Three million square metre milestone

There’s a great story behind this awesome achievement. It tells of people with vision who recognized the potential of this ground-breaking approach, clients who had the faith to run with it, staff who had the talent to implement it – and industry partners who had the enthusiasm to share and contribute to the journey. Underpinning the whole achievement has been a company commitment to continual innovation that has seen PT slabs adapt to constantly changing times.

The story

The story of Contech and PT slabs began in the mid-1960s, when the company’s founders, Rob Irwin and Rob Robinson, heard about and saw the benefits of PT slabs and introduced them to the market for specialist applications. Back then, most buildings were constructed with conventional reinforced concrete slabs and regular construction joints.

About 30 years later – when the use of PT slabs was still in its infancy – Paul Wymer and then Jeff Marchant joined the team, with the latter particularly interested in producing PT slab designs using traditional design chart methods. At the time, the commercial building market was starting to look for higher quality warehouse slabs, so Paul and Jeff worked together to streamline the design and construction process with the aim of delivering high performance slabs. The pair developed flowcharts in-house to document the overall design process, then Jeff converted the charts into an automated, and therefore faster, design process. This in turn enabled the development of alternative slab layouts.

2002 signalled a major step forward when a client, Progressive Enterprises (now Woolworths New Zealand), commissioned Contech and Allied Concrete to deliver a full delivery flooring project for a distribution centre (DC). The two companies recognized the need for a new model that ensured the delivery of premium quality floors with certainty of performance and a single point of responsibility.

Together they designed and delivered a high performing, high quality DC that turned out to be the springboard for further PT floor projects at scale.

Word quickly spread about the advantages and results of the new delivery model – and this in turn led to a rapid increase in the number of PT floors delivered each year. Allied Concrete established a specialist flooring contractor – Conslab – to focus on delivering projects, while Jeff kept developing and refining the design process and integrating more elements with the Contech in-house software.

These included:

• building-consent submissions
• CAD drawings
• job costings
• racking and forklift designs
• tendon/joint locations, so that manufacturers of perimeter-wall panels could proceed seamlessly ahead of the physical building-construction program.

Other innovations included the introduction of couplers to minimize the number of movement joints in large floors. Couplers are still in use today, while a range of processes and products have been enhanced to allow the analysis of more complicated floor layouts and loading applications.

Derek Bilby, CEO of Contech, is quick to point out that the success and overall development of PT floors by Contech and the wider New Zealand construction market could only have been made possible through the collective effort of the wider Contech team.

“They included our founding employees, technical material experts, BBR VT International anchorage and component experts, design engineers, project engineers, regional managers, supervisors and field operatives. Without their insights, efforts and commitment, we wouldn’t have evolved to where we are today.”

He also acknowledges the Conslab team, who work closely with Contech in designing, configuring and constructing PT floors that meet building owners’ requirements for quality and performance. “Conslab has been involved in about half of our projects since 2000,” says Derek. “We consider them an invaluable part of the team.”

 

The highlights

So far, Contech has installed PT floors in about 420 building projects, with the largest to date – and the largest floor slab ever produced in New Zealand in a single project – being a 74,000m2 floor for a brand new Foodstuffs Distribution Centre.

About a third of all the PT floors are in buildings with floor areas ranging from 15,000m2 to 74,000m2. That’s in stark contrast to one of the earliest PT floors of just 2,000m2, which was installed in 1983 to create a roller-skating rink in Auckland for commercial builder Haydn & Rollett – who, incidentally, is still one of Contech’s key customers.

The future

Just as it has always done, Contech is looking to and preparing for the future, particularly in terms of New Zealand’s path to a low-emission, climate-resilient future.

The New Zealand Government has committed to zero carbon emissions by 2050 and Contech – along with its colleagues in the wider building sector – is exploring all options to help achieve that goal. Areas of particular focus include:

• increasing the efficiency of the material used in buildings
• reducing the impacts of buildings’ structural elements
• reducing whole-of-life carbon footprints
• improving buildings’ ability to withstand climate-change events
• improving the building lifecycle – from buildings’ placement to their design and construction and considerations for their re-use and ultimate disposal
• reducing emissions that result from repairing and replacing building elements damaged in earthquakes – this includes balancing the carbon cost of seismic repairs, refurbishment work and seismic strengthening with doing nothing or building new
• ensuring that design solutions are both resilient and materially efficient, while exploiting opportunities to reduce the whole-of-life embodied carbon in buildings in New Zealand.

Given Contech’s success with post-tensioning and the technique’s many and considerable advantages over more traditional methods – especially its potential in helping New Zealand to meet its zero-carbon goal – the company’s commitment to innovation will continue. Watch this space!