Chinese standards (related to): 'GB/T 13788-2017'
| Standard ID | GB/T 13788-2017 (GB/T13788-2017) | | Description (Translated English) | Cold rolled ribbed steel bars | | Sector / Industry | National Standard (Recommended) | | Classification of Chinese Standard | H44 | | Classification of International Standard | 77.140.60 | | Word Count Estimation | 11,185 | | Date of Issue | 2017-07-12 | | Date of Implementation | 2018-04-01 | | Older Standard (superseded by this standard) | GB/T 13788-2008 | | Quoted Standard | GB/T 2101; GB/T 2103; GB/T 17505; GB/T 21839; GB/T 28899; GB/T 28900; YB/T 081 | | Drafting Organization | China Metallurgical Building Research Institute Co., Ltd., Anyang Heli Chuang Metallurgical New Technology Co., Ltd., Anhui Maanshan Ironfield Steel Wire Mesh Co., Ltd., Tianjin Yinlong Prestressed Materials Co., Ltd., Metallurgical Industry Information Standards Institute | | Administrative Organization | National Standardization Technical Committee (SAC / TC 183) | | Proposing organization | China Iron and Steel Industry Association | | Issuing agency(ies) | General Administration of Quality Supervision, Inspection and Quarantine of the People Republic of China, China National Standardization Administration Committee | | Summary | This standard specifies the terms and definitions, classification, grades, dimensions, shapes, weights and tolerances of cold rolled ribbed bars, technical requirements, test methods, inspection rules, packaging, marking and quality certificates. This standard applies to prestressed concrete and ordinary reinforced concrete cold-rolled ribbed steel bars, but also for the manufacture of welded wire with cold-rolled ribbed steel bar (hereinafter referred to as steel). |
GB/T 13788-2017: PDF in English (GBT 13788-2017)
GB/T 13788-2017
GB
NATIONAL STANDARD OF THE
PEOPLE’S REPUBLIC OF CHINA
ICS 77.140.60
H 44
Replacing GB/T 13788-2008
Cold rolled ribbed steel bars
ISSUED ON. JULY 12, 2017
IMPLEMENTED ON. APRIL 1, 2018
Issued by. General Administration of Quality Supervision, Inspection and
Quarantine of the PRC;
Standardization Administration of the PRC.
3. No action is required - Full-copy of this standard will be automatically &
immediately delivered to your EMAIL address in 0~60 minutes.
Table of Contents
Foreword ... 3
1 Scope .. 5
2 Normative references ... 5
3 Terms and definitions ... 5
4 Classification and designations ... 6
5 Size, shape, weight, and allowable deviation .. 6
6 Technical requirements ... 13
7 Test methods ... 15
8 Inspection rules .. 16
9 Packaging, marking, and quality certificate ... 17
Foreword
This Standard is drafted in accordance with the rules given in GB/T 1.1-2009.
This Standard replaces GB/T 13788-2008 “Cold rolled ribbed steel wires and
bars”. As compared with GB/T 13788-2008, the main technical changes of this
Standard are as follows.
- RIVISE relevant provisions on classification and codes;
- ADD the designations of high-elongation cold rolled ribbed steel bars.
CRB600H, CRB680H, and CRB800H;
- ADD the shape, size and mark diagram of four-sided ribbed steel bars;
- RIVISE relevant provisions on the designation and chemical composition;
- ADD the mechanical property requirement for high-elongation cold rolled
ribbed steel bars CRB600H, CRB680H, and CRB800H;
- RIVISE relevant provisions on percentage elongation after fracture,
percentage total elongation at maximum force (Agt) and tensile-to-yielding
ratio;
- RIVISE relevant provisions on test methods;
- DELETE Appendix A “Determination methods of steel bars at percentage
total elongation at maximum force”;
- DELETE Appendix B “Reference designations and chemical composition
of wire rods for cold rolled ribbed steel bars”.
This Standard was proposed by China Iron and Steel Association.
This Standard shall be under the jurisdiction of China National Standardization
Technology Committee (SAC/TC 183).
Drafting organizations of this Standard. Central Research Institute of Building
and Construction Co., Ltd., Anyang Heli Techtronic Co., Ltd., Anhui BRC & Ma
Steel Weldmesh Co., Ltd., Silvery Dragon Prestressed Materials Co., Ltd.
Tianjin, and China Metallurgical Information and Standardization Institute.
Main drafters of this Standard. Yue Qingrui, Feng Chao, Tao Ran, Zhai Wen,
Guo Sihong, Ai Tieling, Li Yajie, Zhang Pingyuan, Xie Zhian, Liu Baoshi, Wang
Xianhua, Du Ruiqing, Zhang Ying, Wang Yujie.
Cold rolled ribbed steel bars
1 Scope
This Standard specifies the terms and definitions, classification, designation,
size, shape, weight, allowable deviation, technical requirements, test methods,
inspection rules, packaging, marking, and quality certificate of cold rolled ribbed
steel bars.
This Standard is applicable to cold rolled ribbed steel bars for prestressed
concrete and ordinary reinforced concrete, and cold rolled ribbed steel bars
(known as steel bars for short hereinafter) for manufacturing welded mesh.
