Principal Investigator: Christopher Tuan
About this Project
Brief Project Description & Background
Many chemical products are available for use in highway and bridge deicing and new products are introduced each year. Although manufacturers provide performance data under specific conditions, a standardized test procedure for acceptance of a new deicing chemical is needed to confirm the manufacturersâ€™ claims and to compare competing products under the same controlled conditions and at various application rates. Several lab tests will be conducted and the correlation with field performance will be studied. Based on the results, a performance rating system will be developed.
Variables affecting winter maintenance operations include the type of precipitation, air and pavement temperature, traffic, wind, time of day, day of week, and the maintenance equipment. The main objective is to identify the best practices for normal deicing operations in Nebraska, based on the performance rating of deicing chemicals. Optimum deicer/brine ratios and the associated application rates are to be determined for various weather conditions. The best practices will ensure effective deicing operation and economical use of deicing chemicals, which will help reduce the adverse effects on concrete pavement and improve the safety for wintry travel.
Nebraska Department of Roads spends over $4 million per year on highway deicing chemicals. A performance rating system and quality assurance methodology will ensure that the best value chemicals are procured and that performance is consistent throughout the season. Accurate information regarding the relative performance of different chemicals at specific environmental conditions will aid in decision-making to optimize the chemical combinations and application rate. It is anticipated that at least 5% reduction in operating cost (or $200,000/year) could be achieved without compromising the level of service for the traveling public.
The ability of state DOT's to adequately clear roadways during winter weather conditions is critical for a safe and effective freight transportation system. Variables affecting winter maintenance operations include the type of precipitation, air and pavement temperature, traffic, wind, time of day, day of week, and maintenance equipment. The main objective of this study is to identify the best practices for normal deicing operations, based on the performance rating of deicing chemicals. Optimum deicer/brine ratios and the associated application rates will be determined for various weather conditions. The best practices will ensure effective deicing operation and economical use of deicing chemicals. Common deicing chemicals include sodium chloride, magnesium chloride, calcium chloride, calcium magnesium acetate, potassium acetate, potassium formate and carbohydrate (corn or beet) -based deicer solution. Deicers are in the form of pellets or liquids. Liquid deicers are commonly used for pre-wetting road salt or other chemicals, or used as liquid solution. Several laboratory tests for deicer performance evaluation have been developed. However, none of these tests have been correlated with field performance data nor have provided standardized results to ensure an acceptable performance in the field. Nebraska will serve as the test bed for this study although the results can be generalized to other locations. This is an ideal test site because a large quantity of automatic vehicle location (AVL) system data from NDOR plow trucks will be available. The AVL data includes truck location with GPS coordinates and time stampsIn addition, the snow plow trucks are equipped with digital cameras which take snapshots of the roadway. These on-board systems also will provide real-time surface temperatures, air temperatures, wind speed, deicer application rates, and roadway conditions. The field data will be available for correlation analysis with the data from laboratory testing through the use of Maintenance Decision Support System (MDSS). The correlations between the field deicing performance and the laboratory testing are crucial for the development of the best practices using competing deicing products for a variety of weather conditions. Costs of using competing deicing chemicals at different application rates will be compared. The end result will be clearer roads during snow events which will lead to a safer and more efficient freight (and passenger) roadway system.