Preparation of warm masonry mortar. Benefits of Using Warm Mortar for Ceramic Blocks Make your own warm masonry mortar

Ceramic block is a progressive building material, which is one of the alternatives to brick, the use of which is widespread in low-rise construction. This is an artificially created stone with a high percentage of voids, intended for laying load-bearing and partition walls, ceilings and fences.

From this article you will learn the technology for the production of ceramic blocks, their technical characteristics, advantages and disadvantages, as well as receive recommendations on the choice and features of block laying.

Purpose, production technology

The strength characteristics of ceramic blocks make it possible to use this material in the construction of residential and industrial buildings up to 9 floors high. Also, the ceramic block can be used as a facing material when filling frame buildings, in which case the number of storeys of the building being erected is not limited.

According to the provisions of GOST No. 503, the material is called "Ceramic stone", such names as porous or warm ceramics, ceramic stone, large-format brick are also common.

The technology for the production of ceramic blocks is similar to the production process for making bricks. The raw material composition includes the following components:

• fusible clay;
• burnable additives - sawdust, peat, straw, husks;
• water;
• chemical modifiers (if necessary, to give the material improved performance).

Burn-out additives, they are also porizers, provide a decrease in the density of clay during firing by giving it a cellular structure. The more porizers are added to the composition of the raw material, the better the thermal insulation characteristics of the material will be, and the lower its strength.

A mixture of clay with a porizer is called a mixture, it is processed in a clay grinder, where the material is ground to the smallest fibers. Next, blanks of the required shape are formed from the charge on the press extruder, the process is as follows - the mixture is moistened and enters the vacuum chamber, in which air is removed from the charge, then the composition is forced through the extruder die, which forms a beam from the charge with voids inside.

The beam is cut into blocks using a string cutting machine, after which the blanks are delivered to the dryer, where, at a temperature gradually increasing from 35 to 110 degrees, the blocks harden within 72 hours. The next stage is ceramization, which takes place in a tunnel oven at a temperature of 1000 degrees. In the process of ceramization, the porizers contained in the mixture burn out and the material acquires a cellular structure.

This completes the production process - the blocks are stacked on pallets and packed in stretch film. Some manufacturers of ceramic blocks additionally grind the surface of the products, which allows them to be laid using a seamless technology using special glue. Also, in premium ceramic blocks, the pores can be filled with basalt or expanded polystyrene, which eliminates the possibility of masonry mortar entering the cells.

1.1 Advantages and disadvantages

The widespread use of ceramic blocks in residential construction is due to the fact that this material has many operational advantages. Consider the main advantages of ceramic blocks:

1. Porous kerambolok has low thermal conductivity due to the presence of voids in its structure; it is possible to build a warm house from it with a minimum wall thickness.
2. Large-format ceramic blocks are laid much faster than bricks, since in size one block of 380 × 250x219 mm replaces 15 standard bricks. This allows you to maintain a high pace of construction and save on the consumption of masonry mortar.
3. Due to the cellular structure, the material has good soundproofing abilities.
4. Ceramic blocks are completely non-combustible, they do not emit substances harmful to the human body when in contact with fire. The composition of the material contains only natural, environmentally friendly raw materials.
5. Due to the low density (800 kg/m 3 , which is comparable to the density of wood), the weight of ceramic blocks is minimal. A small mass of a house made of ceramic blocks makes it possible to build a building on a conventional strip foundation, saving on laying a powerful foundation.

However, it has a porous ceramic block and disadvantages. Initially, we note the fragility of the material due to the many internal voids - when transporting, loading and unloading it is necessary to be as careful as possible. Also, the material is prone to moisture absorption, for protection against which it is required to perform waterproofing of the first row of masonry. The problem is also the low frost resistance of ceramics, due to which there is an obligatory need for facing the facade of the house with bricks, thermal panels or its coating with thermally resistant plaster.

Material Specifications:

• density - 780 kg / m3;
• frost resistance class - F25;
• volumetric water absorption - 12%;
• vapor permeability - 0.14 g / mchPa;
• sound absorption - 53.5 dB;
• thermal conductivity, 0.25 W/mK;
• strength class - M100;
• voidness - 50%.

The dimensions of ceramic blocks are defined in the GOST standard No. 530 "Brick and ceramic stone", according to which there are 14 standard sizes of products. The most common of these are:

• 250*120*140 (replaces 2.1 bricks);
• 380*250*219 (replaces 10.7 bricks);
• 510*250*219 (replaces 14.3 bricks).

