Most people are sure that polymer concrete and cement-polymer concrete are two names for the same material. In fact, they are completely different building mixtures, having high performance strength.
No cement is added to polymer concrete (plastic concrete), but various polymers act as binders. In polymer cement concretes Portland cements mixed with polymer additives are added.
There are two types:
1. Filled - high molecular weight organic compounds fill the voids between filler particles (gravel, crushed stone, quartz sand).
2. Frame - the voids remain unfilled, and the polymer serves only to bind the mineral filler particles 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 performance-improving additives are aqueous dispersions polymers (vinyl chloride, vinyl acetate, styrene, latexes, polyamide resins and others). Their use makes it possible 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 tensile strength, and hardeners to reduce the hardening time. The composition of cement-polymer concrete also includes Portland cement.
It gets its characteristics from an organic binder. This ensures that loose 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 severe loads, as well as the effects of acids and sudden changes in temperature. Strength becomes even higher if the solution is kept in conditions low humidity (40-50%).
Characteristics:
- moisture resistance;
- wear resistance;
- high chemical resistance;
- resistance to temperature changes;
- increased tensile strength;
- absence negative influence on living organisms;
- high level of adhesion to surfaces;
- fast hardening;
- good breathability.
The only thing that can become a stumbling block and negate 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 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 mixture.
Production
The most commonly used additives in the production of polymer concrete are water-soluble resins, PVA and latexes. When ready mix dries, a film forms on the surface of its particles, swelling upon contact with large quantity moisture. However, this does not affect the strength characteristics.
There is no single correct ratio of components in a recipe yet. But most often, manufacturers mix cement with additives not exceeding 20% of the cement part.
The highest quality solution is obtained from a cement solution with water-soluble polyamide or epoxy resin and a hardener (polyethylene-polyamine).
The production of a cement-polymer mixture occurs 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. Polymer 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 building facades.
Designers and architects love it because it is easy to form and can be applied by hand and mechanically. A special stamp is applied to the surface of the poured concrete a certain number of times, simulating various natural structures(stone, cobblestone, tree, paving slabs and others). 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, swimming pools, borders, barbecue areas, and building facades.
Polymer coatings for concrete can give the material additional improved properties of wear resistance, durability and strength. Thanks to them, the monolith can last more than 20 years.
Manufacturers and cost
In Russia, production and supply are carried out by the following companies: TeoKhim LLC, BASF CJSC (representative of the German concern BASF), DI-Trade LLC, Moscow representative office of DUROCEM ITALIA, Zika LLC (representative of the Swiss company SIKA), LLC "Topbeton"
The price for a polymer concrete self-leveling floor starts at 400 rubles per 1 m2; further increases in cost depend on the high cost of polymer additives, working conditions and footage.
(otherwise known as cast stone) – a material that combines strength and beauty natural stone with an affordable price (thanks to cheap mineral additives) and ease of manufacture. The ability to use almost any aggregate (sand, granite and marble chips, glass and many others) guarantees variety. And the presence of a polymer binder makes them durable, resistant to water and overheating.
Let's look at typical technological processes for producing polymer concrete, as well as the possibility of creating it yourself.
What will you need?
To obtain the product you need:
- The filler is of a fairly coarse fraction (sand, crushed stone, coarsely crushed glass).
- Finely ground aggregate, reducing the cost of the material. This is a powder made from graphite, quartz or andesite.
- Binder - about 5 percent will be needed. For this purpose, one of the polymer resins is used. For example, polyester (unsaturated), urea-formaldehyde, furan, epoxy.
- Hardeners, plasticizers, special modifying additives, dyes.
- Release agent and gelcoat for outer coating.
Production methods
The production process can occur using batch or continuous technology.
- In the first case, the containers used to make the material must be washed after each completed cycle. But it is possible to make polymer concrete in a very ordinary bucket or concrete mixer.
- Continuous technology is mainly used in large industries. At the same time, they work harmoniously, organizing a single chain, special injection molding machines, dispensers and automatic mixers.
The following video talks about the production and spraying of lightweight polymer concrete:
Process
To make casting stone, you will need a mold well coated with a special release agent (otherwise it will be impossible to remove the finished product). The mold can be made of silicone, fiberglass, metal or even chipboard (budget option).
- A layer of gelcoat is applied to the release paste. desired color.
