A step-by-step look at Surface Application - Procedures and Rates for Haul and Access Roads

1. DUSTAC APPLICATION INSTRUCTIONS A step-by-step look at Surface Application - Procedures and Rates for Haul and Access Roads

2. The Use of Polymers • The use of polymer based dust suppression is recognised as the most effective form of dust control • A polymer is a large molecule composed of repeating structural units • Although the term polymer is sometimes taken to refer to plastics, it actually encompasses a large class of natural and synthetic materials • Both synthetic and natural polymers are used in road stabilisation • This applies to haul roads and other trafficable surfaces. • The benefits of these type of products include reduced water application more stable road surfaces and a long term sustainable management program. • Dustac is a natural polymer

3. Pre Treatment Considerations • The road substrate should consist of a well graded aggregate. • The road should be graded, profiled and compacted to accepted engineering standards prior to dust suppression or stabilization operations • Calculate the road surface area m2 and apply Dustac solution in 500 meter or 1000 meter sections. • The area treated at any one time is dependent on weather conditions and equipment availability. • Insure the surface is wet. If necessary pre-water with at least 1 Litre per m2 • Accurately determine the water-cart distribution rate, area covered, speed, gear and engine revs when wetting out the area.

4. Application Guidelines • The recommended rate of application for Dustac is between 400 and • 800 mL per m2 depending on road base and traffic usage. • Dustac should be applied in multiple applications at the rate of 25mL per m2 • The rate of application of Dustac solution must be at least 1 litre per meter squared – effectively a 2.5% solution • Dustac should be applied continuously in 4 to 8 applications per day. • Should the surface dry out water should be applied to match up the moisture horizons. • Once the desired dose is applied the surface should only be watered as and when required to settle dust emissions • This will be a lot less than before the application of Dustac.

5. It is recommended that the standard dose of 25ml/m2 be applied weekly as a ongoing maintenance dose • This may be reduced to fortnightly once sufficient solids have been incorporated into the top 25mm to 50mm of the road profile • Although a continuous watering program is required, as rule of thumb a Dustac treated road is likely to require 70% less water than a road maintained solely with raw water • Any water applied to the road surface will serve to rejuvenate the Dustac and continually reseal the road • The timing and frequency of these applications will be determined by the quality of the road base, traffic frequency and type and climatic conditions • The volume at which the Dustac solution should be applied is 1L/m2 • This means 250 litres of Dustac should be added to 10,000 litres of water – effectively a 2.5% solution