Alabaster is construction material widely used for leveling and filling walls. It is a type of gypsum, so these concepts are often confused. Let's put these materials “on the shelves”.
Are gypsum and alabaster the same thing?
Gypsum is a calcium sulfate hydrate, natural material widely used in many branches of life and industry. They make from plaster building mixtures, it is used by sculptors, gypsum is also known in medicine.
Gypsum is a wide group of materials with different impurities, compositions and applications.
Alabaster - what is it? This type of gypsum mineral used in construction has a narrow specific application. That is, errors in the substitution of concepts, according to by and large, No. It's just that gypsum is a broad concept, and alabaster is a narrow one.
Characteristics of alabaster
When choosing building and finishing materials, professionals first of all form their attention to the technical indicators of dry mixes and working solutions.
Stucco properties:
- Composition - calcium compound hemihydrate;
- Compressive strength (average) - 4.0 MPa;
- Flexural strength - 2.0 MPa;
- Binder grade (gypsum) - G4 and higher;
- Color - white or light gray (almost white);
- Water consumption per 1 kg of dry mix - 0.65-0.70 liters;
- Setting time 6-30 minutes from start to finish.
General performance properties stucco (alabaster):
- The solution fits well on a prepared surface of any material;
- High adhesion;
- Surfaces can be perfectly flat in short time(up to 5 minutes);
- When dry, alabaster does not crack, does not dry out and does not change its volume at all;
- The solidified layer of mortar absorbs noise, therefore it can be used as additional remedy protection of premises from sounds;
- Alabaster is warm to the touch, prevents heat loss.
Application of alabaster
We have already found out that alabaster is a building material used in the repair and construction of residential and public buildings, namely:
- As dry mixes for the preparation of plaster and putty solutions;
- For repairing cracks, potholes;
- Alabaster is part of the gypsum partitions of interroom and interroom.
Building gypsum has found application in decoration and renovation works ah due to the properties of fast setting and perfect leveling of the surface, as well as good adhesion. An alabaster layer is used to prepare the base for wallpaper, tiles, decorative plaster in bathrooms, toilets and living rooms, bedrooms.
The surface of the cured stucco must not be exposed to moisture. When arranging walls in bathrooms, alabaster should be insulated with tiled cladding.
How to breed alabaster
The correct preparation of the working solution depends on overall result finishes and usability. There are several subtleties in this matter.
Proportions
SNiP regulates the amount of water for mixing a solution of alabaster plaster in the amount of 1 kg of dry mixture per 0.65 liters of liquid. This proportion is appropriate for the preparation of putty and plaster mortar.
For mixing the installation and repair mortar, proportions of 1 kg of dry alabaster to 0.5 liters of water are suitable.
To make a liquid solution for putty, you need to take water and mixture in a 1: 1 ratio.
To extend the setting time of the solution, you can add 2% of the volume of carpenter's glue of animal origin, for example, bone glue, to it.
Choice of dishes
Before dissolving alabaster, you need to choose the right dishes. A metal container is definitely not suitable for kneading - the solution will stick to it as it dries, and it is not easy to clean such a plaque.
To prepare the working mixture plastic will do, or better - a rubber container. In order not to stain the vessel, you should lay a dense plastic bag by hooking it over the edges of a bucket or basin.
Professionals note: alabaster does not stick to rubber. If you need to prepare a single batch of material, use a cut rubber ball.
Correct kneading
How to breed plaster of paris:
- Pour the required measured amount of water into the container;
- Gradually introducing the dry mixture, stir the solution with a spatula, for large volumes use construction mixer or a drill with a nozzle;
- Add dry mixture until a suitable paste consistency is obtained.
For plaster, the mixture should take the consistency of sour cream - the same plastic and moderately soft.
Working with a solution
With diluted alabaster, you can plaster a wall, fill up a gap or a pothole, fill a gutter.
How to cover up cracks with alabaster:
- The strobe / crevice / pothole must be cleaned with a stiff brush from loose material, and the dust must be swept away with a soft bristle.
- Treat the working surface with a deep penetration primer. It will improve the adhesion of the materials and protect the repair area from further delamination.
- Knead the working solution. For repair, we use the ratio of the mixture to water 1: 0.5.
- With a spatula, apply the solution in the direction of the gap, remove the excess mixture in a transverse motion and level the surface.
Working with alabaster is no different from using other plaster mixes. To cover the surface of the structure, dilute the solution 1: 1 and apply in a thin layer with a spatula.
