Polymer concrete products. polymer concrete. Polymer additive for concrete - properties, advantages

polymer concrete

In the process of development of building technologies, new materials and concrete mixes appear, for the preparation of which special fillers are used. This allows you to create durable composite materials with high performance, decorative properties. Polymer concrete - one of these compositions, is gaining popularity in the market of building materials.

The material, along with the traditional components - sand and gravel, includes polymer resins based on epoxy, furan, polyester as a binder. Polymer concrete is in demand in the construction industry, it is used to create sculptures, make original furniture, as well as in the ritual sphere.

Polymer concrete (cast stone, polymer cement, concrete polymer, plast concrete, plast concrete) was invented in America as a stronger and more durable alternative to ordinary concrete

Polymer concrete has a number of significant advantages associated with improved mechanical characteristics compared to conventional concrete, resistance to aggressive environments, lightness, and an expanded color palette that allows imitation of natural stone. Consumers of the composite are convinced that it is a reliable composition with a wide range of applications. We will consider the material in detail, delve into the technology, evaluate the advantages and disadvantages, and study the recipe.

Material advantages

Composite concrete, due to the peculiarities of the formulation, has a number of positive characteristics. They are used in various situations where the use of traditional concrete will not provide the desired result.

The main advantage of the composite:

• Increased resistance to moisture penetration into the composite array. Water drops quickly evaporate from the surface of the material, I do not have time to saturate it with destructive moisture.
• Resistance to significant temperature changes, allowing polymer concrete to maintain integrity, regardless of the duration and number of freezing cycles.

  

  This material is one of the new types of concrete mixtures, where instead of silicate or cement (used during the preparation of ordinary concrete), a polymer is used.

• The resistance of the material to aggressive substances, chemical reagents, which allows the use of polymer concrete in various areas without surface protection using special coatings.
• The possibility of restoring mechanically damaged sections of the composite array using a restoration mixture.
• Increased strength characteristics with a relatively small mass of the composite, allowing the production of various products with extended performance properties.
• The absence of roughness on a perfectly smooth, absolutely non-slippery surface of the material. This property allows the artificial stone to remain clean for a long time, and, if necessary, various contaminants are easily removed from the surface of the material.
• Expanded color range of polymer concrete imitating natural marble, malachite, granite. The created artificial stone is difficult to distinguish from the real one, which makes it possible to provide a wide range of applications for the composite.
• The possibility of recycling, use in the manufacture of technological waste, which significantly reduces the cost of products manufactured in conditions of waste-free technology.



Pros: strength, low weight, impact resistance, elasticity is many times higher than that of conventional concrete

Weak sides

Along with the positive aspects, polymer concrete has disadvantages:

• susceptibility to the effects of open fire and elevated temperature, causing the destruction of the material;
• increased, when compared with concrete, price, due to the cost of purchasing special resins.

Components of polymer concrete

If you want to prepare polymer concrete at home, study the composition of the composite. To prepare polymer concrete, use the following ingredients:

• A binder, which is used as urea-formaldehyde, polyester, epoxy and furfural acetone resins.
• Large-fraction crushed stone filler. The size of the crushed stone fraction required for the formation of the composite can be up to 4 centimeters, however, crushed stone 1-2 cm in size should make up the bulk of the composition.
• Screened and cleaned quartz sand. The size of quartz particles should not exceed 5 mm, the presence of clay inclusions, dust is not allowed.

  

  For polystyrene concrete (where polystyrene is taken as a filler), there are standards

• Crushed graphite powder with a particle size of not more than 0.15 mm, quartz flour, used as a ground filler, which reduces the need for expensive resins.
• Building gypsum used in the presence of urea-formaldehyde resin in the composite formulation.
• Surfactants, additives with antiseptic properties and ingredients that increase the volume of the array, increase the thermal insulation properties of the finished composite.

Classification

Polymer concrete, depending on the concentration of the filler, the share of which in the total volume is up to 80%, is divided into classes:

• especially heavy, cubic meter, which weighs from 2500 to 4000 kg;
• heavy, with a density of 1800-2500 kg/m3;
• light with a specific gravity of 500-1800 kg/m3;
• lightweight, the mass of a cubic meter does not exceed 500 kilograms.

