BRAKING TRACTION ON SANDED ICE

Traction enhancement on iced pavements using abrasives was evaluated. The abrasives tested were five distinct gradations of sand built from a single host material. Four of the sands represented standard gradations as specified by the FAA, SAE, ASTM, and Transport Canada. Braking traction at a relatively fixed slip rate was measured with a full-size, self-contained instrumented vehicle. All tests were performed on an ice sheet inside a large refrigerated room. Results showed that coarse sands perform best on cold ice surfaces and that finer sands excel on warm ice. Sands with most of their grains about 1 to 2 mm in diameter performed well independent of ice temperature. The concentration of a sand on ice strongly influences the degree of traction enhancement, as does the temperature of the sand when applied to the ice. The results suggest that a mathematical expression could be generated that would relate sand type and concentration, along with several other influential parameters, to braking traction coefficient on ice.