Perlite insulation is made from rock volcanic character of the same name (perlite). By appearance the material resembles sand or gravel, it all depends on the size of the fractions: the larger they are, the greater the resemblance to gravel, and vice versa.
As a result of a volcanic eruption, lava comes into contact with the soil surface. Glass inclusions are immediately formed at the edge of this flow. Further, under the influence of groundwater, the process of hydration occurs, which leads to the formation of perlite. If you need to find out what it is, you need to consider the technology for the production of insulation.
In its original form, the material is unremarkable. To give the desired properties, it is subjected to processing. It is necessary to achieve swelling of perlite. To do this, the rock is heated to 1100°C. As a result, the pores of the material explode. This process is called swelling. It leads to the disintegration of the rock into many fractions. Specifications:
- a high degree of porosity (70-90%), which is due to the sharp heating of the rock and the transition of the liquid contained in its composition into a gaseous state;
- rounded shape of fractions with brilliance, which gives a resemblance to pearls;
- bulk density varies depending on the size of individual particles: 45-200 kg / m³ (for sand), reaches 500 kg / m³ (if perlite-crushed stone insulation is considered);
- the size of the fractions varies from 1 to 10 mm;
- not exposed to fire, resistant to high temperatures (up to 900 ° C);
- relatively low thermal conductivity: from 0.043 to 0.053 W / (m * K);
- perlite is a hygroscopic material, which is due to the large-pore structure, however, after contact with liquids, the fractions do not lose their properties;
- light weight;
- provides sound insulation;
- long period of service;
- the quality of the material is not affected by aggressive compounds;
- the insulation does not contain harmful impurities;
- does not rot;
- perlite is resistant to mold;
- the material is unattractive to insects, rodents.
Building mixtures are often prepared based on bulk type perlite, slabs, wall products, and blocks are used. The wide range of applications is due to the many useful properties this material. In its composition are found:
- silica;
- oxides of potassium, aluminum, magnesium, iron, sodium, calcium;
- water (1%).
There are several types of this material, the difference between the options lies in the dimensions of the fractions.
The building material is a group of lightweight concrete. It is used as an additive, because it has good sound and heat insulation characteristics. As a result of its use in construction, several problems are solved at once: strength is ensured, the intensity of heat loss and noise is reduced. For the manufacture of concrete mortar, perlite should be used, the size of the fractions of which varies from 0.16 to 2.5 mm.
Composition of perlite concrete: water, Portland cement, sand, expanded perlite. The volume of components may vary. It all depends on the degree of density of the material to be obtained. Perlite concrete properties:
- resistance to fire;
- breathability;
- there are no harmful compounds in the composition;
- light weight, which allows you to build structures on your own.
This material is often opposed to expanded clay concrete, aerated concrete, polystyrene concrete. In order not to waste time on the manufacture of the mixture, you can purchase ready blocks. Perlite concrete products are more often used in the construction of low-rise buildings. The lower limit of the density limit is 600 kg/m³.
Material with worse characteristics is not used in the construction of load-bearing structures.
The block made of perlite concrete has large dimensions. For comparison, it can replace 3-4 bricks. Due to the low weight of the product, it is easy to install. This process is accelerated, because instead of several bricks, it is necessary to use 1 block of perlite concrete. The standard dimensions of such products (length, height) are 390x190 mm. The width varies between 70-190 mm.
Heat-insulating perlite plasters
The use of material based on expanded perlite fractions helps to reduce thermal conductivity by up to 50%. Additionally, the weight of the structure is also reduced. Besides, perlite sand plaster makes the surface more attractive. Due to the presence of perlite in the composition of the mixture, properties such as fire resistance and sound absorption are improved.
In terms of the quality of thermal insulation, a material with a thickness of 3 cm can replace 15 cm brickwork.
Perlite-based plaster is versatile, because. Can be applied to surfaces of various materials- brick, concrete, metal, wood and slag concrete. The advantage is the ability to paint the plaster layer without pre-treatment surfaces. The same goes for wallpapering. Due to the roughness, finishing materials fit well on the plaster.
In addition to perlite, the composition of the mixture includes cement, water, and air-entraining additives. The ratio of components varies significantly, but expanded sand is always taken in the same amount. Possible options ratio of cement and perlite: 1:4, 1:5, 1:6, 1:8.
The less expanded sand in the composition of the mixture, the worse it is. thermal insulation properties. However, at the same time, the highest density indicator is noted.
The lifespan of perlite sand, and is it harmful to health
Given the origin of the material and the process of its processing, it can be argued that it is completely environmentally friendly. Harmful substances are not part of perlite. And even during production, it remains clean. Means, the material can be used for any purpose without risk to human health. The only exceptions are cases when perlite is combined with other materials. Then the quality of the mixture should be assessed.
A significant share in the structure of perlite is glass. Thanks to the swelling technology, the properties of the material are improved. They also note a long period of operation. It is believed that perlite can serve for an unlimited period without loss of properties.
Perlite insulation technology
If used backfill thermal insulation, then the space between the outer and inner walls, the finishing material and the draft surface in the room is filled with perlite of various fractions. The design includes a drainage system. In the case when it is planned to fill perlite between the walls, waterproofing is provided, since the material absorbs moisture. Fractions fill free space as walls are erected.
If expanded perlite is planned to be used for the purpose of thermal insulation of a roof or ceiling, it is first laid particle boards or their equivalent from drywall with diffusion-penetrating properties. Perlite is poured on top, the layer should be 1 cm. Then the insulation is covered with kraft paper, fiberglass or corrugated cardboard.
To remove moisture from the thermal insulation layer, the design provides drainage tubes. The thickness of the insulation is determined taking into account the needs of the owner of the object and climatic conditions terrain. In most cases, a layer within 10-15 cm is sufficient.
Comparison of perlite and vermiculite
First of all, note the similarity in the origin of materials. So, perlite and vermiculite with the desired properties are obtained artificially (blowing technology). Comparisons are made for the size of the fractions. If you need to choose a material with the smallest particles, it is recommended to pay attention to perlite. Vermiculite is darker, it provokes soil oxidation. This material is somewhat less hygroscopic than perlite. Expanded sand releases liquid more easily, which means it dries faster. When insulating with perlite, the effect is better, because the thermal conductivity of vermiculite is higher.
