Quality systems for ready mixed concrete plants


The recently released National Construction Pipeline Report 2016 paints a bright picture for the New Zealand building industry across the duration of its forecast period to 2021.

Auckland residential building is projected to increase by another $3.3 billion by 2017, while Waikato and the Bay of Plenty are predicted to soon become the second largest region by value of work.

With such a period of intense construction anticipated across residential, commercial and civil sectors over the coming years, it is crucial that building products can be relied upon.


Quality issues

The issue of quality building products has been topical recently, attracting a degree of media attention. Along with a focus on plumbing fittings and glass balustrades, seismic grade steel reinforcing mesh has been in the spotlight.

These current concerns, along with the shadow of leaky buildings, demand that issues of product performance be addressed to ensure confidence amongst architects, designers, engineers, builders and their clients.


Audited ready mixed concrete

New Zealand consumers of ready mixed concrete can take comfort in the knowledge that concrete produced and supplied by a plant certified under the New Zealand Ready Mixed Concrete Association (NZRMCA) Plant Audit Scheme meets robust standards.

The NZRMCA was formed over half a century ago in 1963, and continues to grow in size. Today, 44 member companies now control around 180 ready mixed concrete plants throughout New Zealand.

Quality monitoring was the prime reason for the formation of the NZRMCA and, in turn, the creation of the audit scheme.

The scheme operates to audit NZRMCA members’ ready mixed concrete plants, as defined in New Zealand Standard NZS 3104 Specification for Concrete Production.

The scheme provides a rigorous audit of the quality systems in place at a ready mixed concrete plant. Audits are carried out by the Plant Audit Committee — a group of experienced engineers, which includes representatives from IPENZ and the New Zealand Concrete Society.

The scheme operates under an assurance programme certified to ISO 9001 and audited by Bureau Veritas Quality International.


What the scheme requires

Compliance with NZS 3104 and the relevant parts of related documents is mandatory under the scheme, along with an appropriately qualified concrete tester at each plant, as well as a suitably qualified plant engineer.

Records must be properly maintained, with original copies retained on-site to provide an audit trail confirming the test records analysed are correct and complete.


Specific benchmarks audited

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 mean concrete strengths, aggregate quality, equipment calibration, production and testing record keeping, as well as technician training.

In addition to the benchmarks audited, the frequency of testing within each quarter year must be submitted to the committee. Failure to maintain testing requirements can result in the withdrawal of an audit certificate.

Audit certificates are issued for a period not exceeding 12 months. Where plants fail to meet the criteria, their audit certificate is removed.

When using ready mixed concrete from plants outside of the scheme, remember the purchaser is responsible for ensuring the product supplied complies with NZS 3104 in accordance with the New Zealand Building Code.

A full list of audited plants is available on the scheme’s web site at www.rmcplantaudit.org.nz.


Confidence in the future

The independently verified scheme for ready mixed concrete demonstrates an ongoing commitment to maintain product performance.

With record volumes of concrete currently going out of the gate, this offers a great deal of assurance if, as the National Construction Pipeline Report 2016 predicts, national construction value sustains a rate of growth forecast to peak at $37 billion in 2017 — a level not seen in 40 years.