Fighting against ice in different countries
Every year, the utility service and residents of different countries with snowy winters face with the same problem: snow drifts and ice. If the snow drift is just inconvenient and difficult to move, then the icing on the roads and sidewalks is dangerous for health and life. In different countries, this problem is solved differently. We shall consider 5 ways to fight against ice, used around the world.
This method was used 40 years ago and it is still sprinkled on the roads and sidewalks of Moscow and other cities of Russia. This method is very cheap, however, the salt is an active chemical, it can lead to corrosion of metal products, spoils clothes and shoes, can cause allergies in humans and corrodes the skin of animals and birds. Not to mention the fact that the salt is absorbed into the ground and can get into the ground water, rivers, soil.
In Moscow, the problem is solved in the proactive way: before the snowfall, roads and pavements are treated with a liquid mixture of the calcium salt of hydrochloric acid and dietary salt (28%).
In other cities, the main method of removing snow and ice is a mixture of sand and salt: in the afternoon sidewalks and roads are sprinkled with this reagent and in the evening they clean the snow.
Because of the constant changes in temperature, on the roads of St. Petersburg frost or slush appears. Petersburg communal services use technical salt, the cheapest reagent. In addition there are roads treated with sand or special blend «Bionord», which consists of 3 components: bishofit (magnesium chloride), salt (sodium chloride) and calcium chloride. However, if the thermometer below — 10 ° C, the effectiveness of the reagent decreases.
Stone chippings and sand
Is used by many European countries, including Austria, Germany, Sweden, Finland and others.
Nowadays, the European countries almost do not use chemicals for removal of the snow and ice. Salt may only be used in hazardous areas of roads, such as in Berlin. In other cases, a gravel and rock dust are used — they are certainly more expensive than salt and sand, but are more economical because they can be reused and do not harm the environment.
This method is called friction: it does not remove the frost, but improves traction. To use friction method for icing, you need to follow certain condition — after or during a snowfall to clean the road almost to the asphalt. In some cities, you can find special boxes with gravel, which can be used by the pedestrians.
Torgeir Vaa Method
Swedish scientist Torgeir Vaa invented a new way to deal with snow and ice, the sand mixed with hot water (at 100° C) and sprayed on roads and sidewalks. Hot water melts the snow, after solidification, due to literally melting the sand; the surface becomes rough and not slippery. The surface can treated this way every 3-7 days or until the new snowfall. However, for such works must the special expensive equipment must be used.
In America and Canada for the treatment of roads primarily magnesium chloride (bishofit) is used. It is effective, but has even more corrosive effect on metal then the technical salt.
The following method is used throughout the New Zealand. Roads are processed with calcium magnesium acetate or calcium chloride. Acetate hazard to metals can be compared with water and it doesn’t affect the environment. The disadvantage of this method is its limitation on the use of temperature — just to — 7°C, and a pretty high cost.
One of the methods of organic icing is the application of urea (carbamide, diamide of carbonic acid). Since the substance has virtually no harm to the metal, it is most often used for the treatment and disposal of ice with suspension bridges. Urea is non-toxic, but it is many times more expensive that salt and isn’t effective for large cities.
In some cities in Japan during the winter there’s big snowfall, but the utility services doesn’t clean the roads, they only take away the snow. Ice in Japan is a common phenomenon, though in some cities the asphalt is heated, so all the snow melts immediately and ice just doesn’t form. Sidewalks near the houses are cleaned by the locals, not by the employees of special services. Studded tires, by the way, are prohibited in Japan.
In many cities of the world the «winter problem» is solved in this way, that is — the snow is not removed in principle.