The raw material for the production of perlite is volcanic rock, which, when heated, is able to increase in volume (swell). As a result heat treatment Perlite aluminosilicate water-containing rocks of volcanic origin receive a non-toxic, non-combustible, lightweight and highly efficient insulation - expanded perlite.
Application area
Due to its high physical and technical properties, this material has found wide application in various industries:
- metallurgy,
- energy,
- construction,
- agriculture,
- medicine,
- food industry,
- oil refining,
- production of cryogenic equipment.
Perlite as a heater is able to withstand temperatures ranging from -200°C to +900°C. The material has a high moisture absorption capacity - it can absorb liquid up to 400% of its weight. Perlite is chemically neutral to action weak acids and alkalis, does not contain heavy metals. The environmental friendliness of the insulation allows it to be used in the insulation of residential buildings without risk to human health. This material is not only completely safe for humans, it does not cause allergies and contributes to the creation of a favorable microclimate in the house. In addition, this material is quite simple and easy to work with.
The low bulk density of the material (100 kg/m 3) explains the high acoustic properties of the insulation produced from it. Plaster mixtures with expanded perlite sand also play the role of a heater.
A plaster layer 3 cm thick in terms of its thermal insulation characteristics is equivalent to a 15 cm brickwork. High heat and sound insulation qualities of the insulation are well manifested in the installation of "floating" plank and concrete floors, asphalt floors, for leveling and improving the sound insulation characteristics of floors between floors, between walls and floors, in the insulation of the piping system.
Neutral pH perlite eliminates corrosion of piping and wiring electrical networks located in the floor area. Perlite is especially popular as a heater in the implementation of "warm" floor systems, since it is not prone to expansion when heated, does not shrink, and is absolutely non-combustible. In addition, it does not die and is not of interest to insects and rodents. To improve the sound and heat insulation properties of the concrete solution, perlite is also added to it. wide area The use of this material perfectly confirms its high physical and technical properties.
Options for using expanded perlite as a heater
- Perlite sand (backfill insulation)
- Thermal insulation boards
- Roof insulation
- Dry mixes
Backfill perlite insulation
One of effective solutions to facilitate the construction of the house, along with an increase in its heat-conducting characteristics, is the use of backfill insulation based on perlite sand. This step allows you to reduce heat loss by almost 50%. Backfill can be used in layers between external and internal wall cladding, interior finishing and wall cladding, in all voids of wall masonry.
Thermal insulation boards
The largest amount of perlite in world practice is used in the manufacture of molded heat-insulating products (more than 60%). Bitumen, cement, gypsum, liquid glass, clay, lime, polymers act as a binder. Given the high hygroscopicity of perlite, it is better to use materials based on it for internal insulation, however, there are techniques that allow you to apply thermal insulation materials based on foamed perlite in external insulation.
Thermal insulation boards are widely used for insulation of residential and commercial buildings. The thermal conductivity of the material reaches 0.118 W/(m-°C).
The main advantages of using perlite boards are their low weight and high sound and thermal insulation characteristics. In addition, structures insulated with this material are reliably protected from decay, are not damaged by rodents, and are not affected by mold and fungi.
Dry mixes
Perlite sand mixed in a dry state with cement or gypsum is dissolved with water directly on the construction site. The resulting composition fills the cavities in brick, concrete, walls, grout cracks and seams. Expanded perlite is used in the preparation of adhesive and putty mixtures, self-leveling floors, mortars for repair work, in the installation of "warm" floors, etc. The thermal conductivity of mixtures is on average 0.2 W / (m-°C). According to the type of binder, perlite compositions are classified into cement-pearlite, gypsum-pearlite, lime-pearlite.
Roof insulation
In the thermal insulation of roofs and ceilings, bitumen-perlite is especially popular. With his participation, high-strength insulating layers of the required shape are created. In addition, the material can be combined with bituminous cover layers and insulating boards. Bitumen-perlite does not need to be heated before application. The thermal conductivity of bitumen perlite is 0.067 W/(m-°C). Using perlite as a heater, you choose a safe, economical, durable, non-combustible material with high physical and technical characteristics.
In many countries of the world, perlite backfills are used to create warm sloping roofs. In addition, such an effective heat insulator as perlite concrete is used in roof insulation. It has high wind and fire resistance, and in tandem with perlite-magnesium thermal insulation boards, it acquires high thermal resistance.
Perlite as a heater: types and applications
The raw material for the production of perlite is volcanic rock, which, when heated, is able to increase in volume (swell). As a result of heat treatment of perlite aluminosilicate water-containing rocks of volcanic origin, a non-toxic, non-combustible, light and highly effective insulation is obtained - expanded perlite.
Perlite insulation
In construction, there are many applications for expanded perlite. It is most successfully used for thermal insulation of floors, walls, ceilings between floors and for the construction of attics and attics.
One of the properties of perlite is the ability to “flow around” bumps and protrusions. This allows you to easily and quickly determine the level of the floor. In addition, perlite inorganic material with a neutral pH, so pipelines and electrical communications placed under the floor will not corrode.
Heat must not only be created, but also accumulated and stored. So, installation of a warm floor will allow you to save from 10% to 50% of thermal energy. It has been experimentally verified that in rooms with a height of up to 3 meters, the savings in thermal energy is 15-30%, and at a height of more than 3 meters - up to 50%. In this case, the warm floor serves as a kind of “shield” so that the heat does not “run away” to the lower floors or basements, and the cold does not penetrate into the house. As you know, porous materials have the highest thermal insulation properties, because they are made up of a large number of closed, air-filled pores. Air in a stationary state has a very low thermal conductivity and 0.02 W / (m * K) at t 20 ° C. Accordingly, the porosity makes it low thermally conductive, which means it is optimal for backfilling in a warm floor. Unlike other heaters, perlite is a natural material, and therefore it is environmentally friendly.
To make a perlite concrete floor, use ready mix"Porit" for screed.
