The effect of CMA deicers on concrete properties

The paper presents the results of an investigation of the effects of concen trated calcium-magnesium acetate (CMA) solutions on concrete. Concrete spec imens were manufactured following guidelines for structures exposed to free ze-thaw cycles and deicers (water-cement ratio, w/c = 0.45 and air-entraini ng admixture) employing two cements obtained by blending a Portland clinker with 20% of ground limestone, or 40% blast furnace slag. Following 28 days of curing, the specimens were immersed for 8 months at 20 degreesC in two concentrated (25%) CMA solutions prepared using (a) a commercial CMA-based deicing chemical or (b) pure calcium and magnesium acetates blended to obta in the same Ca/Mg molar ratio (0.43) as the deicer. Continuous exposure to both CMA solutions led to a significant decrease in load capacity, mass los s and marked visual deterioration The aggression was particularly strong in the case of the deicer solution, and was mitigated by the use of the slag cement. (C) 2000 Elsevier Science Ltd. All rights reserved.