Managing Unsealed Pavements With Low Or No Water Solutions

In the last article, we discussed how poorly managed pavement moisture impacts road pavement structure by reducing bearing capacity and cohesion, causing decompaction and ultimately lead to cause pavement failures.

We also discussed how pavement moisture and free water must be managed from construction to maintenance. When not considered, issues such as surface cracking, potholes, shoving, rutting, and erosion are invariably the outcome.

Government road agencies, contractors, and asset owners have a well-established design, construction and maintenance tools for traditional sealed pavements that can prevent or counter these failure types – as long as the budget is available to do so!

However, even in public infrastructure, the amount of unsealed roads far outweighs the number of sealed pavements. In industries, such as mining, this statistic is even higher due to the cost of maintaining a sealed surface under such heavy loadings. Due to the massive loading, presence of tracked machinery, and relatively short-term life of haul roads, most mines, quarry and construction projects don’t have the means or materials to invest into the sealed pavements that a pavement design program would spit out. So they make do with what they have got – and employ water carts and graders to maintain their roads and manage dust.

However, in many cases water can last less than 10 minutes due to the evaporative forces of temperature, sunlight, and heavy traffic. However, grading without due consideration of cross and longitudinal drainage and compaction, coupled with continual watering leads to more dust and faster road degradation. Overwatering also increases the risk of unplanned vehicle movements and causes more fines to pump to the surface. When dry, these particles are lost as airborne dust and the unsealed pavement degrades quicker as it is losing the element that helps bind the material together naturally. The dust situation is worse – so we throw more water at it and continue the cycle!

The need to combat these problems has led GRT to develop low and zero water technologies that deliver cost-effective solutions for the public and private sectors. Three key approaches developed by GRT are outlined below:

1. GRT: Haul-Loc has been developed to make watering work! Instead of lasting 10-20 minutes, even in extreme conditions, GRT: Haul-Loc extends the dust suppressing the effect of sprayed water by at least 2 hours. This leads to dust controlled roads achieved using far fewer trucks and removes the risk of slips due to wet haul roads surfaces. This has been used across successfully across climactic conditions from New Zealand to Brazil, and from India to Central Australia.
2. GRT7000. Where GRT: Haul-Loc will reduce water consumption by at least 50%, GRT7000 can drive water savings in between 95-99%. GRT 7000 is a high quality, clear drying polymer seal. Depending on traffic type and volume, this will last between 12 weeks and 18 months. It can be used to provide a waterproof and completely dust free surface for uses ranging from heavy road trains, eco-tourism resorts and improving connectivity between remote communities
3. GRT: Wet-Loc – Completely waterless, long-term dust control. With results lasting up to 12 months, GRT: Wet-Loc can handle any traffic type and volume. It is a clear, ultra safe synthetic fluid that can eliminate the need for water from road maintenance and dust control activities. Because it holds moisture (but not water), it maintains the fines where they need to be – leading to greatly improved pavement cohesion. This prevents airborne dust being generated and also the development of surface corrugation and potholing thereby greatly reducing the need for maintenance grading.

Traditional methods of building and maintaining unsealed roads are no longer viable. Community and workplace heath and safety, and environmental impacts aren’t adequately managed by watering alone. The engineered application of these GRT products for dust suppression, soil stabilisation, and erosion control delivers benefits and cost savings from the first few hours of application.

For more information, please Contact Us