Stabilization Techniques for Unpaved Roads

An amendment to Virginia House Bill 1400, Item 490, No. 1h, calls for the Virginia Transportation Research Council to “continue its evaluation of soil stabilizers as an alternative to paving low-volume secondary roads.” In response, promising soil stabilization products were evaluated with the relatively new technique of deeply mixing chemical additives into unpaved roadbeds. This work is based on the construction of a 1.75-m-long trial installation on Old Wheatland Road in Loudoun County, where seven commercially available stabilization products were applied to the unpaved road. A rigorous evaluation of treatment performance will provide the basis for recommendations to the Virginia Department of Transportation's operating divisions regarding improvements to the maintenance practices for gravel roads. Results thus far indicate that the introduction of soil stabilizers through deep mixing is a promising technique. The life-cycle cost analysis indicates that constructing a standard bituminous surface-treated roadway and maintaining it as such is much more cost-effective than using any of the products in this trial. Further, the analysis indicates that using the bituminous surface treatment alternative is also much more cost-effective than maintaining an unpaved road.