Alexandria asbestos-cement products - asbestos steel sheet, asbestos cloth, brake tape LAT-2, EM-1, EM-K, asbestos crumb, SHAON cord, KAON asbestos cardboard, asbestos cutting fabric and delivery
Asbestos cement is a fire-resistant material consisting of cement with the introduction of asbestos fibers [1] [2]. The presence of asbestos in the structure of the fibers plays a bearing role and it is its presence that contributes to the increase in fire resistance.
Due to the reinforcing properties of asbestos fibers, the non-hardened asbestos-cement mass is characterized by high extensibility and plasticity, which makes it possible to produce various volumetric and figured products from semi-finished sheet products that have not yet hardened. In the solid state, the tensile strengths[3]:
bending up to 30 MN/m² (300 kgf/cm²)
for compression up to 90 MN/m².
Impact strength is 1800-2500 J / m² (1.8-2.5 kgf m / cm²). Density is 1550-1950 kg/m³.
Asbestos cement has durability, frost resistance (after 50 freeze-thaw cycles, a decrease in strength by 10%), water resistance, fire resistance, and chemical resistance.
Disadvantages: moisture deformation (without additional hydrophobization and reinforcement), brittleness, health hazard.
Manufacturing
Structure at the break of an asbestos-cement pipe
Asbestos-cement products are produced by pouring specially prepared asbestos fibers with Portland cement. The asbestos content is 12-20%, low-grade asbestos is usually used [3]. They are produced on sheet-forming machines or by continuous rolling of semi-dry mass. Products are used after complete solidification. The form factor of such products can be quite diverse: from plates (sheets), slate to pipes and products of a special shape. Asbestos-cement products have increased strength, fire resistance and water repellency. Typical products are roofing asbestos-cement slate, asbestos-cement pipes. Asbestos cement has found wide application in construction.
asbestos-cement structures and products
made of asbestos cement - a building material consisting of an aqueous mixture of cement and asbestos. Asbestos cement is used in construction from con. 19th century Blocks and slabs were made from it, which were easily cut with a saw, processed with an ax, it was possible to hammer nails into them, they were not afraid of fire and had electrical insulating properties. But due to the high consumption of asbestos, these products were not economically viable. The production of thin sheets from a mixture of asbestos with cement using cardboard machines, proposed in 1900 by the Czech L. Gatchik, turned out to be more profitable. Production of asbestos-cement products for con. 20th century has become a major industry. These are more than 3 thousand items in various branches of technology (construction, rocket science, fire fighting equipment, etc.). Many types of roofing material, drainage and sewer pipes, non-combustible fabrics, etc. are produced on the basis of asbestos cement. These products are durable, waterproof, fire-resistant, frost-resistant, and not subject to chemical attack. The most common asbestos-cement structures in construction, for example. for covering buildings (frame structures), creating internal partitions, lining elevator shafts, etc. Most asbestos-based industrial materials have no alternative.
The issue of environmental friendliness of asbestos cement is still open. There is an opinion that asbestos and products from it are dangerous for human health. The thinnest, invisible to the eye asbestos fibers, getting into the body, cause pulmonary diseases. Such diseases are indeed possible in people who work directly with asbestos. Therefore, at asbestos enterprises, air purification is the most important condition for safe work. As for the finished products made of asbestos, then, protected by two or three layers of paint, they are not at all dangerous, and the harmlessness of asbestos-cement pipes has been reliably proven by doctors.