AT recent times many people arrange a “floating floor” to insulate the room. A feature of such a floor (see Fig. 1) is the absence of a rigid connection between the screed (4) and the floor slab (5). This type of floor compensates for the thermal deformation of the concrete floor due to its heating and cooling, and also solves the problem of sound insulation.
One way to build a floating floor is based on the use of perlite. In this case, a layer of expanded perlite (2) is poured on the floor slab (5). After that, along the perimeter of the room in which the floor is arranged, a vibration isolating tape (6) is laid. The level of this tape must match the level of the concrete floor (4) being poured. This tape will prevent the transmission of vibrations from concrete screed into the wall (1). After that, a waterproofing film (3) is laid on the perlite, which prevents the perlite layer from getting wet during the installation of a concrete screed.
Perlite is extremely effective in thermal insulation of buildings. To do this, at the construction stage, it must be filled in the cavity between the walls (Fig. 2). At the same time, perlite insulation is poured directly from the bag (or through a bunker) into the wall from above at any convenient interval (no more than 6 m). By the time the window sill is installed, the cavities under the door and window slots should already be filled. If necessary, perlite can be poured, wait until it “settles down” and top up. All openings that may be in the wall and through which perlite insulation can spill out must be closed by the time the insulation is poured.
Perlite filling of the cavity between the carrier and facing masonry poured in layers after laying 3-4 rows of bricks. Waterproofing pads are placed on the working breaks in the insulation. If necessary, the insulating layer can be made of any required thickness. Since construction is a long-term process, when working with perlite insulation, the cavities between the walls should be covered from rain.
Having high heat-shielding properties, expanded perlite does not age and is not destroyed by pests of animal and vegetable origin. It should be noted that perlite backfills are used to insulate walls made of wooden and frame structures. Such insulating gaskets do not burn, and therefore increase the fire safety of houses.
Perlite roof insulation
In world practice, perlite backfills are often used in the construction of warm sloping roofs.
1. Perlite roof backfill. First, diffusely permeable bottom cover boards (eg gypsum boards) are laid on the rafters. Perlite is poured into the cavity between the “sheathing” and the “crate” and compacted by 10%.
During the installation of the lower roofing layer from the “lining”, a waterproof lining of glassine or film is laid on it. The points of connection with the gutter, as well as the places of passage through the roof, are hermetically isolated with a dense adhesive tape.
Advantages of perlite thermal insulation: 1) perlite backfill insulation does not lose its properties over time; 2) provides sound insulation; 3) does not rot; 4) does not burn; 5) rodents and ants do not start in it.
2. Perlite concrete insulation flat roof. For perlite-concrete insulation of a flat roof, it is recommended to use the ready-made mixture "Porit" for a light screed. If necessary, the roof can be strengthened reinforcing mesh. The minimum recommended roof slope for normal water drainage is 1/8.
Properties of heat-insulating perlite concrete:
– dry density 350-500 kg/m3;
- the minimum limit of compressive strength is 1.5-3.0 kgf / cm 2
Expanded perlite is used for insulation of floors, walls, roofs, ceilings between floors, attics and attics
Expanded perlite sand is used for thermal insulation and sound insulation. It will help you quickly and inexpensively insulate your home.
The technology of wall insulation with penofol and perlite from the inside
Almost any construction of private houses needs warming measures.
The installation of insulation is also in some cases required by the apartment building.
To provide heat in the house, there are a large number various materials, one of them is penofol.
It is worth familiarizing yourself with the features and installation process of this material in more detail.
Advantages and disadvantages of penofol
This material is a polyethylene that foams during production and covered with an aluminum coating, which reaches a thickness of 14 microns and has a purity of 99.4%. Aluminum coated material can be on different sides or both at the same time.
Its class and properties of heat and vapor barrier depend on this..
First of all, you should familiarize yourself with positive characteristics, which play a significant role when choosing a material for insulation:
- High degree of environmental friendliness. The components from which this insulation is produced are not toxic, since their use is allowed for the storage of food products.
- Minimum thickness value. Similar insulation materials usually exceed a thickness value of 4 mm. If we compare penofol and mineral wool, then 8.5 cm of the second material can provide the same insulation properties.
- No need to use vapor barrier materials , because penofol is characterized by a low level of vapor permeability.
- High soundproofing properties, which allows you to provide acoustic and structural sound insulation at no additional cost.
- The installation process is quite simple, there is no need for overalls and the use of specialized equipment.
- The heater is non-flammable.
- Easy transportation, insulation can be rolled up and packed in a car.
- Rodents do not damage such material.
- Each batch produced undergoes mandatory certification in the sanitary and epidemiological station.
In addition to the positive aspects, it is also worth noting other nuances, which in some cases are disadvantages when using penofol:
- Due to the softness of the insulation, it cannot be used for internal insulation in the case of wall decoration with plaster or wallpaper.
- Difficulties in attaching all classes of material, except for C, which is equipped with a self-adhesive coating. Connection is best done adhesive compositions, it is believed that nailing penofol worsens its properties as a heater.
- Penofol is significantly inferior in its characteristics to other types of heaters.
Basically, this heater used to decorate the walls of a house or apartment from the inside. If there is a need to insulate the house from the outside, then it is better to stop at a different type of heat-insulating composition, and use penofol as an additional layer, thereby enhancing the properties of reflection of thermal energy.
Where is the best place to insulate?
Such material is suitable for providing insulation 
walls, both internally and externally.
Before deciding on which side it is better to use such material, it is better to weigh the pros and cons.
It is generally believed that the use of insulation on the inside of the walls is not recommended due to a decrease in living space, the risk of the formation of fungal microorganisms and mold, the accumulation of a large amount of moisture, etc.
In the case of penofol, there is no reduction in area, but certain classes of material pass moisture in only one direction - this should be taken into account during installation.
wall pie
For a better understanding of the further installation process, it is worth getting acquainted with the device of the wall pie, which consists of various layers of material. The sequence of layers is indicated in the direction from the inside of the wall to the outside:
- interior finishing materials;
- panel osv;
- penofol;
- frame racks;
- windproof material;
- crate;
- exterior finish.
The wall cake is indicated for the frame variety of the house. For other types of structures, some materials may be excluded or added as needed.
