 mm for mesh of high accuracy and ±10 mm for meshes normal accuracy.

The allowable deviation of the length of the free ends of the cross rods should not be more than ±5 mm for mesh of high accuracy and ±10 mm for meshes normal accuracy.

2.1, 2.2. (Changed edition, Rev. N 1).

2.3. Cruciform joints of rods in their intersections perform resistance spot welding according to GOST 14098.

2.4. The mesh must be welded all the intersections of the rods.

Allowed nesvarenie intersection of 1 m of length of a mesh in an amount which shall not exceed:

two — for meshes manufacturing high precision;

four «"normal «"

Two extreme rod around the perimeter of the mesh must be welded at all intersections.

(Changed edition, Rev. N 1).

2.5. (Deleted, Rev. N 1).

2.6. Strength of welded cruciform joints in shear is not standardized.

2.7. The breaking strength of the rods in the field of welding when the tensile test shall be not less than the values specified in GOST 10922.

2.8. The precipitate rods in a cross connection shall not be less than 0.8 mm and not more than 2.5 mm.

2.6−2.8. (Changed edition, Rev. N 1).

2.9. Each roll should consist of one segment. The party is allowed 10% of coils, consisting of two segments.

2.10. Weight of a roll of netting should be 400−1300 kg. During transportation of the meshes in open vehicles the mass of coils should be 900−1300 kg allowed weight of a roll of 400−900 kg in the amount of 10% of the total party.

When transporting grids in boxcars, the mass of the coil should be 400−500 kg.

(Changed edition, Rev. N 1).

2.11. The design characteristics of the meshes given in the Appendix.

(Added, Rev. N 1).

3. ACCEPTANCE RULES

3.1. Mesh show for acceptance by the parties. The party should consist of a grid of one brand, one shift production and is decorated with a single document about quality that contains:

— name and trademark of manufacturer;

— the symbol grid;

the weight of the party;

— number of coils;

the results of the tests.

3.2. To check the quality of meshes from the party taken one roll. In each selected coil check:

— diameter of longitudinal and transverse rods;

the mesh width in three places at the extreme longitudinal bars and the size of editions of the transverse rods;

step of longitudinal and transverse rods in three different cells;

— length five the free ends of the cross rods;

— the straightness of the transverse rods in three different cells;

— the presence of the weld in cruciform joints;

— the magnitude of precipitation cores in three cross connections;

— temporary tear resistance of wire in welding rods of not less than three samples.

3.1, 3.2. (Changed edition, Rev. N 1).

3.3. If unsatisfactory validation results of at least one of the indicators, it conducted a re-test of the doubled sample.

The results of re-examination extends to the whole party.

4. TEST METHODS

4.1. The presence of the weld in cruciform joints check the outer surfaces of the outer loop of the mesh.

4.2. Width (mm), calculated with an accuracy of 1 mm according to the formula

,

where is the distance in light between extreme longitudinal bars determined by measuring rail with supports;

the diameter of the wire in the plane of the mesh, measured with a caliper;

 — the length of the loose ends from the end of the cross rod to the surface of the longitudinal rod.

Step of longitudinal and transverse rods measure in light of caliper, and the straightness of the rods and the length of the free ends check of the measuring ruler.

Measuring instruments must meet the requirements of GOST 8.002* and GOST 8.326**.
______________
* On the territory of the Russian Federation there are PR 50.2.002−94.

** On the territory of the Russian Federation there are PR 50.2.009−94.

4.3. Breaking strength of the rod in the weld areas checked according to GOST 10922.

4.4. The amount of precipitation in wire cross connection is determined according to GOST 14098штангенциркулем with an accuracy of 0.1 mm.

Sec. 4. (Changed edition, Rev. N 1).

5. MARKING, PACKAGING, TRANSPORTATION AND STORAGE

5.1. Each roll of netting should be tied with soft wire of no less than three places.

5.2. Each roll of netting should be attached to the metal or plywood the label, which indicate:

is the trademark or name and trademark of manufacturer;

— the symbol grid;

— the weight of a roll in tons;

— the batch number.

5.3. Transportation marking must contain basic, additional and informational inscriptions according to GOST 14192.

5.4. The mesh is transported by railway and automobile transport in accordance with shipping rules applicable on the transportation of this type, and the technical conditions of loading and fastening of cargoes, approved by the Ministry of Railways of the USSR. Transportation by rail produces carload or small shipments in open and covered wagons.

Loading and unloading should be carried out in a mechanized way: in open cars — cranes with lifting capacity of 3 t, in covered wagons — lift trucks with a lifting capacity of not less than 0.5 T.

When small shipments in boxcars quantities not exceeding 10 tonnes for protection of vehicles and cargo from mechanical damage rolls of nets and their ends should be wrapped in paper according to GOST 8828 and packaging cloth according to GOST 5530 or other packaging materials that do not impair the quality of packaging.

5.5. Mesh should be stored in closed warehouses and stored not more than three tiers.

5.2−5.5. (Changed edition, Rev. N 1).

APPLICATION (reference). The design characteristics of meshes

APP
Reference

APP. (Added, Rev. N 1).



The text of the document is verified by:
the official publication of the
Mesh metal. Types.
Specifications: Sat. Standards. -
M.: IPK Publishing house of standards, 2003