Products
Asbestos-cement pipes are a promising type of multi-purpose product with a set of unique properties:
not subject to corrosion and decay
not prone to "overgrowth"
have high strength and low thermal conductivity
durable, cold hardy
several times cheaper than similar products made from other materials
Asbestos-cement pipes are still in great demand by builders. Non-pressure pipes are used: for laying communication cables and electrical cables, for constructing free-flow sewerage pipelines, for drainage collectors, for chimneys and air ducts, for drainage through roads and crossings, instead of metal and wooden posts for fences, for replacing bricks when constructing cellars, for overlapping roofs of garages and industrial buildings, for the construction of foundations. Non-pressure pipes are completed with polyethylene and asbestos-cement couplings. This allows you to exclude the weakest sections of the heat pipe. Pressure pipes are used: for laying pressure water supply, reclamation and irrigation systems, when laying pressure networks of drinking and industrial water, forporous sewerage, heating mains, ventilation, for thermal insulation in thermal units, for drainage collectors, chimneys, air ducts, gas ducts, for foundations in wetlands, for draining through roads and crossings, for fence posts, as casing pipes for wells, for manufacturing durable livestock feeders, trays, for the manufacture of garage floors, gutters. For example, asbestos-cement pipes have proven themselves well when used in heating systems. In countries such as Germany, Belgium, Austria, gas pipeline networks made of asbestos-cement pipes have been in operation for over 30 years. In the Russian Federation, a pilot 40-kilometer section has been in operation for 18 years.
The low coefficient of thermal conductivity of asbestos cement allows you to minimize the cost of thermal insulation. The pipeline from it does not require protection from the effects of stray currents and groundwater.
Cord asbestosThe cord asbestos of general purpose consists of fibers of chrysotile asbestos mixed with cotton and other chemical fibers. According to the structure, it is divided into two groups: without a core and with a core. Coreless cords are produced, ranging in size from 0.7 to 8 mm in diameter, which are a cylindrical body consisting of several additions of single-strand yarn twisted together. In this case, the direction of twist is opposite to the direction of twist of the single-filament yarn. Cords with a core are produced with a diameter of 10-25 mm. As the core, asbestos threads, yarn, roving in several additions or asbestos downy cord of the ShAP brand, entwined on the outside with asbestos thread, or yarn in several additions, are used. Are issued in reels or bays. It is used for thermal insulation of hot pipelines, as a seal in various thermal units. Working environment: gas, steam, water, working environment temperature up to + 400 gr.С, vibration-resistant.
Asbestos stuffing boxes
Asbestos stuffing box packings Asbestos and non-asbestos stuffing box stuffings are used to fill stuffing boxes to seal movable joints of various machines and devices. These materials are used in the chemical and petrochemical industries, mechanical engineering, metallurgy and metalworking, electrical engineering and power industry.
Sheet asbestosK sheet include profiled, flat and special purpose. Flat cladding sheets are produced: pressed (high strength) and non-pressed natural gray, painted or textured. They are used for interior decoration of auxiliary premises of residential and public buildings, panel cladding, sanitary cabins, as fences for balconies, stairs, etc. The products are distinguished by durability, high strength properties, fire resistance, bioresistance. They belong to the group of non-toxic and non-combustible materials. Not so long ago, facade slabs appeared, the basis of which are high-strength pressed asbestos-cement sheets. They are intended for facade cladding and interior cladding of residential, public and industrial buildings and structures, for the manufacture of wall panels, partitions, suspended ceilings and other structures for construction, except for ventilation shafts. A protective primer layer and a colored acrylic-polyurethane coating, resistant to atmospheric and mechanical influences, are applied to the base of the facade slabs. It can be additionally sprinkled with decorative crumbs, for example, from natural stone. The unique application technology allows obtaining coatings with high performance.
Asbestos Cement SlateAsbestos cement roofing slate is inexpensive, easy to install and one of the best known roofing materials. Asbestos-cement slate sheets are produced on sheet-forming machines by molding a mixture consisting of Portland cement (a hydraulic binder most commonly used in modern construction), asbestos and water, followed by hardening. Fine asbestos fibers, evenly distributed in the cement, form a reinforcing mesh that significantly increases the tensile strength of the slate and impact strength. A slate roof is several times cheaper than tiles and tin, and the simplicity of its construction makes it easy to equip the roof of your home. Solutions to a number of environmental, architectural and economic problems are the use of special water-dispersion paints applied to the front surface of the sheet. In the production of painted slate, persistent dyes are used, they have high hiding power, weather and light resistance, they are used for industrial and domestic coloring of slate and other asbestos-cement products, which are not only weatherproof, significantly extended in service life, but also aesthetically attractive. Asbestos-cement roofing is traditionally widely used in Russia. It is adapted for all climatic zones. Among other advantages are the comparative cheapness of materials (several times cheaper than tiles, metal, polymers), low costs forbut its content. In addition, building materials made from substitutes are far from always environmentally friendly.