Scope of use

Most of the inhabitants are sure that polymer concrete and cement-polymer concrete are two names for the same material. In fact, these are completely different building mixtures with high strength characteristics.

Cement is not added to polymer concrete (plastic concrete), and various polymers act as a binder. Portland cements mixed with polymer additives are added to polymer cement concretes.

There are two types:

1. Filled - high-molecular organic compounds fill the voids between the particles of the filler (gravel, crushed stone, quartz sand).

2. Frame - the voids remain unfilled, and the polymer serves only to fasten the particles of the mineral filler together.

In the first case, the amount of the mixture ranges from 20 to 50%. In the second case, it does not exceed 6%.

It is considered a high-strength material in which aqueous dispersions of polymers (vinyl chloride, vinyl acetate, styrene, latexes, polyamide resins, and others) act as additives that improve performance. Their use allows you to change the properties of building materials for the better and improve its technical performance.

Applications, production and sales

Compound

Resins are added to polymer concrete more often than others:

• epoxy;
• polyurethane;
• methyl methacrylate;
• polyvinyl.

Various plasticizers are added to the resins to improve elasticity and increase resistance to stretching, and hardeners to reduce the setting time. The composition of cement-polymer concrete also includes Portland cement.

Gets its characteristics due to the organic binder. This contributes to the fact that free particles of gravel or crushed stone are fastened together, turning into a strong monolith with a complete absence of cracks. As moisture evaporates, a special film forms on the surface, adding strength and increasing adhesive properties (adhesion to other surfaces).

Thanks to this, polymer concrete becomes extremely resistant even to serious loads, as well as to the effects of acids and sudden changes in temperature. The strength becomes even higher if the solution is kept in conditions of low humidity (40-50%).

Characteristics:

• moisture resistance;
• wear resistance;
• high chemical resistance;
• resistance to temperature extremes;
• increased tensile strength;
• no negative impact on living organisms;
• high level of adhesion to surfaces;
• fast curing;
• good breathability.

The only thing that can become a stumbling block and cross out all the advantages of this building material is its high cost. It is unlikely that you will be able to buy polymer concrete cheaply. The price directly depends on the amount of the connecting element used. Filled polymer concrete is always more expensive than frame concrete. Additives can be painted in absolutely any color. This also affects the final cost of the building mix.

Production

As additives in the production of polymer concrete, water-soluble resins, PVA and latexes are most often used. When the finished mixture dries, a film forms on the surface of its particles, which swells when a large amount of moisture enters. However, this does not affect the strength characteristics.

The only correct ratio of components in the recipe does not yet exist. But most often, manufacturers mix cement with additives not exceeding 20% ​​of the cement part.

The highest quality cement solution is obtained with a water-soluble polyamide or epoxy resin and a hardener (polyethylene-polyamine).

The production of a cement-polymer mixture is as follows:

1. Special water for polymers with a small amount of cement is poured into the concrete mixer;

2. Equal amounts of ash and slag are added.

3. The solution is mixed.

4. Polymeric and other additives are added.

5. Finally knead.

Application

The material can be used for landscape design (paths and terraces), interior and exterior decoration of walls, floors and facades of buildings.

Designers and architects love it because it is easily shaped and can be applied manually and mechanically. A special stamp is applied to the surface of the poured concrete a certain number of times, imitating various natural structures (stone, cobblestone, wood, paving slabs, etc.). The dried surface can subsequently be painted in the desired color with acrylic-based paints.

They can also be used to decorate fireplace portals, fences, plinths, stairs, pools, borders, barbecue areas, building facades.

Polymer coatings for concrete can give the material additional improved properties of wear resistance, durability and strength. Thanks to them, the monolith is able to last more than 20 years.

Manufacturers and cost

In Russia, the following companies are engaged in production and supply: TeoChem LLC, BASF CJSC (a representative office of the German concern BASF), DI-Trade LLC, the Moscow representative office of DUROCEM ITALIA, Zika LLC (a representative of the Swiss company SIKA), LLC "Topbeton"

The price of a polymer concrete self-leveling floor starts at around 400 rubles per 1 m 2, a further increase in the cost depends on the high cost of polymer additives, working conditions and footage.

