Do-it-yourself polymer concrete production. Polymer concrete - technical characteristics of the material, advantages. Ingredients and tools needed to prepare the solution. Transparent concrete: some features

The main difference between polymer concrete and other concrete mixtures is the use of organic compounds in the production. Polymer concrete is a mixture of various binders and polyester resins, which are combined with various substances (catalysts, hardeners and solvents). Polymer concrete in its physical and mechanical characteristics is much superior to other types of concrete. He has increased plasticity, increased strength, he is not afraid of water and frost, resistant to abrasion. If you wish and have some knowledge of production technology, it will not be difficult to make polymer concrete with your own hands.

Polymer concrete surpasses all other types of concrete in terms of mechanical and physical characteristics.

Where is this material used?

Due to all its positive characteristics, the applicability of this material in construction is much higher than that of others. This material is used:

• as an insulating coating of concrete;
• when laying high-strength bricks;
• as a weatherproof paint material;
• at decorative finishing of facades of rooms;
• for putty and plaster;
• as an adhesive mortar for facing tiles;
• underfloor heating.

Due to its characteristics, such as high plasticity and low porosity, stable strength, which is achieved in a short period of time, polymer concrete can be produced by vibroforming. Including it can be used to work with products of small forms of architecture, decorative items for furniture and load-bearing structures.

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Transparent concrete: some features

Every day there are improvements, including in the construction industry. Concrete is more known for its strength than its light transmission. So it was until that time, when a novelty appeared on the market - transparent concrete. This material is a mixture of concrete and glass strands, which allow ordinary cement mortar to take on the increased hardness of the concrete mortar, plus a rather significant transparency.

Due to the presence of glass fibers in the composition of concrete, silhouettes can be seen through it.

The technical name for transparent concrete is litracon. It is carried out in the form of blocks, not much more than a brick, and because of the transparency it seems completely weightless. This material can rightfully take its place among the decorative and building materials. According to manufacturers, such blocks, in addition to being used in the construction of partitions, can even be used for paving sidewalks, since glass fibers make up only 4% of the total part of the concrete solution, and the material retains many of the advantages of the concrete mixture.

Due to the presence of glass fibers in the composition, it is possible to see the silhouette of a person or, for example, a tree through the new material. Blocks made of this material allow you to fill the living space with light, make it light and airy. It seems that the walls practically do not exist. It is preferable to use such blocks in rooms that were originally built "deaf", this applies to corridors and closets. If you use LED lighting when building a transparent concrete partition, you can achieve amazing effects.

The sizes of the produced blocks can be different, which does not prevent the transmission of light through them at all. These blocks transmit solar and electric rays at a distance of up to 20 meters. And the production technology can change depending on the requirements of the customer. Glass fibers can be distributed both around the entire perimeter of the block, and concentrated in a certain part of it, and in some cases there is the possibility of forming certain contours.

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Stamped concrete: basic properties

Stamped concrete is widely used in paving sidewalks, pavements, swimming pools, on facades and in the interior.

In recent years, decorative forms of concrete have become increasingly popular. This technology is widely used in paving sidewalks, swimming pools, pavements, in the interior and on facades. Increasingly, surface finishes with colored concrete are being used, which is also an innovation in the construction industry. Such concrete is produced by imprinting a texture on the surface of the concrete, thereby imitating any surface - from stone to tile.

For the production of stamped concrete, M-300 grade concrete is used using fiberglass as a reinforcing material. After pouring concrete into molds, its surface is imprinted with molds and, as a final step, it is treated with varnish, which prevents moisture from penetrating into the pores of concrete, and the effect of moisture repulsion occurs.

Another name for stamped concrete is press concrete, which fully reflects its essence: a matrix with a pattern is printed on the surface of the coating, which makes it possible to create a complete imitation of a stone coating with minimal labor. Stamped concrete combines the main consumer characteristics - wear resistance and decorative appearance. In addition to a large selection of textures for the production of concrete, there is the possibility of staining it in various colors.