- A composite mixture consisting of the above ingredients, previously well mixed in a concrete mixer, is placed inside the mold. In large industries, where the volumes are very large, the mixture is placed in a mold using a concrete paver. If the products are small and the technological process is periodic, then this is done manually.
- Now it is necessary that the laid mixture be subjected to vibration (vibration compaction). The time of this procedure is approximately two minutes. In a factory, a resonant vibration platform is used for this; in small production, a vibration table is used.
In production conditions at a polymer concrete manufacturing plant, if necessary, heat treatment is carried out for faster hardening of parts. In other cases, they wait for the natural completion of this process.
We will tell you 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 using continuous technology and significant 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 you limit yourself to only branded turnkey equipment, then the costs will be significantly less - from 30 to 50 thousand dollars.
But it is still not always possible to find money for a purchase, especially in our difficult times. However, you can get by with even less money. If you purchase all the necessary cars and other things separately. And make some things yourself. Read more about this option below.
List of equipment and devices
So, here is a list of equipment and devices that you cannot do without:
- A ready-made vibrating table will cost about 27 thousand rubles. If you want to save money, weld the table yourself using two-millimeter metal corners (60-gauge). We weld a vibrator to the table industrial type- ready.
- A mixer that will combine all 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 construction mixer. It will be much cheaper - the cost depends on the volume and power. It’s even cheaper to make the mixer yourself from iron barrel and electric drive with gearbox.
- You will also need a compressor system with a gun. Without it, you won’t be able to apply the gelcoat evenly. The pistol costs between $50 and $100. You can take car compressors - two from ZIL will be enough. They are connected in parallel and attached to metal platforms mounted on a strong frame.
- Molds made of fiberglass or silicone are not yet widely available. 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.
- An exhaust hood will be required - at the casting stage, production is characterized by harmful fumes. Accordingly, we will purchase and personal protection: gloves, respirators.
- For finishing works You will need electric tools: grinding and polishing machines. And also a drill, jigsaw, grinder, router (if necessary).
We will talk about emissions into the atmosphere from the production of polymer concrete further.
This video will tell you about another method of producing polymer concrete:
Air emissions from such production
As mentioned just above, during casting there is a release of harmful components.
- In particular, it is styrene, which is found in resins used as a binder. As soon as we open a hermetically sealed container with such resin, the evaporation of poisonous gas begins.
- In addition, the hardener (usually methyl ethyl ketone peroxide) is also extremely dangerous. However, it is not volatile and requires only protecting your hands with rubber gloves.
These facts force polymer concrete manufacturers to carefully equip the casting room, making it airtight, installing a powerful hood above the table, and not forgetting about their own protection (respirator). And if all these measures are followed, and the air escaping into the hood is cleaned, then there will be no emissions into the atmosphere (after all, the room is sealed).
Read below to learn how to make elastic polymer concrete yourself (with your own hands).
DIY creation
And now we’ll talk about how to make small products from fashionable cast stone yourself, spending a minimum of money. For example, these could be flower pots, countertops, window sills (especially popular, as they are warmer than marble or granite).
Choosing a room and its arrangement
First you need to think about the room - you will need 80 square meters total area. It is advisable to look for a suitable house somewhere on the outskirts. And 12 square meters You will immediately need to fence off the casting room, and you will have to try to seal all the cracks as much as possible. To prevent styrene from leaking.
In the center of this room we make a table on a frame made of iron corners, covering it with a chipboard tabletop. We set its surface level - this is important! We install a hood above the table - a metal box with an electric motor.
To make it light, we attach fluorescent lamps on top. We put the same table in the next room - for finishing and other work. Here we will place tools and containers for drying chalk and sand (low metal boxes).
Necessary raw materials
Required raw materials:
- River quartz sand (packaged in 20 kilograms). It needs to be dried well.
- Sifted chalk - we also dry it.
- Polyester resin - bought in 20 liter buckets.
- Hardener, gelcoat, release paste.
Manufacturing process
- You will need a clean plastic bucket for stirring, a 450-watt hammer drill and a construction mixer (we will attach a hammer drill to it, weld a drill for perforating - we get a mixer).
- We make the form from laminated wood boards, making it collapsible. It is convenient to apply the release paste with a brush, rubbing it with a nylon stocking.
- We dilute the gelcoat with resin (adding 10 percent of it) and apply it with a flute brush. We do this twice. Make sure that the hairs from the brush do not stick.
- Having mixed the resin with the hardener in a clean bucket, add 15 percent chalk, and then add sand in portions. The mass should become viscous. To remove air bubbles, tap the bucket on the floor from time to time.
