Polymer concrete
In the process of development of construction technologies, new materials and concrete mixtures appear, for the preparation of which special fillers are used. This makes it possible to create durable composite materials with high performance characteristics and decorative properties. Polymer concrete is one such composition that is gaining popularity in the construction raw materials market.
The material, along with traditional components - sand and crushed stone, includes polymer resins based on epoxy, furan, and polyester as a binder. Polymer concrete is in demand in the construction industry, used to create sculptures, make original furniture, and also in the ritual sphere.
Polymer concrete (cast stone, polymer cement, concrete polymer, plastic concrete, plastic concrete) was invented in America as a stronger and more durable alternative to ordinary concrete
Polymer concrete has a number of serious advantages associated with improved mechanical characteristics compared to conventional concrete, resistance to aggressive environments, lightness, and an expanded color palette that allows it to imitate natural stone. Consumers of the composite are convinced that it is a reliable composition with a wide range of applications. Let's look at the material in detail, delve into the technology, evaluate the advantages and disadvantages, and study the recipe.
Advantages of the material
Composite concrete, due to its formulation, has a number of positive characteristics. It is 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 mass. Water droplets 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 its 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 conventional concrete) a polymer is used
- The material’s resistance to aggressive substances and chemical reagents, allowing the use of polymer concrete in various areas without protecting the surface with the help of special coatings.
- Possibility of restoring mechanically damaged areas of a composite mass using a restoration mixture.
- Increased strength characteristics with a relatively low weight of the composite, allowing the production of various products with enhanced performance properties.
- Absence of roughness on a perfectly smooth, absolutely non-slip surface of the material. This property allows the artificial stone to remain clean for a long time, and, if necessary, various contaminants can be 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 allows for a wide range of applications for the composite.
- Possibility of recycling and use in the production of technological waste, which significantly reduces the cost of products produced under waste-free technology.
- susceptibility to open fire and elevated temperatures, causing destruction of the material;
- higher price compared to concrete, which is due to the cost of purchasing special resins.
- A binder used as urea-formaldehyde, polyester, epoxy and furfuralacetone resins.
- Coarse crushed stone filler. The size of the crushed stone fraction required for the formation of the composite can be up to 4 centimeters, but crushed stone measuring 1-2 cm should make up the bulk of the composition.
- Screened and purified quartz sand. The size of quartz particles should not exceed 5 mm; the presence of clay inclusions and dust is not allowed.
For polystyrene concrete (where polystyrene is used as a filler) there are its own standards
- Crushed graphite powder with a particle size of no more than 0.15 mm, quartz flour, used as a ground filler, reducing the need for expensive resins.
- Construction 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 massif, increasing the thermal insulation properties of the finished composite.
- especially heavy, cubic meter, which weighs from 2500 to 4000 kg;
- heavy, with a density of 1800-2500 kg/m3;
- lightweight with a specific gravity of 500-1800 kg/m3;
- lightweight, the mass of a cubic meter does not exceed 500 kilograms.
Pros: strength, light weight, impact resistance, elasticity is several times higher than that of ordinary concrete
Weak sides
Along with the positive aspects, polymer concrete has disadvantages:
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:
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:
Scope of use
Polymer concrete - what is it? Step by step we make the mixture with our own hands. Polymer concrete (also known as cast stone) is a material that perfectly combines the beauty and strength of natural stone with an affordable price (available thanks to inexpensive mineral additives) and ease of manufacture.
When creating, you can use almost any type of aggregate (glass, marble/granite chips, sand), which guarantees you will get the most interesting polymer concrete products.
Due to the fact that it contains a binding polymer, the stone is durable and resistant to frost, water and overheating. Next, we propose to consider standard technological processes for the production of polymer concrete, as well as how to make polymer concrete with your own hands.
What will you need?
To create this type of product we need:
- Coarse fraction filler (crushed stone, crushed large glass, sand).
