The Ports Authority has been working with Beca International Consultants, McConnell Dowell Constructors and independent engineers to review cracking at the redeveloped wharf.
Bim Tou, General Manager of the Ports Authority, said the engineers have confirmed the cracking is secondary surface cracking, meaning the overall structural integrity of the wharf is not in doubt.
The cracking is less severe than first estimated, with the average width of cracks just 0.2mm, he said.
“However, the independent engineers have advised that it is prudent to carry out sealing to provide additional protection against the penetration of moisture in this environment which could lead to premature corrosion of the reinforcing steel.”
There are a number of products and techniques available to seal the cracks and the Authority is working to identify the best proposal.
Test sections of the wharf will be subjected to crack filling and sealing processes over the coming months.
Tou said he had previously hoped the concrete slab would require minimal maintenance for a number of years.
“We realise that, in the same way we had a programme of inspection and repair of the old wharf surface, we will have to carry out ongoing routine inspection and maintenance on this surface.
The good news is that the experts are offering a range of solutions that should make sure we get the expected design life out of the Avatiu Wharf apron.”
A number of causes, which may have operated individually or together, have led to this surface cracking, he said.
The new wharf was opened last April after a 17-month upgrade project, which cost $27 million.