It is worth paying attention to the need to provide a vapor barrier layer in the wall cake. Opinions on this matter differ, however, in most cases, vapor barrier for insulation from the inside of the room is not used.
Wall pie device
If penofol is used in insulation from the outside, then a vapor barrier layer is necessary, because the material tends to pass vapors in only one direction (except for type C).
Penofol wall insulation technology
Installation of this heater has differences regarding the selected variety, namely in the way it is attached.
If type A is used, then the fastening is made on a more massive insulation, in the case of type B, the fastening is autonomous, and type C has its own adhesive base.
The sequence of actions is as follows:
- Until the moment of attaching the insulation to the wall, the construction of the frame is carried out, in which there will be a space on both sides of this material of 20 mm, this will provide the maximum effect from the use of penofol. For such a process, it is better to use slats 1.5-2 cm in size, which are attached with dowels, while maintaining a distance of 1 m.
- The next step is to check the condition of the wiring. It should be borne in mind that aluminum is present in the insulation, which easily conducts current and it is very important to ensure that all wires are fully insulated.
- After these events, the insulation itself is attached directly.. This is done with a furniture stapler. The cutting of the strips is done with a knife or scissors, the joints are aligned close to each other, then glue them with aluminum tape.
- Next, the construction and installation of a wooden frame is carried out, on which any kind of panels are attached to further provide interior decoration.
Perlite, advantages and disadvantages
Another type of wall insulation is perlite, or rather materials based on it.
It can be both blocks, bulk materials, and in appearance ordinary plaster. Perlite is a volcanic glass in which molecular water is present in a bound state.
During the production process, such a composition is exposed to a temperature of 800 degrees, due to which it is achieved high level porosity.
The advantages of perlite include:
- light weight;
- low level of thermal conductivity;
- soundproofing;
- good absorbent properties;
- hygroscopicity.
It is also worth paying attention to some of the disadvantages in using this heater, although there are few of them:
- when working with perlite, there is a possibility of harm to the body, because fine aluminosilicate dust is released when cutting blocks or mixing the solution;
- if the moisture level in the material rises to 10%, then this promises a loss of its properties by 90%. The material requires the obligatory equipment of the wall cake with a layer of waterproofing;
- it is very problematic to find such a heater on sale;
- on the market there are often fakes of this type of insulation, which is difficult to distinguish from the original.
The use of pearlite sand in structures with high vibration is prohibited.
Wall insulation with perlite
They insulate with perlite mainly houses built of bricks or blocks. The need to carry out insulation with perlite is thought at the stage of building the foundation, which determines the amount required material insulation and its variety.
For strip foundations with basement use a solution of perlite plaster. The process of warming sand from perlite is as follows:
- Warming begins at the stage of building the walls of the house.
- Perlite sand is mainly used, weighing 60-100 kg per m3.
- They lay the walls, and after laying 3-4 layers of bricks, pour insulation material into the interstitial space.
- To prevent shrinkage of the sandy material, it is compacted by tapping.
When insulating walls with perlite plaster, it is possible to carry out surface finishing with any finishing material.
Interwall insulation with perlite
Conclusion
Depends on the choice and installation of insulation comfortable accommodation in home. It is very important to choose the most suitable material depending on the individual characteristics building. For wooden houses good option will be penofol, and for stone houses - perlite. The thermal conductivity of the latter, in comparison with brick, exceeds 5 times, for example, 3 cm of perlite is enough to equalize the thermal conductivity of 15 cm of brick.
Insulation of walls with penofol from the inside and technology of insulation with perlite from the outside
In this article, you will learn how to insulate walls with penofol and perlite from the inside and outside of the building.
INTRODUCTION
For more than half a century, expanded perlite sand has been used as a heater, both in its pure form and in heat-insulating products. The unique properties of expanded perlite have led to the widespread use of this material in industry and construction.
Lightweight (50-250 kg/m3), non-combustible, porous gravel sand is used today for thermal insulation of buildings, structures and equipment. It operates at temperatures of -200 +875°C. With its help, issues of fire protection, acoustic insulation are solved, it is used as fillers in lightweight concrete, paints, linoleum, etc.
The world level of expanded perlite production reaches 20 million m3 per year. In the 90s, the annual growth in the production of this material in the world averaged about 10%.
The leader in the production of expanded perlite and products from it is the United States. About 7 million m3 of this product is produced there annually. 70% of expanded perlite is used in construction. In order to imagine the value of this volume, it is enough to say that in 2001 Russia produced and received about 8.5 million m3 of all heat-insulating materials, including perlite, for export.
At the beginning of the 1990s, the volume of expanded perlite output in the Soviet Union was 2.0 million m3, with 90% produced in Russia. Today, the annual volume of expanded perlite production in Russia does not exceed 240 thousand m3.
An analysis of foreign and domestic experience in the use of expanded perlite in construction shows that in addition to the traditional areas of application of this material, known both in Russia and abroad, new areas have appeared and are being intensively developed, which are still little mastered.
Mortars and plasters
In our country, expanded perlite is undeservedly little used in plasters. Especially promising is the use of warm perlite plasters in rural and individual construction. A layer of such plaster with a thickness of 3 cm in terms of its thermal insulation properties is equivalent to 15 cm of brickwork. The plaster is applied on brick, concrete, slag concrete, metal mesh, wood and without any additional work can be painted or wallpapered. It can be insulated both heated and unheated premises. In the USA, for example, at least 130,000 m3 of expanded perlite is used for this purpose.
Table (1): Approximate dosing options (thermal insulation compounds)
|
Cement / perlite Proportion by volume |
cement, kg |
Perlite , m 3 |
Water, l |
Air-entraining additives, liter |
|
Table 2 ) : Expected physical and technical characteristics
|
Perlite
cement/aggregate |
Compressive strength (compressive strength), kg / cm 2 |
Dry density kg/ m 3 |
Wet density kg/m 3 |
thermal conductivity (thermal conductivity), W/m 0 C |
|
|
24.1-34.4 |
544-640 |
808 ± 32 |
0.10-0.11 |
||
|
15.8-23.4 |
448-544 |
728 ± 32 |
0.09-0.10 |
||
|
9.6-13.7 |
384-448 |
648 ± 32 |
0.08-0.09 |
||
|
5.5-8.6 |
320-384 |
584 ± 32 |
0.07-0.08 |
Note: there are also mortars and plasters based on gypsum, lime with different thermal and strength characteristics.