- Filler of a smaller fraction of fine grinding, which will reduce the cost. It can be andesite, graphite or quartz powder.
- Binder - only 5% of the total volume. Usually these are polymer resins, for example, urea-formaldehyde, polyester (unsaturated), furan.
- Plasticizer, hardener, dye, modifying additives.
- Release agent for molds and separation, as well as gelcoat for coating the outside.
Creation methods
The production process can be carried out using continuous or batch technology.
- Typically, continuous technology is used only in large-scale production. At the same time, dispensers, injection molding machines and automatic mixers are used to coordinate production and organize a single chain.
- During periodic production, after each completed cycle, the containers in use should be constantly washed. But there are also advantages - you can make polymer concrete even in a concrete mixer or bucket.
Process
To create a casting stone, you will need a mold that is generously lubricated with a special release agent (otherwise you will not be able to remove the finished product). Usually they use a mold made of plastic, metal, silicone, and sometimes chipboard (with a modest budget).
- Apply a layer of gelcoat of the desired shade to the release paste.
- Next, we put a composite mixture into the mold, which consists of the above-described elements, which should be mixed well in advance in a concrete mixer. In large production, where the volume of mixtures is much larger, a special concrete paver places the mixture into the mold. If you intend to create a small product from polymer concrete, and the process is periodic, this action is performed manually.
- Next, it is necessary that the mixture, which is placed in the mold, be subject to vibration compaction. This procedure lasts no more than two minutes. To do this, a resonance platform is equipped at the factory, and a vibrating table is used in small industries.
Important, that during production at the factory, in some cases, heat treatment is carried out so that the part hardens faster. But usually the hardening process is completed naturally.
Now let's look at what equipment is required.
Equipment for creating polymer concrete
Nuances of choice and cost
For those who immediately decided to become a polymer concrete tycoon and set their sights on continuous technology, large-scale production should be organized, which means there is a need for special conveyor equipment. It includes machines for casting, mixing, finishing, dosing, as well as a mechanized warehouse. Since purchasing a “complete” set will cost several million dollars, you can first buy only the basic elements on a turnkey basis, thanks to which the initial costs will be reduced to 50 thousand dollars.
But even such an amount can become unaffordable for a novice businessman during a crisis. But the good news is that you can get by with even less money if you buy the required minimum equipment separately. There are some elements you can do yourself, and next we'll look at how to spend less and get more.
Equipment and devices
So, this is a list of things you definitely can't do without:
As you can see, polymer concrete technology and creating conditions for production are not that expensive if you can prepare the equipment yourself.
Atmospheric pollution from polymer concrete production
As we mentioned earlier, casting produces fumes that are harmful to the human body. This is usually styrene, which is found in resins. This type of production cannot be done without resins - they are used as a binder. As soon as the sealed container with resins is opened, the toxic fumes begin to poison your health. In addition, the hardener (often methyl ethyl ketone peroxide) is also dangerous. But it is not volatile and to protect yourself from it, you only need rubber gloves for your hands.
Note, that it is these factors that oblige the manufacturer to equip the foundry room extremely carefully, designing it as a sealed unit, and also not to forget about installing a powerful hood and purchasing respirators. If these measures are followed, the air will be purified and there will be no emissions into the atmosphere.
Do-it-yourself polymer concrete production technology
Now we’ll talk about how to make products yourself at minimal cost. These can be flower pots, window sills, countertops (they are quite popular, as they are warmer than granite and marble).
Choosing a room
First you need to think about a suitable room - approximately you should have approximately 80 m 2 at your disposal. Ideally, this will be a house on the outskirts. From this area we immediately allocate 12 m2 for the foundry, but we will have to work hard to achieve full. In the center of the room we place a table on a frame made of corners, the tabletop will be made of chipboard.
The table should be leveled on the surface - this is very important! The hood should be comfortably located above the table. For lighting, use a fluorescent lamp. In the next room we will need another table for finishing and other types of work. Tools and containers for drying sand and chalk should be placed nearby (low metal boxes are suitable for this).
