GOST R 52544-2006

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  ГОСТ Р 52544-2006

GOST R 52544−2006 weldable rolled reinforcing periodic profile A500C and B500C classes for reinforcement of concrete structures. Specifications

GOST R 52544−2006

Group В32

NATIONAL STANDARD OF THE RUSSIAN FEDERATION

ROLLED WELDABLE REINFORCING PERIODIC PROFILE CLASS
A500C AND B500C FOR REINFORCEMENT OF CONCRETE STRUCTURES

Specifications

Weldable deformed reinforcing rolled products of A500C and B500C classes
for reinforcement of concrete constructions. Specifications

OKS 77.140.60
OKP 09 6000

Date of introduction 2007−01−01

Preface

The objectives and principles of standardization in the Russian Federation established by the Federal law of 27 December 2002 N 184-FZ «On technical regulation», and rules for the application of national standards of the Russian Federation — GOST R 1.0−2004 «Standardization in the Russian Federation. The main provisions"

Data on standard

1 DEVELOPED by the Technical Committee for standardization TC 375 «steel Products from ferrous metals and alloys», branch of FSUE SIC «Construction-NIIZHB», FSUE «tsniichermet im. I. P. Bardina"

2 SUBMITTED by the Technical Committee for standardization TC 375 «steel Products from ferrous metals and alloys"

3 APPROVED AND put INTO EFFECT by the Federal Agency for technical regulation and Metrology dated 17 may, 2006 No. 97-St

4 INTRODUCED FOR THE FIRST TIME


Information about the changes to this standard is published in the annually issued reference index «National standards», and the text changes and amendments — in monthly indexes published information «National standards». In case of revision (replacement) or cancellation of this standard a notification will be published in a monthly information index «National standards». Relevant information, notification and lyrics are also posted in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet

1 Scope

This standard applies to welded rebar periodic profile A500C and B500C classes designed for reinforcement of concrete structures.

2 Normative references

This standard uses the regulatory references to the following standards:

GOST 7566−94 metal Products. Acceptance, marking, packing, transportation and storage

GOST 10884−94 thermomechanically hardened Steel bars for reinforced concrete structures. Specifications

GOST 10922−90 and Reinforcing cage welded products, welded joints of reinforcement and embedded products for reinforced concrete structures. General specifications

GOST 12004−81 Steel reinforcement. Test methods tensile

GOST 12354−81 Steel alloyed and high alloy. Methods for determination of molybdenum

GOST 12359−99 (ISO 4945−77) Steels carbon, alloyed and high alloy. Methods for determination of nitrogen

GOST 14019−2003 (ISO 7438:1985) Materials of metal. Method of bend test

GOST 14098−91 welded Joints of reinforcement and embedded products for reinforced concrete structures. Types, designs and sizes

GOST 21014−88 ferrous metals. Terms and definitions of defects

GOST 22536.0−87 carbon Steel and unalloyed cast iron. General requirements for methods of analysis

GOST 22536.1−88 carbon Steel and unalloyed cast iron. Methods for determination of total carbon and graphite

GOST 22536.2−87 carbon Steel and unalloyed cast iron. Methods of determining sulphur

GOST 22536.3−88 carbon Steel and unalloyed cast iron. Methods for determination of phosphorus

GOST 22536.5−87 (ISO 629−82) carbon Steel and unalloyed cast iron. Methods for determination of manganese

GOST 22536.7−88 carbon Steel and unalloyed cast iron. Methods for determination of chromium

GOST 22536.8−87 carbon Steel and unalloyed cast iron. Methods for determination of copper

GOST 22536.9−88 carbon Steel and unalloyed cast iron. Methods for determination of Nickel

GOST 22536.12−88 carbon Steel and unalloyed cast iron. Methods for determination of vanadium

GOST 27809−95 Cast iron and steel. Methods for spectrographic analysis

GOST 28473−90 Iron, steel, ferroalloys, chromium and manganese metal. General requirements for methods of chemical analysis

GOST 29273−92 (ISO 581−80) Weldability. Definition

OST 14−1-34−90 Statistical acceptance inspection of metal products for correlations between the parameters.

Note — When using this standard appropriate to test the effect of reference standards in the information system of General use — on the official website of the Federal Agency for technical regulation and Metrology on the Internet or published annually by the information sign «National standards» published as on January 1 of the current year and related information published monthly indexes published in the current year. If the reference document is replaced (modified), then the use of this standard should be guided by the replaced (modified) document. If the reference document is cancelled without replacement, then the situation in which the given link applies to the extent that does not affect this link.

3 Terms and definitions

This standard applies the following terms with respective definitions:

3.1 reinforcement bars periodic profile: Rods with evenly spaced on the surface at an angle to their longitudinal axes transverse ribs to improve bonding with concrete.

