Six-to-eight months away from the opening of the Mackays to Peka Peka (M2PP) section of the Kāpiti Expressway - one of eight sections of the Wellington Northern Corridor. The M2PP Alliance (which comprises the NZ Transport Agency, The Fletcher Construction Company Ltd, Beca Ltd and Higgins Contractors Ltd) and key suppliers such as Firth continue to work at a high pace to bring the project in ahead of the initial opening date of mid-2017. More than two years ago Firth upgraded two of its plants at Ōtaki and Kāpiti in readiness for the high volumes of concrete required for the project - and they have been busy ever since.
“The ground improvement and piling work at M2PP is done now but the Alliance is keeping us very busy, which we are certainly not complaining about,” says Alistair Bennett, National Technical / Materials Engineer for Firth. “It hasn't slowed up at all as we continue to supply a variety of concrete mixes for beams, bridge decks, barriers and panels.”
The $630 million project will deliver 18km of four-lane expressway through Paraparaumu and Waikanae, including a new bridge over the Waikanae River. The new route will improve safety, reduce congestion and provide more reliable journey times into and through the Kāpiti Coast.
As the project has progressed Firth has received more and more requests for special, tailor-made mixes to assist with various requirements on site.
“Key structural elements have a considerable amount of steel reinforcing in them,” explains Alistair. “If you stand side on to some of the reinforcing cages it can be difficult to see daylight coming through them. This is driving requests for much higher workability in the mixes without compromising on strength or shrinkage.”
“The team at Firth has come along for the ride with us on this project,” says John Palm, Project Manager for the Alliance. “The design specifications are a new standard on this project and are based on a 1 in 2500 year seismic event. This has created huge challenges for ourselves and Firth with the amount of steel required in the structures. They have adapted their mixes to be more workable and are doing a good job in keeping up with the changes.”
Firth has also created low heat hydration mixes, high quality surface finishes, sprayed concrete, and decorative panels to add to the variety of products required on site. Appointing a Project Coordinator, Pete Bevan, has helped to bridge the gap between M2PP site engineers and Firth production staff. “The testing requirements throughout the job have been very extensive,” says Ian Morby, Area Operations / Sales Manager (Wellington) for Firth. “Every load of the 43,000 m3 already supplied has been slump tested on site before placing.”
“Having one contact from Firth for communication has also been extremely helpful,” adds John. “This has made a big difference and we are really pleased with how everything is working.”
The demand for concrete will start winding down over the coming months as the individual structures are completed, on track for opening the expressway ahead of schedule.
To view a flyover video of the expressway click here.
Project Details
Principal: New Zealand Transport Agency
Customer: M2PP Alliance
Location: McKays to Peka Peka, Kapiti Coast
Product: Firth Certified® Concrete
