Technology asbestos-cement products. Technology of manufacturing asbestos-cement products required to asbestos-cement materials

Asbestos cement products are made mainly by wet method of molding. Much less often use semi-dry and dry methods for molding. The latter - in the manufacture of only flat sheets and tiles.

The wet method of technology begins with compiling compilation from asbestos of several stamps so that when molding, ensure high filtering ability, density and water retention. After that, the fiber of asbestos fiber is produced. The embroidered asbestos is thoroughly stirred with cement in water until a homogeneous mass is obtained. The latter is diluted by an additional amount of water, as a result of which an asbestos-cement suspension is obtained, in which, if necessary, additional substances (additives) can be introduced. In asbestos-cement suspension, the mass of water is more than 10 times higher than the mass of cement. The finished suspension is directed to molding asbestos-cement products - sheets or pipes. At the same time, the large part (over 96%) of free water is filtered and removed. Sheets give the necessary dimensions and shape. Facing sheets and roofing tiles are additionally pressed. The fencing of the knitting part, under the influence of which asbestos-cement products acquire the required mechanical strength, occurs in warehouses or in autoclaves (with sandland portland cement). Finished products by their coloring and facial treatment can be attached to the necessary outer surface.

To date, more or less specific compositions (mixtures) of asbestos of different deposits were established in the production of asbestos-cement products. They are normalized by special technological maps.

Operation of asbestos, largely determines product quality. At the first stage of mechanical processing on the runners within 12-15 min weakens the relationship between the finest fibers of asbestos. In the second stage - in the holland-avenue or other apparatus (6-8 min), asbestos is separated by the finest fiber. Usually, the roller is preferable to wet method, i.e. on the runners in the presence of water. Golubender, i.e., the metal tank, inside of which the drum rotates, equipped with knives, is always a hydraulic fluffy, since the separation of asbestos hit by the runners, on the finest fiber occurs in the pockets between the drum knives as a result of the exposure to the rapid vortex movements of water jets. In the same device, a mixture asbestos with cement in aquatic environment is usually carried out. Water simultaneously with the loading of cement is added from the bottom of the recovery (collection of waste water).

Asbestos-cement mass is relatively fast (for 8-10 minutes) acquires sufficient homogeneity, since the smallest cement grains that carry high negative electric pressure on the surface are rapidly deposited and firmly held on the developed surface of the fine-fiber asbestos, also carrying a high, but positive charge in water and alkaline Medium. If sand cement is used, then the smallest particles of dispersed sand are also precipitated on asbestos fibers, albeit with a longer mixing suspension (12-13 minutes). To obtain a movable suspension, 1 wt is required. Dry asbestos-cement mix to add at least 4-5 wt.h. Waters, which is specified by the calculation, depending on the grades of asbestos in the mixture.

The manufactured asbestos-cement mass enters the anti-stirrer to obtain a certain mass supply to maintain the continuity of the molding machine. From the mixers, the mass is sent by a groove into metal baths, which are part of the leaf-forming machine. At the same time, recovery water, selectable from the bottom of the recovery, continuously flows into the gutter, which allows you to maintain the necessary consistency of the mass. Asbestos-cement suspension, which enters the laid cylinders of the leaf-forming machine, usually consists of 8-10% dry matter at 90-92% water. But there are also other leaf-forming machines on which a higher concentration asbestos-cement suspension is used, for example, up to 40-45% dry matter (it is up to 15% asbestos, up to 85% cement).

Fig. 9.30.

1 - bath; 2 - full drums with a mesh surface; 3 - asbestos cement mass; 4 - clamping roller; 5 - endless cloth tape; 6 - Vacuum box; 7 - format drum; 8 - support shaft; 9 - press shaft; 10 - flushing device; 11 - squeeze rollers

asbestos-cement mass in the groove. From the surface of the drum, the asbestos-cement mass layer is removed by an endless cloth ribbon 5. Walking on a ribbon vacuum box b. (with a vacuum of about 300 mm Hg), a pre-dehydrated asbestos-cement mass is transferred to a metal formatable drum 7, which removes the mass from the ribbon of the cloth and pins it to its surface with concentric layers, while it is compacted between rotating metal cylinders. When the asbestos-cement layer on the drum reaches the necessary thickness, it is cut through the forming cylinder, and the raw leaf is removed. The pressure of the press part of the leaf-forming machine is usually 0.2-0.4 MPa, for a second undercurrent shaft 10.0-12.0 MPa, for a press shaft - up to 40.0 MPa. As a result of the compression, the moisture content in the sheet is significantly reduced and reaches 25%.

In the manufacture of flat small products, the sheet is additionally cut into tiles, which piles are pressed under high pressure (up to 40 MPa) on the hydraulic press. If fibrous sheets are made, then the excitement is made on special machines of a scalged type of periodic action. There are continuous operation machines that are used in all automated lines.

Products are harden in stroke chambers at a temperature of 50-60 ° C, a relative humidity of 90-95% for 10-14 hours, and then 5-7 days in a warmed warehouse. Faster, hardening in the autoclave under the action of a steam pressure of 0.8 MPa, which allows the use of sandy cement and eliminate the maintenance of products in the plant's warehouse.

In the production of pipes, the principles of molding remain the same, but they use special pipe-forming machines with removable format drums (rallies). The pipe and leaf-forming machines do not have fundamental differences in the designs of mesh cylinder baths, vacuum-containing devices and cloth cleaning devices.

At the end of the scanning process of asbestos-cement layers, the format rope is removed and installed new. To make it easy to remove the rolling pin, the diameter of the pipe slightly increase. For this purpose, the grid in the ends are slightly stretched using metal wedges and the pipe is fragmented on a special calender.

A dry method of molding asbestos-cement sheets provides for the oxbesta frelt and mixing it with cement and sand in a dry form. 12-15% water is added to the subsequent moisture, and the mass on the conveyor belt rollers or under the press is added. The products are hardening to which the floor and facing tiles are mainly related to autoclaves. Dry method allows to use short-fuel asbestos preferably the 6th grade.

Such a protective layer reduces the scope of asbestos into the surrounding air environment and increases slate service life of 13 15 times. The global mining of chrysothilasbesta is 95 and the whole group of acid-resistant asbestos no more than 5. The chemical composition of chrysotypesbestos is expressed by the 3MGO2SI022H20 tons formula. Asbestos molecules are firmly related to each other in one direction the side connection with neighboring molecules is extremely weak.

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Ministry of Education and Science of Ukraine

Odessa State Academy of Construction and Architecture

Department of "Processes and Apparatuses in Building Material Technologies"

COURSE WORK

by discipline: " Technology of waterproofing and thermal efficient materials»

on the topic: "The workshop for the production of asbestos-cement sheets"

Performed:

art. c.

zac. kn. No.

Checked:

Odessa 2014

Introduction ................................................... .................................................. ...............four

Nomenclature of products ................................................ ............................................ 6.

The characteristic of the used raw materials ............................................... ...................nine

Technological scheme for the production of asbestos sheets ................................ 12

The main physico-mechanical properties of the product obtained .................... 17

Mode of operation of the workshop and offices ............................................. ............................. 21.

Calculation of workshop performance ............................................... .......................... 21.

Selection of the main technological equipment ......................................... 23

Quality control of raw materials and finished products ............................................ ..... 25.

Safety and labor protection in production ................................ 27

Methods for assessing the quality of the product obtained ............................................. .... 29.

List of source used ................................................. ..................... 41.