3.2 rebar nominal diameter mm Reinforcement bars, the actual diameter of which is subject to the permissible deviations corresponds to the diameter of the range in table 1.

3.3 the actual diameter of reinforcing bar , mm Diameter of equal-sized square round smooth rod with a length of 1 m with the same mass, that rolled periodic profile defined by the formula

, (1)

where is the mass of rolled periodic profile, g;

 — length of rolled periodic profile.

3.4 nominal cross-sectional area , mm: cross-sectional Area of the rental, equal to the cross sectional area of round smooth stud of the same nominal diameter.

3.5 elements of the periodic profile of reinforcing bar (see Appendix a):

3.5.1 longitudinal rib: a Continuous longitudinal projection formed along the axis of the reinforcing bar when it is rolling.

3.5.2 transverse rib: a Rib located at an angle to the longitudinal axis of the rental.

3.6 geometrical parameters of the periodic profile of reinforcing bar:

3.6.1 fin height , mm: the distance from the top point of the transverse rib to the body surface rental, as measured perpendicular to its axis.

3.6.2 step transverse ribs , mm: the Distance between two adjacent stiffeners, measured along the axis of the rental.

3.6.3 the total distance between the ends of the transverse ribs , mm the sum of the distances between the ends of the transverse ribs, measured in the plane perpendicular to the axis of rolling (for example, for the profile according to figure A. 1 ).

3.6.4 the angle of inclination of the transverse edges : Angle between the axis of the transverse edges and the longitudinal axis of the rental.

3.6.5 angle of inclination of the side surfaces of the transverse edges , degree: the angle of the side surface of the transverse rib to the longitudinal axis of the rental.

3.6.6 width of the transverse ribs mm Size on top of the trapezoidal cross section of the rib in its cross section perpendicular to the axis of the rib.

3.6.7 ovality, mm: the Difference between the largest and smallest cross-sectional dimensions of rolled products. For a periodic profile in figure A. 1 — difference between actual dimensions and .

3.6.8 the relative size of the shear of transverse edges of a periodic structure : the projected Area of transverse ribs on a plane perpendicular to the axis of rolling, is related to the product of the circumference of the nominal diameter for the actual average step for those ribs.

4 Classification and assortment

4.1 Reinforcement bars are subdivided:

according to the method of production classes:

A500C — hot-rolled, without further processing or thermomechanically strengthened in the flow of rolling,

B500C — mechanically hardened in a cold state (cold-drawn);

— products:

bars,

Hanks.

In the designation of the class:

As — hot-rolled or thermomechanically strengthened reinforcement bars;

In — cold-deformed reinforcement bars;

With — weldable;

500 yield strength of at least 500 N/mm.

4.2 Nominal diameter, cross sectional area and weight of 1 m of the length of the rental must match the values given in table 1.


Table 1 — Nominal diameter cross-sectional area and weight of 1 m length of reinforcing bar

Nominal diameter , mm	Nominal cross-sectional area , mm	The nominal mass of 1 m length of the rental, kg
4,0	12,6	0,099
5,0	19,6	0,154
6,0	28,3	0,222
8,0	50,3	0,395
10,0	78,5	0,616
12,0	113,1	0,888
14,0	153,9	1,208
16,0	201,1	1,578
18,0	254,5	1,998
20,0	314,2	2,466
22,0	380,1	2,984
25,0	490,9	3,853
28,0	615,8	4,834
32,0	804,2	6,313
36,0	1017,9	7,990
40,0	1256,6	9,865
Notes 1 At the request of the consumer reinforcement bars are manufactured with a nominal diameter: 4,5; 5,5; 6,5; 7; 7,5; 8,5; 9; 9,5; 45; 50 mm. 2 the Nominal mass of 1 m of length of rental is determined on the basis of the nominal diameter at steel density equal to 7.85 g/cm.

4.3 Periodic profile of reinforcing bars shall consist of at least two rows of transverse ribs, having a Crescent-shaped and not interconnected with longitudinal ribs. Delivery of rebar without longitudinal ribs.

The values of the parameters of the periodic profile and the relative area of the shear shall meet the requirements set out in table 2.


Table 2 — Parameters of the periodic profile of reinforcing bar

The name of the parameter of a periodic structure	The value for the rental class
	A500C	B500C
Nominal diameter, mm	6−40	4−12
Permissible deviation from the nominal cross-sectional area and weight of 1 m length profile, % of rental with a diameter of, mm:
to 5.5	-	±4,5
5.5 «8 incl.	±8	±4,5
«To 8.5» 14 «	±5	±4,5
«16» 40 «	±4	-
The relative size of the shear of the transverse edges of the profile , at least to the diameter of, mm:
to 4 incl.	0,036
4.5 «6 cyl.	0,039
«6,5» 8 «	0,045
«8,5» 10 «	0,052
«To 10.5» 40 «	0,056
The height of transverse rib mm	(0,065−0,1)	(0,05−0,1)
The step of transverse ribs , mm	(0,4−1,0)
Relative pitch of the transverse ribs , at least	-	3
The angle of inclination of the transverse ribs	35°-60°
The angle of the side surface of the ribs , nothing more	45°
The total distance between the ends of the transverse ribs , mm, not more	0,2	0,25
The roundness of the reinforcing bar, mm, not more than, diameter, mm
to 5.5 incl.	-	0,5
from 6 «to 14 incl.	1,2	1,0
«16» 25 «	1,6	-
«28» 40 «	2,4	-