How long does alabaster dry
As stated in technical characteristics, the drying time of alabaster from the moment of initial setting to solidification is 5-30 minutes. That is, the solution must be worked out in 5 minutes. If the gypsum begins to harden in a bucket, it is useless to dilute it, such material should be thrown away.
Experienced craftsmen mix up to 5 kg of the mixture at a time; for local repairs, a little alabaster should be prepared.
As already mentioned, animal glue will help to extend the setting period of the solution. For 1 kg of dry mixture, it is enough to add a tablespoon of bone glue. It will not affect the quality of the finished material.
For more than one millennium, this unique building material has been used in the construction and repair of premises, for decoration, making sculptures, and vessels. Alabaster, which is more often called plaster of paris, aesthetic and easy to handle.
On the intricacies of breeding alabaster
The main feature of water mixtures with alabaster is their fast solidification. This circumstance should be taken into account before proceeding with its breeding. In addition, the setting speed leads to the formation of solidified mixture residues in the containers from under it. Therefore, sometimes it is not easy to remove them from metal buckets and tanks.
To save yourself from mistakes when breeding alabaster, you must:
- prepare the mixture in small portions to prevent it from solidifying earlier than five minutes later
- for dilution, it is better to use containers made of rubber or silicone, which are easy to clean
- put a plastic bag inside the container, the upper edge of which is securely fixed before stirring
- strictly observe the ratio of alabaster and water for the preparation of a specific solution
- Pour dry alabaster into water gradually, stirring constantly until a mass without lumps and bubbles is obtained
At what proportions are plaster of paris obtained?
Plaster of paris can be prepared for various finishing operations. For each of them regulatory documents certain requirements for the preparation of asbestos mortar are provided. So, if it is supposed to be used to fill the strobes when performing work related to the laying of electrical wiring, one kilogram of alabaster should be diluted in half a liter of water.
In the case of preparing a plaster based on alabaster and lime, a kilogram of dry powder is diluted in 650 grams of lime mortar or water. A liquid putty solution, with the help of which irregularities on the walls are leveled, a kilogram of dry stucco is poured into a liter of water.
The main thing when breeding alabaster is to pour the dry mixture into the water. If this is done in small portions while stirring, the formation of lumps is minimized.
However, a quality solution is also provided:
- using power tools in the form of a drill with stirring attachments
- moistening the alabaster while stirring by hand, after which it is intensively stirred with a spatula
- the inadmissibility of diluting the mixture, which has set, with a liquid due to loss of quality
The main property of alabaster is the ability to quickly harden, mixing with water. This creates a solid and stone-like surface. Due to these properties, it is widely used in various industries construction, industrial production, art. With its help, seams in surfaces, holes and irregularities are closed.
When conducting electrical wiring with alabaster, wires and cables are fixed in specially prepared grooves. They putty walls and other surfaces of premises, various building structures.
However, ordinary alabaster quickly sets and hardens, after which it is not recommended to re-mix it with water. The quality of such a mixture deteriorates sharply.
Have experienced craftsmen there are methods of prolonging the action of the ready-made solution. According to one of them, a small amount of wallpaper glue is added to a container with such a solution.
After that, it is tightly closed with a piece. plastic film... The masters claim that this allows increasing the setting time without losing the quality of the alabaster mixture.
Types of alabaster
Different types of alabaster, as a natural mineral for the manufacture of stucco are mined in many countries.
So calcite alabaster is formed by streams of calcareous water and sediments. It can have various, predominantly greenish hues. It is destroyed when exposed to hydrochloric acid, in contrast to gypsum alabaster.
Gypsum alabaster is the main raw material for the manufacture of gypsum. As a result of its processing at high temperatures in special devices, a powder-like binder for construction is obtained. If it is subjected to a finer grinding, the resulting powder can be used for molding operations. Specially purified raw materials are used for the production of gypsum for medical purposes.
There are rare forms of alabaster. In Italy, China and the USA, in addition to white, alabaster of pink and black colors is also mined. There is reddish and brown alabaster.
The setting time is different:
- fast-hardening, which begins to solidify after a couple of minutes and finally sets in a quarter of an hour
- normally hardening with the beginning of setting not earlier than after six minutes and final hardening after half an hour
- hardening slowly, which begins to set no earlier than twenty minutes
For the most part, the powder of modern stucco is white... The most applicable in construction is such a gypsum, which is marked G-5, G-6.
