1、BS 6744:2016Stainless steel bars Reinforcement of concrete Requirements and testmethodsBSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06Publishing and copyright informationThe BSI copyright notice displayed in this document indicates when the documentwas last issued.
2、The British Standards Institution 2016Published by BSI Standards Limited 2016ISBN 978 0 580 89625 5ICS 77.140.15; 91.080.40The following BSI references relate to the work on this document:Committee reference ISE/104Draft for comment 15/30320587 DCPublication historyFirst published December 1986Secon
3、d edition August 2001Third edition May 2016Amendments issued since publicationDate Text affectedBS 6744:2016 BRITISH STANDARDContentsIntroduction by Lee Brankley, CEO, CARES iiiForeword iv1 Scope 12 Normative references 13 Terms, definitions and symbols 24 Designation 75 Standard diameters 76 Dimens
4、ions, mass and tolerances 87 Steelmaking process 98 Chemical composition 99 Surface quality 910 Surface geometry 911 Conditions of supply 1212 Mechanical and physical properties 1213 Product identification 16AnnexesAnnex A (normative) Test method for determining the corrosion resistance ofstainless
5、reinforcing steel in chloride contaminated concrete 17Annex B (informative) Guidance on durability 19Annex C (informative) Guidance on magnetic properties 25Annex D (informative) Guidance on coefficients of thermal expansion 26Annex E (normative) Design guidance: constitutive relationship 26Annex F
6、(informative) Guidance on welding 29Annex G (normative) Performance at elevated temperatures 30Annex H (informative) Quality assurance 30Annex I (informative) High-strength bars 33Bibliography 34List of figuresFigure 1 0.2% proof test 2Figure2Typical stress-strain curve (relation) for stainless rein
7、forcing 5Figure A.1 Geometry of the specimens 18Figure B.1 Example predictive model indicating where carbon steelreinforcement can be replaced by stainless steel reinforcement for a givenchloride surface content, design life and reinforcement depth 24Figure E.1 Idealized design curve from BS EN 1992
8、-1-1:2004+A1:2014 27Figure E.2 The constitutive law of stainless reinforcing steel 28Figure E.3 Example of design model for stainless reinforcing steel 29List of tablesTable 1 Symbols 6Table 2 Standard diameters 7Table 3 Nominal cross-sectional area of reinforcing steel and nominal mass permetre run
9、 8Table4Tolerances on mass per metre run 8Table 5 Chemical composition (cast analysis)% by mass of typical, commerciallyavailable BS EN 10088 stainless reinforcing steel designations 10Table 6 Minimum relative rib area, fRmin11Table 7 Ranges for the rib parameters 11Table 8 Strength and ductility pr
10、operties 14Table 9 Bend test formers 14BRITISH STANDARD BS 6744:2016 The British Standards Institution 2016 iTable B.1 Prescriptive guidance advice 22Table D.1 Comparative thermal coefficient of expansion data 26Table E.1 Youngs modulus for stainless reinforcing steel 27Table H.1 Acceptability index
11、, 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 = 0.90) 31Summary of pagesThis document comprises a front cover, an inside front cover, pages i to vi,pages 1 to 36, an inside back cover and a back cover.BRITISH STANDARDBS
12、6744:2016ii The British Standards Institution 2016Introduction by Lee Brankley, CEO, CARESBS 6744 is widely specified, both in the UK and internationally. I believe thatBritish Standards remain the choice of informed construction procurement teamsbecause they are performance-based and are developed
13、in partnership withindustry.CARES welcomes the publication by the British Standards Institution ofBS 6744:2016, Stainless steel bars Reinforcement of concrete Requirementsand test methods, which was developed by Technical Committee ISE/104 withcontributions and support from CARES. Its content forms
14、an essential part of thetechnical framework used to improve the durability of reinforced concretestructures in chloride containing environments.I am pleased to introduce BS 6744:2016 and commend its performance-basedapproach which will make a valuable contribution to the appropriate use ofstainless
15、steel reinforcing bar in the UK and internationally.Developments in the field of the measurement of corrosion resistance anddurability guidance have been taken into account during the development ofBS 6744:2016. The test method for determining the corrosion resistance ofstainless reinforcing steel i
16、n chloride contaminated concrete and the guidanceon the durability aspects of the corrosion resistance of the reinforcement will beuseful tools for engineers.The 2016 update will help to maintain BS 6744s pre-eminent position in the UKand, more importantly, internationally, as the preferred choice o
17、f standard whenstainless steel reinforcing is required.BRITISH STANDARD BS 6744:2016 The British Standards Institution 2016 iiiForewordPublishing informationThis British Standard is published by BSI Standards Limited, under licence fromThe British Standards Institution, and came into effect on 31 Ma
