The new State Highway 25A Kopu-Hikuai bridge is another step closer to completion with the precast concrete side barriers now in place and further work to connect the bridge deck to solid ground at the abutments completed, says Waka Kotahi New Zealand Transport Agency.
The bridge is being constructed to plug a 124-metre-wide expanse that was created after Auckland Anniversary Day flooding was the catalyst for a section of the highway to be washed away, closing a main arterial route to the eastern seaboard.
Construction began in June after the Government committed to fund Waka Kotahi an initial cost estimate of $30-40 million in May, which was later revised to be closer to $50 million.
The announcement of an unexpected early completion date on or around December 20 has boosted optimism of an economic recovery in the Coromandel just in time for the busy summer period.
Providing a full update on the week’s work at the Taparahi site, Waka Kotahi highlighted work being done on the bridge’s deck:
“Last week the team lifted and placed 44 barriers along each side of the bridge deck. At the eastern abutment, the team poured the concrete for the expansion joint and knock-off block.
“Soil nailing of the slip face above the bridge continues with night work as well to speed up progress. Drainage installation under the bridge and at the western abutment is under way.
“The team also completed the pavement layers for the new road at the eastern approach. These are the crushed rock layers that will be sealed with a layer of asphalt.
“This week, the team will set up the reinforcement and do the concrete pours, which connect the barriers to the bridge deck and form and pour the expansion joint and knock off block at the western abutment. They will also start reinstatement of the road at the western approach.
“Asphalt, road marking and barriers will be completed over the next few weeks ahead of the bridge opening.”
While there has been a huge focus on the new bridge, Waka Kotahi said other teams have been working along SH25A itself.
“This work will ensure the highway is in good condition, safe and more resilient ahead of its reopening by Wednesday, December 20. Getting the repairs and maintenance work done now means we limit the impact and disruption our activities have on the road users once the road reopens.”
By the time the road is reopened the following will have been done:
23 culverts replaced
11.5km of side drains with kerb and channel and riprap drains
Seven bridges strengthened
6.6km of new seal
New centre lines, edge lines and edge marker posts were installed along the 28.2km highway.
Maintenance work on seven bridges along SH25A includes a new technique for strengthening bridges with a high-tech tape “glued” to the underside of the bridge decks (shown above).
Alongside work to repair cracks in the concrete and repaint steel girders, the fibre-reinforced polymer tape is being applied with high-strength adhesive.
The tape is a comparatively new technology being used more widely as part of bridge repair and strengthening work across the country.
Scaffolding is in place at each of the bridges so workers can carry out other maintenance work to the underside of each bridge.