Raw materials for production
We will need:
- Quartz sand, river (packed 20 kg/bag). It should be dried well.
- Sifted chalk - also dry well.
- Polyester resin - sold in 20 liter buckets.
- Gelcoat, hardener, release paste.
Manufacturing
- To begin with, you will need to purchase a plastic bucket for mixing the components, a hammer drill with at least 0.45 kW capacity, and a construction mixer (we connect the hammer drill to the mixer, then weld a drill bit for perforating and you get an improvised mixer).
- We will make the mold from laminated wood boards; it must be collapsible. Purchase a brush to make it easy to apply the release paste to the surface. It is convenient to grind the paste with nylon products.
- The gelcoat should be diluted with resin (approximately 10% of the total volume) and applied with a flute brush. This procedure should be carried out twice. Make sure that the brush hairs do not stick.
- Mix the hardener and resin in a clean bucket, then add 15% chalk and a portion of sand. You should have a viscous mass. To remove air, occasionally tap the bucket on the floor.
- When everything is ready, pour the solution into the mold. Next, you should smooth the surface - to do this, take the mold together (there should be handles on the mold) and tap it on the floor. Next, the mixture should be left for 40 minutes, and during this time you should not be in the caster.
- When the solution hardens to a “rubbery” state - which can be determined by the hot surface and a certain sound when tapped - remove the product (to do this, simply disassemble the mold) and turn it over with the pouring side down. After this, wait until it hardens completely, and then sand and polish the surfaces.
TB: When weighing the resin, as well as working with it, the gelcoat and the poured mixture, you should only work in a respirator and under a hood. To add the hardener, use a syringe and wear rubber gloves.
Polymer concrete (cast stone, polymer cement, concrete polymer, plastic concrete, plastic concrete) was invented in America as a stronger and more durable alternative to ordinary concrete. The introduction of synthetic binders and hardeners into the new material gave it increased resistance to moisture, frost and irritating chemical factors. And the use of cheap mineral fillers allows you to reduce the price.
So, today we will tell you about polymer concrete, its composition, features, composition, properties, purpose, GOST, fillers and other important factors.
Concept
This material is one of the new types of concrete mixtures, where polymer is used instead of silicate or cement (used during the preparation of conventional concrete). It is introduced into the composition in the form of a viscous fluid liquid (synthetic resin) and imparts many useful properties to the finished polymer concrete products.
In particular, they are very dense and can last much longer than elements and structures made of ordinary concrete. At the same time, without collapsing, cracking or crumbling, withstanding up to 400 cycles of freezing and defrosting, not being afraid of weather disasters and being easily repaired. To repair, just fill the damaged area with a small amount of the mixture - its adhesion is excellent, the product will become as good as new.
Polymer concrete floor (photo)
Advantages and disadvantages
- Strength, light weight, impact resistance, elasticity are several times higher than that of ordinary concrete.
- High ductility, good repairability.
- Ability to easily tolerate rain, heat and cold.
- Calm attitude towards chemical reagents.
- Beautiful appearance, variety of shades and textures.
- Fast drying time of the mixture.
- Dense and smooth surface.
- The price of polymer concrete per m3 is quite high (which depends on the type of components, especially resins).
- It is not always possible to find this material in the public domain.
The following video shows what products can be made from polymer concrete using the example of a fountain:
Types of material
They depend on what type of filler is included in the composition. Its fraction is especially important, determining the final purposes of using cast stone: for decorative products, construction, thermal insulation, construction of floors, window sills, facing tiles.
There are:
- Heavy polymer concrete - contains aggregate with the largest fraction size (from 2 to 4 centimeters). Used for construction work where the loads are very high.
- Structural polymer concrete has a high density - from 1.5 to 3 tons per cubic meter. Also used for construction. The size of the aggregate fraction is no more than 2 centimeters. This category also includes decorative cast stone, which imitates natural expensive stones (marble, for example).
