ARC customises solution for wind farm project

Meridian Energy Australia’s Mt Mercer Wind Farm is a $260 million, 64-turbine operation in western Victoria, which will generate an electrical capacity of 131 MW, enough renewable energy to power the entire city of Ballarat. The wind farm, which is currently under construction, is expected to result in a reduction of more than 400,000 tonnes of carbon dioxide emissions per annum.

In September 2012, Meridian Energy awarded Downer EDI a $70 million contract for the engineering works on the project, which involves the design and construction of the electrical and civil works, including the wind farm substation, 33 kV collector system, internal road network, crane hardstands and wind turbine foundations.

ARC’s (The Australian Reinforcement Company) Rollmax product - a one-directional mat of prefabricated reinforcement - was identified as suitable for wind farm constructions. However, it was specified that there should be no direct welding to the foundations of the wind farm, which was how the reinforcement had always previously been installed.

Lance Cupido, project prefabrication manager at ARC, explains that ARC engineers created a customised solution, known as Rollmax Clipped Bar, where the reinforcing bars were connected using a retaining clip instead of being welded together.

“This was 100% unique to this project, but we now expect the clipped version to be used on wind farm developments in the future,” said Cupido.

“It is particularly useful when applied to fatigue-prone developments. It also ensures that the bars are firmly gripped and retained through the use of clips supple enough to allow simple rolling of the mats.”

Cupido says that Rollmax is manufactured to suit the requirements of each job. It can be rolled in multiple layers and directions, with each roll providing the reinforcement required for a particular layer.

“We estimate that time and labour savings of up to 80% have been achieved compared to laying loose bars on this application. Other benefits have included up to 25% saving on material required, less crane time, faster overall building time, higher accuracy positioning the bars, less potential for placement errors, less susceptibility to weather delays and health and safety benefits,” said Cupido.

Once on site, the product was lifted from trailers into place using a crane, before being rolled out by hand. The products were supplied with a positioning system with two lifting slings, which are placed on the roll for a balanced fit. The lifting slings are used to lift the product directly into position on the slab.