Soil Stabilisation for Unsealed Roads: A Practical Guide for Mining, Rural and Council Applications
Australia has approximately 500,000 kilometres of unsealed roads. They connect farms to markets, mines to processing plants, regional communities to services, and remote properties to the rest of the country. They carry everything from school buses and grain trucks to ultra-class haul trucks and oversized loads. And they are, almost universally, expensive to maintain, prone to deterioration, and a persistent source of dust, community complaints and safety risk.
Annual maintenance expenditure on Australia’s unsealed road network is estimated at approximately $1 billion. The Australian Local Government Association’s 2024 State of the Assets report identified $3.9 billion worth of unsealed roads in poor condition — with significant defects requiring repair or replacement. Federal Financial Assistance Grants to councils have declined from 1% of Commonwealth taxation revenue in 1996 to just 0.51% in 2025–26, even as the asset base councils must maintain has grown substantially. The Roads to Recovery programme has been doubled to $1 billion per year, but ALGA estimates that a $500 million annual shortfall remains simply to maintain existing local road networks at current standards.
The conventional maintenance approach — periodic grading four to six times per year, combined with cyclical gravel resheeting every seven to twenty years — does not solve the problem. It manages the symptoms. Each grading cycle temporarily restores the surface but does not prevent the underlying deterioration that necessitates the next grading. Each resheeting cycle replaces gravel that has been lost to dust, erosion and traffic degradation — only for the replacement gravel to begin the same deterioration trajectory.
Polymer soil stabilisation offers a fundamentally different approach. Rather than replacing lost material and regrading failed surfaces, it modifies the existing road material to resist the deterioration mechanisms that cause failure in the first place. This article covers how polymer stabilisation works, where it applies across mining, rural and council road networks, and the documented cost and performance benefits it delivers.
Why Unsealed Roads Fail: The Deterioration Mechanisms
Understanding why an unsealed road deteriorates is essential to understanding why stabilisation works and why conventional maintenance alone does not.
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Gravel loss (dust generation). Traffic action dislodges fine particles from the road surface. These fines become airborne as dust, representing a direct loss of road material. The fine fraction — clays, silts and fine sand — is the binding component of the wearing course. As it is lost, the remaining coarser material loses cohesion, becomes loose and begins to ravel. The road requires regrading to redistribute remaining material, and eventually resheeting when insufficient material remains to maintain the road profile.
Corrugation. Corrugation forms when traffic-induced vibration causes the surface material to migrate into periodic ridges and troughs. It is accelerated by dry conditions (low moisture reduces cohesion), high speed traffic (greater dynamic forces), poor compaction (loose material moves more easily) and inappropriate material (insufficient binder fraction). Corrugation reduces ride quality, increases vehicle maintenance costs and prompts grading intervention.
Potholing and rutting. Potholes form where localised weakness in the road surface allows traffic loading to displace material. Ruts develop where wheel paths concentrate loading without lateral distribution. Both are exacerbated by water ingress — rain that penetrates the surface weakens the underlying material, and the next heavy vehicle pass displaces the softened zone.
Wet weather failure. Unsealed roads constructed from materials with high clay content become slippery and impassable when saturated. Roads constructed from granular materials with insufficient fines may become soft and rut under traffic when wet. Either way, wet weather stand-downs and road closures are a significant productivity and safety cost — particularly for mining operations, agricultural transport during harvest, and rural communities dependent on single-access roads.
The critical observation is that all of these failure modes are driven by the same underlying deficiency: the road material lacks sufficient cohesion, water resistance and structural integrity to resist traffic loading and weather exposure over time. Grading temporarily redistributes the material but does not change its properties. Resheeting replaces the material but the replacement begins the same deterioration cycle. Only stabilisation modifies the material itself.
How Polymer Soil Stabilisation Works
GRT7000 is a clear-drying polymer emulsion that is sprayed onto or worked into the surface of an unsealed road pavement. The polymer penetrates the wearing course material and forms adhesive bonds between particles — binding fines to coarse aggregate, increasing cohesion, improving compaction and creating a tough, waterproof surface layer that resists the deterioration mechanisms described above.
The stabilisation can be applied in two ways depending on the road condition and the desired outcome. For roads in reasonable condition, GRT7000 is diluted with water, loaded into a water truck and sprayed onto the road surface. Multiple light applications build the polymer concentration in the surface layer progressively, binding the fine fraction and creating a sealed, dust-free surface. For roads requiring rehabilitation, GRT7000 is incorporated into the wearing course during a scheduled grading or resheeting operation — mixed into the material, moisture-conditioned, spread, and compacted in a single pass.
The result is a road surface with materially different properties from untreated gravel. The polymer-bound surface resists tyre shear (reducing gravel loss and dust generation), resists water penetration (reducing wet weather softening and improving all-weather access), maintains its compacted profile under traffic (reducing corrugation and potholing), and retains its fine fraction (extending the life of the wearing course between resheeting events). Critically, the treated surface maintains the natural appearance of the existing material — there is no visual distinction from a well-maintained gravel road, which is important for rural and heritage applications where aesthetic sensitivity matters.
