Abstract
This study shows the results of indoor test at low temperature, on the de-icing action and the melting action of sodium chloride (NaCl) and other chemicals used for winter road maintenance. (1)As to the de-icing action, it was tested that the relation between the changes in the composition of phase and the skid resistance on road after applying chemicals.
The solution on the road will not only be effective in lowering the freezing point, but also be helpful in improving skid resistance, as follows,
(1)The skid resistance is already documented to decrease remarkably as soon as the water on the road has frozen. However, the solution on the road does not become slippenly at the freezing point.
(2)Even when the temperature goes down below the freezing point of the solution, increase of the skid resistance is expected more than the case of perfectly icy road surface.
(2)As to the melting action, the relation between the temperature of ice and the amount of melting ice after adding chemicals was tested to clarify the ice-melting effect by chemicals. As the result, it was concluded that ice-melting degree (ice-melting amount, ice-melting velocity) by chemical is liable to be controlled by the up-and-down variation of the tem- perature.
