Post on 07-Jan-2016
description
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