Molds for artificial stone from Forstone company

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How would you find the cottage walls, if its walls will be surfaced with concrete? Will they be good-looking? If the artificial stone is used, any object will certainly look splendid. The material with its concrete-made “body” and texture to be similar to the natural one came into use about 40 years ago, and this time it could really push the natural stone down revealing a number of advantages.

Advantages

Nowadays, with the help of concrete it is practically quite possible to duplicate the natural stone of any kind, color and dimensions. At the same time, the artificial analogue is, at least, two times cheaper than the natural sandstone, limestone or quarry stone. Besides, a number of problems may be solved, if it is used for decorating of interior and exterior wall surfaces. Just try to assume! How much will it take you to select the required stones to be alike by its color and texture? And what do you say about its dressing? Quite the contrary, the artificial slabs are manufactured on the production lines and can be made of the required kind and dimension. At the same time, unlike to the natural stone properties, which texture quality depends on weather conditions, the slab surface has rather a rich color that can be gained by a number of coloring agents. The products can be made along with a finished combination of stones imitating a certain style of stonework. In a short space of time, you are able to change a certain house wall for some fragment of the medieval castle. There between the natural stone and its artificial analogue is a big difference that involves a quantity of man-hours spent on their laying out. If in the first case laying needs special skills, than in the second case only the producer’s instructions and recommendations shall be followed. The artificial stone is featured with a number of physical and engineering properties. It is stronger and more durable than its natural analogues (e.g. limestone and sandstone). In spite of the fact that the last ones are good-looking they are prone to breaking at their splits and they are fast at failing under influence of water and wind. Their concrete twins have no similar problems. Certainly, by its strength the artificial stone cannot come up with such a monumental matter as granite. But do not forget that the granite inhabits some background radiation to be not found in the concrete products. Since the materials of low volume weight are used as aggregates, the artificial stone is quite easier than its natural analogues. That means that while conditioning your house with the artificial stone you do not need to build the wall foundation embedded elements to make the bed heavier. That is why you do not need to fear for sinking of your building and no cracks and tilts can occur in your structures. The next thing: the concrete product is of monolithic type and therefore no defects can occur inside it, but not as for the natural stone. Regardless of the methods of stone mining (in foreign countries they usually cut rocks, but in Russia the rocks are blown out) some cavities, cracks and other defects may be found inside the stone. These defects are able to affect any wall facing. In addition to, if air cavities are absent, high frost-resistance of the artificial stone is gained. And actually, the artificial stone cannot be considered as the artificial one!

Composition

The artificial stone consists of the main aggregates treated from natural rocks. The sand is a fragment of rocks being split under influence of wind. The cement is a former dolomite treated by means of hydration, milling and firing. In addition to, after contact with water the very binding agent transforms to the so-called “cement stone”. The coloring agents consist of metal oxides and dioxides listed among main constituents of any minerals. Among the artificial stone components the plasticizers of different features are used. For example, one grade of the plasticizers is able to decrease the rate of concrete water (the less content of water, the more plastic concrete), other ones are able to protect against forming of air cavities and the third ones can decrease the rate of abrasiveness. A number of the plasticizers are of natural origin. For instance, the haydite (it makes the product light in weight) is made of the fired and expanded clay. To improve material strength and moisture resistance properties some manufactures prefer to add in the mixture some amount of fiber. If, as a result of wrong laying or in a case of exposure to precipitations the stone splits, the applied fiber will retain it against breakout. The composition may be mixed with gypsum that is able to makes it cure in a short time. However, this type of stone is good enough only for interior surfacing. As a rule, all the additives are original elements. Thus, they do not influence the product ecological condition. But nevertheless, some artificial components are also used. Instead of the cement some acrylic and urea resins, organic concrete and other polymers may be used as binding agents. See binder composition characteristics in the product sanitary certificate.

