BC 1: 2008 BC 1: Implementation Issues. Implementation Issues & Current Revisions. Urghhh!! Since January 2009

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1 BC 1: 2008 Implementation Issues & Current Revisions Since January 2009 by: Chiew Sing-Ping Nanyang Technological University Singapore BC 1: 2008 Implementation Issues Urghhh!!

2 BC 1 Objectives To allow a wider choice of steel materials to achieve greater economy and sustainability To ensure product conformity, quality and traceability in materials from various sources Deliverables: Use only adequate & reliable alternative materials to ensure public safety Optimize usage of alternative materials (e.g. use full design strength) for more competitive design Address long-standing material problems facing the steel construction sector BC 1 Main concerns Two major concerns Adequacy? Reliability? Material performance requirements Quality assurance requirements

3 BC 1 Material performance requirements Steel materials Steel plates, hot rolled & hollow sections, steel for cold forming 1 Non-preloaded & preloaded bolting assemblies Welding consumables Profiled steel sheets Stud shear connectors Strength Ductility Toughness 1 1 * * * Chemical Manufacturing composition tolerances Others 1 1 Manufacturing process Hardness, proof load *all-weld metal Zinc coating - The complete sets of requirements are given in Section 2 of BC1: 2008; Materials which meet these requirements are certified steel materials, as listed in Appendix A of BC1: 2008 Non-certified steel materials JIS G3101 (SS400( SS400,, SS490, etc.) JIS G3444 (STK400, etc.) JIS G3466 (STKR400, etc.) ASTM A500 BS 4360 (43A( 43A,, 50A, etc.) DIN 931 / DIN 933 still being used and available in large quantity!!

4 BC 1 Quality assurance requirements Manufacturer test certificate (MTC) Factory production control (FPC) certificate Why MTC not good enough? BC 1 Design framework Stee l mate rials for s tructural us e in Singapore Ke y: Pass Fail BS EN, ASTM, AS/NZS, JIS & GB For e.g. IS, KS, API by ce r tification (see 4.1.1) Adequacy as s essment (see 4.1 ) by material testing (see ) Not common route!! Re liability as s essment (see 4.2 ) Re liability as s essment (see 4.2 ) Class 1 Clas s 3 Clas s 2

5 BC 1 Cl. 4.4 Alternative route An interim measure for certified steel materials The material can be treated as Class 2 if its adequacy & reliability are guaranteed through material testing and control plan, e.g. material testing based on 1 test unit per batch/heat,, test report from accredited laboratory and material compliance report Implication: We (instead of steel mills) continue to shoulder the quality problem! Key Points of BC 1 (1) We have taken a bold step to liberalize the use of steel materials in Singapore. We now have a wider choice to choose steel from more diverse sources; however, it is important in the process, we do not compromise quality and public safety. While we are liberalizing, we are also tightening in some aspects, especially on quality assurance for the steel products which are being brought into Singapore.

6 Key Points of BC 1 (2) To qualify for Class 1 steel, it will be necessary for stockists, traders and steel specialist builders to purchase from audited mills who have in place proper factory production control system, and for audited mills to provide proper test certification (MTC & FPC) for their products. Steel from non-audited mills can only qualify for Class 2 under alternative route if adequacy and reliable are guaranteed through material batch/heat testing. Key Points of BC 1 (3) Guide is blind to country of origin ; ; all steels are allowed and are treated the same, including BS/EN steels Who produces the steel,, i.e. the mills where the steel come from will now become important The intent is to raise the material quality bar based on trust and shared-responsibility responsibility amongst all key stakeholders

7 Is BC 1 your foe? BC 1 favors European mills with FPC and discredits regional Asian mills without FPC. BS materials from these regional mills without FPC will now be downgraded to Class 2. FPC is no guarantee of quality, material testing is better. BC 1 gives Chinese steel specialist builders an edge over local builders, by-passing many local stockists, traders and service providers in the process. BC 1: 2012 Current Revisions

8 Current Revisions of BC 1 Working title: BC 1: 2012 Design Guide on use of alternative structural steel to BS5950 and Eurocode 3 3 to cover expanded scope:- Additional material categories (Section 2) Specific provision to Clause 4.4 (Section 4) Design parameters to Eurocode 3 (Section 5) Material traceability & reusability for re-use steel (new Section 6 for struts and sheet piles) Update of material standards, and hence the list of certified steel materials (Appendix A) BC 1: 2012 Updates in Section 2 Inclusion of 2 new material categories:- Hot-rolled steel bars round/flat/square bars up to grade 690/1000 based on EN 10058/59/60; Sheet piles hot-rolled sheet piles to JIS A5523 & EN 10248, cold-formed sheet piles to EN 10249; pipe piles & steel piles are already covered under hot-rolled sections and hollow sections. Important Note: Sheet piles to JIS A5528 not- certified (Grades SY295 and SY390)

