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Evaluation of Alternate Anti-Icing & Deicing Compounds Using Sodium Chloride & Magnesium Chloride as Baseline Deicers

Started: June, 2006 Ended: December, 2008 Project ID #4W1095 Status: Completed

Objective

Project Objective The overall goal of this project was to evaluate potassium acetate (KA) and sodium acetate/formate blend deicers (or possibly potassium formate) as alternative anti-icing and deicing compounds relative to NaCl salt-sand mixtures and MgCl2 (baseline deicers) based on various criteria specified by the Colorado Department of Transportation (CDOT).

Abstract

During the winter months, snow and ice control operations are crucial tools to ensure the safety of traveling motorists on highways in northern states. Research has indicated that the detrimental environmental impacts of abrasives (such as sand) generally outweigh those of salts. For example, seven times more material is required to treat a given distance of roadway when using sand as an abrasive as opposed to using salt. Therefore, studies such as this one are being conducted to research baseline deicers as an alternative to abrasives. Chloride-based deicers, known as road salts, play a key role in ensuring safe winter-driving conditions. These road salts can be found in a variety of snow and ice control products that are usually spread out on roadways to melt ice and snow by lowering the freezing point of the snow-salt mixture. These chemicals are used on winter roadways to either prevent the bonding of ice to the roadway (anti-icing) or break the bond between ice and the roadway (de-icing). In recent years, there has been a transition from reactive strategies (deicing and sanding) to proactive strategies (such as anti-icing) adopted by transportation professionals across North America. The ultimate goal of a winter highway maintenance program is to deliver the right type and amount of materials in the right place and time. The U.S. applies approximately 15 million tons of salts each year and spends 2.3 billion annually to keep roads clear of snow and ice. NaCl is one of the most commonly used deicers, as it has been traditionally abundant and inexpensive. However, its effectiveness is minimal below pavement temperatures of 10 degrees Fahrenheit. In addition, NaCl may become unusable due to problems with equipment, storage, handling, mixing, application, and industrial hygiene. The use of such large quantities of salts has raised concerns about their adverse impacts on motor vehicles, the transportation infrastructure, and the environment. Due to concern over potential increases in chloride concentrations in receiving streams, the Federal Highway Administration (FHWA) has begun encouraging the use of acetate-based deicers such as potassium acetate (KA) near environmentally sensitive streams. Acetates offer attractive alternatives to chloride-based deicers due to their non-corrosive characteristics, benign impacts on surrounding soils and ecosystems, and minimized adverse human health effects. Disadvantages of acetate-based deicers include the additional amount of product needed and the associated cost, air pollution, and poor performance in thick accumulations of snow and ice and in temperatures below 23 degrees Fahrenheit. This project will continue to investigate and research the use of chemicals to improve winter road conditions and driver safety.

Contacts

Files & Documents

Sponsors & Partners

  • Colorado Department of Transportation Sponsor

Part of: Winter Maintenance and Effects, Corrosion and Sustainable Infrastructure Laboratory

Project Tagged In: corrosion, Alternative deicer, acetates

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