Dempster Highway test

Figure I. Dempster Highway test (near Inuvik). Temperatures below roadw...

Figure 3. pH survey at Dempster Highway test installation (1976)... 

The first test, installed on a section of Dempster Highway about 40 miles south of Inuvik in the Northwest Territories, was designed for permafrost protection. The 45-ft wide and 130-ft long sulfur foam test pad averaged 4.4 in. in thickness and 11 lb/ft3 in density, with an average compressive strength of 46 psi. The foam was installed on top of the 1.5-ft thick pioneer fill and then was covered with 3.5 ft of granular overfill, in this case ripped shale, to complete the road section. 

The biological oxidation rate of sulfur foam depends on available surface area, temperature) and access of necessary nutrients, as well as on foam composition. Preliminary test data indicate that in all cases the oxidation rate is less than that of elemental sulfur. Soil pH around the foams at Dempster Highway measured two years after installation was never lower than the pH of the surrounding native soil (Figure 3). Sulfur foam s low toxicity is indicated by the LD60 of > 5 gAg (rat) and the 100% survival rate in a fish bioassay with stickleback (96 hr) (8). 

Surveillance of sulfur foam test installation on the Dempster Highway in the arctic and at Anderson Road in Calgary continues, and in both cases the performance is satisfactory. 

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See also in sourсe #XX -- [ , ]

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