- Once ready, pour the solution into the mold. Now let’s smooth the surface: two people take the form (certainly equipped with handles) with their hands and, lifting it, tap it on the table. Leave the mixture (for about 40 minutes) and leave the casting room.
- After hardening to a “rubber” state - this can be determined by a very hot surface and a special sound when tapped - remove the product from the mold (disassembling it) and turn it over with the pouring side down. Allow to harden completely, then sand and polish.
Safety 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. Add the hardener with a syringe while wearing rubber gloves.
The following video will tell you how to make polymer concrete with streaks with your own hands:
The development of the chemistry of synthetic binders and polymers predetermined the emergence of a new material in the construction industry, known as polymer concrete. And although the first patents for its manufacture appeared 80 years ago, practical use the new product was received only in the 60s of the last century. As the name suggests, the developers managed to obtain a building material based on resins and polymers, capable of completely replacing modern cement and slag-cement concrete in composition and characteristics.
What is polymer concrete
Often construction terms can confuse a non-specialist or a novice builder or someone who likes to build with their own hands. At the household level, polymer concrete includes all types building materials, which contain cement, water and polymer resin.
In fact, the technology of building polymers divides such materials into several groups:
- Polymer concrete is a mixed composition that includes mineral ballast or filler, a polymer binder, hardener, stabilizer and adhesive, without the use of cement and water;
- Polymer cement concrete- a material obtained by adding a water-soluble polymer composition to the composition of the parent cement mortar or concrete;
- Concrete-polymer materials are hardened concrete or cement stone, subjected to additional processing with liquid or vapor polymers; usually the liquid contains styrene with a catalyst, which polymerizes in the thickness of the mineral matrix of concrete.
For your information! Polymer concretes made from thermosetting and epoxy resins are also called plastic concretes.
The properties of polymer concrete depend on the composition of the binder, resin, filler used and the method of preparation. Such materials are successfully used not only in construction, but also in mechanical engineering, in chemical industry and even in the production of household items and furniture. The technology of using various mineral fillers to reduce the cost of producing castings from synthetic resins began to be used in the 80s of the last century, and at the beginning of the 21st century, almost 80-90% of plastic products are made using polymer concrete technology, which contains resin and fine ballast powder.
To obtain building grades of polymer concrete, compositions based on five main types of synthetic resins are used:
- Phenol-formaldehyde and urea-formaldehyde polymers;
- Epoxy matrices, including those modified with furan resins;
- Methacrylate and polyvinyl acetate polymers;
- Furfural acetone matrix, or FAM for short;
- Polyester and polyurea resin.
For your information! FAM is one of the few types of binders used for the production of so-called faizol concretes, which have unique properties dampen and dissipate vibrations an order of magnitude better than the most viscous grades of cast iron.
Furfural acetone resins contain volatile substances with very unpleasant smell which may cause suffocation and headache, which are pronounced carcinogens. Therefore, they are used only for the production of polymer concrete, conservation steel structures pipelines and communication systems. For residential premises, polymer concretes are most often used, which contain polyester resins, epoxy and methacrylate oligomers.
The resin content of polymer concrete is relatively small, from 10 to 15%. The rest is mineral filler - marble chips, ground ash, crushed dolomite, calcite, granulated vermiculite, clinker and ordinary Portland cement. Quite rarely, polymer concrete contains a resin with an organic filler based on modified wood fibers mixed with chopped basalt fiber.
Why change ordinary cement mortar to polymer concrete?
Modern grades of concrete based on cement and sand work well in huge masses, where the static load is constant and there are no shocks, vibrations or complex bending moments or torsional forces. In all other cases, it is necessary to introduce special additives into the composition, use expensive metal reinforcement, make multilayer structures, or completely replace cement concrete with metal or polymer concrete. In some variants it is technologically easier to cast a part building structure from polymer concrete than to use reinforced concrete. For example, during the construction of product pipelines.
If we compare the characteristics of polymer concrete with conventional concrete, we can name five advantages of using polymers:
- Strength against bending, torsion and alternating dynamic load is 3-4 times higher. The resin in polymer concrete causes the material to behave like metal;
- The presence of polymers in the composition ensures low water absorption and high frost resistance of polymer concrete structures;
- Certain grades of polymer concrete containing fine particles have low thermal conductivity; if necessary, they can be used without insulation even in the manufacture of floors and ceilings ground floor, basements;
- Good machinability by cutting and drilling, without the risk of pinching or cracking;
- Epoxy resins in polymer concrete make them inert to chemically active substances, organic solvents, gasoline, oil, chlorinated hydrocarbons, hot and sea water. In shipbuilding, polymer concrete is used to make cladding, floors, floors, protective panels and deck elements.