I. Introduction

Materials used to finish building structures and structures, houses and apartments must protect them from environmental impact, to give the final architectural design, create special sanitary and hygienic conditions that reduce dusting, pollution, moisturizing, protection against noise, etc.; Ensure the possibility of restoring the surface of the finish. And also to meet the aesthetic demands of the owner of the building, houses, premises. And, in the end, to satisfy the typical architectural style adopted in this area. All over the world, the production of finishing materials is increasing dramatically, the range is expanding, quality and expressiveness increases, so necessary by the modern city, public buildings and dwelling.

A variety of finishing materials and products used in modern construction are classified according to a technological basis: paints and varnishes, products from natural and artificial stone, ceramics, glasses, metal, forest materials, polymers, etc. as well as in architectural and construction species (materials For outdoor decoration; interior decoration; floors; special purposes). A number of materials and products are used for finishing, both internal interiors and facades of buildings, presenting enhanced operational and aesthetic properties to them. Among the operational properties are the most important are sanitary and hygienic, creating healthy living conditions, work and recreation, as well as fire-resistant, toxicological, radiation characteristics that meet the relevant standards. The conditions of high aesthetic quality are the subordination of the decoration by the laws of beauty, harmony, artistic taste, shaped transmission of color tone, purity, color saturation, color pattern, structural and textural features of the material.

The actual service life, operating costs for current and capital repairs, and the overall service life, taking into account moral aging are actually affected by the technical and economic efficiency of finishing materials. Often this determines the selection of one or another finishing material.

Nomenclature of products

The nomenclature of asbestos-cement products has over 40 items. They can be divided into the following main groups: profiled sheets - wavy and semi-equivalent for roofing and wall sheat; Flat plates - ordinary and features or painted for wall cladding; Panels roofing and wall with thermal insulation layer; Pipe pressure and free and coupling and couplings to them; Special products (architectural, sanitary, electrical insulating, etc.).

Asbestos-cement leaf structures are used in all climatic zones of Ukraine and their production makes the needs of construction. The production of prefabricated asbestos-cement structures satisfies only 6-7% of them.

Further industrialization of construction, a decrease in labor and material consumption, an increase in the durability and reliability of asbestos-cement structures require an increase in the size of wavy sheets up to 6 m, the organization of the production of painted and reinforced sheets, flat pressed sheets, molding elements for panel frameworks.

The profiled sheets are made from asbestos-cement wavy (ordinary and enhanced profile) and semi-equivalent.

Wavy sheets have a rectangle shape with six (eight) waves, the direction of which coincides with the direction of the large side of the rectangle. The length of the wavy sheets of an ordinary profile (V) - 1200mm, width - about 700mm and thickness - 5.5 mm. Sheets wavy reinforced profile (Wu) are somewhat thicker, which allows manufacturing their large sizes. The length of them is 2800 mm, the width is about 1000 mm and the thickness is 8 mm. In recent years, a new type of asbestos-cement wavy sheets has been developed - SV-40-250 size 2500x1150x6 mm. Compared with previously produced sheets, these sheets have a large useful area and less consumption of asbestoscent per 1 m2 of useful area.

Sheets profiled should be strictly rectangular, without cracks and offs. Profiled asbestos cement sheets are used for the device roofing, wall cladding, balconies, etc. Flat facing asbestos cement plates produce unfollowing and extruded increased strengths with a thickness of 4-10mm, wide up to 1600 mm and up to 2800 mm long. In the process of molding, their facial surface is separated depending on the purpose of the decorative asbestos-cement layer, stained with waterproof enamels, polished, and also make relief, imitating ceramic glazed tiles. Plates stained with waterproof enamels recently used to be successfully used for cladding panels, ceilings, walls of sanitary nodes and kitchen of residential and public buildings.

Asbestos-cement slate is inexpensive, easy to install and one of the most famous roofing materials. Wavy asbestos-cement sheets (slate) are the most common roofing material. Until recently, their dimensions were relatively small: the sheets of an ordinary profile were sized in terms of 1200x680 mm and a mass of about 9 kg. Currently, their release is almost universally discontinued and the production of large-sized asbestos-cement sheets of a wavy profile.

The most massive for rural house-building are asbestos-cement sheets of HC size in terms of 1750 * 25 mm. Each of them covers about 1.5 m2 of the roof and compared to a small-sized sheet in has 2 times less junctions.

Modern asbestos-cement roofing sheets - slate, to increase their decorative properties and increasing service life, painted. Staining is made by silicate paints or paints on phosphate binding, using various pigments. In the past, asbestos-cement sheets (slate) had either faceless, gray shade, or could be red or green. Currently, slate is produced in a wide variety of colors: red-brown, chocolate, brick-red, yellow (ocher), blue, etc. The paint, which covers the finished slate sheets, forms a protective layer that protects the product from destruction that reduces its water absorption and increases Frost resistance. Such a protective layer reduces the volume of asbestos discharge into the surrounding air environment and increases the life of slate 1.3 - 1.5 times.

The flat slate is already departed from the consumer market, its disadvantages are still overwhelming its dignity: the laying is complicated due to small sizes (400x400 mm) and is limited to an angle of the slope from 30 °. But also the appearance of a flat slate roof leaves much to be desired, it is easier to replace it with optimal elegant tiles for such such bias and its interpreters (metal tiles and bitumen tiles).

Characteristic of used raw materials

Asbestom They call a group of minerals having a fibrous structure and with mechanical effects capable of decaying the finest fibers. In the production of asbestos-cement sheets apply chrysotile asbestos. The world extraction of chrysotile asbestos is 95%, and the whole group of acid-resistant asbestos is not more than 5%. The chemical composition of chrysotile asbestos is expressed by the 3MGO-2SI02-2H20 formula, i.e. it is a hydrosilicate magnesium. Asbestos molecules are firmly related to each other in only one direction, the side connection with neighboring molecules is extremely weak. This property explains the very high strength of asbestos for stretching along the fibers and good fluidity - splitting across the fibers. The fiber diameter of chrysotile asbestos ranges from 0.00001 mm to 0.000003 mm.

Asbestos has a great adsorption capacity. And in a mixture with a portland cement, with wetting with water, it adsorbs (i.e. good) holds on its surface the products of cement hydration, binding fibers of asbestos, so asbestos cement is like a fine-marked cement stone. Chrysotile asbestos do not burn, however, at a temperature of 0 ° C, it begins to lose adsorption water, the tensile strength is reduced to 10%, and at 368 ° C evaporates all adsorption water, which leads to a decrease in the strength of 25-30%. After cooling, the asbestos restores the lost moisture and former properties from the air. When the asbestos is heated to a temperature of more than 550 ° C, all chemically related water is removed, elasticity and strength are lost, the asbestos becomes fragile, and after cooling the property is not restored. At a temperature of about 1550 ° C, chrysotile asbestos melts. Asbesta has low heat and electrical conductivity, high alkaliiness, however, the acid is easily destroyed.

The quality of asbestos-cement sheets largely depends on the quality of asbestos and the subtleties of cement grinding. In accordance with GOST, the quality of chrysotile asbestos is characterized by the following indicators:

texture (degree of flossability of fibers);
medium fiber length, elasticity, humidity;
the degree of cloghood of dust.

The length of the asbestos fibers is a big impact on the quality of products. This is the main sign of the fission of asbestos on the variety. The larger the average length of the fibers, the higher the grade. For the production of asbestos-cement products, short-fuel Asbestos-3, 4, 5 and 6 of varieties with a length of fibers from 10 mm to several hundredthmm, and their content is 50-24% by weight, the remaining 50-76% falls on the proportion of dust and other non-branched Particles. Sometimes part of asbestos (10-15%) is replaced with basalt or slag mineral wool.