For hot-rolled and thermomechanical reinforced reinforcing bar configuration of a periodic structure in accordance with figure A. 1 and table A. 1, but for cold-rolled — in accordance with figure A. 2 (Appendix a) and the General requirements on the profile in table 2.

By agreement with consumer it is permitted to supply reinforcing bar configuration of a periodic structure different from the requirements of the application And, subject to compliance of properties rental requirements of this standard.

4.4 Reinforcement bars are manufactured with a nominal diameter:

to 6 mm — in rolls;

from 6 to 12 mm inclusive, in coils or rods;

14 mm and over — in bars.

4.5 Bars made:

— measuring length (MD) in the range of 6 to 12 m, as stipulated by the consumer in the order;

— random length (ND) in the range of 6 to 12 m, as defined by the manufacturer. In the party of bars with variable length is allowed in bars with length from 3 to 6 m in an amount of not more than 7% of the batch weight.

Maximum deviations along the length of the rods of standard length plus 100 mm.

4.6 Curvature of bars should not exceed 0.6% of the measured length.

Examples of symbols:

Rebar rods with a nominal diameter of 12 mm, grade A500C, length (MD) 11700 mm:

Rod 12x11700-A500C GOST R 52544−2006

Rebar in coils with nominal diameters of 8 mm, grade B500C:

A coil 8-B500C GOST R 52544−2006

5 Technical requirements

5.1 Properties of reinforcing bars should conform to the standards set out in table 3.


Table 3 — Properties of reinforcing bar

Name of the indicator (characteristic)	The value of the index (content data) for a class
	A500C	B500C
Diameter, mm	6−40	4−12
The dimensions of the periodic profile of rental	4.3 of this standard
The permissible deviations from the nominal values of cross-sectional area and weight of 1 m of length	4.3 of this standard
Minimum relative area of shear transverse ribs periodic profile	4.3 of this standard
Yield strength *, N/mm, not less	500	500
Tensile strength , N/mm, not less	600	550
Elongation , %, not less	14,0	-
The total relative elongation at maximum stress , %, not less	-	2,5**
Attitude , not less	Of 1.08	1,05***
The statistical security of the mechanical properties	5.4 of this standard
The Flexural properties	5.5 of this standard
The Flexural properties with the subsequent straightening	5.5 of this standard
Stamina reinforcing steel. The amplitude of oscillations at maximum stress =300 N/mmand the number of load cycles 2·10, N/mm	150
Chemical composition	5.6 of this standard
Weldability	5.7 of this standard
* As the yield strength of taking physical () or conditional (in) yield stress according to GOST 12004. ** Allowed instead of complete elongation to determine the relative uniform elongation , the value of which shall not be less than 2%. *** For reinforcing bars of grade B500C diameter of 5.5 mm and less may be reduced to 1.03.

5.2 Reinforcement bars of A500C class supplying hot-rolled, without further processing IPI thermomechanically strengthened in the flow of rolling, grade B500C, in cold-worked condition.

5.3 On the surface of reinforcing bars is not allowed:

— cracks;

sunsets, films and shells, degrade its performance.

Classification of defects — according to GOST 21014.

5.4 Statistical indicators of temporary resistance and yield strength listed in table 3, each lot must be not less than 0.95.

5.5 Reinforcement bars shall withstand either of the following tests:

— for a single bending cold to an angle 180° around a mandrel diameter equal to 3;

— bending to an angle of at least 90° with the subsequent straightening angle of at least 20°.

The diameters of the mandrel test bending and subsequent straightening shall be as specified in table 4.


Table 4 mandrel Diameters for test of reinforcing bars on bending and subsequent straightening

Nominal diameter of reinforcing bar , mm	The mandrel diameter during bending
Up to 12 cyl.	5
SV. 12 «16 «	6
«16» 25 «	8
«25» 50 «	10

5.6 Chemical composition of steel and the value of the carbon equivalent shall be as specified in table 5.


Table 5 — Chemical composition of steel carbon equivalent

Analysis	Mass fraction of elements, %, not more							Carbon equivalent
	carbon	silicon	manganese	phosphorus	sulfur	nitrogen	copper
In the bucket test	0,22	0,90	1,60	0,050	0,050	0,012	0,50	0,50
Finished steel	0,24	0,95	1,70	0,055	0,055	0,013	0,55	0,52
Notes 1 For steel containing nitridebased elements, mass fraction of nitrogen is not limiting. 2 For rental with a diameter of 32 mm allowed an increase in steel mass fraction of carbon to 0.26% of carbon equivalent to 0.53% (in the ready-rolled respectively to 0.27% and 0,57%).

