In this section
Non-compliance is a worldwide problem.
Below are listed several case studies and reports on compliance issues from Steel Construction New Zealand and Structural-Safety, UK as part of the ASI's awareness program for non-compliant product in Australia, as well as a product alert from SCA:
SCNZ case studies
Countdown Supermarket case study (PDF) (3 Mb) involving 227 tonnes of prefabricated structural steel imported from China.
Establishing the traceability of imported steel (PDF) (4 Mb) involved a two month delay in constructing an Auckland warehouse.
Structural-Safety (UK) combines the activities of CROSS and SCOSS (Standing Committee on Structural Safety) to work with the professions, industry and government on safety matters concerned with the design, construction and use of building and civil engineering structures.
CROSS (Confidential Reporting on Structural Safety) was established in the UK in 2005 to improve structural safety and reduce failures by using confidential reports to highlight lessons that have been learnt, to generate feedback and to influence change. Reports sent to CROSS are completely confidential, and no personal details or information are included that could be used to identify a project or product.
Structural-Safety has recently ( Feb 2013) issued an alert for distribution in the UK as a result of many recent reports from the scheme entitled Confidential Reporting on Structural Safety (CROSS) about non
compliance and falsification of certification from overseas steelwork supply, mainly from non-European origin.
Contact Peter Key National Manager Technical Development for more on the ASI compliance program: email@example.com
CROSS Reports on Structural Steel Safety in the UK
Latest report from Structural-Safety, UK done on a recent NSW tubular truss non-conformance issue:
Below is a selection of reports from the CROSS web site:
REPORT 585 FAILURE OF SUPPOSEDLY GRADE 10.9 BOLTS
A reporter describes an incident where there was a high potential for collapse when supposedly Grade 10.9 high strength holding bolts failed on a crane base. Sixteen bolts, which had been pre-tensioned in the standard way, all failed within four days. This was found to be a brittle failure and because the bolts were pre-stressed, they failed in a manner which released energy, resulting in the bolt heads being ejected up to 4m above the lifting frame. It is believed the failure was due to delayed hydrogen embrittlement which can be caused in the manufacturing process. This type of failure would be expected to occur within a few days of tensioning bolts as was seen in this case. The investigation is ongoing and no-one was injured. The reporter says that in future, within their organization:
- Bolts of Grade 10.9 or higher to be approved by technically competent person(s) prior to use.
- Hardness and tensile tests to be used as a minimum to verify the metallurgy of all Grade 10.9 bolts.
- Permits to include the need for technical sign off.
- All using this type of bolt to be briefed on this incident.
Presumably the bolts were delivered with the correct certification/ markings, which is why they were installed without any questions? In general, but particularly for safety critical components, inspection and test plans should be developed prior to construction:
- Obtain certification to ensure that all components are sourced only from suppliers who can guarantee compliance with specification.
- Ensure that the products are inspected by competent persons before installation.
- Ensure products are installed in accordance with manufacturer’s and designer’s recommendations.
There is always the possibility of counterfeit components and this was the subject of a SCOSS Alert: Anomalous documentation for proprietary products published in 2013. In the UK organisations such as Highways England use only approved suppliers to avoid installing counterfeit components. See http://www.scheduleofsuppliers.co.uk/NHSS-Schedule-of-Suppliers.aspx . For a company to be listed on the Schedule of Suppliers, it must be accredited by UKAS. In the USA there are programs directed towards detecting counterfeit components including bolts and below is a list of General Indications:
- No manufacturer’s or grade mark (unless certified to a specification not requiring marking)
- Evidence of machining marks
- Poor thread form, evidence of wear, or dressing
- Headmarks shown on the Suspect Fastener Headmark List (USA Department of Energy list)
- Foreign manufacturer not meeting Public Law 101-592 (USA law)
- No markings for nuts or washers packaged with labels indicating that they were manufactured to a code or specification which requires marking
- Headmarkings are marred, missing, or appear to have been altered
- Headmarkings are inconsistent
- Double stamping
- Metric and SAE stamping
- Headmarks with raised marks and depressed marks on samebolt (not normal manufacturing process)
REPORT 259: QUALITY OF SOME IMPORTED STEEL COMPONENTS
We are aware, says a reporter, that the construction industry is procuring many materials such as steel plates, structural sections, and metal castings from outside the UK and that these are often found to have some issues in meeting specification. We have, he continues, had several experiences where the strength and characteristics of castings, plates, and manufactured ‘off the shelf’ products, did not meet the project specifications. Products have also been received with paperwork that demonstrates compliance with specification but when destructively tested did not meet the properties given in the accompanying certificates.
REPORT 299: DOCUMENTATION FOR IMPORTED LARGE DIAMETER STEEL PINS
When designing a large pin connection for an external walkway bridge linking two buildings in the UK a reporter specified 60mm diameter solid circular bar for the pin. Due to the loads, higher grade S355 material was selected, and due to the thickness and external exposure, J2 subgrade was chosen. As the quantities were small and timescales tight, the reporter took the precaution of ensuring suitable material was available from a stockholder. He was assured that it was. Since the specification (S355J2G3) is not common-place and the element was of critical importance the reporter requested a certificate confirming the grade. When received, this indeed certified S355J2G3 material and revealed the material had originated outside the UK. However, a note on the form stated that the material was tested, normalised and supplied as rolled. The implication is that the required ductility was not available from the material as supplied and in fact no information on the ductility / brittle fracture performance of the material was available. In short, the supplied material was not as advertised by the certificate and would only achieve the specified grade if subjected to normalising - a heat treatment process. The layout of the form had misled both the stockholder and the steel fabricator, neither of whom were aware that the material was potentially unsuitable. The problem was resolved by heat treating (normalising) the steel pins. However it highlights the possibility that foreign steel, with poor, confusing or misleading documentation, is being used on safety critical structures in the UK.
