Report on Grade 500E steel reinforcement
Our investigation resulted in a report, published in July 2005, Report on Grade 500E steel reinforcement.
In fact, action addressing the problems identified in the report, and its recommendations, was initiated by us and other industry organisations in the 18 months before publication. These actions are outlined in the following sections.
The investigation indicated that the industry's knowledge and understanding of Grade 500E was limited because:
- alternative methods of manufacture were being used; microalloy (MA) and quench and tempered (QT)
- steel manufactured locally, and imported, was being marketed as Grade 500E
- the properties and limitations of handling, or fabrication, including bending, re-bending, welding, galvanising and threading were poorly understood.
Consequently, the report recommended the following actions:
- general education of the industry on the properties of Grade 500E and its limitations and benefits
- advice and alerts to industry about limitations and benefits of the product and the variation to be expected in manufacturing process, suppliers, bar markings and weldability
- research to provide better information on key issues
- specific advice to fabricators, constructors and designers on the need for care in handling or fabricating Grade 500E
- amendments to New Zealand Standards, including information about the limitations regarding Grade 500E steel.