Effects of Deicers on Concrete Deterioration

Abstract

For periods of up to 95 weeks, concrete specimens were exposed to weekly wetting and drying cycles in either distilled water or in solutions of sodium chloride (NaCl), calcium chloride (CaCl sub 2), magnesium chloride (MgCl sub 2) and calcium magnesium acetate (CMA) with either a 1.06 molal ion concentration, equivalent in iron concentration to a 3% solution of NaCl, or a 6.04 molal ion concentration equivalent in ion concentration to a 15% solution of NaCl to test the effects of deicers on concrete deterioration. Specimens also received air-only exposure. Based on changes in specimens' physical appearance at the conclusion of the tests, as well as changes in the dynamic modulus of elasticity, exposure effects were evaluated. An increase and a decrease in dynamic modulus of elasticity, principally due to moisture content changes, were shown in concretes exposed to distilled water and air, respectively. There was no observable negative impact on these specimen's properties, overall. There was a relatively small negative impact by NaCl and CaCl sub 2 on concrete properties at lower concentrations. NaCl had greater negative effect at high concentrations, but overall it was still relatively small. Measurable concrete damage could be caused by MgCl sub 2 and CMA at low concentrations. Significant concrete changes resulting in stiffness and strength reduction and loss of material could be caused by CaCl sub 2, MgCl sub 2, and CMA at high concentrations.