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1、BRITISH STANDARD BS 4449:1997 Incorporating Amendment No. 1 Specification for Carbon steel bars for the reinforcement of concrete ICS 77.140.15; 91.080.40 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BS 4449:1997 This British Standard, having been prepared under the directi
2、on of the Engineering Sector Board, was published under the authority of the Standards Board and comes into effect on 15 May 1997 BSI 07-2001 First published: BS 4449: April 1969 BS 4461: March 1969 First revision: BS 4449: May 1978 BS 4461: May 1978 Second combined version as: BS 4449: May 1988 The
3、 following BSI references relate to the work on this standard: Committee reference ISE/9/1 ISBN 0 580 27346 6 Committees responsible for this British Standard The preparation of this British Standard was entrusted by Technical Committee ISE/9, Reinforcing steels, to Subcommittee ISE/9/1, Bar, wire a
4、nd fabric for concrete reinforcement, upon which the following bodies were represented: British Cement Association British Coatings Federation British Iron and Steel Producers Association British Precast Concrete Federation Concrete Society Dept. of Environment Building Research Establishment Dept.
5、of Transport Highways Agency Electricity Association Institution of Structural Engineers UK Certification Authority for Reinforcing Steels Amendments issued since publication Amd. No.DateComments 12032September 2001 Indicated by a sideline BS 4449:1997 BSI 07-2001 i Contents Page Committees responsi
6、bleInside front cover Forewordii 1Scope1 2References1 3Definitions1 4Sizes2 5Cross sectional area and mass3 6Length3 7Steelmaking process3 8Chemical composition4 9Bond classification of deformed bars5 10Routine inspection and testing5 11Mechanical properties5 12Fatigue properties of deformed bars6 1
7、3Retests6 14Verification of mechanical properties6 15Product identification7 Annex A (informative) Information to be supplied by the purchaser8 Annex B (normative) Determination of the effective cross sectional area of deformed bars8 Annex C (informative) Recommended formulae for calculating project
8、ed rib area9 Annex D (normative) Bond classification of deformed bars (bond test)9 Annex E (normative) Inspection, testing and certification12 Annex F (normative) Method of test for fatigue properties of deformed bars17 Annex G (normative) Multiplying factors for tensile tests18 Figure 1 Example of
9、rib pattern of grade 460A with four transverse rib series7 Figure 2 Example of rib pattern of grade 460B with four transverse rib series7 Figure D.1 Typical mould for bond performance testing11 Table 1 Preferred nominal sizes2 Table 2 Cross sectional area and mass3 Table 3 Tolerance on mass3 Table 4
10、 Chemical composition of steel grades: cast analysis4 Table 5 Maximum carbon equivalent values: cast analysis4 Table 6 Maximum deviations in chemical composition on product analysis4 Table 7 Tensile properties6 Table E.1 Percentage total strain12 Table E.2 Rebend test formers13 Table E.3 Acceptabili
11、ty index k as a function of the number of test results n for a reliable failure rate of 5 % (pass = 0.95) at a probability of 90 % (1 a = 0.90)14 Table F.1 Test stress ranges for nominal bar sizes17 List of references Inside back cover BS 4449:1997 ii BSI 07-2001 Foreword This British Standard has b
12、een prepared by Technical Committee ISE/9/1, and is a revision of BS 4449:1988, which is withdrawn. This edition introduces technical changes but it does not reflect a full review or revision of the standard, which will be undertaken in due course. This edition contains some of the requirements that
13、 are contained in DD ENV 10080, and aims to prepare the UK market for the eventual publication of EN 10080. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British S
14、tandard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 18, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was
15、last issued. Sidelining in this document indicates the most recent changes by amendment. BS 4449:1997 BSI 07-2001 1 1 Scope This British Standard specifies requirements for weldable steel bars for reinforcement of concrete. It covers plain round steel bars in grade 250, and deformed (type 1 and type
16、 2) high yield steel bars in grade 460, the latter in two ductility categories, 460A and 460B. The weldability requirements for both grades of steel are specified in terms of the carbon equivalent value. A testing facility for material covered by a third party product certification scheme, and a tes
17、ting facility for material not covered by such a scheme, are provided. Steel bars for use as lifting hooks are not included in this British Standard. Steel bars produced by re-rolling finished products, or by rolling material of which the metallurgical history is not fully documented or not known, a
