American Society of Civil Engineers


Dust Measurement to Determine Effectiveness of Rural Dust Strategies


by David L. Barnes, (Institute of Northern Engineering, College of Engineering and Mines, University of Alaska, Fairbanks), Ron A. Johnson, (Institute of Northern Engineering, College of Engineering and Mines, University of Alaska, Fairbanks), Richard Wies, (Institute of Northern Engineering, College of Engineering and Mines, University of Alaska, Fairbanks), Tomas Marsik, (Institute of Northern Engineering, College of Engineering and Mines, University of Alaska, Fairbanks), Clark Milne, (Alaska Department of Transportation & Public Facilities, Fairbanks, Alaska), Susan Underbakke, (Institute of Northern Engineering, College of Engineering and Mines, University of Alaska, Fairbanks), and Dennis Filler, (Institute of Northern Engineering, College of Engineering and Mines, University of Alaska, Fairbanks)
Section: Roads, pp. 506-511, (doi:  http://dx.doi.org/10.1061/41072(359)49)

     Access full text
     Purchase Subscription
     Permissions for Reuse  

Document type: Conference Proceeding Paper
Part of: Cold Regions Engineering 2009: Cold Regions Impacts on Research, Design, and Construction
Abstract: Dust produced from unpaved roads in rural Alaska is impacting the quality of life in many Alaskan and other villages in cold regions. Not only does dust emanating from unpaved roads cause respiratory ailments, but also impacts subsistence food storage and sources as well as safety since dust impacts visibility on village streets. Loss of fine particles also greatly impacts the quality of road surfaces creating increased maintenance costs. Replacing the fines content in unpaved road surfaces is costly owing to the lack of suitable material and equipment in many villages. The expectation for many communities is that paving their roads will solve their problems. In some cases this may be possible. In many rural environments, however, lack of suitable material or cost prohibitive sources, unsuitable foundation materials or inability to maintain the improved roads preclude pavement as an option. A suitable option for many rural villages may be dust control palliatives and institutional controls. However, there is little consensus on how to identify and measure the effectiveness, economics, and environmental impacts of dust control approaches that are compatible with the subsistence lifestyle common in remote rural communities in Alaska and other cold regions. Our objective in this ongoing study is to evaluate different dust control methods used in rural Alaska. These dust control methods include various synthetic polymer type palliatives, calcium chloride, and institutional controls. This paper presents our current efforts to quantify and qualify the effectiveness of dust control measures. Of the different dust control methods, the Alaska Department of Transportation and Public Facilities (AKDOT&PF) has the most experience with calcium chloride (CaCl2). Salts such as CaCl2 (magnesium chloride is another common dust control salt used by others) control dust by adsorbing and retaining moisture in the aggregate surfacing material. These compounds are most effective at suppressing dust when the relative humidity is greater than around 30 to 40 percent (Rushing and Tingle, 2006). During morning hours when relative humidity is typically high and temperatures are low, moisture is retained in the salt treated road surface. As the temperatures rise and relative humidity drops in the afternoon, moisture losses by evaporation from the treated road surface are reduced in comparison to untreated road surfaces. Synthetic polymers comprise several different compounds that promote soil particle binding. Several different products are provided by vendors under the names EK-35, EnviroKleen, Durasoil among others. The compositions of these compounds are typically proprietary. The fraction of loftable fine particles is reduced by the aggregating action of the palliative. Anyone who has driven on unpaved roads has experienced the effect vehicle speed has on the quantity of fine particles lofted by the vehicle. Control of speeds on rural roadways when possible is one of the least expensive means to control dust.


ASCE Subject Headings:
Dust
Measurement
Rural areas
Alaska