Polymer concrete (also called cast or artificial stone, polymer cement, concrete polymer and plastic concrete) is an alternative type of concrete mixture that uses a polymer (synthetic resin) instead of a standard binder. Thanks to this component and cheaper mineral aggregates, the composition is highly moisture and frost resistant, but the price of cast stone is lower. Let's take a closer look: polymer concrete - what is it and is it really worth using this material in construction, as a replacement for the usual concrete?

To answer this question, first of all, we will determine which components the plast concrete includes.

Composition of polymer concrete

The lion's share of the composition of polymer cement is occupied by aggregate and it is added at once of two types:

• Ground - talc, graphite powder, andesite flour, ground basalt, mica and other raw materials.
• Coarse - gravel, crushed stone, quartz sand.

Important! In the production of cast stone, metal dust, cement lime and chalk cannot be used.

Resin is used as a "fastening" component:

• furan-epoxy (must meet the requirements of TU 59-02-039.13-78);
• furfural acetone (FAM), meeting the standards of TU 6-05-1618-73;
• urea-formaldehyde (complies with the standards of GOST 14231-78);

Polyester resin is often used to hold the core together, as it is less expensive than others. It is also allowed to use a monomer of methyl methacrylate (methyl ester) that meets the standards of GOST 16505.

In addition, the composition of the cast stone contains hardeners, plasticizing additives and coloring components. They must also comply with the requirements for chemical additives (GOST 24211).

Depending on one or another quantity and type of components, polymer concrete of different quality can be obtained.

Varieties of polymer concrete

Depending on which filler (or rather, its fraction) you added to the casting stone solution, you can get material both for creating light decorative elements and for building more massive structures.

Based on this, the following classes of polymer concrete are distinguished:

1. Super heavy. The density of such concrete is from 2.5 to 4 t/m 3 . As a filler for super-heavy building material, components with a size of at least 2-4 cm are used. This type of concrete is used for the construction of structures that are under great pressure (bearing structures, foundations).
2. Heavy (density from 1.8 to 2.5 t / m 3). This structural type plastic concrete is suitable for the manufacture of decorative cast stones that imitate marble and other expensive stones. The aggregate size of heavy polymer concrete should not exceed 2 cm.
3. Easy. Since the density of such a material is 0.5-1.8 t/m 3 , it is usually referred to as concrete of the structural and heat-insulating class. This type of concrete polymer features high heat saving rates. The aggregate for its preparation is used the same fraction as for heavy polymer concrete, only its quantity changes.
4. Ultralight. The density of such a composition is from 0.3 to 0.5 t / m 3, therefore it is used for thermal insulation work and in the construction of internal partitions. As a filler, various shavings, perlites, cork and polystyrene with a fraction of not more than 1 cm most often act.

Healthy! Most often, polymer concrete is used for the manufacture of: kitchen countertops, sinks, window sills, columns, steps, monuments, fireplaces, fountains, floors, vases and much more.

There is also the lightest artificial stone, with a filler no larger than 0.15 mm. Such material has found application in the production of decorative elements.

Properties of polymer concrete

If we compare concrete polymer with ordinary concrete, then it is worth noting the fact that, in many of its characteristics, the composition with the addition of resins bypasses the usual mixtures. Polymer concrete has the following properties:

• density - 300-3000 kg / m 3;
• resistance to compression - from 50 to 110 MPa;
• resistance to bending - from 3 to 11 MPa;
• abrasion in the range of 0.02-0.03 g/cm 2 ;
• temperature limit - from 60 to 140 0 С;
• elasticity - from 10,000 to 40,000 MPa;
• thermal conductivity coefficient - 0.05-0.85 W / m K;
• moisture absorption volume - 0.05-0.5%;

The strength characteristics of polymer concrete are 3-6 times higher than those of conventional concrete. The same applies to tensile strength, which is almost 10 times higher for concrete polymer.