18、re not covered by this British Standard. NOTE 1Flash welds in lengths of bar are permissible. However, for some purposes, purchasers may specifically require bars without flash welds. For this reason, the manufacturer should enquire whether flash welds are acceptable for the purposes of the purchase
19、r at the time of enquiry and/or order (see Annex A). NOTE 2All steels conforming to this British Standard are of weldable quality. Appropriate welding procedures and consumables, to each particular grade and quality, should be used (see BS 7123). 2 References 2.1 Normative references This British St
20、andard incorporates, by dated or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For dated references, only the edition cited applies; any subsequent amend
21、ments to or revisions of the cited publication apply to this British Standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 2.2 Informative references This British Standard
22、refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 3 Definitions For the purposes of this British Standard the follow
23、ing definitions apply. 3.1 bar a steel product of plain round or deformed cross section 3.2 hot rolled deformed bar a bar that has been so shaped during hot rolling that it conforms to either the geometrical or the performance test classification given in clause 9 3.3 cold worked deformed bar a bar
24、that has been cold worked to conform to the property requirements of this British Standard and that conforms to either the geometrical or the performance test classification given in clause 9 3.4 nominal size the diameter of a circle with an area equal to the effective cross sectional area of the ba
25、r NOTESee clause 4 and Annex B. 3.5 coil a continuous as-rolled bar in the form of a coil BS 4449:1997 2 BSI 07-2001 3.6 length a piece of nominally straight bar cut to a specified length 3.7 bundle two or more coils or a number of lengths properly bound together 3.8 batch any quantity of bars of on
26、e size and grade, whether in coils or bundles, produced by one manufacturer or supplier, presented for examination at any one time 3.9 longitudinal rib a uniform continuous protrusion parallel to the axis of the bar, before twisting in the case of cold twisted bars 3.10 transverse rib any rib on the
27、 surface of the bar other than a longitudinal rib 3.11 flash weld resistance butt weld, in which the components are progressively advanced towards each other, while the electric current, confined to localized points of contact, causes molten metal to be expelled. When welding temperature is reached,
28、 upset force is applied 3.12 manufacturer an organization that produces reinforcing steel. This includes steelmakers, re-rollers and cold workers 3.13 supplier any organization supplying reinforcing steel to an end user NOTEReinforcing steel may be supplied in lengths or coil, or fabricated in accor
29、dance with BS 4466. 3.14 characteristic strength the value of yield strength having a prescribed probability of not being attained in a hypothetical unlimited test series. The characteristic value is the lower limit of the one sided statistical tolerance interval at which there is a 90 % probability
30、 (i.e. l a = 0.90) that 95 % (p = 0.95) of the values are at or above this lower limit. This definition refers to the long-term quality level of production 4 Sizes 4.1 Range The range of nominal sizes of bars in grades 250 and 460 shall be from 6 mm to 50 mm. NOTEThe preferred nominal sizes of bars
31、are given in Table 1. Table 1 Preferred nominal sizes GradeNominal size mm 2508, 10, 12, 16 4608, 10, 12, 16, 20, 25, 32, 40 NOTE 1If a bar smaller than 8 mm is required, the recommended size is 6 mm. NOTE 2If a bar larger than 40 mm is required, the recommended size is 50 mm. BS 4449:1997 BSI 07-20
32、01 3 4.2 Tolerance The deviation of any cross sectional dimension from its nominal size (other than those of ribs), shall not exceed 8 %. 5 Cross sectional area and mass The cross sectional area and mass of the bars shall be calculated on the basis that steels have a mass of 0.00785 kg per square mi
33、llimetre per metre run. The values for the nominal cross sectional area shall be as given in Table 2. The mass of individual bars shall be as given in Table 2, subject to the tolerances given in Table 3. For bars where the effective cross sectional area is determined as in B.2.2, the nominal mass pe
34、r metre run shall equate to the gross mass per metre run. The total cross sectional area and total mass of two or more bars shall be calculated pro rata on the basis of the values for an individual bar. All cross sectional areas derived from the values in Table 2 shall be expressed to three signific
