- Road officials must contend with higher maintenance costs because a dusty road is a deteriorating road. Once the fine material is lost, the load-bearing aggregate will soon follow. Loss of fines and aggregate results in ruts, potholes and washboards that require costly spot repairs and frequent blading to keep the road in acceptable condition.
- Road users face the serious safety issue of reduced visibility and also the prospect of loose gravel causing cracked windshields, chipped paint and/or broken headlights.
- Local residents must contend with large quantities of dust drifting into their living environment, reducing their quality of life and increasing their chances of developing respiratory health problems.
- Calcium chloride attracts moisture from the air, keeping the road damp even under hot, dry conditions. The moisture film provides a cohesive force that binds aggregate particles together, resulting in a hard and compact surface.
- A beneficial residual effect accumulates with consistent application year after year. As calcium chloride becomes established deeper in the road base, stability improves and frost damage is virtually eliminated.
- Calcium chloride manufactured by Oxy Chem has been used for dust control applications since the early 1920’s. No other dust control product or manufacturer comes close to this level of proven performance.
How can road managers with tight budgets justify expenditures for dust control with calcium chloride?
Several years ago, road managers in South Africa asked this question and subsequently launched a series of field trials to collect the necessary data to develop an answer.1 here are some of the results from their work.
- Blading frequency of roads treated with calcium chloride decreased by about 50% and the expected interval between re-graveling increased from 7 to 14 years.
- A cost/benefit analysis of various maintenance alternatives for a road with 342 ADT indicated that annual application of calcium chloride with a 90 day blading cycle maximized the economic benefits for road managers and road users.
- The greatest economic benefits were realized when aggregate replacement costs and ADT are both high.
- As with Anti-icing/De-icing products, the higher the percentage of active ingredient, (Calcium Chloride) the better the Dust Control product will perform.
This work shows that a dust control program with calcium chloride can be considered an investment that provides a good rate of return, in addition to improving the quality of life for road users and neighbors alike.
LIQUIDOW* 38% Comparison to Mineral Well Brine
Note: Mineral well brine is 5 ½% to 6% Sodium Chloride or salt. Salt in its natural state is a solid. It returns to a solid when evaporated, adding to the dust problem on a gravel road. Think of the highway after a snow storm and how white it is and you can see the salt dust blowing around. Each gallon of 26% Brine weighs approximately 10.5 pounds, 6% equals 0.63 pounds of salt per gallon, or 1,890 lbs. of salt per mile, or almost 10 tons of salt every ten miles, that would not normally be in the environment. Salt ads to respiratory problems for residents, can get into ground water and contaminate lakes and streams. It serves no purpose in a dust control program and is a health and environmental concern as well.
To ensure the safe and effective use of calcium chloride, please thoroughly review the product’s Material Safety Data Sheet prior to use. To obtain an MSDS, contact Great Lakes Chloride, Inc. at 1-269-664-6904 or visit our Blog at www.deicemandave.com.
1 “The Incorporation of Dust Palliatives as a Maintenance Option in Unsealed Road Management Systems.” D. Jones, E. Sadzik, and I. Wolmarans; Paper from 20th ARRB Conference, 19-21 March 2001
- Blade in the spring, while road moisture content and humidity are relatively high. Water road surface prior to blading unless rain has fallen within the last two days. Remove ruts, washboards, potholes and mix in loose aggregate.
- Good drainage is essential to good performance. Shape roads to a 4% or greater crown. Ditches, shoulders and culverts should be reshaped and cleaned as needed.
- Recommended application rates can be provided if not already established in your operation.
- Applications should not be started during heavy rainfall or if rain is threatening.
- During unusually long periods of hot, dry weather, water the road surface during early morning hours as needed to reconstitute the treatment. Re-apply in late summer or early fall as needed.
Frequently Asked Questions
Will an unpaved road treated with calcium chloride corrode my vehicle?
Noticeable vehicle corrosion is not likely to result from driving on an unpaved surface treated with calcium chloride. The calcium chloride tends to stay bound to the soil in the road, so there is little chance for significant contact with exposed metal on a vehicle.
Are dust control treatments with calcium chloride safe for the environment?
Calcium chloride dust control applications reduce sediment load on waterways and save thousands of tons of aggregate that otherwise would be mined from noisy and unsightly gravel quarries. Airborne particulate matter is reduced, improving regional air quality. Ground and surface waters are not likely to be impacted. While over-exposure to chloride has the potential to injure trees, this rarely occurs in dust control applications that follow current standard practices.