Asbestos with undeformed fibers, the size of which in the diameter is more than 2 mm, conventionally referred to as a "cusary" asbestos, and less than 2 mm - "needles". "Embossing" is called asbestos, in which fibers are fine, deformed and confused. Particles of the concomitant breed of greater capacity of more than 0.25 mm are called "Gal", and less than 0.25 mm - "dust".

Portland cement M400. As a binder in the production of asbestos-cement sheets use a special portland cement for asbestos-cement products. In this case, portland cement M400 is applied. Such cement is characterized by a rapid increase in strength both at the beginning and in subsequent timing of hardening, slow down the beginning of the setting (no earlier than 1.5 h) and a sufficiently large grinding of the grinding required in order to create a significant surface of the clutch between cement and subtly flounded fibers asbestos . This cement contains at least 52% 3CAO-SiO2 and not more than 8% of the ZSAO-A12IZ, it should not be mineral additives (except for gypsum). The increase in the strength of the product must occur fairly quickly for the transition of the semi-finished product into finished products. To meet the requirements of GOST 9835-77, a special portland cement with a specific surface area of \u200b\u200b2200-3200 cm2 / g is used to satisfy asbestos-cement sheets. The number of additives in cement is established with the consent of the consumer, but not more than 3% (with the exception of plaster). Gypsum is added to regulate the timing of setting in an amount of at least 1.5% and not more than 3.5% of the mass of cement.

The molding of asbestos-cement products continues longer than products from concrete. In this regard, the beginning of setting from cement for asbestos-cement products should come a little later than an ordinary portland cement, - not earlier than 1.5 hours from the moment of indentation by water, and the end is no later than 10 hours after the start of the lave.

In the manufacture of asbestos-cement sheets, special white and colored cements are also used.

Technological part

Currently, there are three ways to produce asbestos-cement products.: Wet fashion - from asbestos-cement suspension;

Technological scheme of a wet method of production of wavy asbestos-cement sheets using low concentrated suspensions:

Fig.1. Technological scheme of a wet production method.

1, 3, 12, 15, 17 - conveyors, 2, 4, 8 - dispenser, 5 - Runners, 6 - hydropushpool, 7 - bunker, 9 - Turbosmesman, 10 - bucket mixer, 11 - leaf-forming machine, 13 - scissors, 14 - Volzavirovshchka, 16 - Crosscher, 18 - Camera Preliminary hardening, 19 - Conveyor of water hardening, 20 - Sparkler sheets, 21 - shell, 22, 23 - recuperators.

semi-dry - from asbestos-cement mass

Fig.2. Technological scheme for semi-dry molding.

1-roller conveyor; 2nd rolls; 3-sprinkled bunkers; 4-vibrating engineering; 5-Support rolls; 6-reception bath; 7-drive shaft; 8-small rolls; 9-vacuum box; 10-mesh cloth; 11-tensioning shaft.

And sukhoy - from dry asbestos-cement mixture

Fig.3. Technological molding scheme with a dry way.

1-cyclone; 2-bunker; 3-wetting tube; 4-sealing rolls; 5-cutting device; 6-accelerated conveyor; 7-rolling shafts; 8 feeder; 9-layer asbestos-cement mass; 10-rubberized tape.

The wet spread was wetted. Two others apply only in experienced installations.

The process of manufacturing asbestos-cement sheets is made up of the following main technological operations:

1) transportation of cement into closed bins on the pipeline;

2) the dosage of cement by weight dispensers;

3) the supply of asbestos to the consumables with an electric loader;

4) the transmission of asbestos by the conveyor in the expenditure bunker;

5) dosing;

6) primary processing of the mixture;

7) processing asbestos in hydropuses in the presence of a large amount of water;

8) pumping asbestos suspension into a turbo mixer and mixing with cement;

9) stirring asbestos-cement mass;

10) the flow of mass into the antique stirrer;

11) movement of mass on the shafts of mesh cylinders of sheet-forming machines (LFM);

12) molding sheets;

13) cutting on the sheets of the specified sizes;

14) Waves of sheets on mechanized lines;

15) Preliminary hardening in the conveyor.

16) hardening in the humidifier.

17) Moving to the warehouse of finished products and final hardening.

Description of the technological scheme of production of asbestos-cement sheets

The cement is transported by pipeline into closed bins and is dosed strictly by weight by weight dispensers. Asbestos is stored for varieties and stamps in a closed room. The dosage of asbestos is also carried out by weight according to the specified charge.

Asbestos deliver to plants in paper bags in railway wagons. The plant is stored in a closed warehouse on a wooden floor in separate compartments for different brands and varieties. If Asbestos entered the warehouse in Tara, then it can be stored in stacks. Above each compartment or stack indicate the grade of asbestos.

For the manufacture of products, the compost mixture is set. So, for asbestos-cement wavy sheets used to cover the roofing of residential buildings, compesting mixture is set as follows: 50% asbestos of the 5th grade, 50% asbestos of the 6th grade, and the total content of the soft texture should not exceed 50%, including content In the compest compliant mixture, M-60-40 should not be more than 15%. Asbestos varieties and their percentage in the mixtures used are normalized by special technological maps.

Next, the asbestos on special pallets is supplied to the electric loader to the site and is loaded into consumables separately by groups and brands. Of these, Asbestos on inclined transporters are served in the weight dispensers where the ready-made asbestos is going. According to the command from the charge control panel, the dispensers are hung out of the dispensers and with the help of gear and inclined transporters, it goes to the distribution conveyor, from where it goes into the runners, where the mixture is subjected to primary processing (moisturizing, sprinkling). Simultaneously with the loading of asbestos into the runners, it is moisturized with clarified recovery by water, with the help of a special measureer in an amount of at least 5l per 1 kg of dry asbestos. The duration of the processing of asbestos in the runners is 12-15 minutes, the humidity of asbestos is at least 28-80%.

At the end of processing, the asbestos is unloaded from the runners without a residue. Next, the asbestos is subjected to processing in hydropuses in the presence of a large amount of water for the purpose of a good roller. Treatment time 8 - 10 min. Asbestos Esbesta is at least 80 - 90%. The ozbesta roller determines largely product quality. There are three kinds of rolling: dry, wet and semi-dry.

With a dry way, the rush is produced on runners and fuzzles. Asbestos beams are warm up in the runners, the bond between the fibers is disturbed, and in the fuffler (disintegrator) there is a further cleavage of softened beams into separate fibers. The fibers of asbestos in the apparatus for the preparation of asbestos-cement mass - Hollander are flushed. In the wet method of the roller, the asbestos is soaked in water 3-5 days, then mixture kneading on the runners. Water penetrates microchelter and has a propagating effect, as a result of which the fibers are lighter and better. Asbestos hydration increases the elasticity of the fibers, which increases the resistance to the problem during the handling on the runners. Currently, the roller machine is becoming increasingly distributed to form asbestos. Unlike runners, this machine produces a high-quality mesh asbestos by a continuous flow.

Upon completion of the roller, the asbestos suspension pumps pumps into a turbo mixer, where mixing with cement occurs. The amount of cement loaded to one knead in the mixer 600-800 kg.

The cement load into the mixer is made gradually uniform portions from the consuming hopper through the weight dispenser. At the end of the cement load, the asbestos-cement mass is mixed for 45 minutes. The finished mass of the self-shot in the antique stirrer designed for uninterrupted nutrition. Mass in the stirrer is continuously mixed. From the bucket mixers, the asbestos-cement mass enters the shafts of the mesh cylinders of sheet-forming machines (LFM), on which the asbestos-cement layout of the semi-finished product is molded. The molding of the sheets is made on the universal circle - the mesh three-cylinder machine CM 943. Asbestos-cementing rolls automatically by reaching the preceded thickness with a slider removed from the molding drum of the machine. The removed rolled with ribbon transport is supplied to guillotine scissors that are cut into formats with a size of 1750 * 10 mm.