Asbestos fabricsAsbestos fabrics - a fabric of interwoven asbestos threads containing from 5 to 18% binder fiber (viscose, cotton, lavsan) are used as a heat-resistant heat-insulating and cushioning material. They are used in the manufacture of industrial equipment, asbestos-textolites, for sewing heat-resistant clothing, as well as for the manufacture of rubberized fabrics. Supplied in rolls.
Asbestos cardboardAsbestos cardboard of general purpose - is used as a fire-retardant heat-insulating material, as well as for sealing connections of devices, equipment and communications. There are brands - for thermal insulation at a temperature of the insulated surface up to 500 ° C; and there are cardboard grades for sealing connections of devices, equipment and communications operating at a maximum pressure of the medium of 0.6 MPa and a maximum temperature of the medium, ° C: gases - 500; alkalis - 200; inorganic acids, except for fluorosilicic acid 120; solutions and melts of salts 400
Asbestos paper BT (heat-insulating) is made on the basis of chrysotile asbestos (asbestos chips). Asbestos content 98-99%. It is used for thermal insulation of hot surfaces (boilers, pipelines, heating elements), in the production and heat treatment of metals, sheets, etc. Temperature of insulated surfaces: up to + 500 degrees. Fire and explosion proof. Resistant to aging, decay and other biological influences. Asbestos electrical insulating paper is made from asbestos fiber processed as an aqueous suspension with a small amount of binder.
Special purpose products
Special-purpose products include rectangular or circular ventilation ducts, semi-cylinders to protect the thermal insulation layer of pipes from mechanical damage, sheets of double curvature for conveyor galleries, vaulted elements for the construction of summer pavilions of tourist bases, camps, etc. Waterproof umbrellas used in underground subway structures to ensure the watertightness of the supporting structures of the vaults. Arc-resistant asbestos-cement electrical products (ATSEID) are a good electrical material for a wide range of applications with increased arc resistance and electrical strength. They are used for the manufacture of electrical panels, parts and bases of electrical machines, arc chamber bodies, gaskets and plates, induction furnaces, electric furnace enclosures, etc., where protection and operation at high voltages are necessary. Also, ACEID is widely used as a building material (ceilings, window sills), its difference is extremely high strength and fire safety. Irrigation canals are often covered with these boards. In addition to the above examples of the use of asbestos, there are a number of products that include this natural material. Asbestos-cement products are among those types of building materials, the development of which affects the scale of construction, its economy and technical level. Over the past twenty years, Russia has occupied a leading position in the world in terms of asbestos mining.
More about asbestos-cement slabs Asbestos-cement slabs, the price of which depends on many factors and varies from 400 to 1000 rubles per m2, have all the technical characteristics described above. The disadvantage of such material is a rather high cost, which nevertheless pays off with its many positive qualities. Plates are used for: roofing; facade cladding; cladding of commercial buildings; production of window sills, partitions, formwork; construction of outbuildings. The scope of application depends on the type of this product. Their range consists of several types, each of which has its own characteristics. Facade slabs Asbestos-cement facade slabs are used for the installation of ventilated cladding, both in new buildings and long-standing buildings. The work is carried out very quickly, they can be carried out at any time of the year. Main advantages: democratic price; durability; resistance to mechanical damage; fire resistance; environmental friendliness; resistance to moisture and temperature extremes; a wide range of colors and textures. Asbestos-cement slabs for facades are of two types: painted, covered with stone chips. The former have a smooth surface. From above they are covered with dyes that are resistant to climatic factors. The second option is asbestos-cement slabs with a rough stone surface. A crumb of natural minerals adheres to the base and creates a waterproof layer thanks to the epoxy resin that is part of the coating.
