Auckland dome almost ready to house cement

Auckland socialite Gilda Kirkpatrick has called it a "giant white boob", but the large white dome on the Auckland waterfront is almost ready to house thousands of tonnes of cement.

The comparison to a giant breast should be taken as positive, says Holcim project manager Derek Williams, who has overseen the construction of the 28m-high dome at Ports of Auckland and a similar 33m-high dome at Timaru's port.

The two projects are costing $100 million, of which the Auckland dome is about $60 million.

"We are quite proud of it," Mr Williams said during a tour of the site and visit inside the dome opposite Vector Arena.

The dome is due to be commissioned next month when it is sealed to take 30,000 tonnes of cement sitting on two sloping floors, fitted with an aerated floor to ease the flow to two outlets.

From the outlets the cement is pumped to a 300-tonne bin for collection and distribution by tankers.

"It is quite a simple process. Everything is enclosed, pneumatically and by pipes," Mr Williams.

Since the 2mm polyurethane skin was inflated in August last year, it has been sprayed with an insulating foam and reinforced with 500 tonnes of steel and 1100cu m shortcrete, or sprayed concrete, to a thickness of about 600mm.

Mr Williams said the dome technology has a lot of advantages over conventional silos, including a small footprint and height, a relatively short construction time and high environmental standards.

Until now, Holcim has shipped cement to Onehunga. That will end when the new Auckland silo is commissioned.

The Auckland Dome

• $60 million cement dome being built on waterfront
• 28m high
• Inflated skin strengthened with steel and concrete
• 30,000 tonne capacity
• Due to be commissioned next month