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MINISTRY OF SCIENCE AND TECHNOLOGY |
SOCIALIST REPUBLIC OF VIETNAM |
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No. 21/2011/TT-BKHCN |
Hanoi, September 22, 2011 |
CIRCULAR
PROMULGATION OF NATIONAL TECHNICAL REGULATION ON STEEL FOR THE REINFORCEMENT OF CONCRETE
Pursuant to the Law on Technical regulations and standards dated June 29, 2006;
Pursuant to the Government's Decree No. 127/2007/ND-CP dated August 01, 2007 detailing the implementation of a number of articles of the Law on Technical regulations and standards;
Pursuant to the Government's Decree No. 28/2008/ND-CP dated March 14, 2008 defining the functions, tasks, powers and organizational structure of the Ministry of Science and Technology;
At the request of Director of the Directorate for Standards, Metrology, and Quality,
The Minister of Science and Technology promulgates a Circular on promulgation of a National Technical Regulation on steel for the reinforcement of concrete.
Article 1. National Technical Regulation on steel for the reinforcement of concrete (QCVN 7:2011/BKHCN) is promulgated together with this Circular.
Article 2. This Circular comes into force from June 01, 2012.
Article 3. From December 01, 2012, domestically and imported steel for concrete reinforcement shall apply QCVN 7:2012/BKHCN.
From June 01, 2013, all for concrete reinforcement circulated on the market shall apply QCVN 7:2012/BKHCN.
Article 4. From the effective date of this Circular to the time specified in Article 3, organizations and individuals involved in manufacture, import and distribution of steel for concrete reinforcement shall prepare themselves to apply this QCVN.
Article 5. Director of the Directorate for Standards, Metrology, and Quality, heads of relevant organizations and relevant individuals are responsible for the implementation of this Circular.
Difficulties that arise during the implementation of this Circular should be reported to the Ministry of Science and Technology for consideration./.
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PP MINISTER |
QCVN 7:2011/BKHCN
NATIONAL TECHNICAL REGULATION ON STEEL FOR THE REINFORCERMENT OF CONCRETE
Forewords
QCVN 7:2011/BKHCN is drafted and submitted by the Directorate for Standards, Metrology, and Quality and promulgated together with Circular No. 21/2011/TT-BKHCN dated September 22, 2011 of the Minister of Science and Technology.
NATIONAL TECHNICAL REGULATION ON STEEL FOR THE REINFORCEMENT OF CONCRETE
1. GENERAL PROVISIONS
1.1. Scope
This document provides for technical limits of steel for concrete reinforcement, steel for the prestressing of concrete and epoxy-coated steel (hereinafter referred to as “steel for reinforcement of concrete”), quality control of domestic and imported steel for reinforcement of concrete.
This document does not apply to steel for reinforcement of concrete that are shaped steel, plated steel and steel fibre concrete reinforcement.
1.2. Regulated entities
This document applies to manufacturers, importers and distributors of steel for reinforcement of concrete, relevant regulatory bodies, organizations and individuals.
1.3. Definitions
For the purposes of this document, the terms below are construed as follows:
1.3.1. Batch: steel for reinforcement of concrete of the same grade, with the same nominal diameter and belong to the same batch.
1.3.2. Shipment: steel for reinforcement of concrete of the same grade, with the same nominal diameter and label content, imported, distributed or retailed by the same entity at the same location.
1.3.3. Grades of steel for reinforcement of concrete:
Symbols of various grades of steel for reinforcement of concrete are specified in TCVN 1651-1:2008 and TCVN1651-2:2008, to be specific:
- Plain bars: CB240-T; CB300-T;
- Ribbed bars: CB300-V; CB400-V; CB500-V.
“CB” stands for “cốt bê tông” (concrete reinforcement). The next three digits indicate the tensile strength, expressed as megapascal (MPa). “T” stands for “trơn” (“plain”) and “V” stands for “vằn” (“ribbed”).
