News
Certified Concrete – New IRD Premises, Wellington
Size meets sustainability
One Featherston Development, located on the corner of Featherston and Bunny Street, Wellington is set to become the largest commercial office building in New Zealand with a massive floor plate of 3,200m². Built by Fletcher Construction and to be tenanted by the IRD and two other Government tenants, it will consist of retail and service spaces on one level, two levels of car parks and 12 levels of office space. It is being constructed of a precast concrete structure with a substantial concrete shear core at the centre.
Firth’s Wellington Area Manager, Cameron Lee says, “The completed structure has about 14,000m3 of concrete in total, with the piling and footings soaking up some 3,000m3. Some of the piles had to be drilled up to 42m deep as the area sits across the road from the harbour front and is all reclaimed land.”
A special concrete mix was required for the shear walls in the initial floors. It contains a large amount of Fly-ash to reduce the heat of hydration. Firth continues to monitor the heat build-up of the walls over time.
However the scale of the building hasn’t compromised the commitment to green building practices. The tremendous durability of concrete and significant energy savings due to thermal mass were just part of the puzzle. An air conditioning system that incorporates chilled beams and infusers on all office levels and adoption of waste management procedures during construction that achieve at least a 50% waste recycling target, have all contributed to Fletcher Construction targeting a 5 star rating from the NZ Green Building Council.
"Working in this building will contribute significantly towards our sustainability goals as we strive for carbon neutrality in 2012", said Inland Revenue Acting Deputy Commissioner Business Development and Systems, Mary Craig.
The project is not expected to be complete until September 2010, but the concrete structure was completed late 2009.
Certified Concrete - Kopu Bridge
Are we there yet?
We might not be quite ‘there yet’ but at least the journey to replace the Kopu Bridge has begun. Many visitors to the area will have faced the long tail back at the Kopu Bridge over Xmas and although these holidays will not see much change, what people will see is real evidence that work on the bridge is underway.
Construction began in July 2009 to replace the old one-lane bridge with a new two-lane version. However the bridge project also includes 2.5 kilometres of approach roads, including a new link road to State Highway 26 east of the bridge and a four-leg roundabout at the junction of SH25 and SH26.
Progress has been good and this Xmas holidaymakers will see work beginning on the actual bridge structure. Says Karl Campbell, Chief Operating officer – Firth Central Region, ‘We won the contract to supply approximately 6,000m³ of concrete over the next two years for piling, sub structures, superstructure and the bridge decks. Some of the mixes we will be supplying to the job will contain microsilica 600.”
For those unfamiliar with microsilica 600 it is a technology that facilitates high performance in concrete by promoting; increased compressive strength, reduced water permeability and improved abrasion resistance. All vital in a semi-marine environment.
Firth Thames is looking forward to the challenges that supplying this significant project will bring. Already they are making production improvements at the plant to cope with the extra demand. The new bridge will meet modern safety and structural standards and will be an essential link for emergency services. But for visitors the increased traffic capacity and an end to long delays, is the best news.
Currently the new Kopu Bridge is on target to be completed by mid 2012.
Manukau Bridge - Standing the test of time
Contracted to provide approximately 25,000m³ of concrete on the Manukau Harbour Crossing (MHX), Firth Industries has been faced with a series of mix design and supply challenges.
The existing Manukau Harbour crossing is a key motorway bridge connecting Auckland with Manukau City. Built in 1984 it regularly becomes congested at peak times. A duplicate bridge is being built to the east of the existing bridge to accommodate, in conjunction with the original bridge, four traffic lanes and a shoulder lane.
“With the design life of the new bridge set at 100 years there’s been a lot of engineering input required for this project,” says Rob McKinnon, Materials Manager Firth Northern.
The key to future proofing is to provide a dense enough concrete to withstand penetration from chlorides so they cannot rust the reinforcing steel inside. The size of the concrete sections being poured and the saline environment has also meant the mixes on this project have needed to be more complex than they would usually be.
To mitigate cracking and enhance durability, the design of specific mixes was required to slow the onset of heat from hydration. Much of the concrete is temperature-match cured at Firth’s lab to ensure accuracy and confidence in the concrete strength.
Currently most of the substructure (piles and columns) and a large portion of the superstructure are complete with over 15,000m³ of concrete having been poured so far. 8,000 to 10,000m³ of concrete is required to finish the project, the completion date being estimated to be early 2011.
New stand on target for World Cup
The 2011 Rugby World Cup and 2015 Cricket World Cup were catalysts for replacement of the three old eastern stands at AMI’s Stadium in Christchurch. These stands had come to the end of their structural life and construction of the new stand began in July 2008.
The new Deans stand (named in honour of the Deans family that has had connections with Canterbury rugby for more than 100 years) will seat 14,700 and will increase the permanent capacity of AMI Stadium from 36,000 up to a new capacity of 43,000.
Progress has been very good on the project with all the foundations and the first tier of four levels almost complete. The new roof of the Dean’s stand will be larger than the other main stand in the stadium, extending right to the edge of the seating, creating a fully covered-in stand for fans.
“We are about to commence work on the stands roof structure, with the first rafters going up this week,” said Gordon Murdoch, Project Manager, Fletcher Construction.
“Everything is running to schedule, which is a good sign,” said Adrian Jonkers, South Island Manager, Fletcher Construction.
“We have supplied some 6,000m³ spread between Fletcher Construction and their various subcontractors,” said Dominic Sutton, Area Manager Canterbury/West Coast.
The targeted date for completion of the Deans stand is set for January 2010. The new stand may even see a few international cricket games before the 2011 Rugby World Cup games begin.
Big News for Firth!
On Tuesday 3rd March Firth took possession of the masonry manufacturing assets of W Stevenson and Sons Ltd in Auckland and Whangarei. This is the largest acquisition Firth has been involved in since Fletcher Challenge bought Winstone Ltd in 1988.
“In mid February the Commerce Commission finally gave us clearance to purchase the masonry divisions of W Stevenson & Son in Whangarei and Drury,” said David Peterson, General Manager Firth. “Forty-three permanent and fixed term staff from both locations, have joined our company. It has been a difficult and uncertain time for these people over the past few months and we welcome them into the Firth family.”
“Acquisitions remain a key focus for Firth,” added David. “Our aim is for our company to continue to position itself for the future and to grow.”