Those in the business of building roads and highways have a lot of heavy equipment at their disposal. Graders, compactors and excavators are some of the most imposing and impressive machines used for road construction and reclamation. However, as important as they are, one of the most versatile and essential tools used on the jobsite may also be one of the least assuming. It’s a simple chemical compound that comes in the form of tiny flakes, small pellets or as a liquid. Knowing how to apply calcium chloride for dust control and road stabilization is one of the most necessary factors for ensuring the success of a project.
Why Calcium Chloride Matters for Road Construction Projects
It’s no secret to anyone in the road construction business that their work involves a lot of dust and dirt. Machinery working on bare earth can end up kicking a lot of fine particulates into the air. This does more than create a mess, as excessive dust can lead to many long-term issues that impact projects. For example, there’s the potential health risks created by workers and those around the project breathing in contaminants in the air. Any dust that is carried by the wind and settles in other places can lead to environmental impacts such as polluted water sources, which can affect the project’s sustainability and even lead to violations of local environmental regulations. Contractors also should take care to prevent dust because of the harm it can do to their equipment. Fine dust particles can build up inside machinery and cause performance issues as well as breakdowns if not properly addressed.
On top of all these concerns, the erosion of soil through typical construction activities also can have an impact on the overall stability of the completed roadway. It’s for these reasons that many contractors choose to employ calcium chloride to help prevent dust and stabilize the ground underneath their work.
How Calcium Chloride Works
The application of calcium chloride for road stabilization and dust control is common because of its ability to stabilize aggregate. It accomplishes this thanks to three key properties. It is hygroscopic, which means it naturally absorbs moisture out of its surroundings. Once it does, it dissolves into the water to form a clear solution that is deliquescent, meaning it resists evaporation. This resulting solution has a high degree of surface tension, which helps it lubricate the underlying aggregate and improves each particle’s ability to interlock with those around it.
Thanks to its ability to resist evaporating, using calcium chloride for dust control and stabilization means the road base retains an optimal level of moisture. This offers a number of benefits for construction and reclamation projects, especially compared to traditional methods.
The Benefits of Calcium Chloride Road Treatment
Using calcium chloride for road dust control is highly effective because it won’t evaporate as quickly even under direct sunlight and in extreme heat. It serves to keep the road’s surface damp in almost any conditions, ensuring good visibility for drivers and helping to keep the road in optimal condition for as long as possible. Although pure water has been used traditionally for this purpose, the fact that it evaporates so quickly means it must be applied multiple times. This can become an expensive proposition in many environments.
In terms of road stabilization, any dust that is kicked up by traffic runs the risk of resettling wherever the wind takes it. Over time, this means there may be fewer fine particles helping to hold the larger aggregates in place. This can lead to potentially serious stability issues and premature deterioration of the pavement. Calcium chloride helps prevent this by holding the fine dust and other aggregate materials together.
Comparing Calcium Chloride to Other Dust Control Agents
Calcium chloride is far from the only chemical agent used for dust suppression and soil stabilization. Contractors have a range of options that offer their own unique pros and cons, including:
- Magnesium chloride: Like calcium chloride, magnesium chloride draws water out of soil to prevent dust. It also tends to be less expensive upfront, but the fact that it dries out faster means more applications may be necessary than with calcium chloride.
- Lignosulfonates: Made from trees, lignosulfonates are organic binders that can hold soils together. Although this means it presents many ecological benefits, it can become slick when wet and may require more applications to be as effective as calcium chloride.
- Synthetic polymers: Adding a layer of synthetic polymer creates a kind of crust that prevents dust from being lifted into the air. This performance tends to come at a much higher price than using calcium chloride, however.
Application Methods and Best Practices
Calcium chloride typically is deployed in road construction either in liquid solution form or as solid pellets or flakes. When sprayed directly onto the surface of the subgrade, it can serve to suppress dust as well as strengthen the soil. For applications that require additional stability, such as when soils are especially loose or wet, the solid forms of calcium chloride may need to be mixed into the earth during the grading process.
In most cases, it’s recommended that crews perform compaction after applying calcium chloride to ensure the proper density for the resulting subgrade. Grading the surface to facilitate drainage also is necessary, as excessive moisture will dilute the calcium chloride and impact its performance.
Performance Factors and Environmental Conditions
The efficacy of calcium chloride for dust suppression and soil stabilization can be influenced by several external factors, such as:
- Humidity: Excessively dry conditions can hurt the performance of calcium chloride solutions, and may require applications of water or rainfall to reactivate them.
- Temperature: Higher temperatures can accelerate the rate at which calcium chloride absorbs moisture.
- Traffic: The heavier the traffic on the road, the harder calcium chloride has to work to control dust.
When used for dust suppression, calcium chloride typically should be reapplied after prolonged periods of dry weather. Roads that experience heavy traffic also should reapply liquid calcium chloride on a more-frequent basis than quieter roads.
Safety and Handling Tips
In its solid form, calcium chloride must be stored in sealed containers in a cool, dry place to prevent it from clumping. When handling it, workers should be equipped with PPE including gloves, respirators, and safety goggles to prevent direct exposure to skin and eyes. This will prevent irritation. Workers who handle calcium chloride also should wash their hands thoroughly after each use.
Call Rock Solid for Complete Expertise
The use of calcium chloride to keep dust down and stabilize the road base is a great choice whenever you want a long-lasting, easy-to-apply solution. Rock Solid Stabilization & Reclamation is a leader in providing this and other related services to strengthen road construction through base stabilization and full-depth reclamation projects. We work closely with your crew no matter where you’re working to ensure the best overall results for you. To learn more about this and any other capabilities we can offer to you, reach out and get in touch with us today.