Polymer concrete made on acrylic resins. Polymer concrete is an additive in concrete. Methods for the production of cast stone

Polymer concrete is a special building material that is used as a bonding element, as well as to replace lime cements. In some cases, the polymer is used as an addition to Portland cement. It is a versatile, durable composite material obtained by mixing various mineral fillers with synthetic or natural binders. This advanced technical material used in many industries, but most common in the construction industry.

Kinds

Three types of polymer concrete are used in construction. Next, we will take a closer look at their manufacturing technology, scope and compositions in order to have general idea about polymer concretes and their modifications.

Polymer compositions for concrete (polymer-modified concrete)

This type of concrete is made of Portland cement material with a modified polymer such as acrylic, polyvinyl acetate and ethylene vinyl acetate. It has good adhesion, high bending strength and low permeability.

Acrylic polymer modified concrete is characterized by lasting color, which is why it is in great demand among builders and architects. Its chemical modification is similar to the traditional cement variation. The amount of polymer is usually 10 to 20%. Concrete modified in this way has a lower degree of permeability and more high density than pure cement. However, its structural integrity is significantly dependent on the binder of Portland cement.

Concrete may take longer to degrade if it has a high density and less surface area. A relative improvement in the chemical resistance of a polymer-modified material to Portland cement is possible in an acidic environment.

Resin impregnated concrete

Polymer impregnation for concrete is usually done by incorporating a low density monomer into hydrated Portland cement followed by radiation or thermal catalytic polymerization. The modulus elasticity of this type of concrete is 50-100% higher than that of conventional concrete.

However, the polymer modulus is 10% greater than that of normal concrete. Due to these excellent characteristics, among the many applications of polymer building material production can be noted separately:

• decks;
• bridges;
• pipes;
• floor tiles;
• building laminate.

Implementation process technology involves drying concrete to remove moisture from its surface, using monomers in a thin layer of sand, and then polymerizing the monomers using heat flow. Consequently, concrete surfaces have lower water permeability, absorption, abrasion resistance and generally high strength. Also, in order to increase wear resistance, resistance to cold and moisture, polymer bricks, stone, floors, etc. are used.

Polymer concrete

It has nothing to do with our usual Portland cement. It is formed by combining stones with a polymeric binder that does not contain water. polystyrene, acrylic and epoxy resins are monomers that are widely used in the manufacture of this type of concrete. Sulfur is also considered as a polymer. Sulfur concrete is used for buildings requiring high acid resistance. Thermoplastic polymers, but most commonly thermoset resins, are used as the main polymer component because of their high thermal stability and resistance to a wide range of chemicals.

Polymer concrete is made up of aggregates that include silica, quartz, granite, limestone and other high quality materials. The unit must be good quality free of dust, debris and excessive moisture. Failure to meet these criteria may reduce the bond strength between the polymer binder and the aggregate.

Features of polymer concrete

Modern building material is different from its predecessors. It has the following characteristics:

• High resistance to chemical and biological media.
• Compared to cement-concrete products, it has a lower mass.
• Perfectly absorbs noise and vibrations.
• Good weatherability and UV resistance.
• water absorption.
• Can be cut with drills and grinders.
• Can be recycled as crushed stone or crushed for use as a road base.
• Approximately 4 times stronger than cement concrete.
• Good ones thermal insulation properties and stability.
• Ultra-smooth finish that promotes efficient hydraulic flow.

Usage

Polymer concrete can be used for new construction or renovation of old material. Its adhesive properties make it possible to restore both polymeric and conventional cement-based concretes. Its low permeability and corrosion resistance make it suitable for use in swimming pools, sewer systems, drain channels, electrolytic cells and other structures containing liquids or harsh chemicals. It is suitable for well construction and rehabilitation due to its ability to resist toxic and corrosive sewer gases and bacteria commonly found in plumbing systems.