1.3.4. Nominal cross-sectional area of a ribbed bar is the same as that of a plain bar with the same nominal diameter.
2. TECHNICAL REQUIREMENTS
2.1. Steel for reinforcement of concrete:
2.1.1. Dimensions and unit weight (kg/m) and tolerances are specified in Table 1.
2.1.2. Grades and mechanical properties of plain bars are specified in TCVN 1651-1:2008, Steel for the reinforcement of concrete - Part 1: Plain bars (do not apply Rm/ReH ≥ 1,46 in Table 5).
2.1.3. Requirements, grades and mechanical properties of ribbed bars shall comply with TCVN 1651-2:2008, Steel for the reinforcement of concrete - Part 2: Ribbed bars.
2.1.4. Shapes, dimensions and mechanical properties of welded fabric shall comply with TCVN 1651-3:2008 (ISO 6395-3:2007), Steel for the reinforcement of concrete - Part 3: Welded fabric.
2.2. Steel for the prestressing of concrete
Shapes, dimensions, unit weight, tolerances and mechanical properties of steel for the prestressing of concrete shall comply with TCVN 6284:1997 (ISO 6934:1991), Steel for the prestressing of concrete:
Part 1 – General requirements;
Part 2 - Cold-drawn wire;
Part 3 - Quenched and tempered wire;
Part 4 – Strand;
Part 5 - Hot-rolled steel bars with or without subsequent processing.
2.3. Epoxy-coated steel for the reinforcement of concrete
Shapes, dimensions, unit weight, tolerances and mechanical properties of epoxy-coated steel for the reinforcement of concrete shall comply with:
- TCVN 7934:2009 (ISO 14654:1999), Epoxy-coated steel for the reinforcement of concrete;
- TCVN 7935:2009 (ISO 14655:1999), Epoxy-coated strand for the prestressing of concrete.
2.4. International standards, regional standards, foreign standards and ASTM standards applied to shapes, dimensions, weight, tolerances, grades, mechanical properties of domestic and imported steel for reinforcement of concrete shall be declared by their manufacturers.
Table 1 - Dimensions and unit weight and tolerances
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Nominal diameter d mm |
Nominal cross-sectional area a An mm2 |
Unit weight |
Unit weight |
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Requirements b kg/m |
Tolerance c % |
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6 |
28,3 |
0,222 |
±8 |
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8 |
50,3 |
0,395 |
±8 |
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10 |
78,5 |
0,617 |
±6 |
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12 |
113 |
0,888 |
±6 |
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14 |
154 |
1,21 |
±5 |
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16 |
201 |
1,58 |
±5 |
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18 |
255 |
2,00 |
±5 |
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20 |
314 |
2,47 |
±5 |
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22 |
380 |
2,98 |
±5 |
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25 |
491 |
3,85 |
±4 |
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28 |
616 |
4,83 |
±4 |
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32 |
804 |
6,31 |
±4 |
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36 |
1018 |
7,99 |
±4 |
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40 |
1257 |
9,86 |
±4 |
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50 |
1964 |
15,42 |
±4 |
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a An = 0,785 4 x d2. b Weight = 7,85 x 10-3 x An. c Tolerance for a single bar. 1) Diameter d50 only apply to ribbed bars. 2) Nominal diameters under international standards, regional standards, foreign standards and ASTM standards applied by manufacturers are permissible if they are not contrary to relevant regulations of this document. |
a An = 0,785 4 x d2. b Weight = 7,85 x 10-3 x An. c Tolerance for a single bar. 1) Diameter d50 only apply to ribbed bars. 2) Nominal diameters under international standards, regional standards, foreign standards and ASTM standards applied by manufacturers are permissible if they are not contrary to relevant regulations of this document. |
a An = 0,785 4 x d2. b Weight = 7,85 x 10-3 x An. c Tolerance for a single bar. 1) Diameter d50 only apply to ribbed bars. 2) Nominal diameters under international standards, regional standards, foreign standards and ASTM standards applied by manufacturers are permissible if they are not contrary to relevant regulations of this document. |
a An = 0,785 4 x d2. b Weight = 7,85 x 10-3 x An. c Tolerance for a single bar. 1) Diameter d50 only apply to ribbed bars. 2) Nominal diameters under international standards, regional standards, foreign standards and ASTM standards applied by manufacturers are permissible if they are not contrary to relevant regulations of this document. |
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3. TEST METHODS
3.1. Methods for testing mechanical properties of steel for reinforcement of concrete and steel for the prestressing of concrete shall comply with the following standards:
3.1.1. TCVN 7937-1:2009 (ISO 15630-1:2002), Steel for the reinforcement and prestressing of concrete - Test methods - Part 1: Reinforcing bars, wire rod and wire.