5.7 Weldability of reinforcing bars ensure that chemical composition of the steel and technology of its manufacture and control in accordance with Annex B.

5.7.1 To ensure the required strength of welded joints of thermo-mechanically hardened rebars (in brackets — ready for rental) value of the carbon equivalent should be, %, not less:

for hire nominal diameter, mm

		to	10	inclusive	And 0.26 (0,28);
from	12	«	18	«	— 0,30 (0,32);
«	20	«	28	«	— 0,35 (0,37);
«	32	«	40	«	— 0,40 (0,42).

5.8 Statistical indicators of temporary resistance and yield strength of reinforcing bars shall conform to the requirements of table 6. The method of determining the statistical indicators of rental given in Annex B.


Table 6 Statistical indexes of mechanical properties of reinforcing bar

Statistical parameters of mechanical properties, no more
Standard deviation, N/mm				The coefficient of variation
Seventy	70	40	40	0,08	0,07	0,05	0,04
Notes 1 In this table the designations used:  — the standard deviation of the parameter in the General set of tests;  — the standard deviation of the parameter in the party;  — the average value of the parameter in the General set of tests;  — the minimum average value of the parameter in the party. 2 For reinforcing bar in coils may increase the value of norms and 5.0 N/mm.

5.9 At the request of the consumer, the endurance of the hire must meet the requirements of table 3 with the test according to the method of application G.

6 acceptance Rules

6.1 General rules of acceptance GOST 7566.

6.2 Acceptance the control manufacturer

6.2.1 Reinforcement bars from the manufacturer take part in the control of the following characteristics:

— yield strength;

— temporary resistance;

— relative elongation;

— Flexural properties;

— the cross sectional area and weight of 1 m length;

dimension of the periodic profile and the relative areas of shear transverse ribs periodic profile;

— chemical composition and carbon equivalent;

— surface quality;

— the curvature of the bars.

6.2.2 the Party shall consist of reinforcing bar of the same nominal diameter, one of delivery status, one melting ladle, and must be executed by one document on quality.

The weight of the batch should be no more than 70 tons.

Allowed to increase the mass party rentals of class A500C to the weight of the melting-ladle.

6.2.3 From each batch are selected:

— to control chemical composition — one sample;

to control the surface quality, the geometric dimensions of the profile and weight of 1 m of length — 2 sample;

for tensile testing — 2 samples;

to test for bending or bending and straightening — 2 sample.

6.2.4 Each individual test result shall meet the requirements of section 5.

6.2.5 If unsatisfactory test results of at least one of the indicators, repeat tests are carried out on twice the number of samples. The results of repeated tests are final.

6.3 Control of toughness and weldability of reinforcing bars is carried out in accordance with annexes G and B.

6.4 Each batch of reinforcing bars must be accompanied by a quality document issued in accordance with the requirements of GOST 7566.

To document the quality of reinforcement bars indicate:

— nominal diameter;

class of reinforcing bars and the designation of this standard;

— mass fraction (pravachol) to steel chemical elements, is given in 5.6 (table 5) and 7.9;

— temporary resistance ;

— yield strength ;

the elongation or total elongation ;

the test results of the cold bending or the bending and subsequent straightening.

At the request of the consumer in the document as indicative of statistical indicators of the strength properties — minimum average values of each batch of the yield strength , temporary resistance and their standard deviation , the data on toughness and weldability

.

6.5 Input control from user

6.5.1 Each shipment of reinforcing bars the consumer are subjected to incoming inspection.

6.5.2 For quality control of the surface, geometrical parameters and mass of 1 m length of the rental, as well as tensile tests, bending or bending and straightening take one sample.

6.5.3 For reinforcing bar, is supplied with an indication in the document about the quality of statistical indicators of mechanical properties, testing of samples for tensile, bending, or bending and straightening is allowed not to perform.

6.5.3.1 In the event of disagreement in the evaluation of quality control of mechanical properties is carried out in accordance with Annex V.

7 test Methods

7.1 the quality of the surface of reinforcing bars test without the use of magnifying devices.

7.2 For tensile testing used samples of reinforcing bar in state of delivery or after edits.

Tensile tests with the definition of , , and is carried out according to GOST 12004.

7.3 Determination of statistical indicators of the variability of mechanical properties of reinforcing bars in General population in each batch is carried out in accordance with Annex V.

7.4 bending Test in the cold state is carried out according to GOST 14019.