REPORT 326: RAPEX NOTIFICATION ON SOME IMPORTED RHS STOCK
A Government Department in an EU country issued a letter warning about the potential importation of structural steel products that do not comply with the requirements of Council Directive 89/106/EEC - the ‘Construction Products Directive’. It said that the product failures can arise in hot-formed longitudinally welded hollow profiles and cold-formed longitudinally welded hollow profiles of unalloyed construction steels of types S355J2H and S235JRH with nominal dimensions from 80 x 80 x 6mm to 500 x 300 x 12.5 mm. Such products fall within the remit of EN 10210-1.2006 – Hot finished structural hollow sections of non-alloy and fine grain steels - Part 1: Technical delivery conditions and EN 10219-1.2006 – Cold formed welded structural hollow sections of non-alloy and fine grain steels - Part 1: Technical delivery conditions. Due to incorrect aluminium content, these steel products are only suitable for welding in limited applications. In broad terms, there is a risk of failure to the welds without warning. In light of the potential seriousness of the risk, a RAPEX notification was issued. Given the potential seriousness in connection with product failure arising from such hollow profiles, the Department asked building control authorities to make enquiries to ascertain where such products have been used and take all appropriate action in the event that the importation of any such hollow profiles is identified.
BCSA (British Constructional Steelwork Association) issued a memorandum (No 156-12) to all of its members about this RAPEX Notification (notification number Article 22 of Regulation 765/08) in July 2012. An extract says: “The results of the testing showed that most of the sections were made of unkilled or killed steel rather than fully killed steel required by the standards. Fully killed steel has a minimum aluminium content of 0.02%. All the steels tested by the German Authorities had aluminium content that fell below this value. Unkilled or killed steels are steels which have not been sufficiently deoxidised and can develop ‘gases’ during solidification with the formation of blow-holes. This may cause problems when welding and the advice from German authorities is that the products affected can only be welded to a limited extent and that the welds are at risk of failure.”
REPORT 331: CERTIFICATION OF STEEL SHEET PILING
A Government Agency received a proposal to use steel sheet piles produced by an overseas manufacturer. To demonstrate compliance with standards, certification was supplied, indicating that these products carried CE marking. The certificates were passed from sub-contractor to main contractor without comment. Only when the documents were examined by Agency staff were concerns raised about their authenticity. Details on the certificates did not follow the requirements for CE marking of products, namely:
- compliance was quoted with a non-harmonised standard
- the assessment was not carried out by a Notified Body
- other supplied detail suggested that this certificate was invalid.
The information was passed to a local Trading Standards Office (who has authority to investigate such matters, though they do not necessarily have the expertise and detailed knowledge of construction products). Some technical support was provided by the Government Agency to facilitate the subsequent investigation. The ‘certification company’ was found to be a shell company with no base in the EU, and other information was found to be false. The breach was discovered before the purchase of the sheet piles and as there was no prospect of a prosecution, the investigation was halted. Details of the case were entered on Trading Standards’ National Database, but it is possible that this situation may recur.
One of the lessons learnt was that supply chains must appreciate their responsibility to ensure that they have acted with ‘due care’ and rigorously check product certification.
REPORT 284: FALSE CE CERTIFICATES
This report is about falsified documents in circulation within the EU purporting to be CE certificates. In one case it was found that the organisation concerned, which has its origin in the Far East, had set up a company in Europe, which claimed to be a competent consulting organisation providing advice on the European Health and Safety Directive for a variety of products. Documentation from the company was shown to be false and among other errors, one certificate was observed to have used a Notified Body Number for one class of products, which was clearly wrong because the Number is allocated to another class of products. The European company was closed down by the authorities but there is still an internet site offering certification services. Clues as to the illegitimate nature of the site can be found in obvious spelling mistakes and incorrect grammar. The reporter says that sadly the old story about “CE” standing for “Caveat Emptor” has a ring of truth about it.
Reports 259, 299, 326, 331, 338 and 284 follow a common theme and reveal a worrying trend. The fact that there are reports concerning different products suggests that these incidents are not rare. Designers and contractors may need to consider as a matter of ensuring structural safety whether to instigate routine testing of any product purchased from a source which is not well known. The globalisation of material supply and the introduction of CE marking are raising issues about the quality of material received on site. It is clear that CE marking alone may not offer the same level of confidence as quality schemes that have been used historically. CE marking is a standardised method of giving product characteristics against a harmonised EN. It is not a declaration of fitness for purpose in any particular circumstance of use and a reputable product manufacturer's technical information may be more useful if it gives advice on the use of the product in service.
There is confusion over when and if CE marked products need to be used especially in projects which are publically procured. In fact CE marking is a significant topic for Public Procurers. A related issue is the readiness of clients, designers, contractors, suppliers and manufacturers for the introduction of the CPR in July 2013. The Construction Products Regulation (305/2011/EU - CPR) – replacing the Construction Products Directive (89/106/EEC – CPD,) is laying down harmonised conditions for the marketing of construction products. Also of concern is whether in the UK the 'market surveillance' required is in place (via Trading Standards Organisations) and that they have the necessary resource and expertise. Detecting forgeries is not easy and in 2010 the UK Department for Business innovation and Skills issued a warning about organisations falsely claiming to be notified bodies which included the following. “The Department is aware of some cases where organisations either claim or present themselves so as to appear to be notified bodies (e.g. in websites and in their publicity materials), when they actually hold no such appointments. Such claims are misleading manufacturers and importers into using the services of organisations promoting themselves as notified bodies authorised to undertake conformity assessment and certification process, when in fact, they are not authorised to do so".