3.1.2. TCVN 7937-2:2009 (ISO 15630-2:2002), Steel for the reinforcement and prestressing of concrete - Test methods - Part 2: Welded fabric.
3.1.3. TCVN 7937-3:2009 (ISO 15630-3:2002), Steel for the reinforcement and prestressing of concrete - Test methods - Part 3: Prestressing steel.
Standards applied to isothermal recovery test in 1000 hours of domestic steel for prestressing of concrete shall be declared by manufacturers.
Standards applied to isothermal recovery test in 1000 hours of imported steel for prestressing of concrete shall be declared by manufacturers and the declaration and proof that the test has been carried out must be included in the import documentation.
3.2. Methods for testing mechanical properties of epoxy-coated steel for reinforcement of concrete and prestressing of concrete shall comply with the following standards:
- TCVN 7934:2009 (ISO 14654:1999), Epoxy-coated steel for the reinforcement of concrete;
- TCVN 7935:2009 (ISO 14655:1999), Epoxy-coated strand for the prestressing of concrete;
- TCVN 7936:2009 (ISO 14656:1999), Epoxy powder and sealing material for the coating of steel for the reinforcement of concrete.
3.3. International standards, regional standards, foreign standards and ASTM standards applied to test methods of domestic and imported steel for reinforcement of concrete shall be declared by their manufacturers.
4. LABELLING
4.1. The labels must be clear, readable and permanent
4.2. Label of a bundle or roll of steel
4.2.1. Each bundle or roll of steel for reinforcement of concrete shall have a label.
4.2.2. Mandatory information on a label of domestic steel:
- The manufacturer’s name and address;
- The product name;
- Number of the applied standard as declared by the manufacturer;
- Conformity marking;
- Grade of steel;
- Weight of the bundle or roll;
- Nominal diameter;
- Batch number;
- Month and date of production.
4.2.3. Mandatory information on secondary label (in Vietnamese language) of imported steel:
- The manufacturer’s name and address;
- Country of origin;
- Name and address of the importer;
- The product name;
- Number of the applied standard as declared by the manufacturer;
- Conformity marking;
- Grade of steel;
- Weight of the bundle or roll;
- Nominal diameter;
- Batch number;
- Month and date of production.
4.3. Ribbed bar markings
Markings on each ribbed bar must be presented in the following order:
- Logo or abbreviated name of the manufacturer;
- Grade symbol:
CB 240 or CB 2;
CB 300 or CB 3;
CB 400 or CB 4;
CB 500 or CB 5.
- Nominal diameter d;
Example : TISCO CB 240 d10 or TISCO CB 2 d10.
4.4. International standards, regional standards, foreign standards and ASTM standards applied to labelling of domestic and imported steel for reinforcement of concrete shall be declared by their manufacturers.
5. QUALITY CONTROL
5.1. Domestic steel for reinforcement of concrete
5.1.1. Each type (according to their grades and nominal diameter) of domestic steel for reinforcement of concrete shall have a declaration of conformity with provisions in Section 2 and Section 4 of this document on the following grounds:
a) The certificate of conformity issued by a certification body appointed or recognized by the Directorate for Standards, Metrology, and Quality; or
b) A test result that satisfies requirements in this document provided by a laboratory appointed by the Directorate for Standards, Metrology, and Quality in case the manufacturer is applying a quality control system the conformity with ISO 9001 has been certified by a certification body registered with the Directorate for Standards, Metrology, and Quality.