The decoding and feeding facilities of the sheets are fed to the wavyman, where the ravine is subjected to the mechanized lines of stamping molding CM 115 and SM 170 using accelerated hydrothermal hardening. Currently, aggregates are used for automatic manufacture of wavy sheets and laying them into a stack.

Sheets after profiling, having external defects are reset to the standing conveyor to the agitator trimming for processing.

1. Preliminary hardening in the conveyor;

2. Trimming in the humidifier;

3. Ultimate hardening on a warm warehouse.

After a moisturizer, the bulkman is completed. The final hardening of products is carried out in the warehouse of finished products and further on open areas. In the warehouse, sheets withstand seven days, after which there is a reception of the finished products of the OTB and the test of the parties according to GOST 16233 70.

Physical and mechanical properties. Strength and deformation properties:

The tensile strength of the bend Sizg, MPa ............................................. ......... 15 - 42

Tensile strength SRAS, MPa ........................................... .10 -25

The strength of the compression is perpendicular to the lamination of SSJ, MPa.60 - 80

The strength of compressing parallel to the lamination of SSJ, MPa ......... 30 - 40

Modulus of elasticity (deformativity), with axial stretching,

if s \u003d (0.8 - 0.85) SRAS, EP, MPa ................................... .................. (12 - 18) · 1000

The modulus of elasticity in compression parallel to the lamination, either ... (13 - 30) · 1000

Limit deformability with axial stretching, EPR ......................................... (20 - 65 ) / 100000.

Impact viscosity Rude, KJ / m2 ............................................. .............................15

Strength increases with an increase in the content of three-killy silicate with optimal values \u200b\u200bof three-killy aluminate and cement dispersion.

The increase in the asbestos content to a certain value (18-25%) increases the strength of asbestos-cement while simultaneously optimizing technological parameters. The length of the asbestos and the content of dust-like impurities, as well as the accuracy of the dosage of the components of the raw materials, the degree and quality of the oxbestos, the homogeneity of the raw material mixture, the conditions of molding, ensuring the dehydration of the semi-finished product to the optimal value without disturbing its structure, the hardening conditions, stimulating Maximum cement hydration.

Asbestoscert's strength increases with increasing its density. Approximately: SIZG \u003d K · (R0) 2, where K is a constant depending on the quality of raw materials and production parameters. The magnitude of the time increases due to the continuing long time of hydration of clinker minerals and carbonization of hydration products (Table 1). The growth intensity S depends on the composition of the applied cement.

Table 1 Sizgue in time

Humidity affects asbestoscent. In saturated with water asbestos-cement Sizg and SAS below 15-16%, in the dried to constant mass above 12-18% than that of the air-dry (at wg \u003d 8-11%). The coefficient of uniformity of strength Code is in bending 0.65-0.75; With axial tension 0.5-0.6.

The proportionality between the voltages about and relative deformations E asbestos cement is maintained with a short-term action of the tensile load to S \u003d (0.5-0.65) SRAS ,. Within these limits, he behaves like an elastic material subject to the leg. Further growth S leads to some curvature of the direct in the coordinates S - E. Therefore, the modulus of elasticity (deformativity) at S \u003d (0.3-0.4) SOCs, by 4 - 6% more than, for example, at s \u003d (0.9-0.95) SRAS. The EP increases with an increase from the holding in it asbestos, higher grades, as well as with increasing R0. So, an increase in R0 from 1.5 to 1.7 kg / cm3 leads to an increase in EP by almost 1.5 times. At a water-saturated asbestos cement compared to dry EP, it decreases by 15-25% and the limiting deformability increases accordingly.

The shock viscosity of asbestos-cement RYD is accepted to characterize the strength limit during shock bending, which is calculated as the private from dividing the work spent to destroy the sample on the area of \u200b\u200bits cross-section. Ryd to the greatest extent depends on the quality and length of the fibers of asbestos and increases with their growth. So, the shock viscosity of asbestos cement made on Asbesta of the 5th and 6th groups, 1-2.5 kJ / m2, and on Asbesta of the 3rd and 4th groups 3-5 kJ / m2. The growth of asbestoscent density to R0 "1.7 increases, and then slightly reduces the RYD (Table 3).

The effect of the age of asbestos cement on the RYD is irrelevant. Ryd increases, with the introduction of pulp and paper and synthetic fibers to the raw material composition. Impact effects on asbestos cement, especially at low RyD values, can lead to the ruptures of the portion of reinforcing fibers and microtrees. With the values \u200b\u200bof the shock load close to the destructive, and during repeated blows, the product may lose without forming visible cracks to 30-50% of the initial strength. Therefore, during loading and unloading works, during transportation and construction work, the product should be protected from shocks.

Asbestocent has a property of creep associated with the presence of small-crystalline formations in a cement stone characterized by the ability to plastic deformations. Such deformations are significantly manifested with long-term exposure to loads and can reach 55-60% of the limit. Due to the creep, long-term existing loads can destroy asbestos-cement at stresses constituting 70-80% SOC, obtained during material tests of the material. Its creep almost does not manifest. If the loads do not exceed 35-40% of destroying.

Shrinkage, temperature and humidity deformations asbestos cement. During the hardening asbestos cement, a shrinkage of the material caused by the contract (compression) of the system occurs. The transition of a portion of capillary moisture to the composition of neoplasms, as well as drying in capillary bodies, is accompanied by shrinkage. Shrinkage when hardening products depending on the type of cement, semi-finished density, asbestos and hardening modes is 0.35-1.5 mm / m. Shrinkage increases when using highly aluminuth cements, especially with a high specific surface area (3500-4000 cm2 / g). When using a sandy portland cement, shrinkage decreases 1.5-2 times. Shrinking speed - the greatest in the first days of hardening - aged 14-28 days. Noticeably decreases.

Temperature relative deformations of the ET hardened product at a positive temperature, and the immense and under negative, linearly depend on temperature:

eT \u003d AT DT

With changes in the moisture of W asbestoscent, its humidity deformations arise (EW), drying it leads to a shrinkage (-EW), and a water saturation to swelling (+ EW). EW depends on the composition of raw materials for the manufacture of asbestoscerta, its density, age, edges of flooding and drying and can be 0.03-0.3%. The latter value corresponds to the change of W asbestoscent from 0 to 24-25%. Products made onsandland Portland cement Autoclave technology, have EW values \u200b\u200bof 1.5-1.7 times less than when using Portland cement. If the W product is changed on asbestos of the 5th and 6th groups, from a completely dried to a water-saturated state approximately EW \u003d -0.42R0 + 0.88%.

The consequence of the humidity deformations of asbestoscent is its warping that occurs during wetting or drying due to the difference W in the thickness of the material. The maximum magnitude of the boom boom occurs with one-sided moisture (or drying) asbestoscerta, depending on its density and composition after 5-25 minutes. After the start of the process, then it decreases. The storage is disadvantaged, and the large-sized parts of the boaming arrow can reach multiple centimeters. With a strict fastening of the asbestos-cement voltage caused by the drop W, can reach the material strength of the material and lead to cracks in the design. Therefore, asbestos-cement products in the design are fixed with the help of fuel connections that ensure freedom of deformation of the material.

Frost resistance asbestos cement. Thermal conductivity asbestos cement.

Frost resistance asbestos cement is an important condition for its durability. Standards for products from asbestos cement provide regulations of MPZ 25 or 50 of the cycle of alternate freezing and thawing without a decrease in Sizg by more than 10% and without external signs of material destruction.