For your information! The main “value” of a polymer concrete composition is the ability to obtain a high-quality casting, without cavities, ridges, cracks, and with “programmed” mechanical and strength characteristics. The characteristics can be easily adjusted by changing the composition of the material.
For example, in the manufacture of a pipeline, polymer concrete with the addition of polyvinyl alcohol or liquid glass. Alcohol in concrete improves the wettability of cement grains, removes air from the intergranular space and helps the hydration process. After casting the pipeline, due to the intensive binding of water, the inner surface of the concrete pipe quickly dries out and becomes covered with cracks. To make it strong, hard and wear-resistant, concrete is treated with a liquid solution of polystyrene in styrene. The result is a surface that is not inferior in characteristics and durability to cast iron.
Today, the cost of polymer concrete is still quite high, so there is no talk of completely replacing cement in the composition of the material, but as new resins are developed, the prospect of switching to polymer concrete is becoming more and more realistic.
Features of the use of various brands of polymer concrete
Most people will be surprised to learn how many household items are made of polymer concrete. For example, from polyester resin and filler made from finely ground natural stone- gabbro, basalt, marble, calcite are produced artificial stones, sculptures, decorative elements and facing tiles for stone finishing. Tabletops and window sills are cast from inexpensive polymer concrete to look like stone; the cost of a similar product made from natural marble or granite will cost 2-3 times more.
Communication elements - pipes, tanks, wells, drainage trays and even entire collectors - are made from epoxy polymer concrete. Using polymer cement casting, you can easily repair concrete bearing structures, seal the screed and restore the tightness of the container. Polymer concretes, which contain epoxy resin, have exceptionally high adhesion, so they are often used to restore holes and joints of concrete panels in high-rise buildings.
From methacrylate filled with ground glass powder and marble dust, it is possible to obtain such a high-quality imitation of natural stone that similar material is borrowed and used for work by professional restorers. Large granules of marble or calcite can be added to the composition. All polymer plasters, putties, tile adhesives, grouts, that is, almost all materials for decorative finishing houses.
Separately, it is necessary to remember about self-leveling floors. In this case, instead of glass filler, quartz sand crushed into dust is used. Most expensive brands, which contain a modified forced-curing methacrylate, after hardening they provide a perfectly smooth surface, superior in strength to cement screed.
How to make the simplest polymer concrete at home
In order to prepare polymer concrete with your own hands, you will need two components, resin and filler. For the simplest version of polymer concrete, you can use epoxy adhesive or resin, hardener and filler. It is best to use cement, washed and dried river sand or granite dust as part of the material, which you can get in any monument-making workshop.
The resin is diluted with acetone or an alcohol-acetone mixture. Various brands epoxy resin require their own brand of solvent, so to prepare polymer concrete it is necessary to select a thinner. A hardener is added to the resin, stirred and a thinner is added to the composition. After 10 minutes, filler can be added to the adhesive mass in small portions. After another 3-10 minutes of mixing, the polymer concrete will be ready for use.
Conclusion
In a similar way, you can prepare polymer concrete based on PVA, acrylic resin and sand, oil paint and cement filler. Finally, you can add a mixture for self-leveling floors, which will allow you to use the material for casting parts for finishing ceilings and walls, columns, stucco moldings, and pilasters. In any case, such a composition will cost less, and the quality of the products will be no worse than that of purchased options.
Price RUR/kg depending on quantity. Including VAT and packaging.
Packing: plastic canisters 5kg, 10kg, 30kg.
Guaranteed shelf life in manufacturer's containers is 12 months.
Store and transport at temperatures from +5° to +25°C.
label
Packing
Buy a polymer additive for concrete
Polymer-based concrete additive Elastobeton-B manufactured to be heavy-duty polymer cement concrete.
Strength: on dolomite crushed stone – M600-M800; on granite crushed stone– M800-M1000 and more.
Commissioning within 5-6 days.
Polymer additives in concrete Elastic concrete-B is supplied in liquid form.
They are introduced during the production of concrete at the rate of 20 kg of additive per 100 kg of cement.