It is also worth considering the chemical passivity of modern concrete composition, which is determined according to GOST 25246-82. It follows from this regulatory document that at 200 0 C Celsius, the chemical resistance of the concrete polymer components to nitric acid will be at least 0.5%, and to hydrochloric acid, ammonia or calcium solution, at least 0.8%.

Based on this, we can conclude that polymer concrete, which includes resins, has all the qualities necessary for the construction of various objects.

Advantages and disadvantages of cast stone

Polymer cement is often used in the construction of structures that cannot be made from ordinary concrete due to its fragility. Due to the polymer composition, structures will be less susceptible to deformation or destruction.

In addition, polymer concrete has the following advantages:

• Due to the high water resistance and resistance of the concrete polymer to temperature extremes, water drops almost immediately evaporate on the surface of the finished product, as a result of which cracks and other defects do not occur.
• The surface of polymer cement remains smooth throughout the entire service life, so polymer concrete products do not get dirty.
• The variety of colors allows you to create products from this material, stylized as expensive natural rocks (granite, marble and others).
• The material is recyclable with the possibility of reusing concrete polymer.
• Structures made of this lightweight concrete do not require additional processing.

If we talk about the shortcomings of modern material, then it is worth highlighting the following disadvantages:

• Combustibility of polymer concrete.
• The high cost of some binders (however, if you use ground flour as a filler, then the costs will be significantly reduced).
• It is not always possible to find everything necessary for the production of such a composition on sale.

Speaking about the production of polymer concrete, it is worth considering possible options for the manufacture of such concrete.

Methods for the production of cast stone

The manufacturing process of concrete polymer can be continuous or periodic.

Continuous production

In this case, we are talking about large-scale production, for which it will be necessary to purchase the appropriate equipment:

• Vibrating table.
• Stirrer.
• Compressor system with gun.
• Silicone matrices.
• Hood.
• Grinding and polishing machines.

To purchase everything you need, you will have to spend about 250,000 rubles. Even if you consider that you will make some of the equipment on your own, you will have to purchase the most expensive tools. Therefore, we will not stop at this production method and consider a more affordable technology.

Making polymer cement at home

Knowing what polymer concrete is, it becomes obvious why this material is most often used for the production of countertops and decorative elements for a suburban area. Fortunately, for its "home" production, you do not need specialized equipment.

To make polymer cement with your own hands:

1. Rinse and clean the aggregate. After that, dry it until the moisture content of crushed stone or gravel is 0.5-1%. If wet aggregate is used, the strength of the finished product will decrease.
2. Sift the sand and remove impurities from it.
3. Pour crushed stone into the concrete mixer first, then sand and aggregate and mix the components for 2 minutes.
4. Add water and mix everything again.
5. Soften the binder (resin) with a solvent or simply by heating the solid mass.
6. Add a plasticizer, stabilizers and other components to the resin. Stir them separately from the aggregate for 2 minutes.
7. Add hardener.
8. Mix all the ingredients for at least 3 minutes until you get a creamy mixture.
9. Pour the resulting mixture into a paraffin-lubricated matrix or prepared formwork. Try to immediately fill in the volume of the composition that completely fills the form. Polymer concrete sets very quickly, so you need to act quickly.
10. Level the surface and compact the mixture on a vibrating table.
11. Wait a day and pull the finished product out of the matrix.

On this, the production of polymer concrete can be considered finished.

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(otherwise, cast stone) is a material that combines the strength and beauty of natural stone with an affordable price (thanks to cheap mineral additives) and ease of manufacture. The possibility of using almost any aggregate (sand, granite and marble chips, glass and many others) guarantees variety. And the presence of a polymer binder makes them durable, exposed to water and overheating.

Let's consider typical technological processes for the manufacture of polymer concrete, as well as the possibility of creating it yourself.

What will be required?

To get the product you need:

• A filler of a sufficiently large fraction (sand, crushed stone, coarsely crushed glass).
• A finer grinded aggregate that reduces the cost of the material. It is a powder of graphite, quartz or andesite.
• Binder - it will need about 5 percent. In this capacity, one of the polymer resins is used. For example, polyester (unsaturated), urea-formaldehyde, furan, epoxy.
• Hardeners, plasticizers, special modifiers, dyes.
• Mold release lubricant and top coat gel coat.