The frost resistance of asbestos cement affects the composition of raw materials, molding parameters and material density. An increase in the amount and quality of asbestos leads, as a rule, to an increase in the frost resistance of the product. The reduction of frost resistance is manifested when used in the raw materials of an increased asbestos of the soft texture (more than 15-20% of its total content). The composition and dispersion of cement affect the frost resistance of asbestos-cement, changing its porosity and structure. The highest frost resistance has a product made on a Belite cement with a content of 40-45% biculcium silicate.

The reduction of frost resistance depends on the content of three-killy aluminate in cement, so, the increase in its content of more than 6% lowers the frost resistance of the asbestoscerta, the greater the higher the subtleties of cement grinding. This influence can be eliminated by selecting the optimal gypsum additives in cement and its corresponding specific surface. Technological factors contributing to the increase in re asbestos cement at the same time increase its frost resistance.

The thermal conductivity of asbestos cement in air-dry state at r0 \u003d 1.9 g / cm3 is 0.35 W / (m · hail). Changes R0 in the range of 1.5-2 g / cm3 little affect its thermal conductivity. The specific heat capacity of asbestos cement can be received by 0.8 kJ / ° · kg. Asbestos cement is withstanding heating to 150 ° C without reducing strength. When heated to higher temperatures and subsequent air cooled, its strength is reduced as follows:

Temperature, ° C Sizg reduction,%

400 10 - 15

500 45 - 55

600 60 - 70

800 80 - 85

Technological line mode

The mode of operation of the technological line is characterized by the technological features of production, the number of working days per year), the number of shifts per day (n. ), duration of shift in hours (d).

The estimated annual flow of operation of the technological line is determined by the formula:

262 x 8 x 2 x 0.9 \u003d 3772.8 hour;

where: - the coefficient of use of the technological equipment (0.87 ... 0.92).

The final data on the adopted modes are reduced to Table 1.

Table. 2.

Workshop operation.

P / P.	Name workshops, departments	Number of working days a year, day	Number of shifts per day	Duration of shift, hour	Coefficient fitizer use vanya tehnol. Equipments	The estimated annual fund of the work of those. Equipment in hour

	Transportation of raw materials					3772,8
	Dosing					3772,8
	Stirring in a bucket stirrer					3772,8
	Forming sheets					3772,8
	Cutting to the specified sizes					3772,8
	Wave					3772,8

We calculate the daily, replaceable and hourly performance of the technological line using the specified annual performance.

Daily performance determine the formula:

= = ;

where: - the annual workshop performance;

Number of working days per year, day.

Performance in shift Determine by the formula:

= = ;

where: N. - the number of shifts per day.

Performance per hour determined by the formula:

3,98 ;

where: - the estimated annual travel time fund in the clock.

Name of the product produced	Performance
Name of the product produced		in year	per day	in shift	in hour
Asbestos-cement sheets (700x900x5 mm)	15000	57,25		3,98

The obtained data is reduced to Table 3.

Selection of technological equipment for the production of asbestos-cement sheets

The choice and calculation of technological equipment depends on the hourly performance of each machine and the equipment utilization factor.

The required number of cars are calculated by the formula:

M \u003d;

where: M - number of machines, pcs.;

- hour line performance;

Hourly productivity of the machines of the selected type;

The coefficient of use of equipment in time.

Number of roll machines:

M \u003d \u003d 2.2 3 pcs.

2) Number of Holland:

M \u003d \u003d 2.95 3 pcs

After selecting equipment, we bring them a brief description.

The obtained data is reduced to Table 4.

P / P.	Name of technological equipment	Brand, brief description of the equipment	Power engine		Equipment use coefficient
P / P.	Name of technological equipment	Brand, brief description of the equipment			Equipment use coefficient	Single	General
	Roll machine	CM-957. The number of rolls - 7; Dimensions of rolls: diameter - 0.4 m; Length - 0.7m; The number of rollers in sec. - 4.66; The power of the electric motor in kW - 40 and 0.4; Dimensions in M: Length - 3.6; width - 2.35; Height - 2,345; Weight in T - 9.8.	40 kW	120kW
	Hollander	Cm-892 (rotary); Overall dimensions in M: Length - 4.32; Width - 3.25; height - 1.62; Weight in T - 10.7	40kvt.	120kW
	Leaf-forming machine	CM-343A. Overall dimensions in M: Length - 9.91; width - 4.08; Height - 3.85; Masa in T - 27	18.7kW	18.7kW
	Rotary scissors	CM-275. Overall dimensions in M: Length - 14.3; Width - 3.89; Height - 1.6.Mass in T - 1.075; The power of the electric motor in kW - 12.5.	12,5kW	12,5kW

Quality control of raw materials and finished products

One of the main stages of the technology of manufacturing finishing materials are monitoring the quality of the incoming raw materials, for all technological operations, as well as control of already finished products. The quality control of the original raw material is as follows: each party of the raw factory entering the plant supplier must supply a passport, and directly controls the factory laboratory, which checks their appearance, for each type of raw materials, samples are taken, tests and determine the compliance with the properties with the requirements with the requirements GOST.

The test results of the laboratory reports to the technical control department, which gives permission to transfer raw materials into production or brave it, i.e. Returns raw materials, it is necessary with its test results, a supplier enterprise.

Tasks for controlling technological processes include checking the priority and correctness of the operation, the flow rate of raw materials and the compliance of the formulation, the consumption of electricity, steam, air, the size of the transverse section of products, their appearance, etc.

The parameters of all technological processes are given by the factory laboratory, are monitored by the technical control department, as well as workshop laboratories. All control and measuring and weighing devices are periodically checked in accordance with the rules.

The quality of finished products for compliance with the requirement of the GOST or TU controls the factory laboratory. To characterize the appearance of the material, sizing, forms, as well as conducting physicochemical and mechanical tests from each batch, a certain amount is taken, then the required number of samples are made from the selected sample of the material and expose them to all tests regulated by GOST, after What is the conclusion about his quality.

Test results include a passport document that accompanies each batch shipped by the customer of products and satisfying compliance with its standard requirements.

In addition to the test results, the name of the manufacturer, the brand and grade of the product, the main external signs, mass or the number of products in the party, the date of manufacture and retail price is indicated.

Safety and labor protection in production

As is known, some finishing materials, binders and other components of plastic masses (except mineral fillers and pigments) have sufficient toxicity and fire hazard.

Toxic polymers can cause diseases of people employed by their recycling. These materials, as well as the products of their decomposition, which are formed during the production of finishing materials, getting into the ground, water of rivers and lakes, poison the natural and animal world.

Most plasticizers and stabilizers are toxic and combustible is toxic and combustible. Toxic and explosive is most solvents, acetone, benzene, which are widely used in the production of paints and mastic. Plants producing polymer composite materials are characterized by the following rules for labor protection and fire safety:

storage and transportation of toxic raw materials only in tightly closed containers;
it is strictly forbidden to use sources of fire;
fencing moving parts of mechanisms and machines, various production tanks: bunkers, tanks, etc.;
reliable thermal insulation of installations and units operating at elevated temperatures;
ensuring the overall ventilation of all work premises and including the local in each machine and the unit, during which harmful substances are allocated;
grounding of all electric motors, starting devices and aggregates to prevent the formation of statistical electricity and sparks;
accommodation in insulated rooms of technological lines associated with toxic separation of substances and dust.

Workers must take timely instructing on safety and fire equipment, strictly observe personal hygiene rules, in addition, workers are supplied with special clothing and additional protection tools. Also, to pay attention to, work premises must be equipped with materials for medical care victims.

In order to protect the environment from pollution, all ventilation emissions and wastewater should be defined by special cleaning, which would exclude in the air, soil and reservoirs of any pollutants.

