Today, expanded perlite is used in many industries, including construction. Being friable material, it is useful as a filler and baking powder. Despite the fact that in our country the material has been known for a long time, perlite has been widely used only recently. What is expanded perlite? Aspects of application and production features.
Definition
Perlite is an igneous rock that is a by-product of a volcanic eruption. The material is volcanic glass, through which groundwater penetrates, thus forming a specific structure. Perlite is characterized by a structure in which it breaks up into small nuclei. He owes this feature to his name.
Production
Expanded perlite is obtained by grinding and heat treating obsidian volcanic glass. Expansion is carried out using thermal shock at 900-1000 degrees. With sharp heating, gases are released inside the material that explode and give the material a characteristic friability.
Features
In appearance, expanded perlite resembles sand or gravel of a fine fraction, depending on the degree of grinding. It has a color from snow-white to white with a grayish tint. The production of perlite involves its separation into various fractions - from perlite powder less than 0.14 mm in size to perlite crushed stone - 10-20 mm.
In addition, the material is divided into grades that correspond to the bulk density of expanded perlite:
- M75 - up to 75 kg / m 3 .
- M100 - up to 100 kg / m 3 .
- M150 - from 100 to 150 kg / m 3 .
- M200 - from 150 to 200 kg / m 3 .
- M250 - from 200 to 250 kg / m 3 .
- M300 - from 250 to 300 kg / m 3 .
- M350 - from 300 to 350 kg / m 3 .
- M400 - from 350 to 400 kg / m 3 .
- M500 - from 400 to 500 kg / m 3 .
Different grades of material are used for various needs. The thermal conductivity of expanded perlite also depends on bulk density. It can vary from 0.034 W / Mk. The most common to use is the brand of expanded perlite M 75.
Material benefits
Perlite is often used as a heater, this is due to the fact that it has such positive characteristics:
- Natural origin. For this reason, the material is environmentally friendly and has no chemical impurities.
- In perlite, the development of various bacteria is impossible, and rodents do not start in it.
- Perlite does not contain any binders. This means that during operation and storage it does not change its physical properties and does not shrink.
- The material is loose and therefore vapor permeable. This makes it possible to evaporate excess moisture in the room.
- Perlite is not a combustible material, which significantly increases the safety of structures in which it is used as a heater.
Due to such positive properties, expanded perlite is popular in construction.
Stucco mortar
The density of expanded perlite allows the use of material for the preparation of plaster mortars. They are well suited for thermal insulation of houses, since a layer of such plaster only 3 cm thick replaces brickwork in 1 brick.
The advantage of the mixture is that it can be applied to any surface - from wood to slag concrete. At the same time, such plaster does not lose its properties. For its preparation, fine fraction perlite powder is used. After complete drying, such plaster can be subjected to any finish - it is equally good for subsequent staining and for wallpapering.
Mortar
Based on expanded perlite, mortars are often made that are used for masonry or other materials. Such solutions are light, strong and warm at the same time. Drying up, the brickwork turns out from a brick, cinder block or foam concrete which does not have bridges of cold. Also, mortars are used to seal various cracks, joints and other irregularities.
To prepare a dry mixture, perlite sand is mixed with gypsum or cement. It is necessary to dilute with water immediately before starting work, since such a building mixture has the property of quickly solidifying.
Wall insulation
For wall insulation, perlite sand with a fraction of about 6 mm, previously dust-free, is used. It must be laid between masonry. The process can be carried out either manually or using a sandblasting machine. When laying, it is necessary to periodically tap the wall in order to compact the expanded perlite. The thickness of the insulating gasket is usually about 5-10 cm. This is enough to ensure the safety of heat in the house.
Roof insulation
The use of expanded perlite is not limited to wall insulation, since the roof also needs additional thermal insulation. For these purposes, a fraction of the material is used, similar to that required for wall insulation. For the implementation of thermal insulation, perlite must be filled in between the casing and the roof lath, periodically tapping for better tamping of the material.
Bituminized perlite is often used, that is, mixed with bitumen. It has a sticky and strong structure. An advantage is the fact that the laying of bituminized perlite does not require heat treatment and freezes on its own. However, for beginners it is more convenient to use ordinary bulk material, since it is more convenient to distribute without the presence of some skills.
Floor insulation
Additional warming may require not only private houses, but also dwellings in apartment buildings. To do this, it is important to free the surface from the previous coating. Also, some communications or a warm floor system are often placed under the screed.
In order to perform thermal insulation of the floor using expanded perlite, it is necessary to proceed as follows:
- Completely remove the old flooring and, if necessary, the concrete layer.
- For insulation, perlite is used in small fractions - up to 6 mm.
- It must be poured in an even layer. Most often, it is about 3-5 cm. This is enough to hide the unevenness of the floor and perform thermal insulation.
After perlite is poured out, it needs to be tamped slightly so that it is condensed. After that, the floor is ready for pouring concrete screed.
Perlite Products
Today, a large amount of material is produced, each of which has its own characteristic features:
- Silicate-perlite is a material that also includes lime, sand, ash or slag. In this case, the ingredients are mixed and baked in molds in an autoclave.
- Bitumoperlite is a combination of expanded perlite with liquid bitumen. Often used for hydro and thermal insulation of the roof.
- Carboperlite is a pressed mass of expanded perlite sand and lime, followed by gas treatment. As a result, products for piping insulation are obtained.
- Gypsoperlite - a compound of expanded perlite with gypsum by casting or semi-dry pressing.
- Ceramoperlite is a combination of perlite and clay, followed by heat treatment.
In addition, construction is also used for products such as glass perlite, basalt-perlite fiber material, plasterlite, perlite-containing brick, asboperlite cement, perlite cement non-combustible plates.