Druschel, Stephen J.

This report presents the evaluation of winter maintenance efforts, including applications of deicers and anti icers and plowing, in parallel conditions on actual pavements to assess intuitions based on observations and anecdotal evidence. Parallel conditions eliminate the issue of test sections being in slightly different geographies. Four different aspects were evaluated in this effort:

These appendices pertain to report 2017-45, Salt Brine Blending to Optimize Deicing and Anti-Icing Performance and Cost Effectiveness: Phase III.

These appendices pertain to report 2020-32, Hot Shots for Cold Climates - Evaluating Treatment of the Hardest Icy Spots. APPENDIX A: SAFETY PLAN APPENDIX B: INSTRUMENTATION MOUNTING AND POST PLAN APPENDIX C: SITE LOCATIONS WITH INSTRUMENTS INSTALLED APPENDIX D: AVL SALTING EVENTS APPENDIX E: SITE VISITS BY LOCATION AND BY DATE APPENDIX F: LIGHT INTENSITY AND TEMPERATURE/DEW POINT GRAPHS FOR EACH SITE APPENDIX G: PAVEMENT TEMPERATURE MEASUREMENTS (FLIR THERMOGRAPHS) APPENDIX H: DEICER APPLICATION DAY TIMELINES AND WEATHER APPENDIX I: SALTING EVENTS BY DATE APPENDIX J: GENERALIZED WEATHER AROUND SALTING DATES APPENDIX K: CUMULATIVE SALT LOADING BY STUDY LOCATION APPENDIX L: BRIDGE DECK TEMPERATURES BY FIELD VISIT DATES

Nineteen state highway locations around south-central and southwestern Minnesota were evaluated during winter 2019-20 for the application of deicer "hot shots;" extra levels of salt or other chemical treatments used to deice roadways and maintain roadway driving levels of performance. Locations were selected based on previous recordkeeping that indicated difficult winter driving conditions including drifting; blow ice formation; ice fog (black ice formation); roadway shading; and exposed bridge decks. Highways selected were representative of low-traffic-volume roadways classified as rural commuter; primary; and secondary roads. Deicer application amounts were gathered from AVL measurements made onboard plow trucks. Local and regional weather conditions were measured. A total of 909 application passes by plow trucks were found for the nineteen locations of study for winter 2019-20. Hot-shot treatments were observed to comprise 28% of the total treatments. Hot-shot treatments were observed; but neither at the proportions nor in the patterns expected for the studied situations of winter roadway difficulty. Operator judgment appeared to be much more important than any other defined factor. In the balance of winter driving level of service and costs; with costs not only measured in money but also in labor; equipment and environmental impact; perhaps the best investments will be in enhanced operator training and the sharing of experience; roadway and weather information systems; and public education and the management of expectations.

An evaluation of deicers and anti-icers and plowing; in parallel conditions on actual pavements to assess intuitions based on observations and anecdotal evidence. Anti-icer persistence. Deicer effectiveness. Plow effectiveness. Pavement study of anti-icer persistence. Factor interaction such as truck traffic plus snow moisture condition; deicer use or roadway crosswind and deicer distribution have significant impact on differences in winter maintenance performance and deicer efficiency.

This report presents the evaluation of winter maintenance efforts, including applications of deicers and anti icers and plowing, in parallel conditions on actual pavements to assess intuitions based on observations and anecdotal evidence. Parallel conditions eliminate the issue of test sections being in slightly different geographies. Four different aspects were evaluated in this effort: Anti icer persistence, measured in response to actual traffic through drainage off defined roadway sections of an elevated highway; Deicer effectiveness, techniques and materials evaluated at two proximal facilities across six and three parallel treatment lanes of 1,000 feet length; Plow effectiveness, techniques and equipment evaluated at the same locations as the deicer effectiveness evaluation; and, Pavement study of anti icer persistence in response to precipitation, performed using asphalt and Portland cement concrete pavements in a laboratory setting. Results of this work indicate factor interaction such as truck traffic plus deicer use or roadway crosswind and deicer distribution may have significant impact on differences in winter maintenance performance and deicer efficiency.

This report presents the evaluation of chemical treatment practices known as flocculation for purifying construction site runoff of sediment, suspended solids and colloidal particles. Flocculation is generally used in combination with traditional sedimentation and filtration methods related to stormwater pollution prevention and dewatering fluid treatment. In particular, this report presents the best management practices (BMPs) for evaluation and design of flocculant treatment methods and technologies and the associated sizing for flows representative of field operations. Soil samples from across Minnesota, representing the wide range of geologic and geomorphological conditions, were used to identify differences in flocculant applicability and effectiveness.

This report presents an evaluation of wastewaters derived from concrete placement and maintenance and the preparation of best management practices (BMPs). Investigation and documentation of existing practices was done to ensure application to real situations and enhancement of constructability for all BMPs. Laboratory analysis of test specimens was done to provide characterization of factors that are likely to positively or negatively influence concrete wastewater composition. Evaluation of sedimentation and filtration through and absorption by sand and geotextile materials provides a simulation of the known control techniques. Development of a constituent occurrence and control model with a strong statistical base achieved through experimental replication supports development of BMPs that are both environmentally protective and constructible.

This research evaluated the ice melt capacity and field performance factors of deicers and deicer blends and then developed a temperature-based cost model for comparing the relative field performance of the evaluated deicers and deicer blends. Both solid and liquid deicers were evaluated for both deicing and anti-icing methods.