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Lab Investigation of Deicer Impacts on Concrete Microstructure and Pavement Friction Coefficient

Started: January, 2008 Ended: December, 2008 Project ID #4W2007 Status: Completed

Results & Findings

This research examined the impacts of various deicer products on the microstructure of concrete and the friction coefficient of pavement materials. As such, this project will further the understanding of deicer performance, which will assist the Colorado Department of Transportation in their current research efforts to identify safe and effective alternative deicer products. In the long-term, the research may allow all DOTs to utilize better decision-making and management practices with respect to reducing the amount of chemicals and cost for snow and ice removal operations while providing safe, reliable winter highways for the traveling public.  These findings may help DOT professionals to use a more comprehensive and systematic approach to selecting deicer products, an approach that considers not only cost and effectiveness, but also corrosive and environmental impacts.  In addition, bridge and pavement engineers may be able to use this information to improve design specifications for structures such as roads and bridges.

Objective

The purpose of this project was to conduct a laboratory investigation of the impact of deicers on two key performance components of concrete pavement materials.

Abstract

In cold-climate regions such as the northern U.S. and Canada, large amounts of solid and liquid chemicals (known as deicers) as well as abrasives are applied onto winter highways to keep them clear of ice and snow. Transportation agencies are under increasing pressure to maintain high levels of safety and mobility even during the winter months, while working with limited financial and staffing resources and recognizing the corrosion and environmental challenges related to chemical and material usage. Currently, maintenance personnel at the Colorado Department of Transportation (CDOT) utilize two primary compounds for anti-icing and deicing operations, i.e., NaCl (salt) mixed with sand, and MgCl2 liquid deicer. According to the field experience by CDOT, MgCl2 outperformed the salt-sand mixture as a deicer, demonstrating that it is more effective, less toxic, and less corrosive. It also significantly decreases the amount of sediment entering Colorado’s streams and particulates entering the air. CDOT has thus shifted from using primarily NaCl and sand to using MgCl2 liquid deicers for wintertime operation and maintenance of state and national highway systems over the past several years. However, some local governments have banned the use of MgCl2 and returned to using salt-sand mixtures. Consequently, CDOT is interested in efforts to further examine the suitability, acceptability, and good performance record demonstrated by MgCl2 and the continued use of salt-sand mixtures. To this end, CDOT is sponsoring a current research program to identify non-corrosive, environmentally friendly, and cost-effective deicers with good performances in anti-icing and deicing. Through this project, WTI will conduct complementary laboratory testing that will provide additional information through the application of novel laboratory techniques. Specifically, the laboratory investigation will focus on evaluating the impact of deicers on the microstructure of the concrete and on the pavement friction coefficient, two key performance components with infrastructure and safety implications.

Contacts

Files & Documents

Sponsors & Partners

  • Research and Innovation Technology Administration (RITA) Sponsor
  • Colorado Department of Transportation Partner

Part of: Winter Maintenance and Effects, UTC, WTI-1, Corrosion and Sustainable Infrastructure Laboratory

Project Tagged In: Anti-icing, deicers, pavement friction, concrete microstructure

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