Methods for assessing the quality of the product

1.1. The appearance of sheet products check visually.

Survegencies of the surface (bulge, deepening) are measured by a calipercule in accordance with GOST 166-80, and measurements of other defects, if necessary, produced a calipercule,roulette According to GOST 7502-80 or a ruler according to GOST 427-75 with the price of division not more than 1 mm.

The courses are measured in a straight line in the direction of the greatest length.

The dimensions of the knob are measured along and across the product. The dimensions of the knob in the direction of the width of the sheet with one end side are summed.

The length of the surface break is measured along the wave forming; Width - across the break.

1.2 The appearance of leafy products with surface finish (color, intensity and uniformity of color, drawing, finishing character, etc.) Check visually compared with the approved benchmark at a distance of 10 m.

1.3. Compliance with the labeling requirements of standards or technical conditions check visually.

The labeling is considered relevant requirements if it includes all the information provided for by the regulatory and technical documentation for a specific product and at the same time eliminates the possibility of challenge its content.

2. Control of sizes and shapes

2.1. Conduct control.

Control should be carried out ontable , the length of which should be no less than the length of the controlled product, and the width is to exceed the width of the product at least 300 mm.

With all the measurements (except for the thickness control) and the calculations of the average arithmetic value, the results obtained should be rounded to 1 mm when the thickness control is controlled to 0.1 mm.

2.1.1. The length of wavy sheets is measured by a tape measure along both extreme ridges, the length of flat sheets -roulette Along both longitudinal sides at a distance of 30-50 mm from the edge of the product.

Fig.4. Measuring the width of wavy sheets.

2.1.2. Wavy width measuredroulette At both end edges at a distance of 30-50 mm from the edge (Fig. 4), for which metal stops are used (Fig. 5), the width of the flat sheets - a tape measure on both cross-sides of the product at a distance of 30-50 mm from the edge. In total, each product is carried out two dimensions.

Each measurement must be within allowable deviations.

Fig.5. Metal stops for measuring wavy sheet widths.

2.1.3. The thickness is measured by a caliper, a thickness gauge or a wall-keeper in the middle of each of the four sides. The measurement location can be shifted from the middle of the face of the product for no more than 50 mm.

Through the thickness of the product take the average arithmetic value of the results of four dimensions.

2.1.4. The height of the ordinary wave is measured by the TC-1 type calipers or a calorieglubeer using a metal lining (Fig. 6), where- Wave step. Measurement scheme - in accordance with Fig.7.

Fig.6.Metallic pad to measure the height of the ordinary wave.

1 - lining; 2 - sheet

Fig. 7.Shem measurement of the height of the ordinary wave.

The lining is placed on two adjacent crest of waves, except for the extreme (overlapping and overlapping), and a caliper by extending a ruler to measure the depth or calorieglubeer measure the distance from the lowest point of the waves to the top edge of the lining ().

Measuring the height of each wave is produced twice - one at each of the ends at a distance of 50-100 mm from the edge.

For the height of the ordinary wavetake the difference between the average arithmetic value of the results of two measurements and the thickness of the lining.

When measuring the height of the overlapping (overlapping) wave use the same means of control as when measuring the height of the ordinary wave.

The product is shifted in the longitudinal direction for the edgetable. . From the bottom to it, the lining is pressed in accordance with (Fig. 8), the caliper by extending the ruler to measure the depth or calorieglubeer measure the distance from the bottom edge of the lining to the highest point of the non-line surface of the product ().

Measuring the height of overlapping (overlapping) waves produce twice - one from each of the ends of the product.

For the height of overlapping (overlapping) wavestake the difference between the average arithmetic value of two dimensions and the thickness of the lining.

1 - lining; 2 - sheet

Fig.8. Measuring the height of the wave.

It is allowed when determining the height of the wave to apply a ruler instead of a lining, which, when measured, apply an edge to the surface of the product.

In this case, from the average arithmetic value of the results of two dimensions, the width of the line is deducted.

3. Determination of the bearing ability of wavy sheets

3.1. The essence of the method is to destroy the wavy sheet with a load applied in the middle of the span on a single-spare circuit.

3.2. Testing

Sheets lay on the supports of the face up. The load on the sheet is transmitted through the bar.

Between the supports and sheet, as well as between the strip and sheet, soft gaskets are placed (from felt, cloth, etc.) with a thickness of 5 to 10 mm thick.

The sheet is adjusted before destruction and measure the destructive load.

3.3. Processing results

The supporting ability of asbestos-cement wavy leaf () Calculate in kilonitytones per meter (pound kilograms per meter) by formula

where: F.

B. - List width, m.

The result of the calculation is round up to 0.01 kN / m (1kgs / m).

4. Determination of the strength of the wavy sheets by test plate load

4.1. The essence of the method is to create bending stresses in a tested wavy sheet by increasing the load to the regulatory level.

4.2. Testing

The sheet is put on the supports of the face up.

Each tested sheet must withstand the regulatory load without signs of destruction.

5. Determination of strength in a concentrated load from the stamp

5.1. The essence of the method is to bending the bending of whole wavy sheets without destruction by the application of a given regulatory load to a specific section of the sheet using a stamp by one or two-flying circuit.

5.2. Testing

Sheets are tested according to one of the schemes in accordance with Fig. 9.

Fig. 9.Shem Definition of strength.

Test diagram and distance between supports () are given in regulatory and technical documentation for specific products.

The sheet is placed on the supports of the front surface towards the application load.

The load is transmitted through the stamp applied in the middle of the span to the second ridge of the wave, counting the first crest of the overlapping wave.

The load is adjusted to the normative, withstand the sheet under this load at least 5 s, after which the load is removed.

Each tested sheet must withstand the regulatory load without signs of destruction.

6. Definition of density

6.1. The method is to determine the mass of the dry sample and its volume.

6.2. Testing

drying samples;

cooling samples;

weighing dried samples in air;

saturation of samples with water;

weighing saturated water samples;

weighing saturated water samples in water;

The results of all weighing are rounded to 0.1 g.

Samples for drying are placed on the shelves of the drying cabinet in one row at a distance of at least 3 mm between the samples in the row and from the walls of the cabinet.

Samples are dried at a temperature (105-110) ° C at least 24 hours, if the thickness does not exceed 15 mm, and at least 48 hours with a thickness of more than 15 mm.

It is allowed to dry the samples on the electric stove. On one tile followsdry At the same time, no more than six samples, having their plastics in one row.

Duration of drying with the thickness of the samples up to 15 mm inclusive should be at least 30 minutes, with a thickness of more than 15 mm - at least 60 minutes.

Sample cooling should be carried out in the desiccator.

After cooling, the dried samples weighed.

Dried samples are placed in water at least 30 minutes, while the water level should be above the samples of at least 30 mm.

Before weighing saturated water samples from each sample with a soft cloth, water drops are removed on its surface.

Then these samples are weighed immersed in water on laboratory scales with a device for hydrostatic weighing.

When weighing, the sample must be completely immersed in water and should not touch the vessel walls.

6.3. Processing results

Density ( ) In grams, the cubic centimeter is calculated by the formula

For the value of the batch product density, the average arithmetic results of the tests of all party samples are taken.

7. Determination of water absorption

7.1. The essence of the method is to determine the masses of the product sample in the dried and water-saturated states, followed by their comparison.

7.2. Testing

The test consists of the following operations:

drying samples;

cooling samples;

weighing dried samples;

saturation of samples with water;

weighing saturated water samples

When controlling the quality of production by the manufacturer, the manufacturer is allowed to saturate the samples in boiling water or the method of vacuuming.

When fastening in boiling water, the samples are placed in a vessel filled with water and equipped with a lattice to ensure free circulation of water between the samples and the bottom of the vessel.

