Dust control for gravel and dirt roads can be critical during the spring and summer seasons. Without it, many residential areas, mining sites, construction sites and other unpaved zones can become so dusty that they contribute to particle pollution and health issues.
In this article, we’ll discuss the most commonly-used products for road dust suppression. We’ll also talk about some of the factors to consider when selecting road dust control products.
What Can I Put On Gravel and Dirt Roads to Keep Dust Down?
One of the main ways to control dust on gravel and dirt roads is to use dust palliatives. Dust palliatives are products that are applied to surfaces in order to minimize airborne dust. To learn more about the basics of dust suppression, visit our post here: What is Dust Suppression?
For gravel and dirt roads, the most common dust palliatives tend to be water, hydroscopic compounds, and organic non-petroleum products.
Water reduces dust. However, it only works in the short term. In most cases, will need to be applied frequently. Generally, you need a water truck to apply it. For all these reasons, other dust palliatives tend to be a better option because they last longer.
Hydroscopic materials include calcium chloride and magnesium chloride, which work by absorbing moisture to keep surfaces damp and therefore less prone to dust. They can be applied as flakes or as a liquid solution. At Dustech, we sell liquid solutions that are sprayed on unpaved surfaces. Find more details here: Liquid Calcium Chloride, Liquid Magnesium Chloride
Organic non-petroleum products include lignosulfonate, vegetable oils, and other natural materials. They work by binding road particles together.
There are other dust palliative options including synthetic polymers, but we will not discuss them in this article since they are less commonly used on gravel and dirt roads.
How to Apply Dust Suppressants
Liquid dust control products are generally applied using a water truck. You can also use a spray bar attached to a truck. Road preparation is recommended before application in some cases.
Factors that Can Impact Dust Control Product Performance
Consider the factors below when creating a dust control plan for gravel roads.
Humidity can impact product performance. For example, magnesium chloride tends to perform better and longer in lower humidity compared to calcium chloride, if both are applied at the same rate. Inversely, calcium chloride tends to perform better than magnesium chloride during times of high humidity.
Rainfall shortly after application will limit the performance of both chlorides and lignosulfonate. This is one of the reasons that applying product at the right time is important. However, rainfall long after application should also be considered. For example, the binding created by lignosulfonate can be reduced by heavy rains.
The chlorides are also eventually removed by rainfall, but occasional rain can help reactivate chloride-based products since chlorides absorb water. This is especially true for calcium chloride, which tends to need more moisture than magnesium chloride for optimal performance. All these variables should be taken into account when selecting a product.
The material of the unpaved surface can also impact which product will work best. Unpaved surfaces made up of very fine dust particles such as clay would benefit more from lignosulfonates than surfaces in regions with coarser sand particles.
Traffic volume, type, and traffic speed should be considered when determining product, application rate, and application schedule.
Dust suppressants work better and longer on roads that are in good condition. For best results, prepare roads before applying dust suppressants. Here is an article on the Alaska government website with potential road preparation steps that you might need to be do before using palliatives.
If you are tackling a dust control project and would like to chat with us, we’d love to hear from you. Visit our contact page to send a message or give us a call at 1-888-978-3878.