- Polymer concrete of the structural and thermal insulation type has the same size of aggregate crumbs, and its density ranges from 0.5 to 1.5 tons per cubic meter. It has improved heat saving properties and is suitable for foundations and load-bearing walls.
- Heat-insulating polymer concrete is distinguished by the smallest fraction of porous aggregate (shavings, perlite, cork, polystyrene) - no more than 1 centimeter. Its density is from 0.3 to 0.5 tons per cubic meter. Products made from polymer concrete are lightweight, they are good for the construction of internal partitions and for thermal insulation.
- Cast stone, where fine sand (with a fraction of up to 0.15 millimeters) is used as a filler, is suitable for the production of decorative elements and floors.
Specifications
Properties
In many respects, polymer concrete is far superior to conventional concrete. Exceeding the indicators for strength - from four to six times, for overcoming stretching - from five to ten. And in terms of resistance to wear - fifteen to thirty times. The ability to survive frost is also high: from 300 to 500 cycles.
For clarity, we summarize the main parameters in a table.
| Parameter | Meaning | Units |
|---|---|---|
| Density | from 300 to 3000 | kg/m3 |
| Compression resistance | from 50 to 110 | MPa |
| Resistance to bending | from 3 to 11 | MPa |
| Abrasion | from 0.02 to 0.03 | g/cm2 |
| Temperature limits | from 60 to 140 | °C |
| Coefficient of thermal conductivity | from 0.05 to 0.85 | W/mK |
| Elasticity | from 10000 to 40000 | MPa |
| Water absorption per day | from 0.05 to 0.5 | % |
| Maximum freezing cycles | from 300 to 500 | - |
These characteristics indicate the high durability and strength of the new type of material. As for its famous chemical passivity, it is determined by GOST 25246-82.
According to this standard, at 200 degrees Celsius, the coefficient of chemical resistance to nitric acid must be at least 0.5%, and to ammonia, hydrochloric acid and calcium solution - from 0.8%. The results confirm this.
GOST
The general parameters of concrete mixtures are determined by GOST 7473. Polystyrene concrete (where polystyrene is used as a filler) has its own standards. For composition - GOST 27006, for density indicator - GOST 27005, for plasticizers and other chemical additives - GOST 24211.
Now about the standards used in relation to binder components - resins:
- Furfural acetone resin (FAM) must comply with TU 6-05-1618-73.
- Urea-formaldehyde resin - GOST 14231-78.
- Furano-epoxy resin - TU-59-02-039.13-78.
- Monomer methyl methacrylate - GOST 16505.
Composition and structure
If we talk about the composition, then nine parts out of ten are taken up by filler. Which can be used, for example, crushed stone, gravel, mineral flour, quartz sand and even wood shavings. However, other substances can also be used. Talc, graphite powder, crushed basalt, tuff, granite, mica, expanded perlite and others.
It is worth noting that there are a number of materials that are unacceptable for the production of cast stone. In particular, these are metal dust, lime with cement, chalk and limestone rocks.
To fasten the filler “tightly”, take a polymer binder, of which a little is required (five hundredths of a part). One of the thermoplastic or thermosetting type resins works in this capacity. Let's list a few popular resins:
- epoxy;
- furanic;
- phenol-formaldehyde;
- polyester (the most budget option);
- urea-formaldehyde.
Also, polymer concrete must contain a hardener, plasticizers, and coloring agents. They make up a small fraction of the entire composition.
Production and Application
The most important thing in the material is the optimal selection of components that corresponds to the intended purpose. First, the fractionation of the aggregate and its quantity are established. The binder polymer content is then calculated. After this, the components are mixed, placed in molds and allowed to harden (for which a drying chamber is used in industrial production).
Casting stone is used quite widely. These include window sills, facade stucco, and beautiful and durable kitchen countertops. In addition, polymer concrete is used to make floors and stairs, paving and facing slabs, building structures, drainage trays, sculptures and monuments, fountains, plumbing products and much, much more.