The following differences between the actual dimensions and the standard ones are permissible: width - 5 mm, thickness - 5 mm, length - 10 mm. In each standard size of blocks, the thickness of the outer wall should be 8 mm. The difference between ceramic products and other masonry materials is the presence of tongue-and-groove joints on the side edgespreventing the occurrence of cold bridges on vertical seams.

1.2 Porotherm ceramic blocks (video)

The leader in the world market for the production of ceramic blocks is Porotherm (Germany). This is one of the first manufacturers of porous ceramic blocks, which has been operating since 1869. To date, the company owns 230 factories around the world, 2 of which are located in Russia.

The range of Porotherm includes the following types of ceramic blocks:

• Porotherm 51 - large-format wall blocks for laying load-bearing walls;
• Porotherm 51 ½ - additional blocks for dressing vertical seams;
• Porotherm 20 - blocks for filling openings in frame buildings;
• Porotherm 12 and 8 are wall blocks for laying interior partitions.

Among domestic manufacturers, Ketra ceramic blocks deserve attention, the cost of which is 15-20% lower than that of Porotherm. The company manufactures and markets ceramic blocks of NF 2.1, 10.7 and 14.3 sizes. A characteristic feature of the products of this company is that the blocks are produced in different shades - from brown to milky, which expands the design possibilities of the architect.

Also on the market there are a fairly large number of organizations offering turnkey construction services for houses and cottages. Such companies provide customers with catalogs in which they can choose ready-made projects for cottages of various sizes - from 40 to 200 m 2. At the same time, the contractor undertakes the implementation of all stages of construction - from the zero cycle to the decorative finishing of the building.

2.1 What mortar is needed for laying ceramic blocks?

Block laying can be done using ordinary cement-sand mortar, however, block manufacturers recommend using a special adhesive. When using glue that does not form cold bridges, you can get an increase in the heat-saving characteristics of the wall by 15-20%.

Glue for ceramic blocks is often called "warm solution". Its characteristic feature is the presence of a porous filler in the composition, usually perlite is used. "Warm mortar" is more expensive than conventional masonry adhesives, however, due to the fact that when laying ceramic blocks there is no need to fill vertical joints with mortar (due to the presence of a groove-comb system on the blocks), the increase in costs will be minimal.

The proven compositions of the “warm mortar”, the quality of which is beyond doubt, are Kleiser “KTS” and Ferozit 231. It is often possible to come across recommendations that walls made of ceramic blocks must be reinforced with masonry mesh, however, in practice, it is used exclusively to ensure that in the cavity in the mortar did not fall through the blocks, and not to strengthen the masonry, the margin of safety of which is sufficient for low-rise buildings. When working with blocks from leading manufacturers, there is no need to use masonry mesh at all, since the geometry of the cavities in them is chosen so that the glue does not get into the pores.

In recent years, many new types of wall materials have appeared that have high thermal insulation. However, the desired effect is not complete when using a traditional cement-based masonry mortar. The resulting seams do not have good thermal insulation, it is through them that the buildings are cooled and the cost of heating them increases. Also, conventional solutions can cause mold to form on wall surfaces.

Heat-insulating masonry mortar will help to solve the problem. Special compositions help to maintain the thermal parameters of the wall and reduce the heat loss of joints between bricks or large blocks. In their manufacture, porous materials are used, one of which may be perlite.

Features of heat-insulating masonry mixtures

Thanks to the heat-insulating mixture, it is possible to obtain a homogeneous masonry. They have a special composition that allows you to get a plastic and durable material with high strength. The heat-insulating masonry mixture prevents the formation of cold bridges. Thanks to it, good vapor permeability is ensured. Some manufacturers of ceramic blocks and other thermal insulation materials recommend using warm mixes for their masonry.

When choosing a heat-insulating mixture, it is necessary to take into account the following parameters:

• density;
• frost resistance;
• compressive strength;
• coefficient of thermal conductivity;
• use temperature.

Due to the solidification of the porous material, the density decreases and the thermal protection of the material increases. The voids in it, which prevent heat loss, are created through the use of special substances in the composition - expanded clay, perlite, pumice or vermiculite. When preparing the mixture at the construction site, obtain a uniform distribution of the heat-insulating filler. This means that a high-quality composition can be made exclusively in the factory with careful adherence to technology.

The warm solution should have the following characteristics:

• plastic;
• high thermal insulation;
• sound absorption;
• good adhesion;
• decorative attraction;
• low density;
• high-quality seam filling.

Preparation of heat-insulating mixture

The composition should be poured into a tank with warm water (25 kilograms of the mixture requires about 10 liters of water). After that, it is mixed until a homogeneous mixture is formed. The solution should stand for up to 5 minutes, then it is mixed again for several minutes. It should have a creamy consistency. Third-party substances or additives must not be introduced into the masonry mixture.