Production methods

The production process can take place in batch or continuous technology.

• In the first case, the containers used for the manufacture of the material must be washed after each completed cycle. But it is possible to make polymer concrete in the most ordinary bucket or concrete mixer.
• Continuous technology is used mainly in large industries. At the same time, special injection molding machines, dispensers and automatic mixers work together, organizing a single chain.

The following video talks about the manufacture and spraying of lightweight polymer concrete:

Process

To make a cast stone, you will need a mold well covered with a special release agent (otherwise it will be impossible to remove the finished product). The form can be made of silicone, fiberglass, metal or even chipboard (budget option).

1. A layer of gelcoat of the desired color is applied to the release paste.
2. A composite mixture is placed inside the mold, consisting of the above ingredients, previously well mixed in a concrete mixer. In large industries, where the volumes are very solid, the mixture is put into the mold using a concrete paver. If the products are small, and the technological process is periodic, then this is done manually.
3. Now it is necessary that the laid mixture is subjected to vibration (vibration compaction). This procedure takes approximately two minutes. At the plant, a resonant vibration platform is used for this, at a small production site - a vibrating table.

Under production conditions at the plant for the production of polymer concrete, if necessary, heat treatment is carried out for faster hardening of the parts. In other cases, they wait for the natural completion of this process.

We will talk about machines, molds and other equipment for the production of polymer concrete products below.

Necessary equipment

Features of choice and costs

Those who dream of aiming at continuous technology and solid volumes by organizing large-scale industrial production will need special conveyor equipment. Which will include machines for dosing, mixing, casting, finishing, as well as a mechanized warehouse.

All this will cost a tidy sum of several million dollars. If we confine ourselves to turnkey branded equipment, then the costs will be much less - from 30 to 50 thousand dollars.

But still, it is not always possible to find money for a purchase, especially in our difficult time. However, you can get by with even lower costs. If you purchase all the necessary machines and other things separately. And something to make yourself. Below is more about this option.

List of equipment and devices

So, here is a list of equipment and devices that you can not do without:

• Vibrating table - ready will cost about 27 thousand rubles. If you want to save money, weld the table yourself using two-millimeter metal corners (60s). We weld an industrial-type vibrator to the table - done.
• A stirrer that will combine all the components into a homogeneous mixture. If you purchase a powerful vacuum device of European quality, you will have to pay about 10 thousand dollars. But you can also use a domestic concrete mixer or a construction mixer. It will be much cheaper - the cost depends on the volume and power. Even cheaper is to make a mixer yourself from an iron barrel and an electric drive with a gearbox.
• You will also need a compressor system with a gun. Without it, it will not be possible to apply the gelcoat evenly. The gun costs from 50 to 100 dollars. You can take automobile compressors - two pieces from ZIL will be enough. They are connected in parallel and attached to metal platforms installed on a strong frame.
• Molds made of fiberglass or silicone are not yet widely available for sale. They can be ordered for specific products (for example, window sills) from a specialized company. Or make molds yourself, starting with a cheaper material - chipboard with lamination.
• Without fail, an exhaust hood will be needed - at the casting stage, production is distinguished by harmful fumes. Accordingly, we will also purchase individual protection: gloves, respirators.
• For finishing work, you will need electric tools: grinding and polishing machines. And also a drill, a jigsaw, a grinder, a milling cutter (if necessary).

We will talk about emissions into the atmosphere from the production of polymer concrete below.

This video will also tell about another method of manufacturing polymer concrete:

Air emissions from such production

As mentioned just above, during casting, the release of harmful components is present.

• In particular, it is styrene, which is contained in resins used as a binder. As soon as we open a hermetically sealed container with such a resin, the poisonous gas begins to evaporate.
• In addition, the hardener is also extremely dangerous (as a rule, it is methyl ethyl ketone peroxide). However, it is not volatile and requires only the protection of hands with rubber gloves.

