CH480505A - Anti-ice and anti-snow coating for roads, bridges, and other traffic routes - Google Patents

Description

  

  Anti-ice and anti-snow coating for roads, bridges, <B> and other traffic routes </B> The present invention relates to a coating making it possible to eliminate ice and snow covering a roadway.



  We know the danger represented in winter by the unexpected presence of ice or frozen snow on a roadway, in particular on bridges, where the formation of worm is favored.



  Several ways are known to prevent the formation of ice or to remove snow and ice already deposited. In addition to purely mechanical means (snow plows), there are chemical means (NaCl, CaCl salts) which lower the freezing point of water;

    - heat-generating means (heating cables or wires, embedded in the mass of the pavement or on the surface, pipes distributing a heat-carrying fluid on the roadway), which obtain the melting of the snow or ice by adding calories required.



  Purely mechanical means do not remove the last layer of snow or ice.



  Chemical means are generally corrosive and consequently destructive and ruinous for the road; they are also quickly eliminated by the circulation and must be renewed frequently.



  The heat generating means are expensive to install and operate; some even cannot be installed without having to completely redo the roadway.



  The object of the present invention is to overcome these disadvantages.



  It consists of an anti-glaze and anti-snow coating to be applied on a roadway, characterized by its constitution comprising in a binder impermeable to water and water vapor, an aggregate made up of highly hygroscopic salts lowering the freezing point of the water. 'water and / or products causing an exothermic reaction on contact with water. The coating is therefore composed of two distinct groups 1) the binder 2) the aggregate.



  1) The binder can be made of synthetic resins reacting by polyaddition or polymerization, such as epoxy or polyester resins, optionally provided with colored pigments. <B> It </B> can also be constituted by other materials , however, it is important that it is completely watertight and water vapor tight.



  Excellent results have been obtained in particular with epoxy resins, during laboratory tests relating to - the resistance of the coating to traction and to compression; - its resistance to abrasion; - its behavior during cyclic freezing and thawing tests; - its waterproofness; - its grip on a roadway.



  2) The aggregate consists of chemicals, generally highly hygroscopic, such as calcium chloride, sodium chloride, silver iodide, for example. Use will preferably be made of calcium chloride, which is very highly hygroscopic and inexpensive; in addition, it has the advantage of greatly lowering the freezing point of water.



  These highly hygroscopic salts will usually be mixed with chemicals having the characteristic that in contact with humidity an exothermic reaction occurs. It is therefore possible to use quicklime, the reaction of which is strong and rapid, by adding thereto, for example, powdered magnesium or in crystals, the reaction of which is slower, or caustic soda.



  In the plaster thus prepared, each molecule or group of molecules of the mixture of the different chemicals constituting the aggregate will be enveloped by the binder impermeable to. humidity. The coating will thus be in the form of a very large quantity of cavities containing the aggregate, stuck to each other by the binder, but without communication between them.



  Thus when a vehicle or a pedestrian passes over the pavement thus coated and by the friction of the tires or the soles on the plaster, a large number of cavities will be opened and will provide passage to humidity, which, coming into contact with the various chemicals composing the aggregate, will cause the desired chemical reactions, namely a release of calories, preventing the formation or causing the fusion of the worm and / or the lowering of the freezing point of the water, preventing new ice formation.

   If a snowfall occurs, this salt-saturated water will melt the flakes as they fall onto the pavement.



  The more intense the traffic, the stronger and more prolonged the reaction, since a greater quantity of chemicals is. The coating must therefore exhibit a carefully chosen abrasion resistance.



  The service life of the coating therefore depends on its thickness, its abrasion resistance and the intensity of the traffic. It must be composed and applied according to these different factors. .

 

Claims (1)

CLAIM Anti-ice and anti-snow coating to be applied on a roadway, - characterized by its constitution comprising in a binder impermeable to water and water vapor, an aggregate made up of highly hygroscopic salts lowering the freezing point of the 'water and / or products causing an exothermic reaction on contact with water.