In recent years, heat and sound insulating plaster solutions based on expanded perlite sand, binder and various additives (mineral, asbestos, cellulose, waste from natural silk and cotton) have become widespread.
To reinforce the perlite solution, cellulose and glass fibers 10 mm long are used in the amount of 5 ... 10% of the mass of the solution. This is the optimal fiber length at which the samples have greatest strength. With a longer length, mixing of the solution is difficult, its uniformity is disturbed, which adversely affects the strength properties.
Tests have shown that the flexural strength of gypsum and cement samples increases by 1.8...2.3 times with an increase in the fiber content to 7...8%. A further increase in the amount of fiber does not give an increase in strength, and when more than 10% is added, even a decrease in strength indicators is observed.
In foreign construction, lightweight mortars based on expanded perlite are widely used. Mixed in a dry state with gypsum or cement, such compounds are mixed with water directly at the construction site and stacked. They fill cavities in walls, blocks, bricks, grout joints and cracks. This composition has the following characteristics: average density - 650 kg/m3; tensile strength - more than 1.7 N/m2; compressive strength - more than 5 N/m2; thermal conductivity - about 0.2 W / (m * K).
Such a solution is most interesting in the construction of lightweight bricks or foam concrete, the properties of which are close in their thermal parameters to the characteristics of the solution. Masonry on such solutions does not have cold bridges.
Table (3): Approximate dosage options (lightweight concretes)
|
Cement, m 3 |
Perlite, m 3 |
Sand, m 3 |
Water, m 3 |
Air-entraining additives, liter |
|
|
1.51 |
|||||
|
1.08 |
|||||
|
1.24 |
|||||
|
1.05 |
|||||
|
1.75 |
1.13 |
Table (4): Characteristics
|
Dry Density kg / m 3 |
Compressive strength (compressive strength), kg / cm 2 |
Wet density after laying, kg / m 3 |
|
|
1040 |
55.2-62.1 |
1312±80 |
|
|
1200 |
62.1-82.8 |
1280±80 |
|
|
1312 |
75.9-89.7 |
1568±80 |
|
|
1408 |
158.7-172.5 |
1680±80 |
|
|
1584 |
138.6-151.8 |
1760±80 |
Thermal insulation backfills
Perlite sand has found wide application in heat-insulating backfills of walls, floors, ceilings of buildings. The use of perlite sand makes it possible to reduce the thickness of the heat-insulating backfill in comparison with expanded clay widely used in Russia by 2-3 times. For example, to obtain the required thermal resistance characteristics of walls established by SNiP II-3-79 (1998) "Construction Heat Engineering", for buildings whose construction began after January 1, 2000, a 500 mm thick M600 expanded clay (the most common brand) or all 150 mm perlite sand M75. (For climate zone Nizhny Novgorod). Compared to other thermal insulation materials, expanded perlite sand does not emit any harmful substances- environmentally friendly, non-flammable, does not age, pests do not live in it.
To isolate the walls of buildings, perlite sand is used, with a bulk density of 60-100 kg/m3. Backfilling of the cavity between the bearing and facing masonry is carried out in layers after laying 3-4 rows of bricks. To avoid shrinkage during operation, the backfilled layer is compacted by tapping approximately 10%. Waterproofing pads are placed on the working breaks in the insulation. If necessary, the insulating layer can be made of any required thickness. Possessing high heat-shielding properties (0.04-0.05 W / (m * K), expanded perlite does not age and is not destroyed by pests of animal and vegetable origin. Backfilling is carried out both from bags and by means of special sandblasting machines.
Perlite backfills are used to insulate walls made of wooden and frame structures. Such insulating layers are non-combustible, therefore, they increase the fire resistance of buildings.
In world practice, perlite backfills are widely used in the construction of warm sloping roofs. First, diffusion-permeable bottom cover boards (eg drywall boards) are laid on the rafters. Perlite is poured into the cavity between the casing and the crate and compacted by 10%.
When making the lower covering layer from the lining, a waterproof lining of glassine or film is laid on it.
Connection points for gutter, as well as the passage through the roof, are hermetically sealed with sealing and adhesive tapes.
A very interesting material used in sloping roof insulation is bituminized perlite. Perlite particles, previously treated with bitumen at the factory, become sticky when a solvent is added to it. This allows you to create extremely strong insulating layers of any shape directly during the work. Such insulation is well combined with bituminous covering layers and insulating boards, does not require heating before laying.
With the help of expanded perlite, heat and sound insulation of floors is performed.
For the installation of insulated monolithic floors with asphalt or other hard coating, hydrophobized expanded perlite sand with a particle size of up to 6 mm and a bulk density of up to 95 kg/m3 is used. Expanded perlite sand from bags is poured onto the base and distributed by leveling rails so that the thickness of the sand layer exceeds the desired thickness by 20%. The minimum laying thickness is 1 cm. Pipelines and other irregularities are simply recessed into the layer of this well-flowing material. The entire surface is covered with slabs, on top of which a monolithic coating is made. If such layers are not mounted on the basement floor, then, first of all, drainage pipes are laid to accumulate and remove moisture. Under the layer is placed an absorbent protective pad, such as kraft paper (but in no case films).
When installing floors with wooden coating expanded perlite is placed without compaction. Any cavities between beams and lumber, without loss of insulation to various cuts, are filled without difficulty. The incombustibility of the material increases the fire resistance of the floor structure. If it is necessary to prevent dusting and strengthen the upper perlite layer, the layer is sprinkled with cement, followed by light wetting. Another way to strengthen the thermal insulation layer is to cover the perlite with diffusion-open materials, such as, for example, fiberglass, corrugated cardboard, kraft paper, wood fiber boards.
To increase the bearing capacity of the bulk heat-insulating layer, especially when laying monolithic floors, expanded perlite particles are treated with wax. Despite its low dead weight, this perlite, compacted under load, forms a stable, sufficiently strong insulating layer for dry screeds.
