There are various communities with unpaved roads that play a major role in the infrastructure of the transportation industry. There are various locations across India that need immediate and effective development in the roads as they are drastically unpaved and lack any maintenance. These roads can help in providing the people of the region easy, free and comfortable access to work, school, health care facilities and stores for daily commute. They create a complete link between markets both internally as well as externally. They connect farms, mines, forests and wells as well as manufacturers, wholesalers and distributors hence creating the complete link for successful business practices.
Maintaining unpaved roads can be successfully achieved by effective dust control to ensure that the roads are safe to be driven on. Dust suppression systems can also help in reducing the overall cost, extend the life of usage as well as reduce annual maintenance costs that are incurred by the road authorities of a nation.
Using a dust suppression system for unpaved roads will help in increasing the quality of life of all the people living in the area, increase safety aspects while driving and reduce accidents due to underdeveloped roads. It fundamentally provides better and improved roads and driving conditions while also bringing down the maintenance cost. Another added advantage is that the vehicles that are driven on these roads have lesser chances of being damaged due to externally influencing factors.
Using a dust suppression system for unpaved roads is highly important as it not only minimizes the impact on the natural environment but also helps in protecting the health, safety, property and quality of life for those people who live on, work near or travel on these unpaved roads. Dust suppression is a field that is being picked up by the road authorities as its numerus advantages yield practical results.
Dust suppressants:
Suppressants are used to control the level of dust on unpaved roads and can widely range from water to palliative materials such as brine solutions based on sodium chloride, calcium chloride and magnesium chloride to name the most commonly used ones. They are hygroscopic in nature which means that they easily attract moisture from the air which helps in facilitating dust suppression. Natural clays and plant oils can also be used but their results vary and may not be effective in the long run causing a disappointment of expectations.
The most common and temporarily used option for dust suppression ins water for construction sites, gravel pits and quarries. Water moisture which is applied to the location frequency can increasingly help in biding fines to gravel which prevent in the flying of dust with adequate moisture standards maintained.
Dust suppression chemicals:
The control of dust suppression performance of both the salts in based on their ability to keep the road surface damp. The salts along with water create a solution that helps achieve this goal. The solution volume in the road surface changes as it seeks equilibrium with the moisture content of the air. If the relative humidity is high then the solution volume grows. However, if the relative humidity is low then the solution volume reduces drastically.
- Calcium Chloride: Calcium chloride is a commonly used hygroscopic salt that helps in drawing moisture from the air in order to form a solution in unpaved roads that helps in keeping the road surfaces damp at all times even in cases of hot and dry natural climatic conditions. This moisture helps in binding particles together that creates a hard and compact road surface. The overall road stability is improved as the calcium chloride penetrates deep into the road. Using this hygroscopic salt also reduces the chance of frost damage to the roads as the freezing point of the moisture on the road surface is depressed.
Depending on the specific conditions of the unpaved road either solid or liquid forms of calcium chloride can be used to suppress the dust. - Magnesium chloride: magnesium chloride is also another commonly used hygroscopic salt for dust suppression. Unlike calcium chloride, this salt is used only in liquid form at a certain level of concentration. Liquid magnesium chloride and liquid calcium chloride exhibit similar properties in attracting the water. However, under hot and dry conditions calcium chloride will still remain liquid but magnesium chloride will not. This can cause lesser effectiveness in dust suppression in specific conditions.
The chemical action of the two salts may be similar but their commercial application and actual performance are highly different. Lesser amounts of calcium chloride are required to treat the same amount and area of roads as compared to magnesium chloride as their levels of concentration vary.
The application rates of these two salts is determined by the government authorities that result in the success of dust suppression based on that region individually. Hence the most desired product may vary from place to place and there is no one solution that fits all cases.
Preparing the actual chemical solution should be done carefully as the concentration levels may vary and any accidents and damages are certainly not desired.
Effective dust control:
Effective dust control is built and based on the foundation of the quality of gravel. Using the appropriate mixture of fine materials with larger aggregate matter is essential to make sure that the natural binding action can be taken.
Generally, the dust control system should commence in spring while the moisture content and humidity levels in the air are high. An effective dust control system requires a proper drainage system and all ditches and shoulders on the unpaved road should be properly cleaned, filled and reshaped as per the technical need.
Its best to avoid using calcium chloride salts in heavy rain periods as the rain water will simply dilute the salt and bring down the effectiveness of the dust control system and cause run off on the unpaved roads.
In periods of extremely high temperature’s or dry weather its best to water the entire road surface in the early morning time period so as to reconstitute the original treatment.
