Influence of NaCl Aqueous Solution on Compacted Snow: Field Investigation

Slippery road surfaces are a threat to traffic safety, especially in winter when snow falling on roads forms a hard crust that is extremely difficult to remove. To prevent this hard crust formation, salt is applied to roads. However, large amounts of salt are harmful to the environment and expensive. Therefore, optimization of salt applications has become a priority for transportation agencies. This study evaluates the effects of sodium chloride (NaCl) aqueous solution on compacted snow through a field investigation. A test car was driven on snow mixed with different amounts of aqueous NaCl solution (from 0% to 40% by weight); this experimental run was repeated approximately 20 times. A scraping test was also performed to evaluate the compacted salted snow’s strength. The study found that an aqueous solution content of 10% by weight keeps snow loose and easily removable from the road, but an aqueous solution of 5% by weight weakens the snow substantially, allowing the snow mixture to be more easily plowed.