The objective of this project was to develop materials to aid winter maintenance practitioners in making informed decisions on the use of road salts, specifically sodium chloride. To accomplish this, a detailed literature review was conducted, followed by a laboratory investigation that monitored ice formation and precipitation of salt at various concentrations and temperatures. Using the information collected through the previous tasks, a one-page fact sheet and educational video were developed to aid winter maintenance practitioners in how to use and apply information shown in salt phase diagrams. Results from the lab testing produced great images and video of ice and salt crystal formation in solution. Limited ice crystal data was collected and analyzed. Detailed ice crystal formation results could provide significant information to advance this topic. Images of ice crystals with bubbles, potentially filled with salt brine, indicate that the solid phase of ice crystals and salt crystals is not pure, implying that many phases can co-exist. This reinforces the concept that ice formed in the presence of salt brine is weaker than ice formed only in the presence of pure water. When measuring pavement friction following the application of salt brine at various concentrations, the results varied between pavement type, salt concentration, and friction measurement technique. There is value in further refining this, or another, performance test method to assess the influence of salt brine concentration on pavement friction.
This manual was created as part of Clear Roads project CR13-04,"Best Practices for the Prevention of Corrosion of Department of Transportation Equipment: A User’s Manual," Published April 2015.
This document is the final report for the Clear Roads project entitled Best Practices for the Prevention of Corrosion of Department of Transportation Equipment: A User’s Manual. The project team was led by researchers at the Western Transportation Institute at Montana State University (WTI) on behalf of Clear Roads, an ongoing pooled fund research effort focused on winter maintenance materials, equipment, and methods. Clear Roads research projects are managed and administered by the Minnesota Department of Transportation (MnDOT). Through this project, the research team developed a user-friendly manual that documents best practices for managing the risk of equipment corrosion, especially in the presence of chemical deicers. The audience for this manual includes operators, mechanics and garage-level supervisors. The manual defines the basic corrosion conditions, with a focus on the need for managing corrosion risks, common modes of corrosion failure, and corrosion-prone parts (priorities) on DOT equipment. This manual addresses design considerations and material selection for corrosion risk management. This manual also lists some commercial products that have been used by DOTs, and presents some successful experiences of DOTs, the US Navy and private companies. It also presents preventive maintenance strategies and tactics.
A manual on environmental best management practices used for snow and ice control was developed using information gain from a literature review, survey, and follow-up interviews. The document presents information on commonly used snow and ice control products and their potential impacts, and pathways into the environment. Following this information is presented on many aspects of snow and ice control operations from material handling and storage, application techniques and equipment, advanced technology for decision making, environmental management tools, pre-storm to mid-storm practices, post storm clean-up, and training. The manual summarizes common areas for improvement in snow and ice control practices to realize material and cost saving, while reducing impacts to the environment.