COMPLIANCE WITH NZS 3402:1989

This article emphasises the provisions of New Zealand Standard NZS 3402:1989 "Steel Bars for the Reinforcement of Concrete". The compliance of any selection of reinforcing steel with NZS 3402:1989 focuses on the performance requirements for reinforcing steel in NZS 3101:1995, the "Concrete Structures Standard". Various statistically based quality assurance measures which should be satisfied for the supply and acceptance of reinforcement are described in detail; they are especially important, because so much reinforcing steel comes from outside New Zealand. A range of tests is available to establish tensile and ductility properties, and other properties that will confirm suitable performance in service. There is a need to assess extensive series of data for tensile tests for successive castings provided by the manufacturer, and the results of bend tests required by the standard or specified by the designer. The manufacturer typically conducts these tests, and includes their results as part of the certification of each bundle. The customer can choose to repeat these tests for the mechanical properties of bars prescribed by NZS 3402. Some examples are given of where the courses of action required by NZS 3402 are unclear, and some suggested interpretations of its requirements are given.