Assessment of Ecological Materials as Alternative Abrasives and Deicers for Winter Road Maintenance and Water Resource Protection

Abstract

The use of chloride-based salt as a deicer for winter road maintenance hasbeen a longstanding practice throughout the state of Minnesota and the country. However, once chloride enters the water, it is not naturally broken down, transformed, or removed from the environment, resulting in accumulation in the watershed and detrimental ecological and water quality impacts in freshwater systems. In order to protect freshwater resources and to prevent this issue from worsening with time, an alternative method for providing sustainable and effective winter road maintenance is needed. In some cold regions of Minnesota, sand is mixed with salt as an abrasive to provide additional traction to the roads, however its effectiveness is not well established. This study aimed to investigate the potential of regionally available organic and inorganic industrial byproducts as alternatives to conventional sand and salts. Candidate materials include corn grit, timber waste, and taconite waste rocks local to Minnesota. Chemical and physical properties of the materials were characterized, including material elemental composition, morphology, particle size distribution, sorption capacity, and specific gravity to establish a foundational understanding of the material. Skid resistance tests and environmental impact assessments were performed to evaluate traction effectiveness and material safety. Based on these results, a recommendation for potential use was made. The results showed potential for corn grit to be used as a sorbent for salt brine deicer with less salt impact and for waste rock to be used as an abrasive in the realm of winter road maintenance. This work may provide potential new material for winter road maintenance as well as a streamlined method for evaluating potential abrasives/deicers, valuable for expediting future studies of alternative materials.