Mining Applications: Haul Roads, Access Roads and Hardstands
In mining, GRT7000 is used to stabilise the wearing course of haul roads, access roads, hardstands and laydown areas. The benefits documented across mining applications include reduced rolling resistance (improving haul truck fuel efficiency by 3–5%), extended tyre life (25% improvement documented at treated operations), reduced grading frequency (up to 75% reduction in grader fleet requirements), and all-weather road performance (reducing wet weather stand-downs by up to 12 hours per event).
For mining operations, GRT7000 works in conjunction with GRT: Haul-Loc polymer dust suppression. While Haul-Loc addresses the immediate dust control challenge by extending the effective duration of water applications, GRT7000 addresses the structural integrity of the road itself. Together, they deliver a road surface that generates minimal dust, resists deformation under heavy loading, and maintains its profile between maintenance interventions. SMART Dosing Units automate the Haul-Loc dosing to ensure consistency across shifts.
A Deloitte cost analysis, supported by SMEC and independent estimators, concluded that while the initial cost outlay for GRT7000 was higher than conventional water-only dust suppression, the ongoing maintenance was significantly less, with equipment utilisation reduced substantially. The analysis demonstrated a break-even point that was reached quickly, with ongoing cost savings compounding over the road’s service life.
Rural and Agricultural Applications: Farm Access, Livestock Routes and Regional Roads
Rural unsealed roads connect agricultural properties to markets, processing facilities, ports and regional centres. During harvest and livestock transport seasons, these roads carry heavy truck traffic that accelerates deterioration. Dust from passing vehicles contaminates crops, fruit orchards and pastures. Corrugation and potholes damage vehicles, delay transport and create safety risks for all road users.
For agricultural properties and pastoral stations with private unsealed road networks, GRT7000 stabilisation eliminates the dust that damages crops, reduces vehicle maintenance costs from corrugated surfaces, and improves all-weather access reliability — ensuring that harvest transport and livestock movements are not delayed by road closures after rainfall.
A documented case study on a 95 km gas field access road network demonstrated the agricultural crossover benefit directly. The GRT7000-treated roads eliminated dust that was affecting neighbouring farming operations, reduced the conflict between the gas field operator and local farmers, and met the strict environmental criteria imposed by the local council. The treated roads became dust-free, waterproof and structurally sound — resolving both the operational and community issues simultaneously.
For oil and gas access roads, renewable energy project access roads, and other infrastructure access in rural areas, GRT7000 provides the same benefits: a durable, dust-free, all-weather surface that reduces ongoing maintenance and eliminates community impact from traffic-generated dust.
Council Applications: Doing More with Less on Local Road Networks
Local councils are under more financial pressure on their road networks than at any point in recent decades. The ALGA president has described councils as being caught in a ‘damage-repair-damage cycle’ where disaster damage diverts limited budgets from planned renewal and preventive maintenance, and deferred maintenance increases long-term costs. Regional councils manage thousands of kilometres of unsealed roads on rate bases that cannot fund the conventional grade-and-resheet cycle at the frequency the roads require.
The Central Highlands Regional Council in Queensland worked with GRT to incorporate GRT7000 as a polymer seal into unsealed pavements, demonstrating the practical application of the technology within a council maintenance programme. The approach integrates with existing council equipment and workflows — GRT7000 is applied using the council’s own water trucks and grading equipment, with GRT providing training and technical support during the initial applications.
For councils, the economic case for stabilisation rests on three pillars. First, reduced grading frequency: a stabilised road that holds its profile for months rather than weeks requires fewer grader passes per year, freeing equipment and labour for other maintenance tasks. Second, extended gravel life: by preventing the loss of fines to dust and erosion, stabilisation extends the interval between resheeting events — deferring a major capital expenditure that can cost $50,000–150,000 per kilometre depending on gravel source distance. Third, all-weather access: stabilised roads resist wet weather failure, reducing road closures, community complaints and emergency repair costs that blow out maintenance budgets.
Unsealed road maintenance: conventional vs polymer-stabilised approach
| Parameter | Conventional (Grade + Resheet) | With GRT7000 Stabilisation | Benefit |
| Grading frequency | 4–6 times/year typical | Reduced by up to 75% | Equipment and labour freed for other tasks |
| Gravel resheeting interval | 7–20 years (100 mm layer) | Extended significantly; fines retained in surface | Major capex deferred; reduced gravel cartage |
| Dust generation | Continuous during dry conditions | Eliminated; polymer binds fines into surface | Health, visibility, crop/community impact removed |
| Wet weather performance | Closures common; boggy/slippery conditions | Waterproof surface; all-weather access maintained | Stand-downs reduced by up to 12 hours per event |
| Corrugation | Returns within days–weeks after grading in dry conditions | Resisted; bound surface maintains profile under traffic | Ride quality maintained; vehicle damage reduced |
| Rolling resistance (mining) | Variable; increases as surface deteriorates | Lower and consistent; 3–5% fuel saving documented | Haul truck fuel savings; tyre life extension |
| Water truck requirement | Continuous watering for dust control | Reduced 50–90% when combined with Haul-Loc | Diesel, operator, maintenance cost savings |
Practical Implementation: Equipment, Application and Integration
One of GRT7000’s practical advantages is that it integrates into existing maintenance equipment and workflows. No specialist plant is required.
