In cold climate regions, chemicals are often applied on roads to facilitate snow and ice removal. A commonly used performance indicator is the ice melting capacity. There is a growing need for stakeholders to measure melting capacity as more commercial products for deicing become available. There are two standardized test methods for measuring melting capacity, SHRP H-205.1 for solid deicers and SHRP H-205.2 for liquid deicers, but there have been concerns that these tests are not accurate. Researchers have developed alternative test methods, including the shaker test, the mechanical rocker test, and the ice cube titration test. This paper summarizes published data on measured melting capacity for sodium chloride (NaCl). The published data were compared with the calculated melting capacity of NaCl. The findings confirm that SHRP tests have low reproducibility and are not able to measure full melting capacity. The newer test methods measured closer to full melting capacity than the SHRP tests did. They also showed improved accuracy, although more data from the newer test methods are needed before conclusions can be drawn.

The ability to melt snow and ice is an important feature of any deicing chemical or product. This ability is called the “melting capacity” and is defined as the grams of melted ice per gram of deicer. A product’s melting capacity determines its applicability for use in snow and ice control. The standard procedures in the United States for measuring melting capacity are SHRP H-205.1 for solid chemicals and H-205.2 for liquid chemicals. However, these test methods have proved to be inadequately accurate for research purposes. There is a growing need to develop improved procedures as more deicing products are released on the market. This paper describes how calorimetry, which measures the heat changes that occur during a process, may be used to measure melting capacity. A calorimeter was custom made for the research described in this paper. The calorimeter required minimal mechanical handling and had high-precision temperature control that excluded the most extreme causes of measurement errors in previously developed test methods. Liquid sodium chloride was tested and compared with the calculated melting capacity. The calorimeter produced accurate results. Tests were also performed on magnesium chloride; the results demonstrated that magnesium chloride had a higher melting capacity than sodium chloride.

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Cold climates cause a great number of challenges when it comes to maintaining road conditions. For instance, snowstorms, frost and ice can all create slippery and even impassible roads. Therefore, in order to ensure vehicular mobility and general road safety, winter road maintenance requires the use of plowing and applying sand or various chemicals. Regarding the latter method, chemicals are applied to weaken bonds in snow and ice, melt snow and ice or prevent ice from forming on the road. A deicing chemical must thus comprise several important elements, one very important element being its ability to melt snow and ice, which is also called its ice melting capacity.