Reinforcing Steel Standards
A number of New Zealand Standards pertaining to reinforced concrete are and will be undergoing revisions/amendments to bring them in line with the changes that have been introduced to the grade of reinforcing steel. This section outlines the significant changes and will be updated as revisions or amendments are confirmed. All standards are available for purchase from the Standards NZ website www.standards.co.nz
Reinforcing Bar, Wire and Fabric
With the introduction of the joint Australia New Zealand Standard AS/NZS 4671:2001, and an overlap period of 12 months, these standards were withdrawn in April 2002.
AS/NZS 4671 Steel Reinforcing Materials
This is the current joint standard, covering reinforcing steel in the form of bar, wire and machine welded mesh. It is one of the many standards that the Australian and New Zealand governments agreed to combine under CER agreement to free up trade between the two countries. This intent has not been realised, as was first envisaged, due to the different design codes between Australia and New Zealand, which require different properties of reinforcing steel. The major difference is in the ductility required for seismic design in New Zealand. The standard was published on 2 April 2001.
This joint standard was originally based on the European reinforcing standard ENV 10080 and is a performance-based standard. Previous standards have been much more prescriptive. This means that the standard now focuses on the properties of the steel, rather than what is in the steel. The most important change from a specifier's perspective is the introduction of three classes of ductility.
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L - Low ductility; will apply to cold drawn products.
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N - Normal ductility; will be the reinforcing standard for non seismic areas.
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E - Earthquake ductility; will be the reinforcing standard for seismic areas. Product complying to this class is available from Pacific Steel.
Other significant changes are:
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Replacement of grade 430 MPa steel with grade 500 MPa steel.
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The reinforcing steel classes are based on ductility
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Unique identification marks required to identify the steel producer.
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Steel producers and steel processors are required to meet the characteristic value bands of the properties specified. To meet these stringent statistical requirements a producer's process need to be maintained under close control ensuring consistent properties
NZS 3101 Design of Concrete Structures
The Concrete Structures Standard, NZS 3101: 2006 has been updated to permit the design of reinforced concrete structures using reinforcing steel as per the steel standard AS/NZS 4671, which was published in March 2006.
AS/NZS 1554.3 Welding of Reinforcing Steel
AS/NZS 1554.3 has been written with the Grade 500 reinforcing steel in mind, to cover the requirements for welding reinforcing steel going into concrete structures designed and constructed in accordance with AS 3600 or NZS 3101.1. The standard sets out prequalified weld preparations, methods for the qualification of welding procedures and welding personnel, workmanship and inspection requirements. This standard also applies to the welding of steel connection devices, inserts, anchors and prefabricated assemblies in the fabrication shop and in the field
The standard was published in October 2002.