Material Traceability

and Reusability in

BC1: 2012

by:

CHIEW Sing-Ping

Nanyang Technological University

http://www.bca.gov.sg/StructuralPlan/others/Design_Guide_BC1_2012.pdf http://www.bca.gov.sg/StructuralPlan/others/Handbook_to_BC1_2012.pdf

Steel Selection & Quality Assurance

BC1: 2008 - Design Guide on Use of Alternative Steel Materials to BS5950

2

Current Revisions ? In short:

- new steel - new design code - reused steel Companion publication: - Handbook to BC1: 2012

BC 1: 2012

Current Revisions of BC 1

Expanded title: “BC 1: 2012 Design Guide on use of alternative structural steel to BS5950 and Eurocode 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 production standards, and hence the list of certified steel materials (Appendix A)

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), only Grades SYW295 and SYW390 to JIS A5523 are certified.

BC 1: 2012 Updates in Section 2

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 4

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-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

BC 1: 2012 Updates in Section 5

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 6NEW!!! (1)

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

BC 1: 2012 Section 6NEW!!! (2)

Traceability/Classification of ex-stock material

BC 1: 2012 Section 6NEW!!! (3)

Class 2Class 1

Key:

Yes

No

Ex-stock materials delivered without

FPC certificate for repeated use- delivered with manufacturer test certificate

- certifiable & listed in Appendix A

Mill has subsequently

obtained FPC certificate?

Material testing for

each batch/lot(see Appendix B)

Batch/lot known?

Material testing for

each batch/lot(see Appendix B)

Correlated NDT for each

member(see Appendix B)

Note: Ex-stock steel materials which do not fit into this flow chart shall be classified as Class 3

100% Correlated Non-Destructive Testing (NDT)?

a) Surface Polishing b) Test Gun c) Portable Computer

Non-Destructive Testing using Portable Optical Emission

Spectrometer (OES)

Correlation of mechanical properties to chemical composition using

verified equations from database analysis

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

BC 1: 2012 Section 6NEW!!! (4)

Reusability assessment

1. Surface condition

– ≥ 85% steel surface free of rust not severe than Grade C (per BS EN ISO 8501-1);

– 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 6NEW!!! (5)

Reusability assessment

3. Shape & straightness

– To comply with BS 5950-2;

– Straightening treatment if necessary

4. Bolts & welded connections

– Visual inspection on used connections;

– Loosened/retrieved bolts not to be re-used

5. Interlock of sheet piles

- Adequate free play to fit together and engaged in a such manner to transfer the in-service forces

BC 1: 2012 Section 6NEW!!! (6)

Reusability assessment

BC 1: 2012 Section 6NEW!!! (7)

Used steel materials with unique/traceable identity

Quality test regime(see 6.2.2.1, 6.2.2.2, 6.2.2.3 & 6.2.2.4)

Re-use Re-conditioningEconomic

feasibility of re-conditioning

Reject & scrap

Pass

Fail

No

Yes

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 (IB) acceptable to BCA and accredited by SAC in the first instance, followed with subsequent surveillance audits at every 6 months

BC 1: 2012 Section 6NEW!!! (8)

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

BC 1: 2012 Updates in Appendix A

Summary (1)

Latest 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

Summary (2)

Companion handbook to BC1 covers:

Design Procedures

Design Parameters for Class 1, 2 & 3

Certified Steel Materials

Non-Certified Steel Materials

Reusability of Steel Materials3