01024575

Component

https://doi.org/10.3141/1979-10

http://scholar.google.com...ston&publication_year=2006

Many state highway agencies use various chemicals to deice or anti-ice pavement and bridge surfaces. Most often these are aqueous solutions of various chlorides (e.g., magnesium chloride, sodium chloride, and calcium chloride) or other chemicals such as calcium magnesium acetate, urea, or others. Possible detrimental effects to concrete caused by these chemicals have not been fully examined and documented. Mortar specimens of three different water-to-cement ratios (0.4, 0.5, and 0.6) were immersed in concentrated solutions of various chemical deicers and held above freezing at a constant temperature of 40 deg F up to 84 days. Considerable expansion and cracking were noted in specimens immersed in the MgCl2 and CaCl2 solutions. Petrographic analysis and quantitative microanalysis were used to positively identify the presence of Mg(OH)2 (brucite) formation in the outer layers of the specimens. Furthermore, the results presented clear evidence of calcium oxychloride formation in the specimens analyzed. Further research is being conducted, including the same immersion test at 40 deg F on portland cement concrete specimens, to identify whether this distress mechanism is of concern for structures such as roads and bridges when subjected to deicing chemicals containing CaCl2 or MgCl2.

01039954

English

pp 60-68

2006

Transportation Research Record: Journal of the Transportation Research Board

0309099897

Print

Figures (9) ; Photos (4) ; References (10) ; Tables (2)

Calcium chloride; Calcium magnesium acetate; Cracking; Deicing chemicals; Expansion; Magnesium chloride; Microanalysis; Pavement distress; Petrography; Portland cement concrete; Sodium chloride; Temperature; Urea; Water cement ratio

Brucite; Calcium oxychloride

Highways; Materials; I32: Concrete

PRP, TRIS, TRB

Mar 3 2006 11:03AM

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