Image: Wilson Portland Cement Works, Warkworth, Rodney County [ca 1910].
Concrete has been a cornerstone of our construction industry for more than 150 years. Its early adoption followed the opening of the Warkworth Cement Works in the 1880s, leading to the manufacture of high-quality local Portland cement and, eventually, nationwide use in infrastructure projects such as the Skippers Canyon Bridge, built in 1901. By Alan Titchall.
The first recorded delivery of cement that was imported here was around 1840, at the same time as the British were sealing the country’s fate as one of its colonies.
Concrete became a building feature in colonial days and included the 1859 concrete piers for a bridge near New Plymouth, and the 1883 Addington Water Tower in Christchurch.
By 1885, Nathaniel Wilson had set up a factory in Warkworth that produced the first Portland cement in the Southern Hemisphere (see separate story).
While timber was the primary construction material in the initial infrastructure build of our country, the need for sturdy structures (wood is susceptible to fire), led to the gradual adoption of concrete. This trend accelerated in the late 19th century with a massive public works programme that also led to major plant expansions at the Warkworth Portland cement factory in the 1890s.
By the early 20th century (1904), we started using American-made rotary kilns, which revolutionised cement production. This same period saw the use of moulded concrete blocks as a cheap alternative to brick, allowing for fast, durable construction, while the 1910s and 1920s saw early developments in precast technology, such as the 1911 Ora Tonu patent.
Translated as “alive still” this involved a reinforced hollow-wall concrete construction method developed by James Annand and is linked to heritage assessments in Dunedin.
Before WW2, Firth Concrete, still producing ready-mix concrete under its certified brand, started making a large range of concrete masonry, paving, segmental retaining walls and brick veneers. Large-scale concrete block production in 1938 became popular in making industrial buildings. Following World War II, concrete also became increasingly popular for homes, especially in the 1950s.
The NZ Prestressed Concrete Institute was incorporated in 1964, later becoming the NZ Concrete Society and now Concrete NZ (one of Contractormagazine’s owners) headed by its longstanding CEO, Rob Gaimster.
Concrete technology has also evolved (read the article on the transition to low-carbon concrete (LCC) by Tim Kleier from Concrete NZ.
In November 2013, Atlas Concrete made the largest single mass pour of concrete here in one day, when some 2746 cubic meters was poured over 16 hours from 60 trucks supplied by three companies into five pumps at Refining NZ’s [now Channel Infrastructure] Marsden Point Oil Refinery.
Concrete has built the nation’s infrastructure and, today, using local materials, is specially formulated for high seismic activity and durability. It often features higher MPa ratings for structural integrity and is tailored for local conditions and specific standards (like seismic)
NZS 3104 (production) and NZS 3109 (construction).
Our local concrete often includes pozzolans to reduce alkali-aggregate expansion, while common strengths include 20 MPa (paths) up to 30 MPa or higher for structural walls. Common finishes, such as U3, U4, and U11, are standard in NZ to meet tough surface requirements, and additives are often used to control setting in varied temperatures.
Major concrete manufacturers in NZ include Atlas Concrete, Holcim NZ and Firth Industries, who produce ready-mix, precast, and specialised low-carbon concrete products for civil infrastructure projects across the country.
The founder of our Portland cement
The founder of our cement industry, Nathaniel Wilson (1836–1919), emigrated from Glasgow with his family and two brothers to New Zealand when he was six years old.
He initially trained as a shoemaker, and in 1864, he purchased a small piece of land adjacent to his parents’ block south of Warkworth village, north of Auckland.
Nearby the site, John Southgate had been making lime since 1851 and had been burning local limestone in a kiln. Nathaniel realised he also had a limestone resource on his land and built his own lime kiln in 1866 to make Roche lime, used in plaster and mortar.
Twenty years later, he took an interest in Portland cement after reading Henry Reid’s book Science and Art of the Manufacture of Portland Cement, and, after experimenting, he and his brothers, John and James, began trading as J.Wilson and Company, which was the first commercially manufactured Portland cement in the Southern Hemisphere.
The quality variability of the local limestone was overcome by adding shells collected from the Mahurangi River and later from Clevedon, while the coke supplied by Auckland Gas Company also caused problems, and for a short period, the company manufactured its own coke using Westport coal.
Our first cement concrete supplier was not, at first, embraced by the authorities, who preferred imported cement. Then the intensive, late 19th-century public works programme dramatically increased the demand for cement. By 1893, the factory was adding major additions to its plant.
Production was increased by using the latest in international concrete technology gained by Nathaniel’s engineer son, William during a trip to the US in 1898. That trip saw rotary kilns and ball and tube grinding mills installed at Warkworth, pushing annual production from 1524 tonnes to 7620 tonnes between 1897 and 1902. Production rose to over 20,000 tons with further expansion in 1903. By 1910, 180 staff were employed at the Mahurangi works.
Around this time, other companies set up cement works at Whangarei Harbour’s Limestone Island and at Milburn near Dunedin.
The ready availability of Portland cement from the beginning of the 20th century saw the quick development of durable structures and port facilities, particularly in Auckland. Projects benefiting from Wilson’s cement included the Rangitoto Beacon, Grafton Bridge and Queens Wharf, as well as Rotorua’s Bath House and Napier’s breakwater.
By 1918, the company had been amalgamated with the NZ Portland Cement Company at Limestone Island, where most of the cement was now produced, while the Mahurangi works focused on hydrated lime.
The Mahurangi works closed in 1929, three decades after Nathaniel Wilson had experimented with the new Portland cement, and the remaining machinery was transferred to Portland near Whangarei.
Handing over the baton