Spray application (maintenance roads). GRT7000 concentrate is diluted with water and loaded into a standard water truck. It is sprayed onto the road surface through the truck’s existing spray system. Multiple light applications at defined intervals build the polymer concentration in the surface layer. This method is suited to roads in reasonable condition that do not require reshaping or resheeting.
Incorporation application (rehabilitation roads). For roads being resheeted or regraded, GRT7000 is mixed into the wearing course material during the construction process. The grader spreads the material, water is applied to achieve optimum moisture content for compaction, GRT7000 is sprayed onto the spread material, and the roller compacts the layer. The polymer is incorporated throughout the full depth of the wearing course, producing a stabilised layer from the outset.
Application in remote and off-grid locations. GRT7000 is a liquid concentrate that can be transported in standard IBCs (intermediate bulk containers) and diluted with locally available water. This makes it practical for remote mining operations, pastoral stations and rural councils where access to specialist materials or equipment is limited. Solar-powered SMART Dosing Units can be installed at fill points to automate the dilution ratio, ensuring consistent product delivery regardless of the operator.
GRT provides engineering support for initial application, including road network assessment, material characterisation, product specification, application training for council or mine site staff, and ongoing technical support. The Central Highlands Regional Council case demonstrated this model, with GRT staff training council crews on the incorporation of the product into different materials during the initial applications.
The Cost-Benefit Case: Invest Once, Maintain Less
The economic case for polymer stabilisation is built on total cost of ownership, not per-litre product cost. The initial application of GRT7000 costs more per kilometre than a single grading pass. But a single grading pass lasts weeks to months. A stabilised surface lasts years. The comparison that matters is the total maintenance cost over the road’s service life.
GRT’s published data, independently analysed by Deloitte with support from SMEC, demonstrated that GRT7000 delivers approximately 37% OPEX savings compared to conventional water-only dust suppression and maintenance approaches. For mining operations, the savings compound through reduced grading, reduced water truck fleet costs, improved haul truck fuel efficiency and extended tyre life. For councils, the savings manifest as fewer grading cycles per year, deferred resheeting, reduced emergency repair costs after wet weather events and fewer community complaints about dust and road condition.
At a time when council road budgets are under unprecedented pressure — with a $500 million annual funding shortfall identified by ALGA, councils caught in a damage-repair-damage cycle from successive natural disasters, and federal assistance grants at their lowest proportion of Commonwealth revenue in three decades — any technology that reduces the ongoing maintenance cost per kilometre of unsealed road deserves serious evaluation. Polymer stabilisation is not a new technology. It is a proven technology that is under-utilised relative to the scale of the problem it can address.
500,000 Kilometres of Opportunity
Australia’s unsealed road network is one of the largest in the world. It is also one of the most expensive to maintain, with a growing backlog of roads in poor condition that conventional grade-and-resheet approaches cannot close within current funding constraints. For mining operations, the cost of poor unsealed road surfaces flows through to every truck, every tyre, every litre of fuel and every shift of production. For councils, it flows through to every ratepayer, every community complaint and every deferred maintenance item on the asset register.
Polymer soil stabilisation changes the equation by modifying the road material itself — not just managing the symptoms of its deterioration. GRT7000 is proven across mining haul roads, gas field access networks, rural agricultural roads, council road networks and international civil applications. It integrates with existing equipment and workflows. It eliminates dust, improves wet weather performance, extends gravel life and reduces ongoing maintenance costs. And it does all of this while maintaining the natural appearance of the road surface.
For council engineers, mine road engineers, rural property managers and civil contractors responsible for unsealed road performance, the question is whether the current cost of maintaining those roads — in grading, resheeting, dust complaints, wet weather closures and vehicle damage — is acceptable. If it is not, polymer stabilisation is the engineering alternative that addresses the cause rather than the symptoms.
Sources and References
ALGA: 2024 State of the Assets Report — $3.9B unsealed roads in poor condition
North Queensland Register / ACM: Regional councils stuck in budget potholes (March 2026) — $500M shortfall, Roads to Recovery doubled to $1B, damage-repair-damage cycle
NSW Audit Office: Road Asset Management in Local Government (2025)
Toowoomba Regional Council: Unsealed Road Maintenance Program — 3,300 km gravel roads, resheeting every 7–20 years
GRT: GRT7000 — polymer soil stabilisation product
GRT: QGC Gas Field Access Road — 95 km stabilisation case study
GRT: Central Highlands Regional Council testimonial — GRT7000 polymer seal in council pavements
GRT: Maintaining Australia’s Unsealed Road Network
GRT: Soil Stabilisation Australia — challenges and solutions
Oil & Gas Today: GRT’s dust-suppression product almost halves costs — Deloitte/SMEC independent cost analysis
GRT: GRT: Haul-Loc
GRT: SMART Dosing Units