Such alabaster is widely used for:
- plastering in dry rooms
- preparation of putty and plaster mixtures according to special recipes
- production of gypsum-based partition panels
- dry plaster in sheet form
- various types of drywall sheets
- gypsum fiber boards and plasterboard
A similar stucco is used where high strength characteristics material. Due to the presence of a coarse-grained component, it has lower strength and greater porosity.
To meet the needs of industries that need high-strength molds for casting parts for various purposes, to perform special work, it is necessary to opt for alabaster, which is distinguished by high strength, marked from G-13 to G-25. Such material corresponds modern standards safety and construction work.
The cost of quality alabaster
Normal building alabaster is considered a relatively inexpensive building material, which makes it extremely popular in the market. It is sold mainly in durable paper multilayer bags, designed for 5-50 kg. One kilogram of ordinary G-5 building plaster can cost an average of 5-15 rubles.
Alabaster, which is distinguished by its high strength, is significantly superior to ordinary stucco. They are made from gypsum stone, as using traditional technologies and complex chemical-technological processes.
Therefore, such materials are indispensable for:
- Completion of drilled wells in the oil and gas industry
- production of ceramics and sculptures
- production of elements decorative design construction projects
- in medicine for the manufacture of orthopedic and dental prostheses
- molding castings in jewelry making
- high-strength molds for the needs of some industries
Passing the object under construction, you can see a large amount of petrified alabaster in a heap of construction waste. It is easy to guess that a newcomer worked here, as a professional knows how to breed alabaster. Let's take a look at why this happens.
Properties of alabaster
It is worth noting that until now, many people do not distinguish alabaster from gypsum. This is especially noticeable in a construction supermarket, if a person asks, they say, is there alabaster or plaster for the walls, and when the seller asks what exactly the buyer needs, then in response he is asked: "What's the difference?" This is what we'll talk about, since these are similar materials, because alabaster is a type of gypsum, but it has its own distinctive characteristics... In addition, 2 inscriptions can appear on one package at once. It is important to understand this, since these materials are bred in different ways.
What is building alabaster and what are its characteristics? To begin with, alabaster:
- translucent;
- grainy;
- it has a grayish tint;
- it contains a lot of impurities, thanks to which it is easy to work with this material;
- plastic;
- more waterproof;
- does not increase in volume and does not crumble after drying.
Alabaster, unlike gypsum, does not freeze for a longer period, which allows this material to be diluted in a slightly larger volume - this is very convenient when working with it.
We breed alabaster
How to breed alabaster? First of all, with water, although you can lime mortar... Now let's look at how to breed it and what proportions should be.
According to building codes, the proportion of alabaster dilution is provided: 1 kg of this building material accounts for an average of 0.6 liters of liquid. By sticking to these rules, you will end up with a mixture that is easy to work with.
Since it is not always advisable to breed alabaster in large volumes, it is important to observe the proportion, counting so that one part of the alabaster (starting from the amount of the dry mixture) should be used for dilution a sixth of the water.
On a note
It seems that alabaster is very easy to dilute, but let's not forget about the example at the beginning of the article. It said that in fact, not so much of this material is used for its intended purpose. Therefore, let's pay attention to some details.
- First, the required amount of water (or lime mortar) is drawn into the container.
- To avoid the appearance of lumps, it is better to stir the solution with a mixer.
- The solution must be kneaded in a plastic container, as this will allow it to remain in a liquid state for longer.
If you dilute the solution correctly, then it will be pleasant to work with it, and a pile of discarded, unused alabaster will not grow near the house. We also invite you to watch a video, thanks to which the process of breeding alabaster will become more understandable.
Video
This video tells about the features of breeding alabaster for the subsequent installation of socket boxes:
Reading time ≈ 3 minutes
The very word "alabaster" came to us from Greece. It suggests that such material was also used in antiquity. In times Ancient Greece so called calcite (calcium carbonate). Now this word is mainly used to name gypsum - calcium diaquasulfate.
It is not clear to many: what is the difference between gypsum and alabaster? Gypsum is very soft, it is easy to scratch it even with a fingernail. Calcite is more durable and can only be damaged with steel tools. Calcite alabaster reacts with hydrochloric acid, in this case gypsum will be inert. Nowadays, the term "alabaster" has no clarifications: it is calcite or gypsum, so we are always talking about the gypsum variety.
Features of gypsum alabaster
Today the production of gypsum alabaster goes through the heat treatment of natural two-water gypsum. It is kept at a temperature of 150 - 180 ° in special apparatus, where the composition of alabaster turns into semi-water gypsum. This product is crushed into a fine powder. The degree of grind affects the scope of application of the substance. The smallest fraction is medical gypsum, the larger one is molding gypsum, and the largest is construction gypsum.
