1. Scope
This part specifies the definition, type, grade, purchasing content, dimension, shape, or weight tolerance, technical specification, testing method, test rules, packing, sign and certificate of quality of the hot rolled ribbed bars of reinforced concrete.
This part is applicable to the general hot rolled ribbed bars for the reinforcement of concrete, and hot rolled ribbed bar with ultra-fine grain.
This part is inapplicable to the recycling steel bar re-rolled by the rolled-steel final product, and remained heat treatment ribbed bars
2. Normative references
The following provisions contain provisions which, through reference in this text, constitute provisions of this Part. For dated reference, subsequent amendments to, or revisions of (excluding corrigendum contents), or Revised Edition do not apply. However, it is encouraged that every part of this Part to research the latest edition of these documents. For undated references, the latest edition of the normative document referred to applies.
GB/T 222 Permissible Tolerances for Chemical Composition of Steel Products
GB/T 223.5 Methods for Chemical Analysis of Iron, Steel and Alloy-The Reduced Molybdosilicate Spectrophotometric Method for the Determination of Acid-soluble Silicon Content
GB/T 223.11 Methods for Chemical Analysis of Iron, Steel and Alloy-The Ammonium Persulfate Oxidation Volumetric Method for the Determination of Chromium Content
GB/T 223.12 Methods for Chemical Analysis of Iron, Steel and Alloy-The Sodium Carbonate Separation-diphenyl Carbazide Photometric Method for the Determination of Chromium Content
GB/T 223.14 Methods for Chemical Analysis of Iron, Steel and Alloy-The N-benzoy-N-phenylhydroxylamine Extraction Photometric Method for the Determination of Vanadium Content
GB/T 223.17 Methods for Chemical Analysis of Iron, Steel and Alloy-The Diantipyrylmethane Photometric Method for the Determination of Titanium Content
GB/T 223.19 Methods for Chemical Analysis of Iron Steel and Alloy-The Neocuproine-chloroform Extraction Photometric Method for the Determination of Copper Content
GB/T 223.23 Methods for Chemical Analysis of Iron, Steel and Alloy-The Dimethylglyoxime Spectrophotometric Method for the Determination of Nickel Content
GB/T 223.26 Methods for Chemical Analysis of Iron Steel and Alloy-The Thiocyanate Direct Photometric Method for the Determination of Molybderum Content
GB/T 223.27 Methods for Chemical Analysis of Iron, Steel and Alloy-The Thiocyanate-butyl Acetate Extraction Spectrophotometric Method for the Determination of Molybdenum Content
GB/T 223.37 Methods for Chemical Analysis of Iron Steel and Alloy-The Indophenal Blue Photometric Methods for the Determination of Nitrogen Content after Distillation Separation
GB/T 223.40 Iron, Steel and Alloy-Determination of Niobium Content by the Sulphochlorophenol S Spectrophotometric Method
GB/T 223.59 Methods for Chemical Analysis of Iron, steel and Alloy--The Sodium Arsenite-sodium Nitrite Titrimetric Method for the Determination of Phosphorus Content
GB/T 223.63 Methods for Chemical Analysis of Iron, Steel and Alloy-The Sodium (potassium) Periodate Photometric Method for the Determination of Manganese Content
GB/T 223.68 Methods for Chemical Analysis of Iron, steel and Alloy-The Potassium Iodate Titration Method after Combustion in the Pipe Furnace for the Determination of Sulfur Content
GB/T 223.69 Methods for Chemical Analysis of Iron, Steel and Alloy-The Gas- Volumetric Method after Combustion in the Pipe Furnace for the Determination of Carbon Content
GB/T 228 Metallic Materials-Tensile Testing at Ambient Temperature (GB/T 228-2002, eqv ISO 6892:1998(E))
GB/T 232 Metallic Materials--Bend Test (GB/T 232-1999, eqv ISO 7438:1985(E))
GB/T 2101 General Requirements of Acceptance, Packaging, Marking, and Certification for Section Steel
GB/T 4336 Standard Test Method for Spark Discharge Atomic Emission Spectrometric Analysis of Carbon and Low-alloy Steel (routine method)
GB/T 6394 Metal Methods for Estimating the Average Grain Size
GB/T 17505 Steel and Steel Products General Technical Delivery Requirements (GB/T 17505 --1998, eqv ISO 404:1992)
GB/T 20066 Steel and Iron - Sampling and Preparation of Samples for the Determination of Chemical Composition (GB/T 20066-2006/ISO 14284:1998, IDT)
YB/T 081 Rule for Rounding off of Numerical Values and Judgment of Testing Values for Technical Standards of Metallurgy
YB/T 5126 Steel Bars for Reinforcement of Concrete-Bend and Rebend Tests (YB/T 5126-2003/ISO 10065 1990, MOD)
3. Definitions
The following definitions are applicable to this Part.