7.5 bend Test with the subsequent straightening is carried out according to GOST 10884.

7.6 fatigue Testing is carried out according to methodology described in Appendix G.

7.7 Geometrical parameters of reinforcing bar checking in accordance with Appendix E.

7.8 Chemical analysis were carried out according to GOST 12354 series, GOST 12359, GOST 22536.0 to GOST 22536.3, 28473 GOST, GOST 22536.5, 22536.7 GOST — GOST 22536.9, 22536.12 GOST, GOST 27809 or other methods providing the required accuracy.

7.9 Carbon equivalent shown in table 5, is calculated by the formula

, (2)

where is the actual mass fraction, respectively, of carbon, manganese, chromium, molybdenum, vanadium, Nickel and copper in steel, %.

8 Marking, packaging, transportation and storage

8.1 Marking, packaging, transportation and storage of reinforcing bars — according to GOST 7566 with the following additions.

8.2 Marking

8.2.1 Reinforcement bars must have a rent-a marking that includes the trademark of manufacturer and designation of class A500C rental or B500C. An example labeling is shown in figure 1.

Figure 1 — Example of marking the rolling of reinforcing bars class A500C production of JSC «Oskol electrometallurgical combine»

Figure 1 — Example of marking the rolling of reinforcing bars class A500C production of JSC «Oskol electrometallurgical combine»

8.2.2 delivery of reinforcing bars with the markings of the manufacturer, which is applied with the use of thickened transverse rib on one side of the rental. The beginning of the read markings indicate two thickened ribs, the number following the usual transverse ribs and the thickened edges is the number of the manufacturer (Annex D). In the case of a two-digit number the manufacturer (figure 2) the initial number of edges specifies the number of tens, and then, after the next thickened ribs and the number of units.

Figure 2 — Example of rolling marking the factory number 14

The direction of read markings

Figure 2 — Example of rolling marking the factory number 14

8.2.3 Permitted other types of rolling marking does not reduce the performance characteristics of the hire and agreed with the consumer.

8.3 Packing

8.3.1 General rules for packaging — according to GOST 7566 with the following additions.

8.3.2 Bars is Packed in bundles weighing from 1.5 to 15 tons At customer’s request, the mass of the cords can be less than 1.5 T.

8.3.3 When supplied in coils each coil should consist of one segment reinforcing bars. It is possible to supply the coils, consisting of two segments, not more than 10% of the batch weight. Coil’s weight shall be from 0.3 to 1.5 T. In agreement with the consumer for cold-rolled grade B500C coil’s weight is allowed from 0.03 to 0.3 t and 1.5 to 3.0 tons.

A coil should be tightly wrapped. The number and the layout of studs stipulate in the order or contract.

8.3.4 Each pair and each coil of reinforcing bar must have a label, which indicate:

— trademark and name of the manufacturer;

— nominal diameter of reinforcing bar, mm;

class of reinforcing bars;

— the designation of this standard;

— the batch number.

Annex a (mandatory). The types and amounts of the periodic profile of reinforcing bar

Appendix A
(required)

A. 1 Configuration, dimensions and limit deviations from the periodic profile of reinforcing bars, ensure compliance with the requirements of table 2 of this standard, and supplied in hot-rolled and thermo-mechanically hardened condition, is shown in figure A. 1 and table A. 1.

Figure A. 1 — Periodic profile, hot-rolled and thermomechanical reinforced reinforcing bar

Figure A. 1 — Periodic profile, hot-rolled and thermomechanical reinforced reinforcing bar

Table A. 1

In millimeters

Nominal diameter of reinforcing bar	The parameters of the periodic profile
			no less				Pred. off %		no more	no less
	Nom.	Pred. off.		Nom.	Pred. off.						max.	min.
6	5,8	+0,3 -0,5	0,4	7,0	±0,6	4	±15	0,6	1,9	45°	60°	35°
8	7,7		0,6	9,3		5		0,8	2,5
10	9,5		0,8	11,5		6		1,0	3,1
12	11,3		1,0	13,7		7		1,2	3,8
14	13,3		1,1	15,9		8		1,4	4,4
16	15,2	+0,3 -0,5	1,2	18,0	±0,8	9	±15	1,6	5,0	45°	60°	35°
18	17,1		1,3	20,1		10		1,8	5,6
20	19,1		1,4	22,3		11		2,0	6,3
22	21,1	+0,4 -0,5	1,5	24,5		12		2,2	6,9
25	24,1		1,7	27,7		13		2,5	7,9
28	27,0	+0,4 -0,7	1,9	31,0	±1,2	15	±15	2,8	8,8	45°	60°	35°
32	30,7		2,2	35,1		16		3,2	10,0
36	34,5		2,4	39,5		18		3,6	11,3
40	38,4		2,7	43,8		20		4,0	12,5

Dimensions that have not installed limit deviations, given to build the caliber and the finished profile is not checked.