In addition, a number of manufacturers produce polymer concrete in the form of ready-to-use dry mixtures. Which manufacturers often call dry plaster mortars. They require an aggregate fraction of no more than 1 centimeter and water (added to the dry composition). Similar mixtures are used to make foundations, seal cracks, construct self-leveling floors, and also repair concrete (and other) surfaces.
The following video describes the production of polymer concrete:
Popular manufacturers
- First, let's mention a company producing polymer concrete from Russia - CJSC "PromKlyuch" from the city of Khimki, Moscow region. The polymer concrete produced by the company is packaged in packaging of various sizes. The material is two-component; its advantageous feature is that it does not require water during production. The company positions its products not just as polymer concrete, but as repair kits that can be used to restore and protect any concrete structures. Polymerizes completely within 24 hours.
- Now the turn of the manufacturer from Germany is a well-known company Silikal GmbH, which is most famous for its self-leveling floor coverings. Polymer concrete of this brand is two-component, based on methacrylate resin. They are distinguished by high density, low shrinkage and quick setting (when repairing, it is enough to wait only an hour). They are used in interior and exterior work, during repairs, creating protective coatings, and making floors.
- Another German company is called "Maurer Sohne", which has long become a world leader in the development and production of protection for various buildings and structures. Including, for example, such solid ones as road and railway bridges. The polymer concrete produced by this company is branded Betoflex, has excellent characteristics and is not the lowest cost. It is especially popular as a so-called “Maurer Betoflex” expansion joint. Which, in addition to the cold-setting components of Betoflex polymer concrete, includes a steel profile and a rubber compensator.
Polymer concrete (also called cast or artificial stone, polymer cement, concrete polymer and plastic concrete) is an alternative type of concrete mixture in which a polymer (synthetic resin) is used instead of the standard binder. Thanks to this component and cheaper mineral fillers, the composition is highly resistant to moisture and frost, but at the same time the price of cast stone is lower. Let's take a closer look: polymer concrete - what is it and is this material really worth using in construction as a replacement for conventional concrete?
To answer this question, we first determine what components plastic concrete includes.
Composition of polymer concrete
The lion's share of the polymer cement composition is occupied by filler and it is added in two types at once:
- Ground – talc, graphite powder, andesite flour, ground basalt, mica and other raw materials.
- Coarse – gravel, crushed stone, quartz sand.
Important! When producing cast stone, metal dust, cement lime and chalk should not be used.
Resin is used as a “fastening” component:
- furano-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 (corresponds to GOST 14231-78 standards);
Polyester resin is often used to hold the filler together, as it is cheaper than others. It is also allowed to use methyl methacrylate monomer (methyl ester) that meets the standards of GOST 16505.
In addition, the cast stone contains hardeners, plasticizing additives and coloring components. They must also meet the requirements for chemical additives (GOST 24211).
Depending on the quantity and type of components, polymer concrete of different qualities can be obtained.
Types of polymer concrete
Depending on what kind of filler (or rather its fraction) you added to the cast stone solution, you can obtain material both for creating light decorative elements and for constructing more massive structures.
Based on this, the following classes of polymer concrete are distinguished:
- Super heavy. The density of such concrete is from 2.5 to 4 t/m 3. Components of at least 2-4 cm in size are used as fillers for super-heavy building materials. This type of concrete is used for the construction of structures that are subject to great pressure (load-bearing structures, foundations).
- Heavy (density from 1.8 to 2.5 t/m3). This type of plastic concrete is suitable for the production of decorative cast stones that imitate marble and other expensive stones. The size of the heavy polymer concrete aggregate should not exceed 2 cm.
- Easy. Since the density of such material is 0.5-1.8 t/m 3, it is usually classified as structural-thermal insulation class concrete. This type of concrete polymer is distinguished by high heat conservation rates. The filler used for its preparation is the same fraction as for heavy polymer concrete, only its quantity changes.