Currently, no more than 20% of the expanded perlite produced in Russia is used for construction. Perlite is practically not used to insulate walls, roofs, ceilings. Meanwhile, due to the increased requirements for thermal protection of buildings, this material is very promising.
Molded thermal insulation products: The largest amount of expanded perlite in world practice is used in molded heat-insulating products (about 60%). Various products are used as a binder: cement, gypsum, bitumen, liquid glass.
Pelite cement slabs. They belong to the group of non-combustible materials and can be used: for fire protection of steel, reinforced concrete and wooden building structures; for thermal insulation building structures residential, public and industrial buildings and structures; for thermal insulation of industrial equipment at a temperature of the insulated surface up to 600 o C, including boilers DKRV and DE.
Asboperlite cement. To insulate power equipment with surface temperatures up to 6000C, perlite-cement compositions with fluffed asbestos are used. Asbestos perlite-cement products are characterized by the following properties: density 200…400 kg/m3; thermal conductivity (at 25 and 3250С) 0.075…0.092 and 0.118…0.145 W/m.K, respectively; ultimate strength in bending - 0.20 ... 0.36 MPa.
silicate perlite. For the production of silicate-perlite, expanded perlite sand is used. The binder can be lime-sand, lime-slag or lime-ash. Silica-perlite can be made by pressing using fine fractions of perlite sand (up to 1 mm) and slaked lime, followed by steaming in an autoclave and molding into metal molds with vibration. The thermal conductivity of silicate-pearlite, depending on the density (100 ... .340 kg / m3) is 0.105 ... 0.239 W / m.K. It is most expedient to use silicate-perlite products for thermal insulation of surfaces of industrial equipment and pipelines at temperatures up to 900oC.
Bitumoperlite. Represents heat, steam and waterproofing material obtained by mixing expanded perlite sand and bitumen. Bitumen perlite is used for insulation and waterproofing of combined roofs, industrial refrigerators and other technological equipment operating at temperatures of -50 ... + 150oC. Modified bitumen-perlite (for example, with phenol-formaldehyde resin LBS-3) becomes more heat-resistant (180 ... 1900C) and can be used to insulate heating systems. Material density 300…450 kg/m3, thermal conductivity 0.08…0.11 W/mK, flexural strength 0.15…0.20 MPa, humidity not more than 2.5%, daily water absorption 5%
Carboperlite. It is obtained by semi-dry pressing of a mass consisting of expanded perlite and lime (ratio 1:8.5 ... 1:10) followed by treatment of the mixture with gases containing CO2. Carboperlite products have a density of 200…350 kg/m3; thermal conductivity (at 25 and 700oC) 0.065...0.905 and 0.137...0.162 W/m.K, respectively; ultimate strength in bending - 0.15 ... 0.30 MPa; compressive strength 0.3 ... 0.8 MPa. Carbolite-perlite products can be used for thermal insulation of surfaces of power, process equipment and pipelines with the temperature of the insulated surface up to 650oC.
Gypsoperlite. Gypsum-perlite thermal insulation products are made on the basis of building gypsum and expanded perlite with a density of 80 ... 150 kg / m3 by casting, vibrating and semi-dry pressing. With a ratio of gypsum: perlite 1:7…8, heat-insulating products with a density of 300…400 kg/m3 and a compressive strength of 0.15…0.5 MPa can be obtained. Gypsum-perlite products are recommended for thermal insulation of surfaces of power and process equipment, gas and steam pipelines at temperatures not exceeding 600oC.
Ceramic perlite. The composition of the mass for the manufacture of ceramic perlite includes 50 ... 60% of expanded perlite sand and 40 ... 50% of ground clay with a particle size of less than 0.25 mm. ceramic-perlite products are subjected to heat treatment at a temperature of 300 ... 9500oC. Physical and technical indicators: density 250...400 kg/m3, compressive strength 0.4...1.2 MPa, linear temperature shrinkage at 8750oC no more than 2%, humidity - 1.2%, thermal conductivity at 200oC - 0.075...0.104 W/ mK.
Glass perlite. To obtain glass perlite, expanded perlite sand with a density of 80...150 kg/m3 and liquid glass with a density of 1250...1350 kg/m3 are used at a ratio of components, %, 50...70: 30...50; heat treatment of the mixture is carried out at a temperature of 300 ... 400oC. Physical and technical parameters: density 180...300 kg/m3, compressive strength 0.3...1.2 MPa, bending strength 0.2...0.7 MPa, thermal conductivity at 200oC - 0.064...0.09 W/mK , limiting application temperature – 600…700oС.
Basalt-perlite fibrous material. A new heat-insulating and structural material was obtained on the basis of expanded perlite sand, basalt fiber and a binder (Portland cement or bentonite).
The composition of the heat-insulating material includes the following components, %: expanded perlite 24…70, basalt fiber 74…20, bentonite clay 9.0…2.0. Material density 150…300 kg/m3, tensile strength 0.2…0.5 MPa, thermal conductivity 0.038…0.041 W/mK.
The composition of the structural heat-insulating material includes the following components, %: expanded perlite 25…35, basalt fiber 25…30, Portland cement 35…50. Material density 590…1100 kg/m3, flexural strength 0.4…11.0 MPa, thermal conductivity 0.096…0.11 W/mK.
Expanded perlite, introduced into the composition of these composite materials, dramatically increases their durability, as it binds the clinker hydration products that cause corrosion of the basalt fiber.
Plastperlite. It is obtained on the basis of urea-formaldehyde and coumarone resins, giving strength, sufficient water resistance and low water absorption. plastperlite thermal insulation boards have the following physical and mechanical properties: density 250…280 kg/m3, compressive strength 0.6…0.8 MPa, daily water absorption 3.3…3.5%, thermal conductivity 0.065…0.07 W/mK.
Perlite brick. It is used for building and industrial thermal insulation with a maximum application temperature of 900oC. The density of such a brick is 400 ... 600 kg / m3 with a thermal conductivity of 0.105 ... 0.176 W / (mK).