Method of manufacturing

As a rule, the artificial stone is made by means of compression and vibro-molding. The composition of cement (or other binding agent), coloring agents and other additives is filled in a special mold or compressed in it. The mixture is rammed down, cured and then dried down. Only the product, being completely dried up, can be used for facing of interior or exterior elements. Only one side of the slab is patterned – the other side (used for laying) is completely flat. Depending on the imitating stone properties the molds may be rigid (plastic and gypsum ones) and smooth (polyurethane ones). For example, the stuff texture to be similar to the natural stone’s (featured with negative angles) may be gained only by means of the smooth mold. The concrete product properties directly depend on quantity of the molds used for filling. Large companies usually use quite a great number of different molds thanks to that repeatability of a certain pattern in a single lot can be hardly seen. It is worth noticing that depending on the product lot the artificial stone colors may vary. But nevertheless, it additionally proves that our stone has unique properties. Specific character

Color fastness is one of the properties that the artificial stone is featured (certainly, if manufacture uses high-grade coloring agents). As a rule, the concrete is made of colored aggregates and, therefore, after a number of years it does not loose its coloring properties and does need additional make-up. Even factory paving slabs are able to retain their coloring. However, if the slabs are made with only their surface colored, their appearance will deteriorate after a time. As it is well known, water has a tendency to sharpen any type of stone. And the artificial stone cannot be considered as an exception. But if the water absorption property is within norm (3 to 8%), the stone retains its mechanical properties. We do not recommend laying the artificial stones where contact with water can take place. The same time, special water-repelling admixtures reduce water negative influence. Such admixture can be used for treating of any surfaces. It coats the surface of a stone with elastic semi-impermeable membrane that protects it against influence of not only the water, but also of high temperature, solar radiation and acid rain. Considering our environment, when winter temperature varies from - 10 to + 5 °C, the facing material should have cold-weather properties. If the product is made of high-grade material, no temperature variations can affect it. Depending on the manufacturer and on the rate of frost-resistance the product can be affected by 100 – 200 cycles (by GOST 70 cycles is enough). The cycle can look as follows: the stone having been frozen in the lab environment down to -15 or - 20 °C is defrosted for 4 hours up to the temperature of +2 °C. Before freezing the stone is kept in water for 4 hours. Of course, in natural environment the stone can hardly find itself in such condition. But nevertheless, it is considered that the stone is influenced by 4-5 cycles. Also, average density of the product is of great importance (the less density, the lighter stone). Even relatively weak bearing structures are able to sustain it. In addition to, low average density is the very property to be important for laying the product. Compression strength is significant property required when paving artificial stone slabs and, therefore, the lasts are able to bear any weight without deformation. The rate of concrete stone strength may be characterized by the following example: one square centimeter of the slab used for paving of 4 cm garden path or ground is able to bear the weight of 500 kg. But it is worth noting that the facing slabs cannot be used for paving. Another nuance: when the artificial stone is heated it neither burns, nor exhales smoke or harmful substances. Therefore, it is the best one to be used for facing of fireplaces. But do not use the artificial stone for facing of the elements exposed to extremely high temperatures.

Range of application

As the material is applied both for interior and exterior surfacing, all depends on your local environment. The stone can be used for decorating of the reception-room, kitchen, home theatre, indoor pool and fireplace, as well as it can be used for surfacing of the door openings and ornamental columns. The stone is perfect for laying on the facade, pedestal, roof, chimneys and vent ducts, windows, balustrades, balcony banisters, staircases and steps. The barrier and supporting walls, angle dummy joints, decorative blocks and booms may be surfaced with the stone as well. No restriction of concrete use (with cement binders) is stipulated in SNiPs as the very material does not emit toxins, formaldehydes and other danger substances. If the premises worked with stone are quite cold for living, you may use the heat floor systems that are offered in the market in great variety. Any possible restrictions may rather depend on your tastes and attitude to comfort. It is just a few steps may be done to change a spacious room for a stony “crypt”. The artificial stone may be used around your house area. The summerhouses, halls, columns, fountains, benches, sculptures and other architectural elements of the classic garden will help you to change your landscape. The decorative pools, pavements and paths, curbs, posts, fences, vegetable gardens, gates etc may be added to the above list. Now, the most popular product is the slab imitating wooden saw-cuts and boards. Really, the natural wood elements can perfectly look at any landscape. No doubt can be made about material condition. Unlike to the wood subject to decay, the concrete has a long life. A decorative thin-walled brick made of concrete may be considered as the other invention that can add some new features. The artificial stone can perfectly match widely distributed country architectural elements: wooden and plastered walls, forging fences, gates, staircase and balcony railing, natural and smooth tiling roofs, modeling and mosaic, grates and lamps taken to the façade and large dimension natural stones. The one thing should be followed – selection of proper color and texture of the stone and harmony of architectural elements. It is worth noting that nowadays the artificial stone is widely used for exterior and interior surfacing of not only private buildings, but also public ones – cafés, restaurants, clubs, supermarkets, hotels and banks. A number of exclusive stylistic facilities may be applied. On the one hand, the concrete stone imitating the natural analogue is the very personification of any tradition. On the other hand, the artificial stone columns or slabs with roughly worked stone design are the perfect ones to match the interior made in the style of minimalism or hi-tech. Besides, the artificial stone can be use for reconditioning of the old building appearance. Quite often, monuments of architecture or natural stone damaged elements are the ones that can be reconditioned by means of the artificial stone, as no substitution can be seen.