3.1 Hot rolled bars
The steel bar delivered under hot rolling condition; its metallurgical structure is mainly composed of ferrite and pearlite, no other textures (for instance, the β-martensite appeared on the base circle) are permitted to exist, which may influence the usability of steel bar.
3.2 Hot rolled bars of fine grains
The grain refining steel bar formed by applying control rolling and cooling technologies during the hot rolling process; its metallurgical structure is mainly composed of ferrite and pearlite, no other textures (for instance, the β-martensite appeared on the base circle) are permitted to exist, which may influence the usability of steel bar, moreover, the grain size is no thicker than 9-level of the grain size.
3.3 Ribbed bars
The cross-section of ribbed bars is round, and it belongs to the ribbed bar of concrete.
3.4 Longitudinal rib
Longitudinal rib indicates the uniform continuous rib parallel to the steel bar axis.
3.5 Transverse rib
Transverse rib indicates those rib un-parallel to the steel bar axis.
3.6 Crescent ribbed bars
Crescent ribbed bars indicate the longitudinal section of transverse rib is crescent and disjoints with longitudinal rib. Crescent ribbed bars indicate the longitudinal section of transverse rib is crescent and disjoints with longitudinal rib.
3.7 Nominal diameter
Nominal diameter indicates the diameter of a circle equals to the nominal cross-sectional area of the steel bar.
3.8 Specific projected rib area
Specific projected rib area indicates the ratio between the projected area of transverse rib on the vertical plane of the steel bar axis, and the product between steel bar nominal perimeter and transverse rib spacing. 3.9 Rib height
The rib height can be calculated by the space from rib peak to the core surface, which is perpendicular to the steel bar axis.
3.10 Rib spacing
Rib spacing indicates the space between two adjacent transverse rib centers, which parallel the steel bar axis.
3.11 Characteristic value
The characteristic value indicates the percent place value corresponding to certain required probability during infinite multiple testing periods.
Foreword I
1. Scope
2. Normative references
3. Definitions
4. Types and grades
5. Order content
6. Dimension, shape weight and tolerance
6.1 Nominal diameter scope and recommend diameter
6.2 Nominal cross-sectional area and theoretical weight
6.3 Surface configuration and dimension tolerance of ribbed bar
6.4 Length and length tolerance
6.5 Bend degree and tip
6.6 Weight and weight tolerance
7. Specifications
7.1 Grade and chemical composition
7.2 Delivery way
7.3 Mechanical property
7.4 Processing property
7.5 Fatigue property
7.6 Welding property
7.7 Grain size
7.8 Surface quality
8. Testing Method
8.1 Testing items
8.2 Tensile, bending and reverse bend test
8.3 Dimension Measurement
8.4 Measurement of weight tolerance
9. Test Rules
9.1 Characteristic value check
9.2 Delivery survey
10. Packaging, marking and quality certificate
Annex A (Normative) Measuring Method of Steel Bar under General Maximum Force Extensibility
Annex B (Normative) Test Rules of Characteristic Value
Annex C (Informative) Design Formula of Specific Projected Rib Area of Steel Bar