- Ultralight. The density of this composition is from 0.3 to 0.5 t/m 3, so it is used for thermal insulation work and in the construction of internal partitions. The fillers most often used are various shavings, perlites, cork and polystyrene with a fraction of no more than 1 cm.
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. This material has found application in the production of decorative elements.
Properties of polymer concrete
If we compare polymer concrete with ordinary concrete, it is worth noting the fact that in many of its characteristics the composition with the addition of resins outperforms conventional mixtures. Polymer concrete has the following properties:
- density – 300-3000 kg/m3;
- resistance to compression – from 50 to 110 MPa;
- bending resistance – from 3 to 11 MPa;
- abrasion in the range of 0.02-0.03 g/cm 2 ;
- temperature limit – from 60 to 140 0 C;
- 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 taking into account the chemical passivity of modern concrete composition, which is determined according to GOST 25246-82. From this regulatory document it follows that at 200 0 C Celsius, the chemical resistance of concrete polymer components to nitric acid will be no less than 0.5%, and to hydrochloric acid, ammonia or calcium solution no less than 0.8%.
Based on this, we can conclude that polymer concrete, which contains resins, has all the qualities necessary for the construction of various objects.
Advantages and disadvantages of casting stone
Polymer cement is often used in the construction of structures that cannot be made from ordinary concrete due to its fragility. Thanks 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 changes, drops of water on the surface of the finished product evaporate almost immediately, as a result of which cracks and other defects do not form.
- The surface of the polymer cement remains smooth throughout its entire service life, so polymer concrete products do not get dirty.
- The variety of colors allows you to create from this material products stylized to resemble expensive natural rocks (granite, marble, etc.).
- The material is recyclable with the possibility of reusing concrete polymer.
- Structures made from this lightweight concrete do not require additional processing.
If we talk about the disadvantages of modern material, it is worth highlighting the following disadvantages:
- Flammability of polymer concrete.
- The high cost of some binding components (however, if you use ground flour as a filler, the costs will be significantly reduced).
- It is not always possible to find on sale everything necessary for the production of such a composition.
Speaking about the production of polymer concrete, it is worth considering possible options for producing such concrete.
Methods for producing cast stone
The process of producing concrete polymer can be continuous or batch.
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 take into account that you will make some of the equipment yourself, the most expensive tools will have to be purchased. Therefore, we will not dwell on this production method and will consider a more accessible 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 suburban areas. Fortunately, you don’t need specialized equipment to produce it at home.
To make polymer cement with your own hands:
- Rinse and clean the filler. After this, dry it until the moisture content of the crushed stone or gravel is 0.5-1%. If you use wet aggregate, the strength of the finished product will decrease.
- Sift the sand and remove impurities from it.
- First pour crushed stone into the concrete mixer, then sand and aggregate and mix the components for 2 minutes.
- Add water and mix everything again.
- Soften the binder component (resin) with a solvent or simply by heating the solid mass.
- Add a plasticizing additive, stabilizers and other components to the resin. Mix them separately from the aggregate for 2 minutes.
- Add hardener.
- Mix all ingredients for at least 3 minutes until you get a creamy mixture.
- Pour the resulting mixture into a paraffin-lubricated matrix or prepared formwork. Try to immediately fill in the volume of composition that will completely fill the mold. Polymer concrete sets very quickly, so you need to act quickly.
- Level the surface and compact the mixture on a vibrating table.
- Wait a day and remove the finished product from the matrix.
At this point, the production of polymer concrete can be considered finished.
(otherwise known as 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 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 used mainly 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 of the desired color is applied to the release paste.
- 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 an industrial-type vibrator to the table - you’re done.
- 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 an iron barrel and an electric drive with a 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 personal protection: gloves, respirators.
- For finishing work 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 premises - you will 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 need to be fenced off for 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:
