As part of a $16 million upgrade to Emerald Airport, Boral delivered Australia’s first stone mastic asphalt runway - an innovation set to redefine durability and cost-efficiency in regional aviation infrastructure. The use of stone mastic asphalt allows the upgrade to last five-plus years longer than usual runway surfaces and forecast to provide significant savings for Central Highlands Regional Council.
The project involved resurfacing the main runway, taxiways, and apron bays, reconstructing the general and eastern aviation aprons and refuelling area, and expanding the general aviation apron while maintaining live airport operations each morning.
Project Challenge
Emerald Airport had not undergone significant runway maintenance in over a decade. The existing surface had oxidised and deteriorated in the sun, with grooving exceeding two millimetres - posing safety and operational risks.
The Council needed a long-term solution that would reduce future maintenance costs and eliminate the need for costly grooving in the 1.9-kilometre runway surface. They also needed to ensure the runways reopened at 5.30 each morning to avoid costly fines.
“For our economy to work well, this airport has got to work really well. We need this airstrip to be in absolutely perfect condition," said Kerry Hayes, Mayor of Central Highlands Regional Council.
Boral Solution
Boral was selected for its deep expertise in stone mastic asphalt (SMA), developed through extensive road infrastructure projects. SMA’s superior rut resistance, durability, and performance in extreme temperatures due to larger aggregate and more binder made it ideal for Emerald’s climate and operational needs.
“The key strength we found with Boral is that they have huge experience in laying stone mastic asphalt across the state on road projects," said PJ Cullican, Partner at GBA Consulting Engineers.
Working with GHD, GBA, and Dr Greg White, Boral helped develop a custom SMA mix design tailored to Emerald’s conditions. The solution met the new Australian Asphalt Pavement Association airport performance specification, including mix design, compaction, surface texture, and friction.
Boral commenced mix design production and placement trials to demonstrate the suitability of dense grade and stone mastic asphalt for the project, ensuring all stakeholders were satisfied with the product selection.
“What SMA is allowing us to do is to stretch the period between construction and that major maintenance over a decade, decade and a half into the future," added Salomon Kloppers, Manager of Emerald Airport.
Boral was selected to both supply and lay 15,000 tonnes of asphalt for the upgrade.
Team Engagement
Boral assembled a dedicated project team, engaging local subcontractors and coordinating night works to ensure the airport reopened by 5:30am daily.
“The team that we've got here have a clear understanding of what's required. The guys have been working around the clock to make sure the project’s being delivered to the highest standard,” said David Daniel, Area Manager for Boral Asphalt.
Saloman Kloppers commended how seamlessly Boral's team integrated with other project partners. “They all want it to be a success. That really helped us, especially in times when things got hard. People really pulled together and made decisions based on what's best for the project.”
Project Outcomes
The SMA runway is forecast to last significantly longer than traditional surfaces, delivering major cost savings and eliminating the need for grooving.
“We've done the maths. If we get one year extra via SMA, the additional cost to put the SMA in is already paid for," said PJ Cullican from GBA Consulting Engineers.
Emerald Airport Manager Salomon Kloppers was impressed that the project was completed on time, within budget, and to full compliance with CASA MOS139 aviation standards. “We've had positive experiences with everyone involved. The compliance outcome has been amazing.”
Central Highlands Mayor Kerry Hayes agreed, "We believe that'll give us maintenance savings over a number of years.”
The upgrade works included:
- 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.
Conclusion
The Emerald Airport stone mastic asphalt runway upgrade sets a new benchmark for regional aviation infrastructure in Australia. Boral’s technical leadership, collaborative approach, and commitment to quality were instrumental in delivering this first-of-its-kind project.
“For Boral to be the first one to deliver it and deliver it well puts us in good stead to specialise in this sort of area. It's a great result for the team and for our clients," said Dean Catterall, Project Manager at Boral Asphalt.
Area Manager David Daniel added, “We're proud to be part of that. I think it's great for Central Highlands, the region, and I actually think it's great for the industry because it just brings it to the next level.”
