NZS 3104:2003 Concrete Production – Proposed Review  

The NZ Standard Specification for concrete production, NZS 3104:2003, will be reviewed later this year by a committee convened by Standards New Zealand.  A revised edition will then be published.   

SESOC will be represented on this committee. Other members include Concrete NZ, BRANZ, readymix companies, and consulting engineers. 

NZS 3104 sets out the minimum requirements for the production of fresh concrete by the supplier, eg the operator of a ready mix concrete plant.  When used in accordance with NZS 3101 and NZS 3109, it provides an Acceptable Solution to the NZ Building Code.

NZS 3104 and supporting audit schemes provide a comprehensive quality assurance system unique to New Zealand.   Each readymix concrete plant operating within NZRMCA’s plant audit scheme has a plant engineer and independent auditing engineers who review production data to ensure the plant’s production meets NZS 3104 requirements.

As well as being a manufacturing standard, NZS 3104 also provides directly and indirectly for the interests of designers and purchasers.   

Overall, the revision aims to improve productivity in concrete construction without compromising quality.    Specific issues in the standard that will be considered in the review include the following, though not all will necessarily be included in the revised standard:

–       Using statistical data when setting or reviewing target strengths for concrete mixes rather than having set target strengths, standard deviations and coefficients of variation;

–       Updating the testing requirements so that 7-day strength testing becomes mandatory rather than be done at the discretion of the concrete plant or project specifications;

–       Better guidance on how within test coefficients of variation are calculated, which determines whether two or three cylinders need to be tested when undertaking compressive strength testing at 28 days;

–       Clarification of the process of undertaking uniformity testing of truck and central mixers where currently sample numbers varying and procedure for testing central mixers is not clear;

–       Review of whether using workability/consistence classes would be beneficial since slump targets are the subject of much debate and specifiers are currently using a variety of approaches to tackle the issue;

–       Clarification of the requirements for companies providing professional scale check services to readymix concrete plants;

–       Better guidance for operators of mobile batching vehicles used to provide small volumes of concrete around New Zealand.

If you think a particular aspect of NZS 3104 could be improved, whether as a requirement, commentary, or appendix, then please let  SESOC President Jason Ingham  know or add your comments below so that SESOC members’ needs can be represented in the review.