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Inhibitor Longevity and Deicer Performance Study

Started: January, 2008 Ended: December, 2010 Project ID #4W1978 Status: Completed

Objective

The objective of this research is to evaluate the cost effectiveness of corrosion inhibitors in deicing chemicals, and their longevity when in storage or on the road. The project also aims to establish a reliable measure to quantify the performance of anti-icing and deicing chemicals.

Abstract

In the northern United States and Canada, snow- and ice-control operations are essential to ensure the safety, mobility and productivity of winter highways. These maintenance activities offer direct benefits to the public, such as fewer accidents, improved mobility and reduced travel costs. They also offer indirect benefits such as sustained economic productivity, reduction in accident claims and continued emergency services. Depending on weather, available resources and local practice, maintenance agencies use a combination of tools for winter road maintenance including anti-icing, deicing, sanding and snowplowing. In recent years, transportation agencies have been shifting from reactive strategies, such as sanding, to proactive strategies, such as anti-icing. Anti-icing can lead to decreased use of chemicals and abrasives, decreased maintenance costs, improved level of service, and lower accident rates. Reliable weather forecasts are key to a successful anti-icing program, as the pavement surface temperature dictates the application rate and timing. When conducted properly, anti-icing can reduce plowing, decrease the quantity of chemicals required and, in many cases, eliminate the need for abrasives . The growing use of deicers has raised concerns about their effects on motor vehicles, transportation infrastructure, and the environment. The types of deicers applied onto highways often contain chlorides because of their cost-effectiveness. Acetate-based deicers (potassium acetate, sodium acetate, and calcium magnesium acetate [CMA]) have been used as non-corrosive alternatives. Electrochemical and weight loss tests have indicated that bridge structural metals corroded considerably less in CMA solutions than in NaCl solutions. Formates (sodium formate and potassium formate) and bio-based products have also emerged as potential alternative deicers, however these have not been widely used mainly due to their high cost, potential impact on concrete and toxicity to aquatic resources. The costs due to corrosion induced by winter maintenance practices have led to the addition of corrosion inhibitors to chloride-based deicers. The inhibitors are often organic and significantly increase the cost. Uncertainties regarding their longevity and performance need to be resolved before decisions can be made regarding the cost-effectiveness of their use. The objectives of the proposed research are to evaluate the longevity of corrosion inhibitors in storage and on the road and their cost-effectiveness, and to establish a reliable measure to quantify the performance of anti-icing and deicing products. Specifically, this Transportation Pooled-Fund study will use laboratory investigation and field tests to answer the following important questions: 1) What is the longevity of the corrosion inhibitors, when in storage or on the road? 2) How long do the inhibitors remain with the deicers when applied onto the road? 3) What are the effects of storage (temperature, UV intensity, exposure time, and type of deicer) on inhibitor longevity and effectiveness? 4) Do the inhibitors contribute to freezing-point suppression or improve the effectiveness of deicers? 5) How does the laboratory test protocol correlate with deicer performance in the field? 6) What is the most effective product to use and its optimal application rate to combat ice formation under various typical road weather scenarios? By answering the first four questions, this research will allow the transportation agency to determine whether the inclusion of inhibitors into liquid or solid deicers is cost-effective, taking into account: the acceptable deicer corrosivity and reasonable duration of protection expected of inhibitors.

Contacts

Files & Documents

Sponsors & Partners

  • Washington Department of Transportation (WSDOT) Sponsor

Related Information

Part of: Winter Maintenance and Effects, Transcend

Project Tagged In: corrosion inhibitor, snow and ice control, longevity

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