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The Press OpEd

30 Mar 2011

Concrete Experts Eager to Help

Rob Gaimster
Cement & Concrete Association of New Zealand (CCANZ)

The Press (Christchurch) Wednesday 30 March 2011

With the myriad lessons of the Christchurch earthquake yet to be fully assessed, it has been somewhat disturbing to see opinions rushed into print that pointlessly pitch one building material against another or that ignore the realities of 21st-century building technology.

The position held by the Cement and Concrete Association of New Zealand (CCANZ) on matters related to the Christchurch earthquake is that we will pull out all the stops in support of the Royal Commission appointed by Prime Minister John Key.

This assistance might include providing expert concrete-related information and supporting any possible assessment of the seismic performance of buildings.

We will make further announcements, as appropriate and in a timely way, about specific steps we can contribute to addressing technical and structural engineering questions that must be answered.

During these necessary phases of investigation, CCANZ does not believe it is useful to speculate about what a conceptual city made of timber would be like, any more than it would be to speculate about what an entire city made only of concrete would be like.

Such speculation ignores the fact that both timber and concrete building materials are integral components of almost all building projects.

Providing opinions on matters that are outside your area of expertise will always put the opinion-giver on less than solid ground.

We wonder if Jim Anderton in his recent contribution to The Press really meant to suggest New York's Twin Towers would have fared better if they had, impossibly, been a wholly wooden structure. We also wonder if he realises that when the historic wooden Government Buildings in Wellington he rightly praises were restored, the timber piling was replaced with concrete?

This reflects the fact that locally made concrete is the silent workhorse of New Zealand's urban development, offering a range of construction advantages such as being durable, recyclable, and fire resistant.

There is no doubt the definition of "modern" buildings will change considerably as a result of the wake-up calls that the natural disasters of Christchurch, and now Japan, have tragically delivered.

Already the New Zealand Society for Earthquake Engineering has suggested that commentators need to cease calling pre-1992 buildings "modern", given the changes in earthquake-related standards and codes made in more in recent decades and the strong likelihood of even more stringent codes.

In all of this, New Zealand is fortunate to have academic experts in both concrete and timber building materials - many of them based at Canterbury University - who, in exercising academically neutral opinions, can give real balance to the arguments about the strengths of different materials for different contexts.

Trotting out these experts to support one-sided arguments is of no help; better to allow genuinely independent expert opinions to be given equal space, and for the best of both worlds to inform each other by focusing on furthering New Zealand's reputation as a developer of world-class knowledge about world-class engineering solutions.

When the time is right, CCANZ expects that interest in precast seismic structural systems (PRESSS) will grow and a wider public debate on the merits of emerging building technologies that have originally stemmed from concrete research can take place.

The Alan MacDiarmid building on Victoria University's Kelburn campus in Wellington is a manifestation of what is known as the damage avoidance design strategy, for instance, and as New Zealand's first multi-storey PRESSS building, it will definitely be part of that next phase of determining how we build in the future.

Building technology has not advanced in the ways that it has and continues to do, with no reason or without the weight of evidence.

Nor does building technology stay static. It moves on - sometimes making huge strides between the end of one decade and the other.

Let's focus on that. And let's leave expert opinions to the full range of qualified experts.