Steel for the reinforcement of concrete
Specification of reinforcing steel — bars, mesh, ductility classes.
Overview
AS/NZS 4671 specifies the steel itself — yield strength, ductility class, and surface profile. Common designations include D500N (normal ductility) and D500L (low ductility, mesh). The ductility class affects how the structure behaves in extreme events.
Key Requirements
- Yield strength (typically 500 MPa).
- Ductility class — L (low), N (normal), E (earthquake).
- Bar marking for identification.
- Test certificates from the mill.
How it's used in the NCC
Supports concrete design under AS 3600 and AS 2870.
Practical Notes
- Mesh delivered to site is typically D500L — fine for slabs on ground but check the spec for any tied/looped reinforcement.
- Keep delivery dockets on file — the bar marks should match the spec.
Where to obtain
The full text of AS/NZS 4671 is published by Standards Australia and must be purchased — typical price A$150–400 per part. Always work from the current edition referenced in the NCC, not an older one.