SA’s first major concrete roadway to deliver big lifetime savings

One of South Australia’s newest pieces of major road infrastructure will also be its first to feature a concrete pavement.

Currently under construction by Lendlease Engineering, the $885 million Northern Connector is a six-lane, 15.5 kilometre motorway that will provide a vital freight and commuter link between the Northern Expressway, South Road Superway and Port River Expressway, delivering a non-stop journey of 43km between Gawler and Regency Park.

Approximately 13 kilometres of the new roadway will be finished with a Plain Concrete Pavement (PCP). 

Project Manager, George Panagopoulos, says concrete was chosen by the Department of Planning, Transport & Infrastructure for the project because it promised a long life and low maintenance solution. 

“The concrete pavement has a slightly higher initial capital cost but is expected to offer increased durability and almost halve the ongoing maintenance costs” he says. 

“In fact, the whole-of-life cost saving is approximately 42 per cent in comparison to a standard asphalt pavement.” 

The decision to go with a concrete solution has also been influenced by promised social and economic returns for the state of South Australia. 

Local content in the construction of the concrete pavement is estimated to be approximately 90 per cent, with the cement and quarry materials being sourced from local businesses. Cement and ground granulated blast furnace slag will be sourced from Adelaide Brighton, reinforcing steel and billet from Liberty OneSteel and quarry products from Southern Quarries and Clinton Sands. 

More than 40 extra jobs have also been created and an additional $11 million injected into the South Australian economy as a result of choosing a concrete pavement. 

With the PCP solution being used for the first time on a major SA road project, there’s also been a welcome transfer of new skills into the local workforce. 

Four of the 19-member concrete paving crew have been brought across from the eastern states, where they worked on the concrete-paved Pacific Highway, to help train up the locals. 

“It means when the next PCP opportunity comes around in South Australia, we’ll have those skills here on the ground,” Mr Panagopoulos says. 

The Northern Connector concrete pavement is being constructed in two layers. A 150mm-thick, low-strength, 5MPa sub-base is first laid on top of the compacted road base, acting as a levelling layer for the subsequent layer. Another 270mm of high-strength 35Mpa plain concrete is then laid as the trafficable pavement layer. Grooves, known as Low Noise Diamond Grooving (LNDG), are cut into the surface along the entire length of the travel lanes to reduce vehicle noise.                                                                                                                   

An onsite batch plant located at Waterloo Corner is supplying the approximately 175,000 cubic metres of concrete needed for the concrete pavement, and with almost half of the pavement laid, the project is well on track for completion at the end of this year. 

The Northern Connector Project is jointly funded, with the Federal Government committing $708 million to the project, and the South Australian Government contributing the remaining $177 million.