Specifications of alabaster
Scope of application
Alabaster found its use in everyday life and in construction. The main direction is construction and repair work. Since it is an excellent bonding component, construction alabaster is used for sealing cracks, seams, leveling surfaces, for example, ceilings. The photo and video show how easy it is to perform these works and how great the result looks. Just remember that he can't stand it high humidity, because of this drawback, it can be used exclusively in rooms with a humidity of no more than 60%. To improve its resistance to moisture, the surface treated with alabaster is covered with paint and varnish pastes. If alabaster dough is to be applied to a surface that strongly absorbs moisture, it must be pre-treated with a primer. Often, alabaster is used as an additive that can accelerate the setting of the solution.
Benefits of alabaster
Among the main advantages of alabaster is its environmental safety. This material from natural ingredients cannot harm health. It perfectly absorbs noise, does not burn, does not let water through. Its fire resistance makes it possible to create fire protective coatings with it. Alabaster coatings look smooth and crack-resistant.
Features of use
Alabaster is easy to use. However, everything must be done very quickly, because the alabaster solution begins to harden 6 minutes after dilution with water. And after half an hour, it will become completely solid. Therefore, those who have already encountered a similar problem and are wondering how to breed alabaster should heed the recommendations and make solutions in portions. After all, a thickened solution is not suitable. Additives in the form of wood glue or wallpaper glue will lengthen the life of the mortar a little, and you will have a little more time to work.
The preparation of the solution is in many ways similar to the principle of working with wallpaper glue. It is necessary to mix alabaster in a proportion of 1 kg of substance to 0.6 liters of water. The finished solution should resemble sour cream. It should be applied immediately after stirring; breaks should not be taken. Reviews of those who often use this substance suggest that immediately after the end of the work, you need to thoroughly rinse the entire tool and container. Otherwise, the rapid hardening of alabaster will make them unsuitable for further use.
The name alabaster is applicable to two types of materials at once. So called stucco (calcium diaquasulfate), as well as calcite (calcium carbonate). These materials are very different from each other, but historically, they have the same name applied to them. If we consider the gypsum composition, then it is softer. Its hardness on the Mohs scale is 2. It can easily be scratched with a fingernail. Calcite is a harder mineral and has a 3 on the Mohs scale. This material can only be scratched by metal objects. These substances also differ in chemical properties... Gypsum mineral is inert to hydrochloric acid, while calcium carbonate enters into a violent reaction with it. Nowadays, when alabaster is mentioned, it usually means calcium diaquasulfate, which is one of the main materials of modern construction.
Properties of building alabaster
This is a fairly ancient building material, as can be judged by the old products made on its basis. Their production dates back to 4 thousand BC. The substance in a ready-to-use form is a white powder. It is allowed in various shades, from yellow to pink. It is obtained as a result of heat treatment of gypsum stone. It is heated and baked, as a result of which it dries up and changes its properties. The stone processed in this way is ground into finished building alabaster.
When mixing the powder with water, it hardens for about 15 minutes, plus or minus depends on external conditions, water temperature and the size of the grinding fraction. During chemical process crystallization, the material generates heat and slightly increases in volume.
It is generally accepted to consider alabaster and gypsum to be the same material, but in reality this is not the case. The former is simply a cheap variation on the latter. Gypsum is used in a very wide range of applications such as construction, dentistry, traumatology and sculpture. The use of alabaster is narrowly targeted. It is intended for the construction industry only.
Alabaster is characterized by the presence of a coarse-grained fraction, which significantly accelerates the process of its setting. This helps to increase adhesion when gluing to foreign surfaces. The coarse fraction is a very valuable property, but it reduces strength. In this regard, certain types of fine gypsum, for example, used in dentistry, are much stronger, which is facilitated by lower porosity.
When using alabaster, sufficient hardness is provided. Thanks to this, the products obtained from it are resistant to mechanical stress and destruction. Alabaster is characterized by fast solidification, therefore, when using it, it is necessary to work quickly.
Where is alabaster applied
After mixing dry alabaster with water, a very elastic solution is obtained, significantly superior cement mixtures... It is lightweight and can be applied in thick layers without the risk of cracking. Although this material is not as hard as concrete, 2 times inferior to it on the Mohs scale, it is superior in stability to low-quality cement-sand plaster mixes.