9 BC 1: 2012 Updates in Section 4 Clause 4.4 Special Case is made more specific and clearer, i.e. the written plan should comprise at least one set of material testing for each batch/lot of steel materials (instead of 100% material testing ) BC 1: 2012 Updates in Section 5 Inclusion of design recommendations to EN 1993 Simplification of design parameters tables for ASTM/AS steel materials* and bolts *Gradual downgrading of material strengths are applied to ASTM/AS steel materials as thickness increases Omission of bolt-nut nut-washer matching tables more appropriate to refer to the material standards Inclusion of GB/T 19879:2005 steels up to Q460, ASTM A1046:2007 profiled sheets, JSS II-09:1981 S10T torshear bolts & other materials deemed suitable

10 BC 1: 2012 Section 6 NEW!!! (1) Addition of new section, i.e. Section 6. Material traceability and reusability Guidelines on the re-use of sheet piles & steel materials in steel strutting system used in ERSS Two important aspects:- Traceability Reusability BC 1: 2012 Section 6 NEW!!! (2) Material traceability The ability to trace back the source of a specific steel material to its original identity as delivered from the mill, through proper identification and quality assurance system Each piece of steel members to be marked with a unique ID for future reference to the FPC certificate, MTC, inspection record & test report

11 BC 1: 2012 Section 6 NEW!!! (3) Traceability/Classification of ex-stock material Ex- s tock materials delivered without FPC certificate for repeated us e - d elivered w ith man ufacturer test certificate - certified & listed in Appendix A Key: Yes No Mill has s ubs equently obtained FPC certificate? Material tes ting for each batch/ lot (see Appendix B) Correlated NDT for each member (see Appendix B) B atch/lot known? Material tes ting for each batch/ lot (see Appendix B) Clas s 1 Clas s 2 Note : Ex- stock steel materials which do not fit into this flow chart shall be classified as Class 3 BC 1: 2012 Section 6 NEW!!! (4) Material reusability The ability of the used steel materials to be reused & to perform adequately as anticipated in the design Good practices:- Apply permanent & systematic marking; Avoid mixing of steel grades; Apply corrosion protection coating

12 BC 1: 2012 Section 6 NEW!!! (5) Reusability assessment 1. Surface condition 85% steel surface free of rust not severe than Grade C (per BS EN ISO ); 1); Minor repair if necessary 2. Sectional dimensions Measured at 3 locations; Measured dimension nominal dimension allowable tolerance, or relegated to next lighter section BC 1: 2012 Section 6 NEW!!! (6) Reusability assessment 3. Shape & straightness To comply with BS ; Straightening treatment if necessary 4. Bolts & welded connections Visual inspection on used connections; Loosened/retrieved bolts not to be re-used

13 BC 1: 2012 Section 6 NEW!!! (7) Reusability assessment Use d ste e l mate rials w ith unique /traceable identity Pa ss Quality te st regime (see , , & ) Fa il Re - use Ec onomic fe as ibility of re - conditioning Ye s Re - conditioning No Re je c t & sc rap BC 1: 2012 Section 6 NEW!!! (8) Quality system Supplier/fabricator to implement a quality system:- Material marking & identification; Documentation of certificates/reports; Record of usage & reconditioning history; In-house inspection & quality test regimes The quality system shall be audited by an independent inspection body acceptable to BCA in the first instance, followed with subsequent surveillance audits at every 6 months

14 BC 1: 2012 Updates in Appendix A All latest standards have been compared against the material performance requirements The lists have been updated, including two (2) new categories of materials, i.e. hot rolled steel bars & sheet piles* *Steel for cold forming is also accepted as certified materials for cold formed sheet piles Summary (1) Implementation issues of BC 1:- BC 1 provides a level playing field for all steel & promotes quality material usage Unless quality and consistency of the steel can be assured through proper factory production control (FPC) certification, steel can at best qualify for Design Class 2 and an appropriate material safety factor should be used There are still plenty of non-certified steel being used, for e.g. BS 4360 Grade 43A, ASTM Grade A500, JIS G3101 Grade SS400, etc.

15 Summary (2) Current revisions of BC 1 to cover extended scope & updated material standards:- Additional material categories steel bars & sheet piles Design recommendations to Eurocode 3 Material traceability & reusability for sheet piles & steel strutting system Update of the list of certified steel materials per latest material production standards Good for stockists/traders and steel specialist builders/suppliers to keep abreast of development Thank you!