Road Dust Control Techniques and Solutions
During the spring and summer seasons, especially in areas such as Minnesota, Iowa, Nebraska, etc., dirt and gravel roads can be difficult to maintain. Without the right road dust control, it can result in excessive amounts of dust in residential areas, construction sites, farms, mining sites, and other unpaved areas.
This article will delve into road dust control techniques and how to choose the right products to assist you in this process.
Cover the Road with Pavement
The most effective (and expensive) method of controlling dust is paving the road. Two popular road paving materials include asphalt and portland cement, as they are durable and effective in preventing the breakdown of soil surfaces.
Paving isn’t always a feasible way to improve gravel road dust control as it is expensive; plus, it isn’t something you want to cut corners on. Thin pavements such as chip seals can quickly fall apart and be frustrating in the long term.
Reduce Traffic and Vehicle Speed
The more vehicles that travel on unpaid roads, the more dust that gets stirred. By reducing the volume of vehicles on the streets, you can significantly reduce how much dust there is. You can either minimize traffic voluntarily or restrict the vehicle type or weight.
Reducing the speed is another idea of how to eliminate dust. According to studies, dust increases with vehicle speed. Even reducing speeds from 40 miles per hour to 20 miles per hour can reduce dust emissions by 65%.
Try incorporating speed bumps and drainage channels across roads to keep speeds low. For example, good drainage can reduce dust, so when water floats, the particles from the soil float up into the road. When more traffic is on the street, the water and wind spread the particles as either mud or dust.
Increase dust prevention by installing barriers referred to as windbreaks. They are designed to reduce the speed and direction of the wind, not stop the wind altogether. Good windbreaks will also not create additional wind eddies or turbulence that results in chaos on dirt and gravel roads.
Popular windbreak materials include picket and board fences with strategic gaps between the pickets, snow fences, berms, or hedges of plants. The most impactful windbreaks are designed to handle wind coming from specific directions.
The maximum-protection wind reduction ranges between 5-8 times the screen's height. For example, if you are preparing for a windbreak that is 25 feet tall, aim to locate it 125-200 feet from the house for maximum protection.
Cover Unpaved Roads with Gravel
Gravel can be another effective way to keep road dust in control. It provides a hard surface that projects the underlying soil from any vehicle wheels; however, it does not reduce the strength of the wind flow itself. When there’s traffic and particularly strong winds, it can still dislodge pieces of gravel and send them into the air.
Traffic will also push the surface-level gravel into the ground if there isn’t a solid base of crushed aggregate. When the road surface doesn’t have a sufficient amount of finite materials to cement the surface gravel in place, traffic will move the gravel away from the driving lanes.
The most effective gravel over an extended period of time is anchored to the surface itself. By mixing gravel with soil adhesives or aggregate mixes, the anchoring process can take place.
Using geotextile fabrics could be helpful in cases where the gravel is lost when it is pressed into the soils under the road. Polymer threads make up these fabrics, and they have extremely high textile strength. Some are even designed to either form a water barrier or allow water through, all while ensuring fine soil does not migrate through.
Water the Road
Another tactic for dust control for gravel roads is using dust palliatives. These are products designed to minimize airborne dust, and they’re applied directly to the surface. When it comes to dirt and gravel roads specifically, the most widely used dust palliatives include water, organic non-petroleum products, and hygroscopic compounds.
While water is an effective agent at keeping dust to a minimum, it only works in the short term. In most cases, water needs to be applied consistently for maximum impact, often applied by a water truck. Other dust palliatives are also commonly used as they have a longer impact.
Use Dust Suppressants
As we mentioned above, there are different kinds of palliatives that can be used. Some work by binding particles together through moisture while other palliatives increase the moisture content itself (salts).
Palliative 1 - Binding Particles Together
An additional dust palliative includes chemicals that work to bind fine particles together or to another, larger particle. These chemicals may be petroleum-based, electrochemical stabilizers, synthetic polymers, or non-organic petroleum.
- Petroleum-based binders include products such as cutback asphalt, emulsified asphalts, and Bunker C. By coating the road particles with a thin layer of asphalt, the particle mass increases, and the chances of becoming airborne decreases. If you haven’t heard of emulsified asphalt, it’s a mixture of water and asphalt that works well when mixed into the top couple of inches of the road surface with a grader.
- Organic non-petroleum dust suppressants include resins and lignosulfonates. Lignosulfonates come from paper manufacturing when lignin is extracted from the wood. It’s a natural polymer that binds soil particles together. They work the best with fine dusts that have high plasticity when they’re in a dry environment.
- Electrochemical stabilizers include ionic stabilizers, bentonite, and sulfonated petroleum. These products are known to neutralize soils that attract water. Electrochemical stabilizers must be worked into the road surface itself, requiring special equipment.
- Synthetic polymer products include acetates and polyvinyl acrylics. They work by binding soil particles together to form a semi-rigid film on top of the road’s surface. They come in the form of either powder or liquid that’s incorporated with water.
Palliative 2 - Increase Moisture of the Road
To increase the moisture of dirt roads, you may either spread water or apply deliquescent salts that attract water. These salts are a type of dust palliative. For example, calcium chloride and magnesium chloride absorb moisture from the air. When soils are treated with deliquescent salts, they have a higher water content versus untreated soils.
So how long do these salt applications last? Rainfall naturally removes salts from the roads. As a general answer, salt applications work for gravel road dust control for one (or maybe a few) years, depending on several factors like the amount of salt used, the volume of water present, and frequency of traffic.
Rely on Ninja Deicer for All of Your Dust Control Products
Finding the proper dust control products is easy with a company like Ninja De-Icer on your side. Our products are affordable and effective in keeping dust prevention in check, all backed by science. Feel free to contact us with any questions!