A laboratory study was conducted to determine the undercutting and disbondment characteristic of 10 chemical deicers. The materials included six discrete deicing chemicals and four blends: calcium chloride pellets, calcium chloride flakes, two sodium chloride products, potassium chloride, pelletized urea, sodium chloride with a small amount of carboxymethocellulose, a blend of sodium chloride and potassium chloride sprayed with urea, a blend of sodium chloride and urea, and calcium magnesium acetate. In the undercutting tests, deicer particles were distributed on 6- x 9- x 2-in. Concrete slabs coveredwith a 1/8-in. Layer of ice. Tests were conducted at temperatures ranging from 0 deg f to 25 deg f in 5 deg f increments. Results were photographed and subsequently measured with a computerized stylus. The disbondment test apparatus measured and recorded the horizontal and vertical forces required to remove ice from a concrete specimen as it was drawn beneath a stationary blade. Each deicer was applied to the 1/8-in. Ice samples and allowed to undercut for 30 min beforedisbondment forces were recorded. The tests showed that at least a 95% complete undercutting is necessary for ice removal by mechanicaldisbondment forces of 2.8 Lb per inch of blade width. This paper appears in transportation research record no. 1268, Highway maintenance operations and research 1990.
Abstract