Unlike traditional concrete structures, it does not require coating or welding of protected PVC seams. You can see the use of polymer concrete on the streets of the city. It is used in the construction of road barriers, sidewalks, drainage ditches, fountains. Also on the street for concrete is added to asphalt during the construction of open areas, runways and other objects that are under open sky and constantly exposed to external atmospheric influences.

polymer concrete

In development construction technologies new materials and concrete mixes appear, for the preparation of which special fillers are used. This allows you to create strong composite materials, which has high operational characteristics, 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, is used to create sculptures, manufacture original furniture as well as in the ritual realm.

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 ordinary concrete, resistance to aggressive environments, lightness, extended color palette that allows you to simulate a natural stone. Consumers of the composite made sure that it reliable composition, which has 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. It is applied in different 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 concrete mixtures where a polymer is used instead of silicate or cement (used during the preparation of ordinary concrete)

• 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.
• Ability to recover damaged mechanically 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 pollution easily removed from the surface of the material.
• Expanded color range of polymer concrete imitating natural marble, malachite, granite. Created fake diamond difficult to distinguish from the real one, which allows for a wide range of applications of 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 positive moments polymer concrete has disadvantages:

• susceptibility to influence 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

Wanting to prepare polymer concrete in living conditions, 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

Polymer concrete (which is also called cast or artificial stone, polymer cement, concrete polymer and plast concrete) is alternative view a 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 a material for creating light decorative elements, and for the construction of 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). Such a structural type plast 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. Light. 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 is distinguished by high rates heat savings. 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, so it is used for thermal insulation works and during the construction 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 worktops, sinks, window sills, columns, steps, monuments, fireplaces, fountains, floors, vases and more.

There is also the most light 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 ordinary 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. From this normative document it follows 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 not less than 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 that 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 reuse concrete polymer.
• Structures made of this lightweight concrete do not require additional processing.

