During the 1987-1988 winter maintenance season, calcium magnesium acetate (cma) and cma-coated sand were applied to the northern half of a 7.5-Mile section of four-lane freeway, us-14, located just south of madison, wisconsin. Road salt (sodium chloride) was applied to the southern half of the section for coparison purposes. The moderately severe winter, with 52.4 Inches of snow during the application period, provided a good basis for coparison of the two deicers. In order to achieve "bare pavement" on us-14, 48% more tons of cma and cma-coated sand than salt were applied, based on lane-mile adjusted driver estimates of material used. About 1% less total "effective"or pure cma (i.E., Excluding the weight of the sand) was required compared with salt. The cma application required 70% more miles and 143% more hours compared with salt; however, some part of the additional cma application effort can be attributed to the dedication of a truck to the cma section while the salt truck had other highway sections to cover. Deicer performance measures were provided by subjective truck driver ratings and by objective field observations. As usedin wisconsin, cma had distinct disadvantages in handling and transport and somewhat poorer deicing performance than salt, but cma did provide at least a minimum level of deicing performance. Given the lower level of use of cma-coated sand and satisfactory performance in all but the coldest conditions, additional research on the economic feasibility of more extensive use of cma-coated sand may be warranted. Reductions in the cost of cma-coated sand may be possible by producing the cma locally and using locally available sand. This paper appears in transportation research record no. 1246, Winter maintenance, roadside management, and rating routine maintenance activities.
Abstract