A. 2 Configuration of periodic profile of reinforcing bars supplied in the cold drawn condition are given in figures A. 2 and A. 3. The relative area of buckling , the dimensions of periodic structure and limit deviations of dimensions are listed in table 2 of this standard.

Figure A. 2 — Crescent Tripartite periodic profile of cold-deformed reinforcing bar

Figure A. 2 — Crescent Tripartite periodic profile of cold-deformed reinforcing bar

Figure A. 3: four — way segmented periodic profile cold-deformed reinforcing bar

Figure A. 3: four — way segmented periodic profile cold-deformed reinforcing bar

A. 3 the roundness of the reinforcing bars periodic profile in figures A. 1-A. 3 in accordance with table 2.

Appendix B (mandatory). The test procedure reinforcing bar on the weldability

Appendix B
(required)

B. 1 Control of weldability (suitability for welding) of reinforcing bars is carried out by tests are widely used in construction, and which have the greatest influence on the mechanical properties of welded joints in accordance with table B. 1.


Table B. 1

The welding method and the type of connection	Nominal diameter of reinforcing bar (profile) , mm	The number of samples for testing
		stretching	slice	the gap	bending
Manual arc welding of long seams lap	10−25	6	-	-	-
Bath-suture welding on steel clamp-plate	20−40	6	-	-	-
Manual arc welding tack cruciform joints	10−40	6	-	-	3
Resistance spot welding	6−40	6	3	-	3
Butt welding	10−40	6	-	-	-
Arc submerged arc welding t-joints	8−22	-	-	6	3

B. 2 For the manufacture of samples of welded joints using rebar that meets the following requirements:

for thermomechanically hardened and cold-rolled — with the lowest value of carbon equivalent for the year of steel production prior to the testing;

— hot-rolled — with the highest value of the temporary resistance for the annual period of production prior to the testing.

B. 3 Testing the weldability of rebar is subjected to the minimum, average and maximum diameters of a set of diameters (gauge), produced by the manufacturer of the reinforcing bar. Reinforcement bars of each diameter are selected for testing from three randomly selected heats that meet the requirements of B. 2.

B. 4 preparation of samples of welded joints

B. 4.1 Design and dimensions of the connections for hot-rolled steel take the same as for the reinforcement class A-III (A400) according to GOST 14098. For thermomechanically strengthened rolled designs and sizes of ports accept the same as for reinforcement A-III (A400) according to GOST 14098 except the length of the brace-pads in bath-seam welding (C15-RS according to GOST 14098), which shall be not less than (4), where the gap between the welded rods.

B. 4.2 Used for the manufacture of welded specimens of hot-rolled steel equipment, welding consumables, parameters of welding modes and peculiarities of technology of welding should be the same as when welding of reinforcement class A-III (A400), in accordance with the requirements of [1]. In welding of samples of thermo-mechanically hardened and cold-drawn steel process parameters are accepted as well as for welding of reinforcement class A-III according to [1], but with the following changes:

— manual arc welding of long seams overlap (C23-Re according to GOST 14098) by suturing «from the edges to the middle», with each subsequent suture is superimposed after complete cooling the previous one.

— in bath-suture welding on steel clamp-plate (type C15-RS according to GOST 14098) flanking the seams that connect the clip-plate with rods, must be applied «from the edges to the middle of the» staggered after complete cooling of the primary («bath») seam;

— contact butt welding (C1-To GOST 14098) should be carried out by the method of continuous melting without preheating. Preheating is allowed only if the welding connections of the rods with a diameter of 32 mm and more.

B. 4.3 Designs and sizes of samples for testing depending on the type of connection, the ways of testing and diameters of reinforcing bars take GOST 10922 same as for the reinforcement class A-III (A400).

B. 5 test procedures and evaluation of their results

B. 5.1 testing of welded specimens in tension, shear and detachment is carried out according to methods and using devices provided 12004 GOST and GOST 10922 for reinforcement class A-III (A400).

B. 5.2 Test samples of cruciform joints bending is carried out around a mandrel of diameter equal to 5 — when the diameter of operating rod up to 12 mm inclusive, or 6 — when the diameter of operating rod more than 12 mm. Transverse rod (smaller diameter) when tested in bending should be located in the zone of maximum bending moment (figure B. 1). Bend test specimens of t-joints of the rods with the plates is carried out manually with the pipe, put on the welded section of the reinforcing bar (figure B. 2).

B. 5.3 Results of tensile testing of samples of butt joints is considered satisfactory if the fracture occurs outside the weld or in the destruction in the area of the welded connection during the temporary resistance not less than 600 N/mmfor hot rolled and thermomechanically strengthened rolled and 550 N/mmfor the cold. The fracture in the weld zone should be flexible, i.e. be characterized by a marked constriction («neck»). Brittle fracture (i.e. at a 90° angle to the axis of the rod and no visible contraction) are not allowed.