Stamped concrete is superior to asphalt pavement and concrete tiles in many of its technical characteristics. It has increased resistance to aggressive environmental components, as well as an increased temperature limit from + 50 to -50 ° С. This coating is easy to clean, it is not slippery, which makes it indispensable when laying the coating in pools. Such concrete does not lose its original color under the influence of ultraviolet rays. When using stamped concrete, stunning decorative effects can be achieved.

The coating made from this material withstands about 300 freeze and thaw cycles, which makes it the absolute leader among other materials. In addition, such concrete is not subject to destruction under the influence of acids and alkalis, which makes it an excellent material for organizing flooring in garages or auto repair shops.

What is this material? How does it differ from the usual concrete mixtures in terms of composition and consumer properties? Is it possible to make polymer concrete with your own hands? Where and how is it used? Let's try to find answers.

What it is

Definition

Let's find out what is polymer concrete? The key difference between the material of interest to us and ordinary concrete is that synthetic resins are used as a binder instead of Portland cement. Typically thermoset; less often - thermoplastic.

Reference: A thermosetting polymer is a polymer in which, when heated, irreversible chemical changes occur, leading to a change in its strength or other properties.
Simply put, once heated, the plastic no longer melts when the same temperature is reached.
Thermoplastic polymers, in contrast, undergo a phase transition with each heating.

Do not confuse our hero with another material - polymer concrete. In our case, polymers are used as the sole binder. Polymer concrete is ordinary portland cement-based concrete modified with synthetic additives to give it any specific properties (increased elasticity, wear resistance, water resistance, etc.).

Key properties

What does the replacement of cement with polymers give in terms of consumer qualities?

• Increased tensile strength. Cement-based concretes have excellent compressive strength, but bending or tensile loads are perceived by the reinforcing cage.
• Reduced brittleness. The material is much more resistant to shock loads.
• Elasticity. Where the concrete monolith bursts, the polymer concrete only slightly deforms.
• Waterproof. Portland cement shrinks significantly during drying, which provides a porous concrete structure. In contrast, polymers, after the final set of strength, decrease in volume extremely slightly; moreover, shrinkage does not lead to porization, but to a slight decrease in the linear dimensions of the finished product.

To clarify: to improve the thermal insulation qualities and reduce weight, in some cases, the use of porous fillers is practiced in the production of polymer concrete products.
In this capacity, expanded clay and perlite sand are used.
However, the pores of the filler do not come to the surface, and if so, the water resistance does not suffer.

• Frost resistance. Actually, this property directly follows from the previous paragraph: there are no pores - there is no crystallization of water in them, tearing the material when frozen.

• Increased wear resistance. The polymer binder is corny stronger than the cement stone at break; tearing off a filler particle from it is much more difficult.
• Chemical resistance. And it is due to the properties of polymers: most of the resins are inert to the action of aggressive gases and liquids.

Application

Let's explore the main applications of polymer concrete.

Production

Regulations

The material we are discussing is considered to be relatively new and of foreign origin; however, the study of the normative documents according to which it is produced will lead to an unexpected discovery. Instruction for the production of polymer concrete and products from them under the number CH 525-80 was adopted in 1981 and remains relevant to this day.

Let's study the main theses of the document. For all polymer concrete products, the normal temperature range is from -40 to +80 degrees Celsius.

Let us clarify: if the upper limit is due to the possibility of using thermoplastic resins that soften when heated, then the lower limit is due to the increased fragility of polymers during freezing.
In the absence of shock and mechanical loads in general, the lower limit of operating temperature can be painlessly increased to the current one in the most severe climatic zones.

Binder

The composition of polymer concrete, according to the text of the document, may include the following polymers:

Aggregate

Rock crushed stone is used as the main filler. The use of sedimentary rocks (limestone, shell rock, etc.) is not allowed: its low compressive strength will significantly impair the performance of the product.

The size of the crushed stone fraction is determined, no matter how funny it sounds, by its maximum diameter:

1. If the largest size does not exceed 20 mm, one fraction is used - 10-20 millimeters.
2. In cases where the largest size reaches 40 mm, it is recommended to use two fractions: 10-20 and 20-40 millimeters. Small gravel will contribute to a denser filling and, accordingly, increase the final strength of the material.

