Costly repairs for motorway

A section of Ramp 4 on the Great North Rd Interchange. Photo / Dean Purcell

Remedial work on Waterview ramp to fix faulty concrete will start later this year.

Investigations are being carried out into weak, substandard, faulty Firth concrete supplied to the $1.4 billion Waterview Connection.

The Well-Connected Alliance building Waterview and the NZ Transport Agency, which will own it, are involved in the work.

A spokeswoman yesterday said: "The NZ Transport Agency and the other organisations in the Well-Connected Alliance are still investigating what repairs will be needed, and how they will be carried out."

This week, Brett Gliddon, the agency's highway manager for Auckland and Northland, said part of the work already completed would be demolished.

"On-site investigations confirm a section of Ramp 4 on the Great North Rd Interchange will have to be repaired. Some retaining walls, footpaths and crash barriers have also been affected," Mr Gliddon said.

The spokeswoman said work on Ramp 4 was ongoing.

"It is likely that construction on Ramp 4 will continue as planned, and then repairs to the affected portion of the ramp will be carried out later this year. The cost of repairs has not yet been finalised," she said.

A whistle-blowing contractor working on Waterview estimated it would take a month to demolish the work. The contractor said repairs probably would not hold up the huge tunnel and motorway interchange job.

"But I'm guessing it would take a month so it's going to cost someone a lot of money," he said, referring to Ramp 4 retaining walls, footpaths and crash barriers.

The worker said a concrete beam also contained weak concrete.

"It's a very, very big structural beam across Ramp 4 and almost holding the whole bridge up. That has to be demolished."

None of the companies involved in the issue front-footed it by revealing how Firth had made then sold the faulty concrete. The worker said the concrete was less than half the strength it should have been.

Questions were put to Fletcher Building, which owns Firth, about these claims, but they were not directly answered by the company.

John Dakin, chief executive of Goodman Property Trust, which is in a joint venture with Fletcher Construction on the new office precinct off Fanshawe St, said the building alongside Fonterra was affected, not the dairy giant's new offices.

The partially built office block affected is named VXV3 until it is leased with naming rights - probably to a major tenant.

Weak concrete

• $1.4 billion Waterview Connection

• $200 million Auckland University science building

• $42 million VXV3 Wynyard Quarter office block

• 35 clients were supplied with substandard concrete to 70 sites

Sources: Transport Agency, Auckland University, Goodman Property Trust, Fletcher Building