These facts force polymer concrete manufacturers to carefully equip the casting room, making it hermetic, installing a powerful exhaust above the table, not forgetting about their own protection (respirator). And if all these measures are observed, and the air leaving the hood is cleaned, then there will be no emissions into the atmosphere (after all, the room is airtight).

How to make elastic polymer concrete yourself (with your own hands), read below.

DIY creation

And now we will talk about how to make small products from fashionable cast stone on our own, spending a minimum of money. For example, it can be flower pots, countertops, window sills (especially popular, as they are warmer than marble or granite).

Room selection and arrangement

First you need to think about the room - you need 80 square meters of total area. It is advisable to look for a suitable house somewhere on the outskirts. And 12 square meters will immediately have to be fenced off for the casting room, and you will have to try to seal all the cracks as much as possible. So that the styrene does not leak.

In the center of this room we make a table on a frame of iron corners, covering it with a chipboard top. We expose its surface according to the level - this is important! Above the table we install a hood - a metal box with an electric motor.

To make it light, we mount fluorescent lamps on top. In the next room we put the same table - for finishing and other work. Here we will place the tool and containers for drying chalk and sand (metal low boxes).

Required raw materials

Required raw materials:

• River quartz sand (packed in 20 kilograms). It must dry well.
• Sifted chalk - we also dry it.
• Polyester resin - in buckets of 20 liters is bought.
• Hardener, gelcoat, release paste.

Manufacturing process

1. You will need a clean plastic bucket for stirring, a 450-watt perforator and a construction mixer (we will attach a perforator to it by welding a perforating drill - we get a mixer).
2. We make the form from laminated wood boards, making it collapsible. It is convenient to apply the separating paste with a brush, rubbing with a nylon stocking.
3. We dilute the gelcoat with resin (adding 10 percent of it) and apply with a flute brush. We do this twice. We make sure that the hairs from the brush do not stick.
4. After mixing the resin with the hardener in a clean bucket, add 15 percent chalk, and then sand in portions. The mass should become viscous. To remove air bubbles, tap the bucket on the floor from time to time.
5. Once ready, pour the solution into the mold. Now let's smooth the surface: two people take their hands on the form (certainly equipped with handles) and, lifting it, tap it on the table. The mixture is left (for 40 minutes) and exit the casting room.
6. After hardening to a “rubber” state - this can be determined by a very hot surface and a special sound when tapped - we take the product out of the mold (disassemble it) and turn it over with the pouring side down. Let it harden completely, then sand and polish.

Security measures: when weighing the resin, as well as working with it, with the gelcoat and with the mixture poured into the mold, we work only in a respirator, under a hood. We add the hardener with a syringe, wearing rubber gloves.

The following video will tell you how to make polymer concrete with stains with your own hands:

Polymer concrete is one of the most recent inventions given to us by process engineers. The peculiarity of this building material is that it contains various polymer additives. Typical components of such concrete are styrene, polyamide resins, vinyl chloride, various latexes and other substances.

The use of admixtures makes it possible to change the structure and properties of the concrete mixture, to improve its technical performance. Due to its versatility and ease of production, polymer concrete is used in our time almost everywhere.

Kinds

There are two types of polymer concrete, each of which is used for certain types of construction work. The first option is filled polymer concrete. The structure of this material contains organic compounds that fill the voids between the filler (crushed stone, gravel, quartz sand).

The second option is frame molecular concrete. The voids between the fillers remain unfilled, and polymeric materials are needed to bond the particles together.

Polymer concrete is concrete in which the mineral binder in the form of cement and silicate is replaced in whole or in part by polymer components. The types are as follows:

• polymer cement - a polymer added to concrete, here it is 5-15% by weight of cement (phenol-formaldehyde resins, polyvinyl acetate, synthetic rubber, acrylic compounds). Very resistant to liquids, shocks and are used for airfield construction, brick and concrete finishing, ceramic and glass, stone slabs;
• plastoconcrete - instead of cement, thermosetting polymers (epoxy, phenol-formaldehyde and polyester) are used as part of the mixture, the main property of such concrete is high resistance to acids and alkalis and instability to temperatures and deformations. They are used to cover structures in protection against chemical aggression and to repair stone and concrete elements;
• concrete polymer is concrete impregnated after hardening with monomers that fill the pores and defects of concrete, which results in strength, frost resistance, and wear resistance.

