Erosion Prevention During Highway Construction by the Use of Sprayed On Chemicals

About the report:

The purpose of this study was to evaluate the erosion inhibiting potential of nine commercial spray on plastic chemicals. All chemicals were also compared with the conventional method of straw tacked with an asphalt emulsion, and with untreated soil. In each case costs of the chemicals were obtained to determine if the most effective chemicals were economically feasible. In Virginia there are three principal physiographic provinces. The soils in each province are significantly different in composition and erodibility. In each area two highway slopes with a vertical height of 15 to 20 feet and a slope of approximately 2:1 were selected to be tested. It was found that the same chemicals were not the most effective in the different areas. Also, no chemical performed better than the conventional method in any of the three areas. Some of the chemicals in certain soils even promoted erosion since soil treated with these showed greater erosion than the untreated soil. In the westernmost area, or the Ridge and Valley physiographic province, Petroset SB and Soil Gard were the most effective erosion inhibitors. Petroset SB is relatively expensive compared to Soil Gard and the conventional method. Petroset SB costs between $501 and $803 per acre, while Soil Gard is $195 per acre and the conventional method $130 per acre. For the soils in the Piedmont physiographic province, none of the chemicals performed well. Aerospray 70 and Curasol AE were the most effective, but performed only slightly better than the untreated soil. Aerospray 70 ranges in cost from $265 to $335 per acre, while Curasol AE costs from $132 to $174 per acre. In the sandy soils of the Coastal Plain physiographic province, Petroset SB and straight asphalt emulsion were very effective. As mentioned earlier Petroset SB is expensive at $501 to $803 per acre, and asphalt emulsion is $252 per acre. Both are more expensive than, but about equal in effectiveness to, the conventional straw-asphalt method.

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