Thickness of the polymer-cement floor Elastobeton-B:
for moderate loads - 20mm, for heavy loads - 30mm, minimum thickness- 15mm.
Unlike magnesium concrete, polymer cement concrete is completely resistant to water.
Polymer cement concrete
Other names: cement-polymer concrete, cement polymer concrete.
As mentioned above, polymer-cement floors based on the concrete additive Elastobeton-B are 20-50% cheaper than magnesium floors. But this is a direct calculation - that is, they took polymer-cement concrete and calculated the price of the components; similarly for magnesium concrete.
But besides this, there are a number of factors that affect the final price of polymer cement concrete and magnesium concrete. The main of these factors are listed below.
1. Transportation.
Transportation of concrete components greatly affects its final cost.
If transport costs are only 1 rub/kg, then delivery main components magnesium concrete, which constitute approximately 23% of the total mass, will increase the price of 1 m³ of concrete by 500 rubles! With a delivery price of 5 rubles/kg, that’s already 2500 rubles/m³!
If you transport all the components of magnesium floors, then at a delivery price of 1 ruble/kg, the cost will increase by 2200 rubles/m³.
With a delivery price of 5 rubles/kg, magnesium floors will become more expensive by 11,000 rubles/m³!
The concrete additive Elastobeton-B is approximately 3.5% of the concrete mass, the remaining components are purchased locally. Accordingly, transportation of a polymer additive for concrete, even over long distances, has virtually no effect on the price of polymer-cement concrete.
The savings are obvious.
2. Storage.
The components of magnesia concrete (in particular burnt magnesia - magnesium oxide) are very sensitive to storage and transportation conditions. Penetration of moisture into components significantly reduces the final strength of magnesium concrete. As a result, you will receive magnesium floors with brand strength M200-M300, instead of M400-M600.
There are no such problems with polymer-cement concrete, since you buy all the components, including additives, locally and can always control their quality.
3. Cost of fillers.
The cost of concrete with the additive “Elastoconcrete-B” depends on the sand fineness modulus (SFM), bulk density sand and bulk density of crushed stone. The higher the MCR and the higher the density of sand and crushed stone, the less cement and concrete additives in relation to sand and crushed stone. Accordingly, the cheaper polymer-cement concrete.
Savings can be up to 2000 rubles. per 1m³ of polymer cement concrete.
4. Equipment corrosion.
Magnesia concrete includes the bischofite component, which causes increased corrosion of both steel and aluminum surfaces of equipment. Equipment (concrete mixers, vibrating screeds, helicopters, etc.) must be constantly washed. But even with careful care, the service life of the equipment is reduced several times, which as a result affects the price of magnesium floors!
Polymer additive for concrete Elastobeton-B does not have a corrosive effect on metal surfaces.
The savings are obvious.
Polymer additive for concrete - properties, advantages
Elakor "Elastobeton-B"- complex modifying polymer additive for concrete (Portland cement concrete).
Cement grade M500D0 is recommended for use. If you want to use other cements, we recommend that you first check them for compatibility with the Additive (see Technology for using the Additive). The fact is that some fillers that are introduced during the production of cement can “conflict” with the additive.
To make colored polymer-cement floors, you can add the pigment yourself directly when mixing concrete or order an additive of the desired color from us.
Colored polymer cement floors can be made on gray cement, but if a “pure” color is required, then white cement must be used.
Properties of polymer-cement floors with the concrete additive “Elastobeton-B”.
- Operation indoors and outdoors outdoors.
- Thickness from 15 to 50mm. Recommended thickness is 20-30mm depending on the load.
- The strength of the coating is: on dolomite filler – M600-M800. on granite filler – M800-M1000 and more.
- Extremely high wear resistance (less than 0.2 g/cm²).
- High impact strength (10-20 kg m depending on thickness).
- Bending strength – no less than 12 MPa.
- Completely dust-free (after polishing).
- The coating is vapor permeable.
- Antistatic coating: specific volumetric electrical resistance – no more than 10 7 Ohms;
specific surface electrical resistance – no more than 10 9 Ohm∙m (test voltage 100V). - Chemical resistance to water, fuels and lubricants, salt solutions, detergents etc.
- The coating is non-flammable (flammability group - NG).
- Fabulous appearance, the possibility of combining several colors, various fillers, etc.
- Easy to clean, can be used with any detergent.
Polymer cement floors - advantages.
