The production of concrete within the building industry contributes around 8% annually to global CO2 emissions. In a bid to do their bit to bring that figure down, two Hawke’s Bay companies have collaborated to develop the region’s first lower-carbon precast concrete building.
Bridgeman Concrete and Lattey Group and have created a lower-carbon precast concrete with 40% less carbon for a Hastings District Council project – a new toilet block at St Leonard’s Park in Hastings
Precast concrete is a construction product made by casting concrete in a reusable mould or ‘form’ which is then cured in a controlled environment, transported to the construction site and manoeuvred into place. Examples include precast beams, and wall panels for tilt up construction.
Mark Hook, CEO Lattey Group, a company founded in HB but now employing 120 people here and at a new 4,500m2 precast plant in Levin, says lower-carbon options is where the precast market is heading.
“Clients want to lower the carbon profile of their projects to meet their sustainability goals. It’s great that we now have a viable and independently certified low-carbon option to bring to market for precast in collaboration with Bridgeman Concrete.
“Some people give concrete a bad rap,” he adds, “but it is an incredibly versatile, adaptable, and durable product that is evolving and will continue to evolve to meet the needs of the market. We can change the components and dramatically improve carbon performance without compromising on strength, a key attribute of concrete.”
Over the past six years Bridgeman Concrete Ltd, which began in Hawke’s Bay in 1967 and has been instrumental in many large local projects including Napier and Hastings’ Hospitals and Te Whiti, the new 6 Wharf project for Napier Port, has been investigating lower-carbon concrete options to improve sustainability and make progress towards the concrete industry’s goal of zero carbon by 2050.
Steve Dighton, Business Development Manager Bridgeman Concrete says the company has made a multi-million dollar investment – including new plant – to develop EcoMax, a concrete product that has between 20% and 60% less carbon than traditional concrete.
“To date we have produced over 5,000m3 of concrete across New Zealand with at least 15% lower carbon.
“The key to EcoMax is replacing part of concrete’s usual cement component with blast furnace slag, a by-product from the steel industry, which gives us the greatest potential for carbon reduction.
“Granulated blast furnace slag is a greener choice with its high carbon sequestration ability. EcoMax can be used in any concrete application from driveways to precast, cast in situ beams to house floors, kerbing to grout mixes and satisfies concrete standards for durability.
“We’re pleased to partner with Lattey Group to develop the lower-carbon precast concrete for the Hastings District Council project,” says Dighton.
Local architect, Brent Scott of Citrus Studio, heard about the lower-carbon precast concrete and specified it for the toilet block in in Hastings.
HDC Parks Assets Manager Colin Hosford says, “Council is pleased to promote the use of carbon-reduced products to help meet its sustainability goals.”
Both Bridgeman Concrete and Lattey Group will continue with carbon reduction measures.
Mark Hook says Lattey Group will continue to experiment, developing concrete to different specifications using a range of cement substitutes, and letting customers, architects and specifiers know about the range of options available.
Steve Dighton says that specifying EcoMax is easy. “It’s about building awareness. Bridgeman will work with contractors to establish the best mix of components for the job and time of year.”
Bridgeman Concrete is currently in discussion with Hawke’s Bay companies who want to use the lower carbon precast concrete.
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