We conducted an extensive literature review and performed laboratory tests to assess the effect of chloride-based deicers on the rebars and dowel bars in concrete and to determine whether or not deicer corrosion inhibitors help preserve the transportation infrastructure. The laboratory investigation exposed concrete samples to four common chloride-based deicers for approximately one year or less, for natural diffusion at room temperature or for cyclic exposure with wet/dry and temperature cycling. Under the experimental conditions in this study, the corrosion inhibitors in deicers helped to preserve the strength of concrete undergoing temperature and wet/dry cycles. While they also slowed down the chloride ingress and subsequent corrosion initiation of steel in concrete, such benefits seem to diminish once the active corrosion of the rebar is initiated. There were small differences in the corrosion behavior of various dowel bars investigated, limited by the short duration of this study. Corrosion inhibitors and other additives in deicers did not show significant benefit in inhibiting the chemical changes of concrete induced by cations and/or anions in deicers. Agencies should be aware of the deleterious effects magnesium chloride deicers can pose on the concrete strength, even though the inhibited magnesium chloride deicers can pose less corrosion risk for steel in concrete, relative to sodium-chloride-based deicers with or without inhibitor. To anticipate better return on investment regarding the preservation of reinforced concrete, agencies should focus on improved concrete mix designs with less permeability instead of procuring the more costly (inhibited) deicers.
August 16, 2010
Xianming Shi, Yajun Liu, Matthew Mooney, Michael Berry, Barrett Hubbard, Laura Fay, Andrea Beth Leonard.
Western Transportation Institute. Montana State University
- # of Pages: 174 p., 4.48 MB (PDF)
- Subject: Deicing chemicals, Reinforced concrete pavement, Corrosion protection, Strength of materials, Preservation, Reinforcing bars, Dowels (Fasteners), Reinforcing steel, Snow and ice control, Corrosion resistant materials, Permeability, Concrete.
- Keywords: Winter maintenance, snow and ice control, deicing chemicals, rebar corrosion, dowel bar corrosion, reinforced concrete, chloride ingress, sodium chloride, magnesium chloride, calcium chloride.
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This abstract was last modified January 22, 2013