Please note: for porous aggregates (already mentioned expanded clay and perlite), a maximum size of 20 mm is acceptable; two fractions are used: 5-10 and 10-20 millimeters.
At the same time, the percentage composition of the aggregate is divided between coarse and fine fractions in the ratio of 60:40 percent by weight.

In addition to coarse, fine (so-called grain) aggregate is used. Usually this role is played by quartz sand - natural or crushed. The requirements for it are mainly reduced to the absence of impurities - dust, silt and clay, which can worsen the adhesion between the aggregate and the binder.

Filler

In addition to the mineral filler, the product contains a ground filler - mineral flour. The standard provides for several options.

It is allowed to use ground crushed stone and quartz sand. For a material that is prepared on the basis of urea-formaldehyde resins, an additional water-binding additive is used - building gypsum (GOST 125-70).

Composition example

As a sample, we will analyze the composition of heavy polymer concrete based on the furan-epoxy binder FAED. The same document SN 525-80 will serve as a source of information for us.

It is curious: BSC performs two functions at once.
It serves as a polymerization catalyst (hardener) and provides dehydration (dehydration) of the raw material.

BSC is an effective and safe hardener with added functionality.

Technology

What does the technology of polymer concrete (more precisely, its production) look like in industrial conditions?

1. Fillers are thoroughly washed from all kinds of contaminants. As we remember, they can adversely affect the final strength of the product.
2. The next step is drying. The moisture content of the aggregate should not exceed 1 percent; it is recommended to keep the mass content of water up to 0.5%.
3. The components divided into fractions are loaded into the mixer.
   The sequence of loading and intermediate operations is strictly regulated:
   1. Gravel is loading.
   2. Sand is added.
   3. Filler added.
   4. The mixture is stirred for 1-2 minutes.
   5. A binder is added.
   6. The mixture is stirred for 3 minutes.
   7. Hardener is added.
   8. Mixing for 3 minutes - and the material is ready for pouring.
4. A separating layer is applied to the inner surface of the mold, which will prevent the polymer concrete from sticking to it. In this role, paraffin, machine oil or technical petroleum jelly are usually used.
5. The mold is poured as evenly as possible and, if possible, without cavities.
6. The last stage is the compaction of the mixture on a vibrating table or using a mounted vibrator. The optimal amplitude is 2-3 millimeters, the frequency is 3000 vibrations per minute (50 Hz). If the mixture is kneaded and laid out in several steps, its compaction is repeated after each calculation.
   Signal to stop the liquid fraction of the material on the surface (usually 2-3 minutes are enough for this).

The form can be removed from the finished product in a day. Curing at room temperature takes from 20 to 60 days. It, however, can be accelerated by heating up to 60-80 degrees; the temperature rises and falls at a rate of 0.5°C per minute to avoid the growth of internal stresses.

As you can see, the production technology does not imply any particular difficulties; in the presence of a binder, hardener, concrete mixer and vibrating table, it is quite possible to make polymer concrete at home.

Nuance: it will be necessary to clean the concrete mixer from the remnants of the mixture extremely quickly.
After adding the hardener, setting takes no more than an hour.

Treatment

What and how are polymer concrete products processed? Can they be sanded and glued?

How to cut and drill this material?

• For bonding, mastics and adhesives based on the same synthetic resins are used. Mastics, in addition to the actual binder, contain stone flour.

In the photo - Belarusian-made polyurethane adhesive with a creative name.

• Normal sandpaper is suitable for sanding. A felt wheel is used for polishing; gloss can be applied using GOI paste (polishing paste developed by the State Optical Institute).

