Scheme Operations

Audit of Concrete Plant Production

The Plant Audit Scheme operates to audit Concrete NZ Readymix Sector Group member’s ready mixed concrete plants as defined in New Zealand Standard NZS 3104:2021 Specification for Concrete Production.

The Plant Audit Scheme is of great convenience to the specifiers and purchasers of concrete. It provides an independent and rigorous audit of the quality systems in place at a ready mixed concrete plant. Without the scheme, purchasers and specifiers would be faced with a costly and time consuming audit of concrete quality for each construction project.

The Scheme is certified to ISO 9001 and undergoes external validation audit by Bureau Veritas (New Zealand) Limited on an annual basis.

The Scheme operates independently from the management of the Concrete NZ Readymix Sector Group both in respect membership of the Plant Audit Committee and finance matters. Ready mixed concrete plants using the scheme are charged separate fees from any Concrete NZ Readymix Sector Group subscriptions.

The Plant Audit Committee comprises five or more Professional Engineers and Registered Engineering Associates with long experience in the concrete production industry. The Concrete NZ Readymix Sector Group are only permitted two nominees on the Committee. The Committee which has three externally appointed members denoted by * is as follows:

The present members of the Committee are:

Additional assessors for plant inspections:

The establishment and monitoring of the production of a ready mixed concrete plant are requirements for the supply of structural concrete for compliance with NZS 3109:1997 Concrete Construction and NZS 3104:2021 Specification for Concrete Production and hence the New Zealand Building Code.

Cement used by the member plants of the Audit Scheme must comply with NZS 3122:2009 Specification for Portland and Blended Cements (General and Special Purpose).

NZS 3104:2021 Specification for Concrete Production is the standard used by the Plant Audit Committee of Concrete NZ to audit and continue auditing of a Ready Mixed plant.

Compliance with NZS 3104:2021 Specification for Concrete Production also requires compliance with a number of other Standards, such as NZS 3112.1-4:1986 Methods of Test for Concrete. The requirements for the calibration of laboratory equipment are also audited by the Committee.

Plants report quality performance data to the Committee annually and are subject to a detailed annual review of data together with an on-site audit every second year. Site audits may also be carried out without warning at any time. Among performance criteria audited are:

In addition to the above, the frequency of testing within each quarter year, must be submitted to the Plant Audit Committee.  Failure to maintain testing requirements can result in the withdrawal of an Audit Certificate.

Performance standards of all plants in the scheme are under regular review. Certificates of Audit are issued for a period not exceeding 12 months. The current status of plants is updated on this Web site.

Where plants fail to meet the criteria, their Audit Certificate is removed and noted on the plant list. It is necessary for such plants to resubmit to an initial reassessment with at least 30 results indicating compliance with the Standard NZS 3104:2021 Specification for Concrete Production.

When using concrete from un-audited plants, the purchaser is responsible for the implementation of the audit process or project testing as required by NZS 3104:2021 Specification for Concrete Production to ensure compliance with New Zealand Building Code.