Usually manufacturers of alabaster offer it in the form of plaster and putty dry mixes. And the material that is sold under the name alabaster is often used on a smaller scale. It is usually mixed with water to level the walls. Such plaster mix adheres very well to different surfaces... In addition to mineral materials such as stone, brick or concrete, it is also used on synthetic surfaces, including foam and expanded polystyrene.
Alabaster provides a high drying rate. Types and application. Properties and solution. Features certain benefits. In this regard, it is often used to seal the strobes left after electrical work or laying plumbing pipes in the walls. The alabaster mixture hardens very quickly, reliably holding the communications inside the strobe. With its help, anchoring in the walls for installation and light is carried out.
From alabaster, as well as from many specialized gypsum compositions, various crafts can be made using casting technology. The prepared solution of a liquid consistency is poured into special forms, pre-lubricated with oil or technical vaseline, and then solidifies. Subsequently, the solid product is removed from the mold.
This is a favorite material for busy craftsmen. hand made stucco molding. The applied alabaster mass is processed with chisels, resulting in a variety of rosettes, columns and other decorative elements stylized as antiquity. Since alabaster is characterized by rapid solidification, in this case, various additives can be used to slow down this process and give the master time to work out the details.
The increased elasticity of the material allows it to be used for minor repairs, for example, sealing cracks, seams and holes in the walls. The composition penetrates well into narrow cavities and seizes reliably, completely hiding such defects. If it is applied in a thin layer, then literally in a couple of hours with favorable temperature conditions you can proceed to the next stage of finishing. The base prepared in this way can be used for wallpapering.
Alabaster is also used as an adhesive. It is used to fix ceiling baguettes, as well as finished plaster moldings. The material has also found its way into the creation of countertops. They are poured into molds and then polished. Special treatment with impregnating compounds makes the countertops waterproof and increases abrasion resistance.
Sand can be added to the alabaster composition, which increases its weight, reduces the cost and prolongs the full setting time. Although alabaster. Types and application. Properties and solution. Features and very versatile, but absolutely unsuitable for floor screed or brickwork. It cannot withstand significant loads, and is more used to conduct finishing works when it is not strength that is important, but the decorative effect.
Benefits of alabaster
The popularity of this material in construction is due to a number of advantages that distinguish it from the background of other cement and polymer mortars. Its advantages include:
- Refractoriness.
- High elasticity.
- Accelerated strength gain.
- Increased adhesion.
- Fast drying.
- Environmental friendliness.
The initial setting of a pure alabaster mortar is 5 to 15 minutes. The final hardness is reached in 2 hours. Thus, when using it, a technical pause between different stages work is greatly reduced. Thanks to the environmentally friendly safety of alabaster, it can be used in interior decoration in children's rooms.
Preparation of the solution
First, water is collected in the container, after which the powder itself is poured. Alabaster is added gradually with constant stirring. It cannot be cooked in large portions, since it dries quickly, significantly exceeding ordinary ones. gypsum plasters... Of course, in the case of mold filling, it can be prepared in large portions.
When mixing, it is most convenient to use by setting it to, or. In the event that the work is done manually, then after pouring the powder into the water, it is better to give it time to absorb it. After that, mixing will be much easier. This will avoid clumps. Unlike cement compositions, the solution on an alabaster base cannot be further "rejuvenated" with water in order to restore its elasticity and use it further. After the first signs of setting, it is better to throw it away until it turns to stone right in the bucket.
In the event that the solution is needed to carry out the sealing of the strobe, then it is worth observing the proportion of mixing 2 parts of the material to 1 part of water. This is the optimum consistency for a high cure rate. For filling forms, the 50-50 ratio is most successful.
To increase the life of the alabaster solution, you can use readily available additional components. For this purpose, ordinary dry wallpaper powder can be added during the kneading step. It should be noted that in this case the bonding property and the final hardness of the alabaster will be reduced. If you constantly close the container from which the solution is drawn, then in it it will remain elastic a little longer.
Calcite types of alabaster
Calcium carbonate is more ancient finishing material, mined in the form of stone, which is processed by carving and grinding equipment. It was this mineral that was first called alabaster, since in ancient times its massive extraction and processing was carried out in Egypt in the city of Alabastron. This mineral transmits light when cut into thin sheets. Because of this, it was previously used for installation in windows instead of glass. This was especially popular in medieval churches. It is characteristic that when overheated, the sheets lose their transparency and do not transmit light until they cool down. This material has a striped pattern like marble, which is due to its displacement in the layers of rocks.