B. 5.4 the Results of the Flexural testing of the compounds according to B. 5.2 is considered satisfactory if the bending angle of 60° sample is not destroyed and does not have any visible cracks. Detachment of the cross rod when testing of cruciform joints made of the contact point and manual arc welding, a symptom of rejection is not.

B. 5.5 test Results shear cruciform joints is considered satisfactory if the force cutoff is not less than 0.3, where a =500 N/mm, is the nominal cross — sectional area of the thinner rod into the coupling, the axis of which is attached test load.

B. 5.6 Results of pull-out test t-joints considered satisfactory if the obtained values of temporary resistance for each tested specimen are not less than 500 N/mm. At the same time allowed the destruction of the test compounds as a fixture on the land, located in the heat affected zone of welding and the zone of fusion of the reinforcing rod to the plate.

B. 5.7 Reinforcement bars welded I think, if the test results all samples tested satisfactory in accordance with B. 5.3-B. 5.6.

Figure B. 1 — Diagram of the Flexural testing of cruciform welded joints

 — the maximum cross-sectional dimension of the subject reinforcing bar

Figure B. 1 — Diagram of the Flexural testing of cruciform welded joints

Figure B. 2 — Scheme of the Flexural testing of t-welded joints

 — the maximum cross-sectional dimension of the subject reinforcing bar

Figure B. 2 — Scheme of the Flexural testing of t-welded joints

Annex b (mandatory). Requirements for statistical indicators of the strength characteristics and the method of their determination

The App
(required)

V. 1 the manufacturer guarantees the consumer the middle values of temporary resistance and yield stress (physical or virtual ) in the General population and minimum average values of the same indicators in each lot (melt) the values of which set of conditions:

;

; (V. 1)

,

where  — rejection values () and set by the table 3;

 — the standard deviation of the actual characteristics of () and in the General population testing;

 — the standard deviation of these characteristics in the party.

B. 2 Required indicators of quality of reinforcing bars provide the technology of production of reinforcing bar when it is mass production and control in accordance with the requirements of section 7 of this standard.

V. 3 Values and determine on the basis of the results of the tests and regulations B. 6-B. 15 of this Annex.

Q. 4 If you want to check consumer the strength characteristics of reinforcing bars, and in cases of disagreement in assessing the quality of reinforcing bar from each batch are testing six samples taken from different coils or bars, and the results of these tests verifies compliance with the conditions for the respective characteristics:

; (V. 2)

,

where is the minimum value of the test features on the test results of six samples;

the average value of the test features on the test results of six samples;

Values and  — according to the document about the quality of this batch of reinforcing bars.

V. 5 Minimum value of relative elongation and shall be not less than given in table 3 of this standard.

V. 6 To determine the statistical indicators of the strength characteristics of reinforcing bars (temporary resistance and physical or conditional yield strength) specified in this standard, use the results of commissioning tests.

Compliance with the strength characteristics of reinforcing bars present standard requirements are determined on the basis of statistical processing of test results of reinforcing bar forming the sampling of the strength characteristics of reinforcing bars.

Conclusions based on the processing of the sample relates to the entire General population.

V. 7 the Sample on the basis of which is carried out to determine the statistical indicators should be representative and cover a sufficiently long period of time (not less than three months), during which the technological process of production of the reinforcing bars has not been changed.

The number of batches should be at least 50.

Q. 8 In the sample must enter the results of the control testing of reinforcing bars, laminated on one or a group of close sizes of sections with one method of steelmaking.

V. 9 When sampling must meet the conditions of random sampling from each batch.

An assessment of the anomalous test results and the test of homogeneity of the sample is carried out according to normative documents.

V. 10 At the statistical processing of results of control tests determine the average value of the strength characteristics of reinforcing bars in the sample (the General population) , standard deviation of this characteristic in the sample and its standard deviation within the party (melting) , and the standard deviation plenochnykh medium .

Value and determined according to regulatory documents.

Q. 11 the Value determined by the experimental method or the method of the scale according to the formula

, (B. 3)

where and  — respectively the mean value and the standard deviation of the distribution of scale on the two tests from the party.

V. 12 the Definition of experimental method carried on at least two batches for each steel grade, class, and profilemaster rolled randomly sampling at least 100 samples from each heat.

V. 13 is determined by the formula

. (V. 4)

14 V. Verification of stability and is carried out in accordance with OST 14−1-34.

Q. 15 the Minimum average value of the strength characteristics of reinforcing bars (,or ) in each batch is determined by the formula

. (V. 5)

V. 16 the Minimum value of test results of two samples (=2) in each lot under inspection shall be not less than the value defined by the formula (V. 2).

