Despite the fact that productionAsbestos-containing building materials in some countries is banned, in Russia, chrysotile cement, which has a truly unique physico-chemical properties, is used for the manufacture of roofing materials and pipes, which are widely used in engineering networks, sewage and drainage systems, garbage chutes.
General information about chrysotile cement
The composite material is chrysotile cement, whichPreviously had the trade name asbestos cement, is obtained as a result of the solidification of a mixture consisting of water, Portland cement and chrysotile. The proportion of Portland cement in the finished material can be from 80 to 90%, chrysotile - from 10 to 20%. The unique properties of this material is due to the fact that chrysotile, which is popularly known as "mountain flax", is capable of splitting into the finest fibers, which have increased tensile strength, elasticity, high adhesion and cohesive properties. These fibers reinforce concrete, increasing its strength and resistance to any external influences.
Chrysotile cement, in which the fibers of chrysotileAre in a bound state, preventing their release into the environment, is safe. In addition, chrysotile in its composition does not react with the alkaline environment of cement stone, so the material has increased resistance to corrosion. It is fireproof, not exposed to putrefactive bacteria, able for a short time to withstand the influence of acidic media. In addition, chrysotile cement is a reliable insulator of electric currents, electromagnetic and radioactive radiations, it is characterized by low thermal conductivity and can withstand the influence of elevated temperatures. Today, the industry produces the widest range of products from chrysotile cement, including pipes, which are used in construction.
Types of chrysotile cement pipes
Chrysotile cement pipes are distinguished according to the conditionsOperation: non-pressure and pressure. In addition, there is a gradation in size: the diameters of the internal section can be from 100 to 500 mm, the length - from 2950 to 5950 mm. Non-pressure pipes are produced in two types - conventional, marked with BNT and thin-walled, marked with BNTT. Pressure chrysotile cement pipes are divided according to their intended use. Those that are used for water pipes are marked with BT, and those intended for heat pipes are designated TT. Depending on the value of the calculated working pressure, they are divided into several classes and can be used in the absence of external loads in conditions from 0.3 to 1.6 mPa.
Chrysotile cement has a low coefficient of temperature elongation, its linear dimensions do not change even at high temperatures.
Installation of pipelines from chrysotile cement pipes
When installing pipelines from non-pressureChrysocel cement pipes designed for laying communication cables, sewage or land reclamation systems, one scheme is used: the preparation of a trench, drainage or diversion ditch- the delivery of pipes and couplings to the place of laying- control of their quality- installation of a pipeline-leak test or passability-filling of the pipeline .
Chrysotile cement pipes and couplings are susceptible to mechanical damage and shock, therefore installation is carried out with care, preferably in manual mode.
The connection between the pipes is carried out with the help ofChrysotile cement or polyethylene couplings, which are mounted on a concrete solution, bitumen, special mastic or a binder solution. It is possible to achieve the best sealing when laying pipelines in wet soils using hot bitumen. In normal dry soils, polyethylene couplings are well proven, which, before being installed on the ends of pipes, are heated to 90-100 ° C.
For installation of pressure chrysotile cement pipes,Which are often used together with steel, flange joints or chrysotile cement clutches are used, and the tips of steel pipes are turned or welded to them with nozzle tips that coincide with the outer diameter of the chrysotile of the cement pipe.
Application of chrysotile cement pipes
In Russia, where the production of asbestos-cement pipesBegan in 1932, has already accumulated extensive experience in their use in a variety of areas, including, and in construction. Their popularity is due to low cost, because the price of such pipes is 2-3 times cheaper than metal and polymer, and the service life is more than 50 years. In addition to pipelines of very different purposes, chrysotile-cement pipes are used as trunks of garbage chutes and as pile pillars for erecting pile foundations, as well as casing wells. Septic tanks and storage tanks for solid waste in autonomous sewage systems are another area of application of this material. Drainage systems are made from chrysotile-cement pipes - for this purpose holes are made on their entire surface or only parts thereof.
In our country, scientific organizations,Engaged in sanitary-epidemiological studies, the possibility of using cryotyl cement pipelines for heat and hot water supply systems was studied. It has been scientifically proven that the organoleptic, chemical and bacteriological properties of water after passing through such pipelines have not changed, which was confirmed by the relevant certificates.