Water is heated to boil and withstand samples in boiling water at least 3 hours, after which they are cooled in the same water to the room temperature.

When applied to vacuum, the samples are placed in the chamber, from which air is pumped out. The residual pressure in the chamber should not be more than 2 kPa (15 mm Hg. Art.). In this pressure, the samples are withstanding at least 5 minutes, after which water is supplied to the chamber. The water level should be above the samples of at least 30 mm. The saturation of samples in the conditions of permanent should last at least 5 minutes.

After removing the vacuum before weighing, the samples must be in water.

After saturation, the samples are weighed on laboratory scales. Before weighing from each sample with a soft cloth, remove the water drops on its surface.

Weighing of each sample must be completed no later than 5 minutes after removing it from the water.

7.3. Processing results

Water absorption ( ) In percent, calculate according to the formula

The result of the calculation is round up to 1%.

For water absorption of the batch of products, the average arithmetic value of the test results of all samples of the party is taken.

8. Determination of waterproof

8.1. The essence of the method is unilaterally exposed to water to the product under test for a certain time.

Fig.10.Shem Definition of waterproof.

When conducting a test by any of these methods, after 24 hours, it is examined in a reverse (non-personal) surface of the product (sample) and the presence or absence of water drops on it.

9. Definition of frost resistance

9.1. The essence of the method consists in multiple alternate freezing and thawing samples saturated water.

9.2. Testing

Samples designed to test for frost resistance are placed in cassettes and all the movements of the samples are produced only in cassettes.

Sample cassettes are immersed at least 48 hours in a water tank so that the water level is above the samples of at least 30 mm.

After saturation, the water is carried out alternate freezing and thawing samples according to the following cycle:

1) freezing - at least 4 hours at a temperature not higher than minus 15 ° C;

2) Towing - at least 4 hours in water at a temperature not lower than plus 10 ° C.

The number of cycles is set in standards or technical specifications on a specific product.

After the established number of cycles of alternate freezing and thawing, the samples thoroughly examine and set the presence of bundles or other damage, comparing test samples with control.

Then, these and control samples are saturated with water at least 48 hours and are tested for bending strength in accordance with clause 4.4.

Over the tensile strength of the samples undergoing freezing and thawing, the average arithmetic value of the test results of all samples is taken.

The strength of the bending of the control samples takes the mean arithmetic value of the test results of all samples.

9.3. Processing results

Residual strength in percentage is calculated as the ratio of the strength of the strength during the bending of the samples subjected to freezing, to the limit of strength during bending control samples.

Bibliography

1. Pakharenko V. A., Yakovleva R. A., Pakharenko A. V. "Processing of polymer composite materials" - K.: Publishing company "Wave", 2006 - 552 p.

2. Pochapsky N. F. "Technology of building products from polymers" - Kiev - Donetsk: Higher School, 1979 - 216 p.

3. Vorobiev V. A. "Technology of building materials and products based on plastics" - M.: Higher School, 1974 -472 p.

4. Fishyev I. A. "Construction Material Science" - M.: Higher School, 2002 - 701 p.

5. Sapozhnikov M. Ya., Drozdov N. E. "The Handbook on Equipment of Plants of Building Materials - M.: Publisher Lit. by building., 1970 - 487 p.

6. Vorobev V. A., Andrianov R. A. "Technology of polymers", Textbook for universities: - 2nd ed. Pererab. - M.: Higher School, 1980 - 303 p.

7. Novikov V. U. "Polymer Materials for Construction" - M.: Higher School, 1995 - 448 p.

8. Materials science. Finishing construction works: Tutorial for NCH. prof. Education, V. A. Smirnov, B. A. Efimov, O. V. Kulkov, and others. - M.: Phredgest, 2002 - 288 p.

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Asbestos cement is obtained by mixing a certain amount of cement, water and asbestos. This material is widely popular in the construction industry, because the asbestos are very well connected with a solidifying cement. Thanks to this quality, the product from asbestoscement is very durable.

The term of their service exceeds the use of metal, plastic and wooden products, several times. In addition, asbestos-cement products, easy to cut and paint. Ready asbestos cement has high durability and frost resistance, as well as waterproof and resistant to fire.

Asbestos cement is used to produce various products. The main is the sheet asbestos, asbestos-cement slate, asbestos fabrics and asbestos cardboard. To date, all products listed above are widely used in the construction sector. When planning a business, manufacturing products from asbestoscent, it is necessary to study the peculiarities of production, as well as to determine the choice of final products.

Let us dwell on the manufacture of asbestos-cement slate. Today, the application of slate is very popular when installing roofing. Modern technologies allow you to produce high quality slate, different design and color. Such slate is sufficiently available, and its installation does not require special equipment and qualifications, therefore enjoys in great demand in the construction industry. Sheet Slate has many advantages, before the roof from other materials. Its price is significantly lower than that of metal or tiles. It is safe, from the point of view of ecology. Sheet slate does not rust, as well as waterproof and fire-resistant. Coating, from such slate, has good noise insulation.

Consider the necessary conditions for the organization of business, for the production of asbestos-cement slate.

Room.

The first thing is necessary for this production, this room. At the initial stage, the room is suitable with a total area of \u200b\u200babout 600 square meters. Suppose that 350 square meters will be assigned to the production premises, and the remaining 250 meters are used as a warehouse. To accommodate equipment and organization of production, such a square is sufficient.

Equipment for the production of slate.

The choice of specialized equipment should be paid to special attention. The selected equipment should have good assembly quality, and its technical characteristics must correspond to the scale of the alleged production. When working with asbestos raw materials, be sure to comply with safety. The hit of asbestos dust in the lungs is undesirable, so the staff must be provided with respirators.

To organize uninterrupted production, it will be necessary:
Bunker for mixing - 80,000 rubles;
Runners - 60000 rubles;
Turbosmeal installation - 180000 rubles;
Hydropushper - 45000 rubles;
Leaf-forming machine - 270000 rubles;
Drying chamber - 250000 rubles.

Personnel for production.

When hiring attendants, it is better to pay attention to people who have experience with similar equipment.

For servicing the planned production, 5-6 people will need (when working 5 days a week, in one working shift):
Master technologist;
Turbosmester driver;
Leaf-forming machine;
Slave loader;
Electrician;
Equipment repair specialist.

Investments and sales products.

To ensure uninterrupted sales of finished products, a competent advertising company is needed. Depending on the disposable funds, you can advertise the finished products using the Internet (create a business card site), presses, television or radio.

In order for production quickly, it is necessary to establish the sale of finished products. The goods can be realized through large construction stores or open their own trading point, cooperation with construction organizations is also possible.

When counting all costs, the following picture is obtained:
Rental of premises - 150,000 rubles per month;
Purchase of equipment - 417000 rubles;
Purchase of components for the manufacture of flat sheets - 600,000 rubles;
Salary - 270000 rubles;
Transport costs - 330000 rubles;
Tax payments - 20000;
Outcome - 1767000 rubles.

Playback of the enterprise.

To analyze the payback of the enterprise, consider pure profits. The cost of one produced flat sheet is 130 rubles. The market value of the sheet on average is 330 rubles. Subject to production at least 200 sheets of products per day and organized sales of goods, profits will be $ 10,000 rubles per month. After paying taxes, rental and wages, the company's net profit will be 560,000 rubles per month. If you divide the total amount of investment on net profit, we get three months. With good conditions and competent planning of such an enterprise, it will fully pay off initial investments for 3-4 months of uninterrupted work.

The numbers above are not accurate. In the process of organizing business, other costs are possible, but they are not so significant. Ultimately, the quality of products produced is usually determining. Quality products that meet modern building standards will always find their buyer.