- Allows you to avoid performing leveling screeds with subsequent application of protective polymer impregnations and coatings or dry reinforcing compounds (toppings). This results in a coating with higher decorative and strength qualities and a significantly lower cost.
- Combines the advantages of latex cement concrete and polyvinyl acetate cement concrete - water resistance and oil resistance.
- Fully complies with SNiP 2.03.13-88 “Floors”.
- The strength is the same as the topping and higher, but not only in the top layer of 2-2.5 mm, but throughout the entire thickness.
- Unlike magnesium concrete, magnesia floors are completely resistant to water.
- When abraded (weared), the polymer-cement floor does not change its appearance, does not lose strength and chemical resistance.
- It is polished during use.
- Does not require reinforcement.
- Short technological cycle of work (6-8 days).
- Start of operation - the next day after completion of work.
- Polymer cement concrete is cheaper than any finishing coating of similar thickness.
Polymer cement floors are used in buildings.
What kind of material is this? How does it differ from conventional 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 the answers.
What it is
Definition
Let's find out what polymer concrete is? The key difference between the material we are interested in and ordinary concrete is that synthetic resins are used as a binder instead of Portland cement. Typically thermoset; less often - thermoplastic.
Reference: thermosetting is a polymer in which, when heated, irreversible chemical changes occur, leading to a change in its strength or other properties.
Simply put, after heating once, the plastic no longer melts when it reaches the same temperature.
Thermoplastic polymers, on the other hand, undergo a phase transition every time they are heated.
Our hero should not be confused with another material - polymer-cement concrete. In our case, polymers are used as the only binder. Polymer-cement concrete is ordinary concrete based on Portland cement, modified with synthetic additives to give it any specific properties (increased elasticity, wear resistance, water resistance, etc.).
Key properties
What does replacing 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 absorbed by the reinforcement frame.
- Reduced fragility. The material is much more resistant to shock loads.
- Elasticity. Where the concrete monolith bursts, the polymer concrete is only slightly deformed.
- Waterproof. Portland cement shrinks significantly when dried, which ensures the porous structure of concrete. In contrast, polymers after the final gain of strength decrease in volume extremely slightly; Moreover, shrinkage does not lead to porosity, but to a slight decrease linear dimensions finished product.
Let us clarify: in order to improve thermal insulation qualities and reduce weight, in some cases the use of porous aggregates is practiced in the production of polymer concrete products.
Expanded clay and perlite sand are used for this purpose.
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 point: if there are no pores, there is no crystallization of water in them, tearing the material apart when frozen.
- Increased wear resistance. The polymer binder is simply stronger than cement stone in tensile strength; It is much more difficult to tear off a particle of filler from it.
- Chemical resistance. And it is due to the properties of polymers: most resins are inert to the action of aggressive gases and liquids.
Application
Let's study the main applications of polymer concrete.
| Application area | Description |
| Floor coverings | A thin polymer concrete coating with fine-grained aggregate allows you to modify the properties of the base, giving it increased wear resistance and water resistance. In addition, polymer concrete floors, as we remember, are resistant to aggressive environments. The material is used indoors and outdoors (in particular, as an airfield covering). |
| Furniture | For the needs of furniture production, beautiful and durable tabletops and work surfaces are made from our material; Polymer concrete slabs are often used as window sills. |
| Plumbing | Kitchen sinks and washbasins made from polymer concrete compare favorably with their metal counterparts in the absence of noise when a stream of water falls on them. They are superior to faience and porcelain primarily due to their appearance, which imitates natural stone. |
| Drainage systems | Polymer concrete trays and, most importantly, are much more durable. The reason is the already mentioned waterproofness of the material: water will not destroy the polymer concrete tray by freezing in its pores. |
| Putties | Mineral-filled resin, after adding a hardener, turns into a quickly setting and extremely durable mastic - efficient material for sealing cracks and other defects in concrete surfaces. |
| Funeral services | Polymer concrete tombstones look at least as good as granite ones; Moreover, their price is noticeably lower than that of natural stone. |
Production
Regulations
The material we are discussing is considered to be relatively new and of foreign origin; however, study regulatory documents, according to which it is produced, will lead to an unexpected discovery. Instructions for the production of polymer concrete and products made from them, number SN 525-80, were adopted in 1981 and remain relevant to this day.
Let's study the main points of the document. For all polymer concrete products it is normal temperature conditions The range is considered to be 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 when frozen.