• Drilling material, in principle, can be done with conventional concrete drills; however, diamond drilling in polymer-bonded concrete gives much better results. The edges of the hole remain perfectly smooth, without chips. For holes with large diameters (for example, under a faucet in a polymer concrete worktop for a kitchen), a diamond hole saw is used.
• The ideal tool for cutting is again a diamond saw. It is also preferable for structures whose appearance is not so important (cutting reinforced concrete with diamond wheels allows you to make the cut edges perfectly even and not change the circle when reinforcing passes); in the case of the same countertop, an inaccurate cut will hopelessly spoil its appearance.

A diamond saw is an ideal tool for cutting material.

When processing the material, in general, it is worth avoiding its strong heating. Temperatures above 120 - 150 degrees are contraindicated for a thermoplastic binder.

Conclusion

→ Concrete mix

Technology for the production of polymer concrete products

In accordance with the developed and accepted classification according to the composition and method of preparation, P-concrete is divided into three main groups:
- polymer-cement concretes (PCB) - cement concretes with additives of polymers;
- concrete polymers (BP) - cement concrete impregnated with monomers or oligomers;
- polymer concrete (PB) - concrete based on polymer binders. Polymer cement concretes (PCB) are cement
concretes, during the preparation of which 15 - 20% is added to the concrete mix, in terms of dry matter, polymer additives in the form of aqueous dispersions or emulsions of various monomers: vinyl acetate, styrene, vinyl chloride and various latexes C KS-30, C KS- 50, SKTs-65, etc.

Polymer cement concretes have high adhesion to old concrete, increased strength in air-dry conditions, increased water resistance and water resistance. Polymer solutions do not contain large gravel in their composition, and polymer mastics contain only mineral flour.

Rational areas of application of such concretes are wear-resistant floor coverings under dry operating conditions, restoration of concrete structures, repair of airfield pavements, masonry mortars, etc. In the production of floors, various dyes are allowed to be added to polymer-cement concretes and mortars.

Concrete polymers (BP) are cement concretes, the pore space of which is completely or partially filled with a cured polymer. Filling the pore space of cement concrete is carried out by impregnating it with low-viscosity polymerizable oligomers, monomers or molten sulfur. As impregnating oligomers, polyester resin of the GTN-1 type (GOST 27952), less often epoxy resin ED-20 (GOST 10587), as well as methyl methacrylate MMA monomers (GOST 20370) or styrene are used. As hardeners for synthetic resins, the following are used: for polyester resin PN-1-hyperiz GP (TU 38-10293-75) and cobalt naphthenate NK (TU 6-05-1075-76); for epoxy ED-20 - polyethylenepolyamine PEPA (TU 6-02-594-80E); for metal methacrylate MMA - a system consisting of technical dimethylaniline DMA (GOST 2168) and benzoyl peroxide (GOST 14888); for styrene (GOST 10003) - organic peroxides and hydroperoxides, or azo compounds with accelerators such as cobalbit naphitenate, dimethylaniline. Styrene also self-polymerizes at elevated temperatures.

The manufacture of BP products or structures includes the following main operations: concrete and reinforced concrete products are dried to 1% moisture, placed in a hermetically sealed container or autoclave, where they are evacuated, then the monomer or oligomer is poured into the autoclave, impregnated, after which the impregnating layer is drained. The polymerization of the monomer or oligomer in the pore space of concrete is carried out in the same chamber or autoclave by heating or by radiation with radioactive Co 60. In the thermocatalytic method of curing, hardeners and accelerators are introduced into the monomers or oligomers. Depending on the required conditions, the product is impregnated completely or only the surface layer to a depth of 15-20 mm.

The impregnation time of concrete is determined by the overall dimensions of the product, the depth of impregnation, the viscosity of the monomer or oligomer. The time of thermocatalytic polymerization at a temperature of 80-100 °C is from 4 to 6 hours.

The scheme of the plant for the production of concrete-polymer products is shown in fig. 7.4.1.

Concrete and reinforced concrete products that have been dried in the chambers (12) are fed by an overhead crane (1) to the impregnation tank (10), in which the products are evacuated and then impregnated. Then the product enters the container (3) for polymerization, and then the polymerized products enter the holding areas (14).