When heated to high temperatures 1000-1150 the rock swells, forming a mass 10-12 times greater than the original volume. Expanded perlite sand is a highly effective insulation that has good thermal insulation functions, and is also a completely environmentally friendly substance.
This sand is different in that it contains from 2% to 5% bound water. Due to its chemical nature, this building material is inert, biologically and chemically stable.
Specifications and properties of perlite sand
Expanded perlite sand is a high-quality building material that has the characteristics of all the most effective heaters. He is persistent, inert and light. In addition, it has a high temperature resistance. The most common is sand according to GOST 10832-91.
Perlite sand has the following strengths:
- Thermal conductivity. Expanded sand has a high thermal conductivity due to the fact that 99-100% consists of glass, and the percentage of porosity reaches 85% in places. In addition, it directly depends on the bulk density, which can be from 30-40 to 350-400 kg/m3. Temperature, material moisture content, type and porosity also affect thermal conductivity.
- Sound absorption. Sound and noise insulation is an integral part of modern building materials. Now production technologies are aimed at increasing sound insulation and reducing sound transmission. So, in silicate materials, the effect of sound absorption is achieved due to two parameters: the porosity of the material and its structure. Porous glassy systems have the highest sound-absorbing effect. The fact that perlite sand has the highest soundproofing at the lowest bulk density is quite justified. If you are trying to create the most soundproof room, then perlite sand with a bulk density of 30 to 50 kg / m3 is perfect for this task.
- Water absorption. Perlite expanded sand is a very moisture-intensive building material. The volcanic rock from which this material is produced has the thinnest capillaries. The latter absorb liquid. In other words, this sand should not be used in places with high humidity.
Features of expanded perlite sand:
Production technology
At present, the technology of 2-stage heat treatment is widely and quite successfully used, thanks to which expanded perlite sand with a bulk density of not more than 150 kg/m3 is obtained. The resulting raw material has predominantly closed type grain porosity.
Production is carried out in a shaft furnace, which entails the following advantages of this technology:
- Increase technological possibilities perlite sand;
- Obtaining several types of porous structures on the same production line. So, it is possible to obtain perlite with an open and closed porous type, which minimizes water absorption and increases strength;
Scheme of expanded perlite sand production
Applications
The most popular perlite sand is used in construction. For more than half a century, it has been used as a reliable and high-quality insulation both in its original form and as part of thermal insulation products. Insulation of floors, walls, interfloor ceilings and attic with perlite sand will allow you to keep the warmth and comfort of your home for a long time.
Plaster mixtures that use perlite sand as constituent element, are distinguished by exceptional attractiveness, as well as a high degree of thermal insulation.
Perlite-based plaster is perfect for finishing rooms that require increased sound insulation, heat-saving indicators and better acoustics.
Light building mixtures based on perlite are widely used both abroad and in domestic construction. Cavities in blocks, walls and wells, seams and cracks will perfectly accept cement mortar based on this building material. Such a solution is most cost-effective when laying from light brick or foam block, the properties of which are close in nature to the structure and characteristics of the composition.
On the video - cooking homemade plaster mixture based on perlite:
Perlite sand on bituminous mastic is great solution for waterproofing and roofing tasks. Mastic is an elastic, astringent substance that has high performance strength and elasticity.
Agroperlite (perlite sand) with a slightly larger grain fraction is one of the varieties of processed rock that is used in agriculture to grow plants. When this substance is added to the soil, moisture is retained and accumulated, which allows plants not to dry out and constantly replenish their water balance.
Moreover, perlite is a natural leavening mineral that is used to grow juicy tomatoes. This sand is environmentally friendly, as it does not emit various acids and waste.
Examples of the use of agroperlite
Application of Perlite for Plants Perlite for Greenhouses
Advantages and disadvantages
So, perlite sand different kind and fractions has, of course, different kinds strengths and has certain disadvantages. However, grouping them together, you can structure the pros and cons of using perlite as follows:
Perlite Benefits:
- Not flammable, has high threshold temperature effects;
- High heat, sound, waterproofing properties;
- Biologically resistant and inert, does not contribute to the reproduction of rodents and bacteria;
- Durable, environmentally friendly material;
Weaknesses of perlite and agro-perlite sand:
- Such sand is not available in all hardware stores, and its cost is slightly higher than similar products;
- Before use, the sand must be moistened, as it is very dusty;
- Its white and cream color gives certain difficulties in agrarian business, especially in determining the degree of spoilage of the soil;
- Due to the presence of a positive electric charge, it does not participate in ion exchange.
Perlite vs Vermiculite - What's the difference?
Firstly, perlite sand is slightly larger than vermiculite. In addition, if vermiculite is a completely natural material, then perlite sand is an artificial material obtained by swelling glass. Perlite is soil neutral, while vermiculite can cause soil acidification if added in excess. Both elements make it lighter and airier, and also stimulate moisture retention for plants.
Photo of packaged perlite sand
What can replace
Perlite is not an indispensable material. In construction, many varieties of sand will take its place, and in the agricultural sector it can be completely replaced with coarse sand, moss or tree bark. Replacement options are endless. But perlite sand, of course, has such exceptional qualities, which are not so easy to replace exactly.
The lifespan of perlite sand and is it harmful to health
Perlite sand is a versatile and useful, expanded and vitreous material, which is used in a fairly wide industrial and economic spectrum. Its prevalence is not impressive, but the price is within reasonable limits, which makes its use cost-effective.
The average cost of perlite sand of various fractions
The sand has a white, light and cream color, therefore it is not entirely appropriate in the agricultural sector, but it serves well as a heater or a binder for various building mixtures. Because the sand is environmentally friendly and clean. It can be used in the construction of residential buildings and their insulation. If you close your eyes to problems with water absorption and some impracticality in crop production, you can confidently rate perlite sand for a solid five.
Since it is impossible not to take into account the shortcomings of this building material, a score of 4.5 will be quite objective. We hope that our advice will help you more accurately determine whether you should use this building material, weighing all its pros and cons.
Perlite is granules of volcanic lava, resulting from rapid cooling in contact with earth and water. Perlite thermal conductivity coefficient λ = 0.045 to 0.059 W/(m² K). The melting point is from 950 to 1300°C, and the beginning of softening or sticking is 850°C.
