Increasing Friction on Roadway Ice with Water-Heated Sand

Abstract Snow and ice pose danger to users on roadway networks, airports, and parking facilities, requiring large amounts of deicing or anti-icing chemicals. The environmental impacts of deicing/anti-icing chemicals, typically chloride-based salts, can include degraded drinking water supplies and destruction of native aquatic and terrestrial flora and fauna, which can promote the spread of invasive species. This study investigates an alternative to chloride-based salts, which involves the application of a sand type that has been rarely used in North America, namely water-heated sand. In this study, we measured the friction coefficient on asphalt pavement core samples below freezing temperature for several winter road surface treatment conditions, including bare pavement, bare ice, dry sand on ice, and water-heated sand on ice. As expected, bare pavement produced the highest friction, while bare ice produced the lowest friction. Dry sand on bare ice exhibited friction similar to that of untreated bare ice. Water-heated sand melts into ice on the road surface and refreezes, while still protruding above the ice. The increased surface roughness of water-heated sand is an effective alternative to chemical treatments for improving winter road safety, while also reducing negative environmental impacts.