Monomers and catalysts are stored in separate containers (7,9). To avoid spontaneous polymerization of components and impregnating mixtures, they are stored in refrigerators (11).

BP have many positive properties: with the strength of the original concrete (40 MPa), after complete impregnation with MMA monomer, the strength increases to 120-140 MPa, and when impregnated with epoxy resins, up to 180-200 MPa; water absorption in 24 hours is 0.02-0.03%, and frost resistance increases to 500 cycles and more; abrasion resistance and chemical resistance to solutions of mineral salts, oil products and mineral fertilizers increase significantly.

Rice. 7.4.1. Scheme of a plant for the production of concrete-polymer products: 1 - cranes; 2 – tank for hot water; 3 - polymerizer; 4 - auxiliary premises; 5 - vacuum pump; 6 – low pressure steam supply system; 7 - tanks for the catalyst; 8 - compensation tanks; 9 – monomer storage tanks; 10 - reservoir for impregnation; 11 - refrigerators; 12 - drying chambers; 13 - control post; 14 - platforms for curing concrete

Rational areas of application of BP are: chemically and wear-resistant floors of industrial buildings and agricultural premises, pressure pipes; power line supports; pile foundations used in harsh climatic conditions and saline soils, etc.

The main disadvantages of BP include: a complex technology for their production, requiring special equipment and, as a result, their high cost. Therefore, BP should be used in construction practice, taking into account their specific properties and economic feasibility.

Polymer concretes (PB) are artificial stone-like materials obtained on the basis of synthetic resins, hardeners, chemically resistant aggregates and fillers and other additives without the participation of mineral binders and water. They are intended for use in load-bearing and non-bearing, monolithic and prefabricated chemically resistant building structures and products, mainly at industrial enterprises with the presence of various highly aggressive environments, for the manufacture of large-sized vacuum chambers, radio-transparent, radio-tight and radiation-resistant structures, for the manufacture of basic parts in machine-tool and machine-building industry, etc.

Polymer concrete and reinforced polymer concrete are classified according to the type of polymer binder, average density, type of reinforcement, chemical resistance and strength characteristics.

Compositions, the most common in construction, polymer concrete and their main properties are given in table. 7.4.1. and 7.4.2.

Polymer solutions do not contain crushed stone, only sand and mineral flour.

Polymer mastics are filled with one flour.

For the preparation of polymer concrete, the following synthetic resins are most often used as a binder: furfural acetone FA or FAM (TU 59-02-039.07-79); furan-epoxy resin FAED (TU 59-02-039.13-78); unsaturated polyester resin PN-1 (GOST 27592) or PN-63 (OST 1438-78 as amended); methyl methacrylate (monomer) MMA (GOST 20370); unified carbamide resin KF-Zh (GOST 1431); as hardeners for synthetic resins are used: for furan resins FA or FAM-benzenesulfonic acid BSK (TU 6-14-25-74); for furan-epoxy resin FAED - polyethylenepolyamine PEPA (TU 6-02-594-80E); for polyester resins PN-1 and PN-63-hyperiz GP (TU 38-10293-75) and cobalt naphthenate NK (TU 6-05-1075-76); for metal methacrylate MMA - a system consisting of technical dimethylaniline DMA (GOST 2168) and benzoyl peroxide (GOST 14888, as amended); for urea resins KF-Zh - aniline hydrochloride (GOST 5822).

Acid-resistant crushed stone or gravel (GOST 8267 and GOST 10260) are used as large aggregates. Expanded clay, shungizite and agloporite are used as large porous aggregates (GOST 9759, 19345 and 11991). The acid resistance of the listed fillers, determined according to GOST 473.1, must be at least 96%.

Quartz sands (GOST 8736) should be used as fine aggregates. It is allowed to use screenings when crushing chemically resistant rocks with a maximum grain size of 2-3 mm. The acid resistance of small aggregates, as well as crushed stone, should not be lower than 96%, and the content of dusty, silty or clay particles, determined by elutriation, should not exceed 2%.

