Boral constructed Australia's first stone mastic asphalt runway as part of a $16 million upgrade of Emerald Airport's facilities.
 

The Emerald Airport Upgrade involved resurfacing the main runway, taxiway and apron bays, reconstructing the general and eastern aviation aprons and refuelling area, and expanding the general aviation apron. The works were primarily performed at night to enable the airport to return to live operations from 5.30am each day. 

Australia's first stone mastic asphalt runway is expected to last five-plus years longer than usual runway surfaces and forecast to provide significant savings for Central Highlands Regional Council, the airport owner, in future maintenance costs due to the longer lifespan. Using stone mastic asphalt also eliminated the need to cut costly grooves in the 1.9-kilometre runway surface. 

Stone mastic asphalt – containing larger aggregate and more binder – provides very good rut resistance properties, superior durability and performs well in hot and cold weather, which were key considerations for Emerald Airport's operators.

Boral was selected for the Emerald Airport Upgrade due to our operational and technical expertise developed through our extensive use of stone mastic asphalt in road projects. Boral's stone mastic asphalt was produced and placed meeting the new Australian Asphalt Pavement Association airport performance specification requirements including asphalt mix design performance characteristics, geometrics, compaction, surface texture and friction survey.

The mix design production and placement trials in early October demonstrated the suitability of dense grade and stone mastic asphalt. Under a short project timeline and stringent deliverables, the project team maintained high safety and quality standards that met the expectation of the stakeholders. The main runway works were completed in early 2020.

The works involved:

  • Removal of unsuitable subgrade material and rock blanket replacement.
  • Deep asphalt patches in the runway and apron parking area.
  • Surface milling the apron parking area, providing a dense-graded variable thickness corrector and the final surface layer on the same night.
  • Runway dense graded asphalt at variable thickness surface corrector
  • Stone mastic asphalt 14mm final surfacing layer thickness ranging from 45mm to 60mm.
  • Removal and replacement of the airport ground lighting.
  • Construction of the flanking material.
  • Fuel-resistant membrane.
  • Temporary and permanent line marking of the apron and runway.
  • Developing an overall design to satisfy CASA MOS139 National Aviation Standards as part of the upgraded design and construct contract.