Fire protection of metal and wood with special substances.
Fire protection of metal and wood with special substances
Fire protection of wood
Fire protection of woodspecial compounds that take the form of solutions or mixtures, aimed at protecting materials of organic origin from ignition. Most compounds for fire protection of wood and fabrics have a transparent or slightly colored texture. According to the developments made by the All-Russian Research Institute of Fire Defense of the Ministry of Internal Affairs of Russia, fire protection of wood should be carried out in accordance with clear requirements, since the fire safety of the structure depends on it. Fire protection substances must be packed in containers with clear markings, the packaging must prevent the loss of fire-retardant properties of the composition during the shelf life. Fire protection of wooden structures is carried out by treating wood with special agents — fire retardants. Currently, two main methods are used: fire protection of structures made of wooden materials using special paints and varnishes and using mixtures of fire-retardant salts. The latter method is recognized as more effective and universal. Fire protection of wooden structuresis applied to the surface of materials in several ways: with a brush, sprayer and by immersing wooden parts in the solution. When applying the substance, it is necessary to use respirators and gloves. Impregnation of wooden structures with a fire retardant substance is carried out at a temperature above zero ° C, best of all, at + 10/+ 15 ° C, while the material must be treated at least three times in a row. The interval between applying layers of fire retardant substance should be at least six hours. Fire protection of wood based on impregnations is ensured by the chemical interaction of the impregnation components with wood cellulose, which makes the surface layer of the wooden structure as resistant to flame as possible. Modern fire retardant impregnations are also characterized by bioprotective and antiseptic properties, therefore they are able to protect the wooden structure from mold and wood-staining fungi, and also increase the service life.Fire protection of wooden structuresbased on paints is ensured by the creation of a heat-protective layer that protects the surface of the structure from combustion. To obtain high quality fire resistance of the material, it is enough to apply a thin layer of the agent, no more than a few millimeters thick. When choosing a composition for fire protection, pay attention to the fact that all such substances must pass a test for fire protection efficiency and certification tests, based on the results of which the manufacturer must have the relevant documents on hand.
Fire protection of metal
The fire resistance limit of metal structures is from 0.1 to 0.4 hours, while the minimum values of the required fire resistance limits of the main building structures, including metal, are from 0.25 to 2.5 hours, depending on the degree of fire resistance of buildings and the type of structures.
Fire protection of metal structuresis based on the creation of heat-insulating screens on the surface of structural elements that can withstand high temperatures and direct exposure to fire. The presence of these screens allows slowing down the heating of the metal and maintaining the structure's functions during a fire for a specified period of time. Fire protection treatment of metal building structures is carried out using such fire-retardant compounds as paints, mastics, and plaster compounds. Fire protection of metalalso increases the degree of fire resistance of metal in case of fire, and preserves structures for a specifically planned period. The substance performs the function of slowing down the heating of metal in its fluid state, which prevents the violation of the geometric parameters of the structure and the destruction of structures. Fire protection of metal ensures the safety of structures for up to 30 and up to 180 minutes at a heating temperature of more than 500 degrees. As in the case of wood, fire protection of metal structuresis produced in several ways. The most effective methods are concreting and plastering metal structures with cement-sand mortars, or special heat-insulating plaster. Modern methods of fire protection of metal structures are provided by means of heat-insulating plasters consisting of cement or gypsum, perlite sand or vermiculite, liquid glass; fire-protective coatings made of asbestos or granulated mineral fiber, liquid glass, cement, etc.; intumescent paints, which are complex systems of organic and inorganic components. The fire-protective effect of these paints is based on the swelling of the applied composition at temperatures of 170-200C’ and the formation of a porous heat-insulating layer, the thickness of which is several centimeters.
As in the case of wood, fire protection of metal structuresis produced in several ways. The most effective methods are concreting and plastering metal structures with cement-sand mortars or special heat-insulating plaster. Such methods of fire protection of metal structures are provided by means of heat-insulating plasters consisting of cement or gypsum, perlite sand or vermiculite, liquid glass; fire-protective coatings made of asbestos or granulated mineral fiber, liquid glass, cement, etc.; intumescent paints, which are complex systems of organic and inorganic components. The fire-protective effect of these paints is based on the swelling of the applied composition at temperatures of 170-200C’ and the formation of a porous heat-insulating layer, the thickness of which is several centimeters, which significantly increases the degree of fire resistance of metal structures. The most modern method is recognized as fire protection of metal with special paints that increase in volume. The essence of its protection is that at temperatures above 500 degrees, the paint composition begins to increase in volume, forming a porous heat-insulating layer several centimeters thick. Thus, when exposed to high temperatures, a foamed layer is formed, which is a coked melt of non-combustible substances. The formation of this layer occurs due to gas and vapor substances released during heating. The coke layer has high heat-insulating qualities, and thus provides the most effective fire protection of metal.