For the preparation of polymer concrete, andesite flour (STU 107-20-14-64), quartz flour, marshalite (GOST 8736), graphite powder (GOST 10274 as amended) should be used as fillers, ground aggloporite is allowed. The specific surface of the filler should be in the range of 2300-3000 cm2/g.

Gypsum binder (GOST 125 as amended) or phosphogypsum, which is a waste product of phosphoric acid production, is used as a water-binding additive in the preparation of polymer concretes based on KF-Zh binder.

Fillers and aggregates must be dry with a residual moisture content of not more than 1%. Do not use fillers contaminated with carbonates, bases and metal dust. Acid resistance of fillers must be at least 96%.

If necessary, polymer concrete is reinforced with steel, aluminum or fiberglass reinforcement. Aluminum reinforcement is mainly used for polymer concrete based on polyester resins with pre-tensioning.

The materials used must provide the specified properties of polymer concrete and meet the requirements of the relevant GOSTs, TUs and instructions for the preparation of polymer concrete (SN 525-80).

The preparation of a polymer concrete mixture includes the following operations: washing of aggregates, drying of aggregates and aggregates, fractionation of aggregates, preparation of hardeners and accelerators, dosing of components and their mixing. Drying of materials is carried out in drying drums, ovens, heating cabinets.

The temperature of the fillers and fillers before feeding into the batchers should be within 20-25 °C.

Resins, hardeners, accelerators and plasticizers are pumped from the warehouse into storage tanks by pumps.

Dosing of components is carried out by weight batchers with dosing accuracy:
resins, fillers, hardeners +- 1%,
sand and crushed stone +-2%.
The mixing of the constituent polymer concrete mixtures is carried out in two stages: the preparation of the mastic, the preparation of the polymer concrete mixture.
The preparation of mastic is carried out in a high-speed mixer, with a rotation speed of the working body of 600-800 rpm, the preparation time, taking into account the load, is 2-2.5 minutes.

The preparation of polymer concrete mixtures is carried out in forced mixing concrete mixers at 15°C and above.

The technological process of forming polymer concrete products consists of the following operations: cleaning and lubricating molds, installing reinforcing elements, laying polymer concrete mixture and molding products.

The lubrication of metal molds is carried out with special compositions in% by weight: emulsol -55 ... 60; graphite powder - 35 ... 40; water -5 ... 10. It is also allowed to use solutions of bitumen in gasoline, silicone lubricants, a solution of low molecular weight polyethylene in toluene.

Concrete pavers are used for laying, leveling and smoothing the mixture. Compaction is carried out on vibrating platforms or using mounted vibrators. Compaction of polymer concrete products on porous aggregates is carried out with a weight that provides a pressure of 0.005 MPa.

The duration of vibration is prescribed depending on the stiffness of the mixture, but not less than 2 minutes. A sign of good compaction of the mixture is the release of a liquid phase on the surface of the product. The compaction of polymer concrete mixtures is more efficient on low-frequency vibration platforms with the following parameters: amplitude 2–4 mm and oscillation frequency 250–300 per minute.

The curing of polymer concrete under natural conditions (at a temperature not lower than 15 ° C and a humidity of 60 - 70%) occurs within 28 - 30 days. In order to accelerate hardening, polymer concrete structures are subjected to dry heating for 6–18 hours in chambers with steam registers or aerodynamic furnaces at a temperature of 80–100°C. In this case, the rate of rise and decrease in temperature should be no more than 0.5 - 1 ° C per minute.

A typical technological scheme for the factory production of polymer concrete products is shown in the graph (Fig. 7.4.2).

Rice. 7.4.2. Technological scheme for the production of polymer concrete products on a production line. 1 - storage of aggregates; 2 - bunkers for receiving crushed stone and sand; 3 - drying drums; 4 - dispensers; 5 - concrete mixer; 6 - vibration platform; 7 – thermal treatment chambers; 8 - post stripping; 9 - warehouse for finished products

The preparation of the polymer concrete mixture takes place in two stages: at the first stage, the binder is prepared by mixing the resin, microfiller, plasticizer and hardener, at the second stage, the finished binder is mixed with coarse and fine aggregates in forced-action concrete mixers. The binder is prepared by mixing dosed microfiller, plasticizer, resin and hardener in a continuously operating turbulent mixer. Mixing time of the loaded components is no more than 30 s.