National features

Nowadays, mainly the domestic manufacturing concrete stones made on the basis of the other country (west ones) technologies are offered on the market. The matter is, that use of local raw materials and labor that is cheaper than the other country’s one, fast transportation, absence of discharging, intermediate storage, overcharging and other expanses, all of them are the very facts that make the product cheaper. In addition to, Russian climatic conditions and raw material specific properties were at the bottom of the activities directed to correction of new foreign technologies. For example, the Russian and American sands differ in their properties. The same is about cement. The artificial stones are often manufactured using white cement, which unlike to the gray one easy gains any required color while no unexpected color tone can be formed. But not all of the domestic cement factories are able to control their product color spectrum to avoid its changing from one production lot to another one. Thus, many reputable companies started up their serial production of artificial stones only after a thorough study of the local raw material composition and properties have been made, and the required filling agents have been selected.

Quantity

It is quite a simple thing to specify quantity of the artificial stone slabs need for stone works. You should carry out the procedures as follows. Calculate the surfacing area: multiply length by height and then subtract the surface area of windows, doors, openings etc. Then, determine if any angle elements would be used. If so, calculate length of exterior angles. After that, calculate the required quantity of flatbed elements: multiply length of angle elements by 0.2 and subtract the obtained result from the surfacing area. Consider any unforeseen consequences: the angle and flatbed slabs should be specified with allowances.

Surfacing

Correct surfacing of the facing and pavement stone slabs results in their long life, as well as helps to retain their properties under influence of different temperatures. As a result, no additional operating expenses are required. The facing slabs can be fastened to any surface: reinforced concrete, brick, wood and even plywood walls, as well as to any metallic structures. But the wall should be covered with a lath (wood is preliminary covered with underlay) and plastering. The artificial stone is fixed both, with the help of usual cement mortar and adhesives. It is considered that the mortar is the best one to be used for surfacing the house exterior and fireplace, as its coefficient of temperature expansion is similar to the one of the stone. At the same time, adhesives have high elastic and adhesive properties. Adhesive is selected on the basis of the stone shape and architectural aims. Surfacing is made by two methods: seamless surfacing and flushing. In the first case the slabs are fit to each other. Adhesive is put on the slab back surface in full amount (some portion of adhesive should come out of the slab edges). Flushing is made with a distance 1.5 – 2.5 cm to be between the slabs. The very method of surfacing can be applied using a great number of artificial stone shapes and concrete bricks. The flushing adhesive type should be similar to the one used for stone adhesion. To obtain perfect sealing of joints the seams are filled with adhesive. Otherwise, getting under facing moisture can frost and break it. Paving with artificial stone slabs should be made after laying of basement. A layer of crushed rocks perfectly suits the laying bed. Then a layer of sand or reinforced concrete mortar is put. A layer cement mortar is used as a last layer. If you lay slabs around your house, we recommend to grade the ground surface by 1 : 40 to make snow and rain water come out off the house area. Preferably, the paths should be made just a little lower the place where the lawn may be located – you can easily cut your grass. Besides, your lawn-mower may be operated in safe conditions.