Frictional Characteristics of Sand and Sand-Deicer Mixtures on Bare Ice

• Published in: Transportation Research Record: Journal of the Transportation Research Board
• Main Authors: Hossain, M. Makbul, Bajorski, Peter, Yang, Wei-Shih
• Format: Article in Journal/Newspaper
• Language: English
• Published: SAGE Publications 1997
• Subjects: Mechanical Engineering; Civil and Structural Engineering; Ice Sheet
• Online Access: http://dx.doi.org/10.3141/1585-05; http://journals.sagepub.com/doi/pdf/10.3141/1585-05

Frictional characteristics of sand and sand-deicer mixtures were investigated as functions of temperature, gradation, and application rate. Results of a laboratory cold-room study in which sliding friction was measured with a British pendulum tester are described. Four temperatures, three sand gradations, four brine concentrations, and four sand-application rates were investigated. All tests were performed on an ice sheet in a cold room, where sand temperatures were maintained close to ice temperatures. Three categories of materials were tested: sand alone, sand-salt mixtures, and sand-brine mixtures. Results showed that sand-brine mixtures outperformed the other two, with significantly greater sliding friction. Two brine concentrations were found suitable in two temperature ranges. Below −12°C, 2.5 percent brine (by weight) gave good results with a fine sand (passing the No. 30 U.S. sieve but retained on the No. 50 sieve) at a sand application rate of 1 g over a test area of 100 × 200 mm, with a sand-to-brine ratio of 1:1 by weight. This rate is equivalent to field application of 183 kg of sand per lane-km. Friction was achieved by generating a bond between sand and ice by using a low-concentration brine (2.5 percent by weight). At temperatures above −12°C, satisfactory results also were obtained with 25 percent brine mixed with the same sand at a ratio of 2:1 by weight. In this case, friction was increased by roughening the ice surface with a higher-concentration brine (25 percent by weight).