35、ant figures. Table 2 Cross sectional area and mass Table 3 Tolerance on mass 6 Length The permissible deviation from the nominal length shall be mm. Other tolerances may be agreed at the time of enquiry and order. 7 Steelmaking process The melting process and type of deoxidation of the steel shall b
36、e at the discretion of the manufacturer. Nominal size mm Cross sectional area mm2 Mass per metre run kg 6a 28.30.222 850.30.395 1078.50.616 12113.10.888 16201.11.579 20314.22.466 25490.93.854 32804.26.313 401256.69.864 50a1963.515.413 a This is a non-preferred size. Nominal size mm Tolerance on mass
37、 per metre run % 69 8 and 106.5 12 and over4.5 +100 0 BS 4449:1997 4 BSI 07-2001 8 Chemical composition 8.1 Cast analysis The chemical composition of the steel, based on cast analysis, shall be in accordance with Table 4. Bars of both grades shall have a carbon equivalent value, based on cast analys
38、is, not exceeding the maximum values given in Table 5. The following formula shall be used to calculate the carbon equivalent value, where the chemical symbols represent the percentages of each element: In cases of dispute, the appropriate methods of test given in BS 6200-3 shall be used. Table 4 Ch
39、emical composition of steel grades: cast analysis Table 5 Maximum carbon equivalent values: cast analysis 8.2 Product analysis and permitted deviations 8.2.1 The maximum deviations on product analysis from the values specified for cast analysis (see Table 4 and Table 5) shall be as given in Table 6.
40、 NOTEThe product analysis may vary from the cast analysis due to chemical heterogeneity arising during the casting and solidification processes. Table 6 Maximum deviations in chemical composition on product analysis 8.2.2 Samples for product analysis shall be taken in accordance with the appropriate
41、 method of BS 6200-3. 8.2.3 During product analysis, any bar that falls outside the maximum deviation limits for the composition range of a specified element, given in Table 6, shall be deemed not to conform to this British Standard. ElementGrade 250 % (max.) Grade 460 % (max.) Carbon0.250.25 Sulfur
42、0.0600.050 Phosphorus0.0600.050 Nitrogen0.0120.012 NOTE 1The maximum value for nitrogen does not apply if the chemical composition shows a minimum aluminium content of 0.020 %, or if sufficient other nitrogen binding elements are present. NOTE 2Nitrogen content is not normally given on a release cer
43、tificate. GradeMaximum carbon equivalent value % 2500.42 4600.51 ElementDeviation above the specified maximum given in Table 4 and Table 5 % Carbon0.02 Sulfur0.005 Phosphorus0.005 Total nitrogen0.001 Carbon equivalent value0.03 carbon equivalent value = C Mn 6 - - CrMoV+ 5 - - NiCu+ 15 - -+ BS 4449:
44、1997 BSI 07-2001 5 8.2.4 If, during product analysis, a single sample falls outside the maximum deviation limits for the composition range of a specified element, given in Table 6, further samples shall be selected for analysis from the remainder of the batch as follows: a) at least two samples from
45、 the same cast for delivered masses up to 5 t; b) at least five samples from the same cast for delivered masses up to 20 t; c) at least eight samples for delivered masses over 20 t. If any of the further samples analysed fall outside the maximum deviation limits for any element, the batch shall be d
46、eemed not to conform to this British Standard. 9 Bond classification of deformed bars 9.1 General Deformed bars shall be classified either as type 1 or as type 2 as follows. Either: a) in accordance with their surface shape, as specified in 9.2; or b) for bars that do not conform to the surface shap
47、e bond classification scheme of 9.2, in accordance with 9.3. 9.2 Bond classification by surface shape Bond classification by surface shape shall be as follows. NOTERecommended formulae for calculation of the projected rib area are given in Annex C. 9.3 Bond classification by performance The performa
48、nce tests described in Annex D shall be conducted at an appropriate testing laboratory. The bond classification established at the laboratory and given on the test report shall be regarded as final. 10 Routine inspection and testing Routine inspection and testing shall be carried out as described in
49、 Annex E, and either: a) for material covered by a third party product certification scheme, as in E.2; or b) for material not covered by a product certification scheme, as in E.3. 11 Mechanical properties NOTEAll bars should be free from defects, e.g. seams, porosity, segregation, non-metallic inclusions, etc., which can be shown to adversely affect the mechanical properties. 11.1 Tensile properties The yield strength Re, stress ratio Rm/Re, and elongati
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