2 Normative references
The following documents are essential to the application of this document. For
the dated references, only the versions with the dates indicated are applicable
to this document. For the undated references, the latest version (including all
the amendments) are applicable to this document.
GB/T 2101 General requirement of acceptance packaging marking and
certification for section steel
GB/T 2103 General requirements for acceptance, packing, marking and
quality certification of steel wire
GB/T 17505 Steel and steel products General technical delivery
requirements
GB/T 21839 Steel for prestressed concrete - Test methods
GB/T 28899 Wire rods for cold rolled ribbed steel bars
GB/T 28900 Test methods of steel for reinforcement of concrete
YB/T 081 Rule for Rounding Off of Numerical Values and Judgement of
Testing Values for Technical Standards of Metallurgy
3 Terms and definitions
The following terms and definitions are applicable to this document.
The range of nominal diameter of CRB550, CRB600H, and CRB680H steel
bars is 4 mm~12 mm. The nominal diameter of CRB650, CRB800, and
CRB800H is 4 mm, 5 mm, and 6 mm.
5.2 Shape
5.2.1 The transverse ribs on the surface of steel bars shall conform to the
provisions of 5.2.1.1~5.2.1.6.
5.2.1.1 The transverse ribs of two-sided and three-sided ribbed steel bars shall
be crescent. The longitudinal section of transverse ribs of four-sided ribbed
steel bars shall be crescent and shall not intersect with the transverse ribs.
5.2.1.2 Transverse ribs shall be uniformly distributed along the circumferential
ring of the cross section of steel bars. The inclination of one rib of two-sided
ribbed steel bars shall be reversed with the other rib. The inclination of one rib
of three-sided ribbed steel bars shall be reversed with the other two ribs. The
inclination of the two adjacent transverse ribs of four-sided ribbed steel ribs
shall be opposite to that of the other two transverse ribs.
5.2.1.3 The included angle β between the center line of the transverse rib and
the longitudinal axis of the steel bar of two-sided and three-sided ribbed steel
bars is 40°~60°. The included angle between the axis of the transverse rib and
the axis of the steel bar of four-sided ribbed steel bars shall be 40°~70°; the
angle between the two rows of ribs can be 35°~75°.
5.2.1.4 The bevel angle α between the two sides of the transverse rib and the
surface of the steel bar of two-sided and three-sided ribbed steel bars shall not
be less than 45°. The bevel angle α between the two sides of the transverse rib
and the surface of the steel bar of four-sided ribbed steel bars shall not be less
than 40°. The transverse rib shall intersect the surface of the steel bar in an arc.
5.2.1.5 The sum of rib spacing of two-sided and three-sided ribbed steel bars
shall not be greater than 20% of the nominal circumference (∑fi ≤ 0.2πd). The
sum of rib spacing of four-sided ribbed steel bars shall not be greater than 25%
of the nominal circumference (∑fi ≤ 0.25πd).
5.2.1.6 The specific rib area fr shall be determined by the equation (1).
Where.
K=2, 3, or 4 (two-sided ribs, three-sided ribs, or four-sided ribs);
demand parties, it can also be delivered according to a specified length. When
the steel bar is delivered according to a specified length, the length and
allowable deviation shall be determined through consultation between the
supply-demand parties.
5.5 Bending
The bending per meter of straight steel bars shall not be more than 4 mm. The
total bending shall not be greater than 0.4% of the total length of the steel bar.
5.6 Weight
5.6.1 The weight of a coiled steel bar shall not be less than 100 kg. Each coil
shall be made up of a steel bar. When CRB650, CRB680H, CRB800, CRB800H
are used as steel bars for prestressed concrete, there shall be no welded joints.
5.6.2 The straight steel bar, according to the same designation, the same
specification, and the same length, shall be delivered in bundles. The weight of
the bundle shall be determined by consultation between the supply-demand
parties.
6 Technical requirements
6.1 Raw material
The raw material for manufacturing steel bars shall be in accordance with the
provisions of GB/T 28899. The wire rods produced according to other standards
can also be used.
6.2 Delivery state
The steel bar is delivered in cold working state. It is allowed that low
temperature tempering is implemented after cold rolling.
6.3 Mechanical and processing properties
6.3.1 The mechanical and processing properties of steel bars shall conform to
the provisions of Table 3. When carrying out a bending test, there shall be no
crack on the surface of the bent part. The bending radius of repeated bending
test shall conform to the provisions of Table 4.
7.3.2 The sample may be mechanically straightened. But there shall not be any
heat treatment and other cold working.
7.3.3 The initial test force applied to the sample is that, 70% of the nominal
tensile strength of the sample multiplies by the nominal cross-sectional area of
the sample.
7.3.4 The loading speed is 200 MPa/min±50 MPa/min. The initial load shall be
completed in 3 min~5 min. After holding the load for 2 min, the relaxation value
shall be recorded.
7.3.5 The sample length is not less than 60 times the nominal diameter.
7.3.6 The relaxation rate of 1000 h is allowed to be calculated from the test data
of at least 120 h.
7.4 Size measurement
7.4.1 The height of the transverse rib is the average value of the height of each
column of transverse ribs of the same section. MEASURE the average distance
to determine the distance between transverse ribs, that is, MEASURE the
center distance between the 1st and 11th transverse ribs in the same column
and DIVIDE i......
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