The polymer concrete mixture is prepared by sequential mixing of dry aggregates (sand and crushed stone), then a binder is fed into a continuously operating concrete mixer. Mixing time of aggregates (dry mix) 1.5-2 min; dry mix of aggregates with a binder - 2 min; unloading of polymer concrete mixture - 0.5 min. Sand and crushed stone are fed into the concrete mixer by batchers. The mixer must be equipped with temperature sensors and an emergency device for supplying water in case of a sudden accident or in the event of a disruption in the process, when it is necessary to stop the reaction of polymer structure formation. 164

The polymer concrete mixture is fed into a suspended type concrete paver with a mobile hopper and a smoothing device, which evenly distributes the polymer concrete mixture according to the shape of the product.

The polymer concrete mixture is compacted on a resonant vibration platform with horizontally directed vibrations. Oscillation amplitude 0.4-0.9 mm horizontally, 0.2-0.4 mm vertically, frequency 2600 counts/min. Vibrocompaction time 2 min.

Laying and vibrocompaction of the mixture is carried out in a closed room equipped with supply and exhaust ventilation. Simultaneously with the formation of polymer concrete structures, control samples of 100X100X100 mm in size are formed to determine the compressive strength of polymer concrete. For each product made of polymer concrete with a volume of 1.5 - 2.4 m3, three control samples are made.

Heat treatment of polymer concrete products. To obtain products with desired properties in a shorter time, they are sent using a floor conveyor to the heat treatment chamber. Heat treatment of products is carried out in an aerodynamic heating furnace, PAP type, which ensures uniform temperature distribution throughout the volume.

After heat treatment, finished products are automatically moved by a conveyor to the technological bay, removed from the mold and sent to the finished product warehouse. The released mold is cleaned of foreign objects and polymer concrete residues and is prepared for molding the next product.

Quality control should be carried out, starting with checking the quality of all components, the correct dosage, mixing modes, compaction and heat treatment.

The main indicators of the quality of the prepared polymer concrete are the self-heating temperature after molding, the rate of increase in concrete hardness, its strength characteristics, including uniformity after 20-30 minutes. After vibration compaction, the polymer concrete mixture begins to heat up to a temperature of 35-40°C, and in massive structures - up to 60-80°C. Insufficient heating of polymer concrete indicates poor quality of the resin, hardener or high humidity of fillers and aggregates.

To determine the control strength indicators of polymer concrete, samples are tested in accordance with GOST 10180 and instruction SN 525 - 80.

When performing work on the manufacture of products and structures from polymer concrete, it is necessary to comply with the rules provided for by the head of the SNiP on safety in construction, the sanitary rules for the organization of technological processes approved by the Main Sanitary and Epidemiological Directorate of the Ministry of Health and the requirements of the Instruction on the technology of manufacturing polymer concrete (SR 52580).

Innovative technologies delight us more and more every day. New developments also affected the construction industry. In particular, the creation of new building materials, among which polymer concrete is in great demand. It is a mixture, the composition of which consists of various polymeric substances, and not of the cement or silicate that has long been familiar to us. This material has a lot of positive properties, due to which it is superior to conventional building mixtures.

Polymer concrete: characteristics

Due to the huge number of its positive properties, the cement-polymer mixture justifiably deserves respect among builders. Using this material, any specialist will appreciate its strength and durability. Polymer concrete does not give in to moisture, does not deform, perfectly reacts to temperature changes and bad weather. Dries quickly and adheres well to any surface. This material has a high resistance to stretching, good air permeability. It is not affected by any chemical reactions.

But the most important of all the properties of polymer concrete is that it is environmentally friendly, does not pollute the environment and does not harm human health in any way. The polymer mixture is allowed to be used even in the construction of public catering facilities, various grocery outlets, as well as other food industry buildings.