18、y 2016. It wasprepared by Technical Committee ISE/104, Concrete Reinforcing and Pre-StressingSteels. A list of organizations represented on this committee can be obtained onrequest to its secretary.SupersessionThis British Standard supersedes BS 6744:2001+A2:2009, which is withdrawn.Information abou
19、t this documentAttention is drawn to the fact that compliance with this document mightinvolve the use of patents applied to steel designation 1.4162 (see 3.1.24). Thepatent holder agrees to make the material available for production of stainlessreinforcing steel bars on reasonable and accessible and
20、 non-discriminatory terms.Information on designation 1.4162 may be obtained from: Outokumpu StainlessLtd, Europa Link, Sheffield, South Yorkshire S9 1TZ.This standard has been revised so that it can be used in conjunction withBS 8666, Scheduling, dimensioning, bending and cutting of steel reinforcem
21、entfor concrete Specification, but also to take into account the requirements ofEurocode (EC) 2 (specifically BS EN 1992-1-1 and BS EN 1992-1-2) and theConstruction Products Regulations (CPR) 1 with respect to constitutiverelationship and durability. It has also been revised to act as the nationalap
22、plication standard for BS EN 104031, Steel for the reinforcement of concrete Stainless steels (in preparation).The decision was taken to remove other uses of steel in concrete, which meansthat plain bars and grades 200 MPa and ribbed bars above grade 500 MPa areno longer covered by this standard. Th
23、ese products are covered by otherstandards. This is with the exception of 500 MPa bar and 650 MPa ribbed barwhich are now in an informative Annex (Annex I). The standard is open to otherstrength grades of ribbed bar on the basis that the designers know that theseare outside normal UK practice and, o
24、nce over 600 MPa, outside EC2.Informative annexes have been prepared to give guidance on durability,magnetic properties, coefficients of thermal expansion, constitutive relationship,welding, performance at elevated temperatures and quality assurance. As far asis possible, the revision has been writt
25、en to reflect the requirements of BS 4449.The test method in Annex A is based on the method in BS EN 480-14 adapted bySchnning, Randstrm and Adair for determining a critical chloride thresholdlevel for stainless steel rebar 2 and that in Testing for chloride threshold levelsof stainless reinforcing
26、bar 3.Copyright is claimed on Figure B.1. Copyright holders are Ove Arup b) the number of this British Standard (BS 6744);c) the nominal dimensions of the product (see Clause 6);d) the BS EN 10088 (all parts) steel designation number (see Table 5);e) the strength grade (see Table 8);f) the ductility
27、 class (see Table 8); andg) the durability class (see Table B.1).EXAMPLEIn accordance with this British Standard, a ribbed bar with a nominal diameterof 20 mm, a nominal length of 12 000 mm, steel designation number 1.4301,and strength grade 500 ductility and durability is designated thus:Ribbed bar
28、 BS 6744:2016-2012000-1.4301, B500B.CCTL%.5 Standard diametersThe range of diameters of ribbed stainless reinforcing steel bars shall befrom6mmto50mm.NOTE 1 The range of standard diameters is given in Table 2.NOTE 2 Other diameters may be made available on request.Table 2 Standard diametersGrade Nom
29、inal diametersmm500 6, 7, 8, 10, 12, 14, 16, 20, 25, 32, 40, 50BRITISH STANDARD BS 6744:2016 The British Standards Institution 2016 7(2 of 2)6 Dimensions, mass and tolerances6.1 Nominal cross-sectional area and mass per metre runThe nominal cross-sectional area and mass per metre run of the bars sha
30、ll becalculated in accordance with BS EN ISO 15630 using a test sample of length notless than 0.5 m.The values for the nominal cross-sectional area and nominal mass per metrerun, MmR, of individual bars shall be in accordance with Table 3.The tolerances on mass per metre run shall be in accordance w
31、ith Table 4.NOTE 1 The values for the nominal mass per metre run are calculated from thevalues of the nominal cross-sectional area using density values in BS EN 10088 (allparts).NOTE 2 Stainless steel hot rolled bars and coils are subsequently descaled inaccordance with Clause 11. This can lead to a
32、 reduction in the mass per metre.Hence, the calculation should be undertaken on a descaled rebar, unless themanufacturer can demonstrate a clear correlation between an as rolled sample anda descaled sample for each diameter tested.Table 3 Nominal cross-sectional area of reinforcing steel and nominal
33、 mass per metre runNominalsizeNominalcross-sectionalareaNominal mass per metre runA)Steel designationStandardausteniticB)Austenitic withMo additionB)Austenitic-ferritic(Duplex)B)mm mm2kg kg kg6 28.3 0.224 0.226 0.2217 38.5 0.304 0.308 0.3008 50.3 0.397 0.402 0.39210 78.5 0.620 0.628 0.61212 113.1 0.