Conformity certification shall be carried out according to typical sample test methods and manufacture process evaluation; supervision through samples taken at the factory or on the market in combination with manufacture process evaluation (Method 5 in Appendix II of Decision No. 24/2007/QD-BKHCN) and regulations on conformity assessment in TCVN 1651:2008, steel for reinforcement of concrete.
5.1.2. There must be a conformity marking on the label of each bundle or roll of domestic steel for reinforcement of concrete is sold on the market.
5.2. Imported steel for the reinforcement of concrete
5.2.1. Each type of steel (according to their grades and nominal diameter) in a shipment of imported steel for the reinforcement of concrete must undergo inspection or conformity certification in accordance with Section 2 and Section 4 of this document according to Method 7 in Appendix II of Decision No. 24/2007/QD-BKHCN).
The inspection or conformity certification of imported steel for reinforcement of concrete shall be carried out by domestic or foreign certification bodies appointed or recognized by the Directorate for Standards, Metrology, and Quality.
5.2.2. If a shipment imported steel for reinforcement of concrete already has the certificate of conformity with provisions of Section 2 and Article 4.4 under Method 2 granted by a certification body appointed or recognized by the Directorate for Standards, Metrology, and Quality, the importer is not required to have the shipment undergo inspection or certification under Method 7.
5.2.3. Imported steel for reinforcement of concrete must undergo state inspection of quality as prescribed in Circular No. 17/2009/TT-BKHCN.
A declaration of conformity is not required if a shipment of steel for reinforcement of concrete has already undergone such an inspection as prescribed in Decision No. 24/2007/QD-BKHCN.
5.2.4. There must be a conformity marking on the label of each bundle or roll of imported steel for reinforcement of concrete that is being sold on the market.
5.3. Steel for the reinforcement of concrete circulating on the market
5.3.1. There must be a conformity marking on the label of steel for reinforcement of concrete circulating on the market; the label content shall comply with Section 4 of this document.
5.2.3. Steel for reinforcement of concrete circulating on the market must undergo state inspection of quality as prescribed in Circular No. 16/2009/TT-BKHCN.
5.4. Conformity certification, declaration of conformity, conformity markings and conformity assessment methods
5.4.1. The Certificate of conformity, declaration of conformity, conformity markings and conformity assessment methods mentioned in Articles 5.1, 5.2 and 5.3 shall comply with Decision No. 24/2007/QD-BKHCN.
5.4.2. The appointment or recognition of a certification body shall comply with Circular No. 09/2009/TT-BKHCN and Circular No. 11/2011/TT-BKHCN.
5.5. Other cases
In the cases where domestic steel for reinforcement of concrete cannot be evaluated for conformity certification under Method 5, Directorate for Standards, Metrology and Quality shall decide on a method or apply Method 7.
6. RESPONSIBILITIES OF VARIOUS ORGANIZATIONS AND INDIVIDUALS
6.1. Domestic manufacturers shall comply with regulations on declarations of conformity and labeling specified in Sections 2, 4 and 5 of this document.
During the process of declaration of conformity mentioned in 5.1.1.b of this document, the manufacturer shall test each type of steel at least every 06 months and retain the documents for at least 10 years.
6.2. Importers shall have their imported products undergo inspection, conformity certification, state inspection and labeling in accordance with requirements specified in Sections 2, 4 and 5 of this document.
6.3. Distributors and retailers may only sell steel for reinforcement of concrete that satisfies quality requirements, bear conformity markings and are conformable with provision of Section 4; Domestic steel for reinforcement of concrete shall have copies of declaration of conformity as prescribed in 5.1.1; Imported steel for reinforcement of concrete shall have copies of notification of satisfactory import quality as prescribed in 5.2.3.
7. IMPLEMENTATION
7.1. Directorate for Standards, Metrology, and Quality shall cooperate with relevant authorities in providing guidance and organizing the implementation of this document.
7.2. In the cases where any of the legislative documents or standards referred to in this document is amended or superseded, the newer one shall apply./.
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