Appendix d (mandatory). Methods of testing of reinforcing bars for endurance

Appendix D
(required)

1 For determining compliance with the stamina reinforcing bar requirements of table 2 of this standard annually conduct an endurance test. Test the samples of reinforcing bar minimum and maximum diameters of a set of diameters (gauge), produced by the manufacturer, three samples of each diameter selected from a randomly selected heats of steel.

G. 2 fatigue Testing of reinforcing bar samples was carried out at room temperature under axial tensile action repeated (pulsating) load, characterized by the following parameters in accordance with figure G. 1:

— maximum effort cycle ;

— swipe cycle efforts ;

— the frequency of the input force ;

Values and  — in table 3.

Figure G. 1 — identification of parameters repeated load

Figure G. 1 — identification of parameters repeated load

3 Test performed with test equipment (the pulsators) with a control effort at a frequency of load application from 1 to 200 Hz. Test each sample continues up to 2 million load cycles or until sample breakage, which should be the length of the sample at distance at least 2from the gripper of the sample (where is the nominal diameter of reinforcing bar).

G. 4 rebar recognizes the relevant requirements of this standard for endurance, if all the test specimens withstand 2 million cycles.

Annex D (informative). Numbers of manufacturers of reinforcing bars class A500C and B500C

Appendix E
(reference)

Table D. 1

The name of the manufacturer	N
JSC «Severstal»	1
OJSC «Chelyabinsk metallurgical plant»	2
JSC «West-Siberian metallurgical plant»	3
RUE «Belarusian metallurgical plant»	4
OJSC «Chusovoy metallurgical plant»	5
OJSC «Magnitogorsk metallurgical Kombinat»	6
OJSC «Amurmetal»	7
JSC «Oskol electrometallurgical combine»	8
JSC «Sulin metallurgical plant»	9
OJSC «Magnitogorsk hardware-metallurgical plant»	10
JSC «Salda steel plant»	11
OJSC «Slutsk metallurgical plant»	12
CJSC «Nizhneserginsky metallurgical plant»	13
JSC «Petrovsk-Zabaikalsky metallurgical plant»	14
OJSC «Revyakino metal plant»	15
OJSC Moscow metallurgical plant «Hammer and Sickle»	16
JSC «Beloretsk metallurgical plant»	17
JSC «Revdinsky hardware-metallurgical plant»	18
JSC Metallurgical plant «Electrostal»	19
JSC «Orel steel-rolling plant»	20
JSC «Severstal-metiz»	21
JSC «Mospromzhelezobeton»	22
ZAO NPO «Astrojets»	23
LLC «Industrial complex of A and M»	24
OJSC «Metallurgical plant named. A. K. Serov»	25

Annex E (mandatory). Determination of the geometric parameters of the periodic profile of reinforcing bar

Annex E
(required)

E. 1 the Actual values of the cross sectional area and weight of 1 m length of reinforcing bars to control the deviations of these quantities from the nominal values determined in accordance with GOST 12004.

E. 2 the Height of the transverse ribs periodic profile defined in the location of the maximum height of the ribs of each set of ribs. The height of the ribs is determined using a measuring instrument (Vernier caliper, measuring microscope, etc.) necessary accuracy.

E. 3 Step lateral edges to define each set of ribs by phase measurement of reinforcing bar includes at least five steps of transverse edges, a caliper with a scale division of 0,1 mm.

E. 4 the roundness of the reinforcing bar and the total space between the ends of the transverse ribs define a caliper with a scale division of 0,1 mm.

E. 5 the Angle of inclination of the transverse ribs to the longitudinal axis of the profile is determined using a measuring microscope, or by calculation according to the formula

, (E. 1)

where is the actual core diameter of reinforcing bars, mm;

 — number of visits spiral lines, which are transverse ribs periodic profile defined visually;

 — the actual pitch of transverse ribs, mm.

E. 6 Characteristics of the bonding of rebars with concrete is the relative area of shear of a periodic structure determined by the formula

, (E. 2)

where is the nominal diameter of reinforcing bar, mm;

 — number of rows of transverse ribs (=2 for the profile according to figure A. 1, =3 and =4 for profiles respectively in figures A. 2 and A. 3);

the actual projected area of one row of transverse ribs on a plane perpendicular to the longitudinal axis of the reinforcing bar (figure E. 1);

 — the actual pitch of transverse ribs, mm.

for each series of edges taken as the average value of this quantity for the three edges to be determined in the measurement result using the measuring microscope.

For reinforcing bars periodic profile with two rows of edges (see figure A. 1)is allowed to be determined by the formula

, (E. 3)

where  — the average of the actual values of the parameters of a periodic structure in figure A. 1.

Allowed to use other methods and formulas for determination .

Figure E. 1 — the Area of shear reinforcement periodic profile of rental

Figure E. 1 — the Area of shear reinforcement periodic profile of rental