34、893 0.905 0.88214 153.9 1.216 1.231 1.20016 201.1 1.589 1.609 1.56920 314.2 2.482 2.514 2.45125 490.9 3.878 3.927 3.82932 804.2 6.353 6.434 6.26640 1256.6 9.927 10.053 9.79050 1963.5 15.512 15.708 15.297A)The nominal mass per metre run, MmR, is given by the equation: MmR= M/L.B)Example steel designa
35、tions include: 1.4301 and 1.4311 for standard austenitic; 1.4404, 1.4436 and 1.4429 foraustenitic with Mo addition; and 1.4162 and 1.4362 for austenitic-ferritic (Duplex).Table 4 Tolerances on mass per metre runNominal diametermmTolerances on mass per metre run%6 9.07 to 12 6.0over 12 4.5BRITISH STA
36、NDARDBS 6744:20168 The British Standards Institution 20166.2 Length6.2.1 The nominal length of ribbed stainless reinforcing steel bars shall beagreed at the time of enquiry and order.6.2.2 Unless otherwise agreed at the time of enquiry and order, the permissibledeviation from the nominal length shal
37、l be +100/0 mm or in accordance withBS 8666.7 Steelmaking processUnless a special steelmaking process is agreed when ordering, the steelmakingprocess for steels conforming to the applicable part of BS EN 10088 shall be atthe discretion of the manufacturer.8 Chemical composition8.1 Cast analysisThe c
38、hemical composition of the steel, based on cast analysis, shall be inaccordance with Table 5. In cases of dispute, the methods of test specified in theapplicable part of BS EN 10088 shall be used.8.2 Product analysisThe maximum deviations in product analysis from the values specified for castanalysi
39、s shall be in accordance with those specified in the applicable part ofBS EN 10088.9 Surface qualitySteel bars shall be free from defects or other surface contamination which canbe shown to adversely affect the corrosion or mechanical properties of the steel,as agreed at the time of enquiry and orde
40、r.10 Surface geometry10.1 GeneralMeasurement of geometrical characteristics shall be in accordance withBS EN ISO 15630-1.NOTE The stainless reinforcing steel products covered by this British Standard arecharacterized by their surface geometry, which enables them to bond with theconcrete.BRITISH STAN
41、DARD BS 6744:2016 The British Standards Institution 2016 9Table 5 Chemical composition (cast analysis)% by mass of typical, commercially availableBS EN 10088 stainless reinforcing steel designationsA)SteeldesignationnumberCmaxSimaxMnmaxSmaxCrmaxNimaxMomaxCumaxPmaxNmaxAlloys used for low magnetic per
42、meability1.4311 0.03 1.0 2.0 0.030 17.519.58.511.5 0.045 0.120.221.4436 0.05 1.0 2.0 0.030 16.518.510.513.02.53.0 0.045 0.11Alloys used for corrosion resistance to chloride ingress in concreteB)1.4311 0.03 1.0 2.0 0.030 17.519.58.511.5 0.045 0.120.221.4162 0.04 1.0 4.06.00.015 21.022.01.351.700.100.
43、800.100.800.040 0.200.251.4362 0.03 1.0 2.0 0.015 22.024.53.55.50.100.600.100.600.035 0.050.201.4462 0.03 1.0 2.0 0.015 21.023.04.56.52.53.5 0.035 0.100.221.4404 0.03 1.0 2.0 0.030 16.518.510.013.02.02.5 0.045 0.111.4429 0.05 1.0 2.0 0.030 16.518.510.513.02.53.0 0.045 0.120.22Alloys used for special
44、 applications, e.g. where the steel may be exposedC)1.4501 0.03 1.0 1.0 0.015 24.026.06.08.03.04.0 0.035 0.200.301.4529 0.02 0.50 1.0 0.010 19.021.024.026.06.07.00.501.500.030 0.150.25A)Table 5 does not provide an exhaustive list of designations.B)These are the alloys for which the most academic res
45、earch on chloride resistance is available and whichhave the most historic use for this application. Refer to manufacturers certification for CCTL value.C)Specialist corrosion advice might be required to specify.10.2 Relative rib areaThe geometry, the rib distribution and configuration shall be measu
46、red inaccordance with BS EN ISO 15630-1.The relative rib area, fR, the rib spacing, c, the rib height, max, and the ribinclination, , of the transverse ribs, the projection of the transverse rib and thetransverse rib flank inclination, , shall be measured according toBS EN ISO 15630-1.For relative r
47、ib area, fR, the rib spacing, c, the rib height, max, and the ribinclination, , of the transverse ribs shall conform to Table 6 and Table 7.The relative rib area, fR, shall be regarded as the ruling criterion for the bondperformance of ribbed stainless reinforcing steel products.BRITISH STANDARDBS 6
48、744:201610 The British Standards Institution 2016Table 6 Minimum relative rib area, fRminNominal bar diametermmRelative rib area, fRmin6 0.0357 to 12 0.04012 0.056Table 7 Ranges for the rib parametersRib height, maxRib spacing, c Rib inclination, 0.03d to 0.15d 0.4d to 1.2d 35 to 7510.3 Geometry of
49、rib10.3.1 GeneralSteel bars shall have rows of parallel transverse ribs (normally 2 or 3), equallydistributed around the perimeter with a uniform spacing over the entire length.NOTE Longitudinal ribs might be present or not.10.3.2 Transverse ribs10.3.2.1 Transverse ribs shall have a crescent shape and shall merge smoothlyinto the core of the bar, unless the same product properties can be achieved byother special surface configurations.10.3.2