Speaking of disadvantages 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 production 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 you will need 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 most often for the production of countertops and decorative elements for suburban area this material is used. 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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Polymer cement concrete is called artificial stone material, the binders of which are polymer and cement, the aggregates are sand and crushed stone. Unlike conventional concrete with modifying additives (GKZH-94, Vinsol), which, due to small amounts, practically do not change the structure of concrete, the polymer content in polymer-cement concrete is quite high. This makes it possible to obtain materials with new properties. They have less weight, are frost-resistant, have a slightly greater strength compared to conventional ones, and increased wear resistance. Polymer cement concretes are obtained in three ways:
the introduction of water dispersions of polymers (polyvinyl acetate or synthetic rubber) into the concrete, which decompose in the concrete mixture with the release of water, while the dehydrated polymer acts as an additional binder;
adding water-soluble monomers and polymers (furan and polyvinyl alcohols, epoxy, phenol-formaldehyde resins, etc.) to the mixing water, followed by their curing in concrete by heating or using hardeners;
impregnation of concrete to the required depth with low-viscosity polymers (carbamides, etinol varnish, styrene), which are cured directly in concrete.
Aggregates for polymer cement concretes are quartz or crushed sands, as well as crushed stone of strong and dense rocks size not more than 20 mm. Fine-grained polymer-cement mortars are also used.
The optimal content of a polymer such as polyvinyl acetate is from 15 to 20% by weight of cement in terms of dry matter. Wherein the best way properties of both cement and polymer are used. With such a dosage, the continuity of the cement gel is preserved in polymer-cement concrete, and the polymer, enveloping cement aggregates and aggregate grains, additionally glues them. With an increase in the polymer, the continuity of cement neoplasms is disturbed, which reduces the strength of polymer-cement concretes.
The optimum content of water-soluble carbamide polymer C-89, as well as epoxy polymers DEG-1 and TEG-17 is about 2% relative to the mass of cement. At the same time, the water-cement ratio of the concrete mixture can be reduced to 0.29-0.30 without compromising its workability, as well as durability in aggressive environments. Using various polymer components, it is possible to obtain polymer concretes that are resistant to the action of oil products, fats and salt solutions. Polymer-cement concretes are used for the construction of wear-resistant iols, airfield coatings, tanks for oil products, as well as monolithic structures for working in aggressive environments.
For the preparation of polymer-cement mixtures, paddle mixers or vibratory mixers are used. During mechanical mixing, the mixture is saturated with air, small pores are formed in the concrete, evenly distributed over the volume. Owing to the fact that polymer concrete are still used in small volumes, their mixtures are prepared in mixers located near the installation site. Polymer-cement mixtures have a high viscosity, so vibro-compacting them at low frequencies (3000 rpm) is ineffective. The air is not removed from the concrete, its structure is excessively porous and loose. High-frequency vibration is more expedient, and for rigid mixtures, tamping and vibrocompression.
Polymer-cement concretes prepared on water dispersions of polymers are kept in air-dry conditions, while concretes with additives of epoxy and urea polymers quickly harden in humid conditions.
Plast concretes are artificial conglomerates obtained entirely on organic polymeric binders. They are essentially plastics with mineral fillers of various sizes.
Binders in plastic concretes are low-viscosity thermosetting polymers (phenol-formaldehyde, furan, polyester and epoxy), which, when hardeners are added and under certain conditions, harden, gluing the components into a strong conglomerate. Usually used plastconcrete compositions 1:5-1:15 (polymer:filler by weight).
Petrov's kerosene contact, sulfonic acids and mineral acids, polyethylenepolyamine, diethylenetriamine, etc. are used to cure polymers.
As fillers, pure sands with a grain size of 0.6-2.5 mm and a content of clay and dusty particles of not more than 0.5% are used. Crushed stone and gravel must also be dry and clean and have a particle size of no more than 20 mm. Apart from crushed granite andesite and barite, as well as crushed tripoli and graphite, are used as fillers, depending on the purpose of the plast concrete.
The strength properties of plast concrete are determined by the properties of the binder and filler, as well as the adhesion between them. Plast concretes have high strength, especially in tension and bending. So, the strength or bending of some plastconcrete on epoxy polymers reaches 350-450 kgf/cm2.
Plast concretes are practically waterproof, frost-resistant; they resist wear well, stand in aggressive environments. For example, their resistance against the action of acids is 10 times higher than that of ordinary concretes.
It is expedient to use plastic concretes for waterproofing and anticorrosive facings. They are used to obtain wear-resistant floors, in airfield pavements, as well as for the construction of parts of buildings and structures operated in aggressive environments.
Plast-concrete mixtures are prepared in small volumes directly at the places of their laying due to their rapid hardening. Fillers are loaded into a paddle mixer, then polymeric binders. After 3-4 minutes of mixing and obtaining a uniform mass, a hardener is introduced and mixed for 5-8 minutes.
The prepared portion of the mixture is immediately put into the case. Seal it by tamping or bayoneting.
Plast concretes harden better in dry conditions at 50-100 ° C. Increasing relative humidity above 60% reduces the strength of plastic concrete, especially on polyester polymers. Epoxy resin formulations are less sensitive to high humidity. The heating time of the laid plast concretes is 4-8 hours depending on the type of polymer and the composition of the mixture. During the hardening of plastic concretes, their shrinkage occurs, the magnitude of which depends on the type and amount of polymer.

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 connect with various substances(catalysts, hardeners and solvents). Polymer concrete in terms of its physical and mechanical characteristics far 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 for mechanical and physical characteristics superior to all other types of concrete.

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 insulating coating concrete;
• when laying high-strength bricks;
• as a weatherproof paint material;
• at decorative trim facades of premises;
• 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 threads that allow the usual cement mortar take on increased hardness concrete mortar, plus a fairly significant transparency.

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

technical name transparent concrete- 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 through new material it is possible to see the silhouette of a person or, for example, a tree. 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, when erecting a partition made of transparent concrete, use LED backlight, 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.

AT last years gaining more and more popularity decorative forms concrete. 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 production stamped concrete concrete grade M-300 is used with the use of fiber 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. Apart from large selection textures for the production of concrete, it is possible to color it in different colors.

Stamped concrete in many ways technical specifications outperforms asphalt pavement and concrete tiles. It has increased resistance to aggressive components. external environment, as well as increased the limit temperature regime 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 ultraviolet rays. When using stamped concrete, stunning decorative effects can be achieved.

The coating made from this material can withstand 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 floor covering in garages or auto repair shops.