Advantages and disadvantages

Why has polymer concrete become a worthy competitor to traditional building materials? It quickly hardens and becomes as strong as granite. The curing time frame is significantly shorter than the same period for ordinary concrete.

The polymer component gives its maximum tensile strength to concrete a week after pouring. Ordinary concrete takes about a month to do this.

The composition of concrete includes waste from agricultural and construction work. Previously, they were not processed in any way and in most cases were simply buried in the ground. The use of waste in the preparation of polymer concrete solves the issue of recycling and significantly reduces the negative impact on the environment.

Since these same wastes are distributed almost everywhere, there is already a good raw material base for the production of polymer concrete. No special additives and impurities are usually required to buy. The manufacturing technology of such concrete is available even for novice builders. In the process of preparing a concrete mix, everyone can experiment with the amount of additives and impurities, but the initial list of components remains unchanged.

The disadvantages of polymer concrete include a significant proportion of its artificial components. The composition of the mixture contains about 10% of substances of artificial origin. The second drawback is the lack of standardization according to GOST. It is impossible to be sure that exactly the concrete that is needed is on sale. The third drawback is the high cost due to the price of additives (resins, etc.).

Compound

Fly ash is one of the most important components of polymer concrete. This substance is a product of coal combustion. The use of fly ash as an admixture has a filling effect on fresh concrete. The filling effect is based on the ability of the smallest coal particles to fill all voids and porous formations. The smaller the size of the ash particles, the more fully this effect is observed. Thanks to this feature of fly ash, hardened concrete becomes much stronger and stronger than usual.

Another important component of the concrete mixture is liquid glass. It has excellent adhesive ability and low cost. Its addition to polymer concrete will be very useful if the finished structure will be outdoors or exposed to constant water.

The technical characteristics of multi-type polymer concrete are higher than those of other standard ones and, moreover, it is environmentally friendly - it can be used in the construction of buildings in the food industry. The averages are as follows:

• linear shrinkage 0.2-1.5%;
• porosity - 1-2%;
• compressive strength - 20-100 MPa;
• resistance to heat - 100-180С;
• measure of creep - 0.3-0.5 kg / cm2;
• resistance to aging - 4-6 points.

This type of mixture is used as a structural and decorative finishing material.

Self-manufacturing technology

If you have the necessary knowledge and appropriate materials, you can prepare polymer concrete with your own hands. But it should be noted that there is no definite recipe for the preparation of such concrete, the balance of components is determined on the basis of practical experiments.

The technology for the preparation of polymer concrete is quite simple. Water and a small amount of cement are poured into the concrete mixer. Then slag and fly ash are added in equal amounts. All components are thoroughly mixed. Next comes the turn of the various polymeric components. They are added to the previous ingredients, after which the mixture must be mixed again.

Liquid glass, PVA glue, various water-soluble resins are suitable as a polymer additive. PVA glue can be used in any quantity, as it is an excellent filler with good viscosity. Its addition to the concrete solution significantly improves the resistance parameters of the finished structure, and reduces the percentage of shrinkage.
The ratio between polymers and binders can be from 5:1 to 12:1.

Application

The most rational is the use of polymer concretes as decorative and protective products made of concrete or metal. It is advisable to carry out one or another design entirely only in some cases. Usually this is the manufacture of electrolysis or pickling baths, pipelines or containers for aggressive liquids. The manufacture of building or enclosing structures from this material does not seem to be either expedient or economically viable.

Polymer concrete has a high resistance to external influences, so it can be installed without additional reinforcement. But if there is still a need for an additional margin of safety, then fiberglass or steel is used to reinforce polymer concrete. Other elements, such as carbon fiber, for example, are used much less frequently.

The technical capabilities of polymer concrete make it a convenient and inexpensive material for the manufacture of building decorative elements. To obtain different colors, dyes are added to ready-made solutions, and to give the desired size, they are poured into specially prepared forms. The resulting polymer concrete products are very similar in color and texture to marble, but the cost of such structures is much lower.