In the absence of shock and mechanical loads in general, the lower limit of operating temperature can be painlessly increased to the actual value 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
Crushed rock is used as the main filler. The use of sedimentary rocks (limestone, shell rock, etc.) is not allowed: its low compressive strength will significantly worsen performance product.
The size of the crushed stone fraction is determined, no matter how funny it sounds, by its maximum diameter:
- If largest size does not exceed 20 mm, one fraction is used - 10-20 millimeters.
- In cases where the largest size reaches 40 mm, it is recommended to use two fractions: 10-20 and 20-40 millimeters. Fine crushed stone will contribute to a denser filling and, accordingly, will increase the final strength of the material.
Please note: for porous aggregates (expanded clay and perlite already mentioned) maximum size 20 mm; two fractions are used: 5-10 and 10-20 millimeters.
Wherein, percentage composition The aggregate is divided between coarse and fine fractions in a ratio of 60:40 percent by weight.
In addition to coarse, fine (so-called grain) aggregate is used. Typically, this role is played by quartz sand - natural or crushed. The requirements for it mainly boil down to the absence of impurities - dust, silt and clay, which can worsen the adhesion between the filler and the binder.
Filler
In addition to mineral filler, the product contains ground filler - mineral flour. The standard provides several options.
It is allowed to use ground crushed stone and quartz sand. For material prepared on the basis of urea-formaldehyde resins, a water-binder additive is additionally 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. Our source of information will be the same document CH 525 -80.
It’s interesting: the BSK performs two functions at once.
It serves as a polymerization catalyst (hardener) and provides dehydration (dehydration) of raw materials.
BSK is an effective and safe hardener with additional functionality.
Technology
What does polymer concrete technology (more precisely, its production) look like in an industrial environment?
- The aggregates are thoroughly washed to remove all kinds of contaminants. As we remember, they can negatively affect the final strength of the product.
- The next stage is drying. The moisture content of the aggregate should not exceed 1 percent; It is recommended to keep the mass water content to 0.5%.
- The components separated into fractions are loaded into the mixer.
The sequence of loading and intermediate operations is strictly regulated:- Crushed stone is being loaded.
- Sand is added.
- Filler is added.
- The mixture is stirred for 1-2 minutes.
- Binder is added.
- The mixture is stirred for 3 minutes.
- Hardener is added.
- Mix for 3 minutes and the material is ready for pouring.
- A separating layer is applied to the inner surface of the form, which will prevent the polymer concrete from sticking to it. Paraffin, machine oil or technical petroleum jelly are usually used in this role.
- The mold is filled as evenly as possible and, if possible, without cavities.
- The last stage is compaction of the mixture on a vibrating table or using a mounted vibrator. The optimal amplitude is 2-3 millimeters, frequency is 3000 vibrations per minute (50 Hz). If the mixture is kneaded and laid out in several stages, its compaction is repeated after each laying out.
Signal to stop on the surface of the liquid fraction of the material (usually 2-3 minutes is enough for this).
The mold can be removed from the finished product within a day. Strength gain at room temperature takes from 20 to 60 days. It, however, can be accelerated by heating to 60-80 degrees; the temperature rises and falls at a rate of 0.5 C per minute to avoid an increase in internal stress.
As you can see, the production technology does not involve any special difficulties; If you have a binder, a hardener, a concrete mixer and a vibrating table, it is quite possible to make polymer concrete at home.
A caveat: you will have to clean the concrete mixer from the remaining 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 gluing, mastics and adhesives based on the same synthetic resins are used. Mastics, in addition to the binder itself, contain stone flour.
The photo shows polyurethane glue made in Belarus with a creative name.
- Regular sanding is suitable sandpaper. A felt wheel is used for polishing; gloss can be achieved using GOI paste (polishing paste developed by the State Optical Institute).
- In principle, the material can be drilled using ordinary Pobedit drills for concrete; however, diamond drilling of holes in concrete with a polymer binder gives much best result. The edges of the hole remain perfectly smooth, without chips. For holes large diameter(for example, under a mixer in a polymer concrete work surface for a kitchen) a diamond crown is used.
- The ideal cutting tool 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 edges of the cut perfectly smooth and not change the wheel when passing the reinforcement); in the case of the same tabletop, a sloppy cut will hopelessly ruin its appearance.
A diamond saw is an ideal tool for cutting material.
When processing material in general case You should avoid heating it too much. Temperatures above 120 - 150 degrees are contraindicated for thermoplastic binders.