Accession Number : ADA119681

Title :   Optimizing Deicing Chemical Application Rates,


Personal Author(s) : Minsk,L David

PDF Url : ADA119681

Report Date : Aug 1982

Pagination or Media Count : 63

Abstract : Snow and ice control on highways has come to rely heavily on the use of sodium chloride to maintain a trafficable surface for unimpeded movement. Empirical approaches have led to a wide range of application rates, some clearly excessive, but justified on the ground of safety and expediency. The combination of environmental degradation from the huge quantities of salt entering the environment, along with the increased cost of salt itself and the cost of its application have spurred the search for more precise knowledge of the proper amount of salt to apply to a pavement, considering a range of environmental, traffic and chemical parameters. Since controlled tests in the field are extremely difficult to make, a circular test track of three test pavements, dense-graded asphaltic concrete (DGA), open-graded asphaltic concrete (DGA) and portland cement concrete (PCC), was constructed in a coldroom, Natural snow and ice were applied to the pavements and an instrumented slipping wheel was driven over the surfaces to generate frictional forces. These forces were measured and then used to evaluate the response to salt application with time for three test temperatures. OGA had the lowest friction values at a temperature near the freezing point, but higher initial values or more rapidly increasing values than DGA and PCC following salt application at the two lower temperatures. Optimum application rate of salt on PCC and DGA lies between 100 and 300 lb/lane mile(LM), and a higher rate resulted in slight or no improvement in friction. DGA showed anomalous results: lower friction for 300 lb/LM and higher friction for both 100 and 500 lb/LM. (Author)

Descriptors :   *Roads, *Deicing materials, Dispersing, Rates, Friction, Asphalt, Concrete, Snow, Tires, Test facilities, Laboratory tests, Automotive vehicles, Field tests, Roads, Skidding, Chlorides, Concentration(Composition), Optimization

Subject Categories : Snow, Ice and Permafrost
      Civil Engineering

Distribution Statement : APPROVED FOR PUBLIC RELEASE