Do you have a business idea? On our site you can calculate its profitability online!

Asbestos cement products are made mainly by wet method of molding. Much less often use semi-dry and dry methods for molding. The latter - in the manufacture of only flat sheets and tiles.

The wet method of technology begins with compiling compilation from asbestos of several stamps so that when molding, ensure high filtering ability, density and water retention. After that, the fiber of asbestos fiber is produced. The embroidered asbestos is thoroughly stirred with cement in water until a homogeneous mass is obtained. The latter is diluted by an additional amount of water, as a result of which an asbestos-cement suspension is obtained, in which, if necessary, additional substances (additives) can be introduced. In asbestos-cement suspension, the mass of the water of BEEE than 10 times the mass of cement. The finished suspension is directed to the molding of asbestos-cement products - sheets or 1rub. At the same time, the large part (over 96%) of free water is filtered and removed. Sheets give the necessary dimensions and shape. Facing sheets and roofing tiles are additionally pressed. The fencing of the knitting part, under the influence of which asbestos-cement products acquire the required mechanical strength, occurs in warehouses or in autoclaves (with sandland portland cement). Finished products by their coloring and facial treatment can be attached to the necessary outer surface.

Operation of asbestos, largely determines product quality. At the first stage of mechanical processing on the runners within 12-15 min weakens the relationship between the finest fibers of asbestos. In the second stage - in a hollander-fluff or other apparatus (6-8 min) there is a separation of asbestos to the finest fiber. Usually, the roller is preferable to wet method, i.e. on the runners in the presence of water. Hollander, i.e., the metal tank, inside of which the drum rotates, equipped with knives, is always a hydraulic fluffy, since the separation of asbestos hung on the runners, on the finest fiber occurs in the pockets between the drum knives as a result of the exposure to the rapid vortex movements of water jets in the same The device is usually carried out and mixing fluster asbestos with cement in aquatic environment. Water simultaneously with the loading of cement is added from the bottom of the recovery (collection of waste water).

Asbestos-cement mass is relatively fast (for 8-10 minutes) acquires sufficient homogeneity, since the smallest cement grains that carry high negative electric pressure on the surface are rapidly deposited and firmly held on the developed surface of the fine-fiber asbestos, also carrying a high, but positive charge in water and alkaline Medium. If sand cement is used, then the smallest particles of dispersed sand are also precipitated on asbestos fibers, albeit with a longer mixing suspension (12-13 minutes). To obtain a movable suspension, 1 wt is required. dry asbestos-cement mixture add no less 4-5 wt.ch. Waters, which is specified by the calculation, depending on the grades of asbestos in the mixture.

The molding of sheets and other asbestos-cement products is wet produced on a round-headed molding machine (or semi-head - on the filter tape). The principle of forming products consists in filtering water from the layers of asbestos-cement mass under the influence of hydrostatic pressure to the required seal. To this end in a metal bath , A filled asbestos-cement suspension is a hollow frame-type cylinder, covered with a metal grid (net drum). On the grid, the mass is deposited by a thin layer and partially dehydrated due to water filtration through the grid. Water from the drum is assigned to the thickeners (recuperators) for separating and returning to the production of non-sequential part of the asbestos, and then used for flushing mesh and cloth and liquefaction asbestos-cement mass In the gutter. From the surface of the drum, the asbestos-cement mass layer is removed by an endless cloth ribbon. Passing the vacuum box (with a vacuum of about 300 mm Hg), a pre-dehydrated asbestos-cement mass is transferred to a metal formatable drum, which removes the mass from the cloth tape and pumps it on its surface with concentric layers, while it is compacted between rotating metallic cylinders. When the asbestos-cement layer on the drum reaches the necessary thickness, it is cut through the forming cylinder, and the raw leaf is removed. The pressure of the press part of the leaf-forming machine is usually 0.2-0.4 MPa, for a second undercurrent shaft 10.0-12.0 MPa, for a press shaft - up to 40.0 MPa. As a result of the compression, the moisture content in the sheet is significantly reduced and reaches 25%.

The textbook provides information on the properties of the main raw materials to obtain asbestoscerta - Chrysotile Asbesta and Portland cement.

The conditions of maximum use in asbestos-cement of the reinforcing properties of asbestos fibers, the influence of the quality of Portland cement on the physico-mechanical indicators of asbestos-cement products are considered. Methods for calculating the optimal ratio of asbestos and cement in products are given.

The technological methods of processing asbestos used by the industry and methods for forming various types of asbestos-cement sheets and pipes are described. The physical and mechanical and chemical properties of products are given depending on the quality of the resulting raw materials and the method of their processing. The areas of application of the main types of asbestos-cement construction products are indicated. The necessary technical and economic data is given.

Tables 28, Figures 90, Bibliography - 60 titles.

Introduction

Asbestos cement, as the name itself indicates, consists of asbestos and cement, whose weight ratio depending on the type of product ranges from 10/90 to 20/80.

The cement resists well with compressive loads, but the limit of its tensile strength on average is only 7-8% compression strength. Therefore, in order to get a material with high compressive strength and stretching from cement, asbestos is introduced into it. Asbestos fibers, a diameter of about 30 MK, evenly permeating the mass of cement, like metal fittings in reinforcedon, increase the resistance of the material with tensile loads. The introduction of a small amount (10-20%) asbestos into cement completely changes the physicomechanical properties of cement stone: the resistance to tensile and shock loads increases sharply, thermal conductivity drops significantly. It makes the way with nails and is easily processed.

Fresh-mounted sheets of asbestos cement can be given a complex shape (wavy, halfway or other), dramatically increases their resistance to bending loads. All this makes Asbestos cement with a valuable building material, from which you can create lightweight, durable, non-aggravated and durable designs.

Asbestos-cement industry is one of the fastest growing industries of the USSR national economy. This contributes to the presence in our country of powerful deposits of chrysotile asbestos, the reserves of which are significantly higher than the Canada deposits - the main supplier of this material to capitalist countries. In addition to the main source of Chrysotil Asbestos, the largest in the world of Bazhenovsky - since 1965, two powerful deposits were put into operation - Jetagarinskoye and Ak-Dovuluskoe, and by 1970 another two powerful deposits were completed - Keembaevsky and Youth.

The directives of the XXIII Congress of the CPSU are scheduled to increase the release of asbestos-cement products in 1966-1970. Almost twice.

During this period, the range of asbestos-cement products will change significantly. If there is still a major product mass of products to cover residential and public buildings, the production of structural asbestos-cement products, large-sized flat facing sheets, asbestos-cement pipes for gas and oil pipelines, pipes for planting of drilling fluids will be significantly increased by the end of the fifth anniversary. Sheets for roofs and walls.

To fulfill this huge program, employees of asbestos-cement industry will be able only through the rapid introduction of the latest high-performance equipment, maximum automation and mechanization of production. To do this, you need to know asbestos-cement production well and skillfully use a new technique.

This goal is a real textbook. For seven years, since the third publication, the theoretical ideas about the processes occurring in the Asbestos - Cement system were created, new cars were created, which are successfully applied in industry. These are apparatus for oxbestos, to obtain a homogeneous aqueous asbestos-cement mass and molding of products. Automated technological lines are being introduced. All these changes the author tried to display in the fourth edition of this textbook.

Since construction materials industry students are special courses on the equipment of asbestos-cement plants, safety, maintenance and methods for controlling technological processes, these issues are not considered in the textbook; The designs of used machines and apparatuses are also not considered; Those schemes that are given in the book contribute to understanding and better learning described technological processes.

Technology asbestos-cement products. Technology of manufacturing asbestos-cement products required to asbestos-cement materials

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