Perlite is chemically inert, non-flammable, hygroscopic and has a constant volume. It is characterized by resistance to frost, moisture and various kinds of pests, has excellent thermal and sound insulation properties. High porosity combined with low weight at a relatively low price make perlite a very attractive material for construction.
Application of perlite
- main component of the lungs gypsum plasters, heat-shielding masonry and plaster mortars;
- weight-reducing additive improves the performance and ductility of gypsum plasters, cement-lime masonry mortars and tile adhesives;
- basic thermal insulation material in heat-shielding masonry mortars and heat-shielding plasters performed at the construction site.
- the main component of heat-shielding perlite-concrete self-leveling floors. Such you can make your own solution, mixing in the right proportions 3 parts of perlite, cement and water. Do-it-yourself perlite concrete can be used to fill the floor, or plaster the ceiling. At the same time, you can solve problems with surface irregularities by refusing to use polystyrene foam boards;
- component that reduces the weight of gypsum castings and concrete elements. It is used to reduce the weight of various facade tiles, prefabricated iron concrete structures, plaster casts or decorative concrete elements, window sills;
- loose backfill for thermal insulation of walls and ceilings;
- main component of perlite concrete insulation boards;
- perlite class "0" as a component giving the effect of "pearl" in decorative paints, as well as classes I and II for the Raufaser effect;
- As a powder or in the form of perlite concrete, it is used as a supplement or replacement for expanded polystyrene in floors and ceilings.
- Perlite, depending on the ability to handle it, is used as an addition to classic insulating materials, or as the main material used for insulating floors and attics.
Heat protection solution
Recommended by manufacturers cellular concrete. Also, manufacturers of porous blocks, with a tongue-and-groove connection, prefer perlite mortar. More and more enterprises use it for the production of heat-shielding mortars and plasters, as well as an additive that improves the properties of polystyrene foam adhesive.
Perlite concrete
In terms of thermal insulation and sound insulation is one of the best building materials. Perlite concrete can be used for insulation of floors, ceilings, pouring walls, ceilings, roofs. By mixing the components in an appropriate way, various perlite concretes can be obtained.
In many cases, it can be used instead of expanded polystyrene - there is no need for time-consuming operations for floor insulation with foam plastic, followed by pouring the screed. It can also be used for underfloor heating.
Perlite proportions for concrete mortar
| Recipe for perlite concrete | Material ratio, cement: class III perlite: water | For a 25 kg bag of cement, add a bag of perlite (class III) with a volume of 0.1 m³ + liters of water | Bulk density [kg/m³] | Compressive strength [MPa] |
Thermal conductivity λ[W/(m² K)] |
| 14/4,0 | 1:4:1,25 | 1 + 31,3 | 840 | 3,8 | 0,097 |
| 14/5,5 | 1:4:1,00 | 1 + 25,0 | 920 | 6,4 | 0,078 |
| 16/3,8 | 1:6:1,84 | 1,5 + 46,0 | 670 | 3,2 | 0,110 |
| 16/4,5 | 1:6:1,56 | 1,5 + 39,0 | 740 | 4,2 | 0,087 |
| 16/5,2 | 1:6:1,35 | 1,5 + 33,8 | 800 | 4,9 | 0,073 |
| 18/5,0 | 1:8:1,80 | 2 + 45,0 | 710 | 4,8 | 0,066 |
| 110/5,5 | 1:10:2,0 | 2,5 + 50,0 | 590 | 3,4 | 0,070 |
Other possibilities of industrial use of perlite concrete:
- casting foundations for equipment operating in extreme temperature conditions - from -200 to +800ºC,
- production of reinforced concrete structures, chimneys, energy and refrigeration installations,
- production of single-layer panels for construction external walls sandwich type,
- production of floors for bathrooms, dressing rooms, pool insulation.
Heat-insulating perlite plasters
Plasters in which sand is replaced by perlite retain their properties. They are lightweight and provide excellent thermal and acoustic insulation. They can be used indoors and outdoors. Perlite plaster is permeable to vapors and gases, allows the wall to breathe, and is also non-combustible. Perlite is also one of the two main special aggregates used in plasters for the restoration of ancient walls to remove moisture and soluble salts from them that cause them to corrode.
One centimeter layer of perlite plaster, in terms of thermal insulation, replaces: 0.5 cm of foam, 5 cm of brick or 8 cm of traditional sand-based plaster. Plaster used on both sides of the wall doubles this effect. Applying, for example: a layer of 6 cm on the outside and 3 cm on the inside replaces 4.5 cm of polystyrene foam or 45 cm of brick or 56 cm of traditional sand plaster. If the layer of perlite plaster is thicker than 6 cm, then it is necessary to use plaster mesh. Perlite plaster can be painted with acrylic or other paints. As for gypsum-perlite plasters, an increase in the proportion of gypsum volume in them improves strength characteristics. For a plaster thickness of 18 cm, with a volume of 500 kg / m³ (gypsum / perlite ratio - 1: 1), the strength parameters are 1.25 MPa (compression) and 0.57 MPa (bending), for a mass of 700 kg / m³ (gypsum / perlite up to 3:1) strength parameters 2.97 MPa (compression): 1.73 MPa (bending). With thin layers, the strength parameters are higher. With a layer thickness of 14 cm and 700 kg / m³ of mortar, the compressive strength is 4.61 MPa, and the tensile strength is 2.03 MPa. For 500 kg/m³ respectively 2.19 MPa (compression): 0.91 MPa (bending).
Fire retardant perlite plasters
Plastering the ceiling with a layer of 3.5 centimeters provides 90 minutes of fire resistance, columns and supports, plastered with a layer of 6 cm, provides 180 minutes of fire resistance. A layer of plaster (500-700 kg / m³) 12 cm thick provides fire resistance of the 1st degree for industrial and public facilities.
Construction adhesives based on perlite
An increase in the volume fraction of perlite in the adhesive causes a decrease in its strength parameters. In exchange for this, thermal insulation properties, resistance to fire, lightness of products, fluidity, adhesion, and sound insulation are improved.