Pros and cons

A huge number of positive properties extols the cement-polymer mortar over conventional concrete. Due to the rapid solidification with polymer concrete, after a few days, the first work can be done, which cannot be said about ordinary material. Concrete of the new sample is much more enduring, stronger. For complete hardening, one week is enough for him, and not a month, as for ordinary cement.

Among the positive properties of the polymer mixture is waste-free production. Previously, all agricultural and construction waste was simply thrown away or buried in the ground, thereby polluting our nature. Now recycled material is used for the manufacture of polymer concrete. The use of such technology not only solves the problem of waste disposal, but also protects the environment from pollution.

This building material, unfortunately, has its drawbacks. Among the negative properties, one can single out the inclusion in the composition of artificial materials. The second negative point is the expensive cost of some additives necessary for the preparation of polymer concrete. Due to this, the price of the finished product rises.

Application

Due to the presence of many positive properties, polymer concrete has a fairly wide range of applications. It is used in landscape design, laying out paths and terraces. Walls are finished with a similar mixture, both from the outside and from the outside, they decorate stairs, fences, plinths. Such material easily lends itself to manual work. Various shapes, figures, decorative elements are obtained from it. Its beauty is that it is easily painted after drying.

The use of such a building mixture is suitable for pouring floors. Polymer concrete floors will serve as an excellent protection against moisture. Polymer concrete floors will keep your home warm.

Kinds

Given the technical characteristics and composition, new generation concrete is divided into:

• Polymer cement. This type of concrete has excellent strength. A similar material is used in the construction of airfields, finishing slabs and bricks.
• Plastic concrete. It exhibits the property of excellent resistance to acid-base reactions and temperature imbalance.
• Concrete polymer. This building mixture differs from others in that the ready-made, frozen block is impregnated with monomers.

These substances, filling the holes and defects of the material, provide it with durability and resistance to sub-zero temperatures.

Also, depending on the type of construction work, experts divide polymer concrete into filled and frame molecular. The first type allows the presence of such organic materials as quartz sand, gravel. These materials perform the function of filling voids in concrete. In the second option, the concrete remains with unfilled voids. And the connection between the particles of concrete is carried out by polymeric substances.

The use of concrete made from cement is limited. A polymeric binder that determines such properties of products made of polymer concrete such as chemical resistance and vibration resistance, allow the use polymer concrete and designs from polymer concrete where traditional concrete would fail

Polymer concrete it is produced as follows: sand, limestone, talc, crushed waste from the production of composite materials, such as fiberglass, etc., are mixed with a binder (polyester resin). Coarsely dispersed fillers in polymer concrete - crushed stone up to 50 mm in size and sand with a grain size up to 5 mm. In order to reduce consumption binder and the cost of products, as well as to regulate their properties, a finely dispersed filler is introduced into polymer concrete withparticle size less than 0.15 mm (barite, quartz, andesite flour, etc.). The composition of polymer concrete may also includeblowing agents, Surfactants, flame retardants, dyes, etc.
With a high degree of filling (70 - 80%), inexpensive products with high physical and mechanical characteristics are obtained. Filler, such as sand, gives products durability, resistance to abrasion loads, but greatly increases their weight. In the production of such products, it is necessary to choose a resin with a reduced viscosity. The production parameters should be such that the filler is evenly distributed throughout the volume of the product, does not precipitate due to the difference in the density of the filler and resin. It is also necessary to degas the mixture to prevent the formation of cavities inside the product, which can lead to a decrease in strength. The disadvantage of polymer concrete products is their unaesthetic appearance, which makes it impossible to use these products as decorative elements in the design of premises, etc.

Application of polymer concrete:

Cladding panels;

Foundations for industrial equipment;

Noise-absorbing structures;

Mooring edges and breakwaters;

Water tanks;

Drainage structures;

Road curbs and fences;

Railway sleepers;

Stairs;

Restoration and protection of existing concrete structures;

Capacities and reservoirs for chemically active substances;

Drainage sewers of chemical enterprises.