The Slavdom company offers to purchase heat-insulating masonry mixtures from such manufacturers as RAUF Therme, Porotherm, PEREL and OSNOVIT. They are delivered to all cities of the Russian Federation. You can get to know the products better in one of our offices, which are located in Moscow and St. Petersburg. Contact us! Our staff will help you choose the best masonry mortar for your purposes!

Warm masonry mortar is a building mixture for cellular concrete products: foam concrete, aerated concrete, gas silicate, foam silicate and porous ceramic blocks.

Replacing an ordinary cement mixture with a “warm” one increases the thermal insulation of the masonry by 17%.

The binder in this mixture is traditionally cement, and the fillers are pumice, perlite, expanded clay sand.

A warm solution is also called "light", due to its weight and low density.

Replacing an ordinary cement mixture with a “warm” one increases the thermal insulation of the masonry by 17%. This effect occurs due to different thermal conductivity coefficients. For a cement-sand mixture, this indicator is 0.9 W / m ° C, and for a “thermal” mixture - 0.3 W / m ° C.

Characteristics and main properties

From the school physics course, the fact has long been known that air does not conduct heat well. Based on this, a logical conclusion suggests itself: in order for a building structure made of porous materials to retain heat well, “air-absorbing” substances must be included in the composition of the solution. Most often, such fillers are perlite or expanded clay sand.

External wall structures are often made of lightweight materials with a high coefficient of thermal resistance. In this case, a mixture of lower density than the traditional cement-sand mixture is required as a binder. The latter has a high density (up to 1800 kg/m3), resulting in additional heat loss due to "cold bridges". If the density of the binder "dough" exceeds the density of the wall material for every 100 kg/m 3 , then the heat loss of this design increases by 1%.

If the density of the binder “dough” exceeds the density of the wall material by every 100 kg/m3, then the heat loss of this design increases by 1%.

In order for this physical characteristic of the binder mixture and the wall material to be comparable, it is necessary to prepare a special "warm" solution, the density of which would be 500-800 kg/m 3 . This composition should have high plasticity, crack resistance, good adhesion, water-retaining capacity, sufficient viability.

The strength of the building structure is more dependent on the wall material, and not on the grade of the composition. The brand of the latter, as a rule, must match the technical characteristics of the brick. However, when using a mixture one grade lower, the decrease in masonry strength drops by only 10-15%.

The minimum grades of solutions (from M10 to M50) are used for buildings of the 1st degree of durability, as well as for laying low-rise buildings from highly porous materials, the strength of which is 3.5-5 MPa. Thus, for this type of buildings, binder mixtures with a strength of 1 to 5 MPa should be used.

Additional density reduction

The average density of the binder composition, as mentioned above, reduces the use of low-density fillers. However, a decrease in the density of the mixture can also be achieved in the presence of a traditional filler - sand. When using turbulent mixers and air-entraining additives, the density can be reduced from 1600 to 900 kg/m 3 , which corresponds to a strength of 0.3-4.9 MPa. This mixture corresponds to the grades M4, M10, M25.

One of the ways to reduce the density of building mixtures is to prepare a solution using special mixing equipment - a steam generator. A good effect can be achieved when the cement stone is porous on turbulent mixers. This technology is applicable only with the use of air-entraining additives.

The most effective method of preparing a warm mortar is the simultaneous use of porous aggregates and air-entraining additives.

The choice of the type of porous filler depends on the composition of the raw material base, operating conditions, and the average density of the wall material. Traditional aggregates should have a density of 800 to 500 kg/m 3 and have a strength of up to 10 MPa.

Preparing the mixture

Warm masonry mortar is more often used for the construction of external walls, for internal walls a traditional cement-sand mixture is used. This composition can be prepared with your own hands or with a concrete mixer at low speed. To prepare this “building dough”, you can use ready-made mixtures, in which you just need to add water and mix. If the binder composition is planned to be prepared by hand, then all components are mixed in a dry state, and then water is added.

The “warm” mixture is prepared in the following proportions: 1 part of cement and 5 parts of filler (expanded clay or perlite sand). The dry mixture is stirred and then 1 part water is added to 4 parts dry mixture. The mixed solution should stand for 5 minutes, then it can be used for its intended purpose.

The prepared “dough” should be of medium consistency. Excessively liquid composition will fall into the voids of the blocks, thereby preventing thermal insulation.

Construction work is best done in the warm season. The reason for such seasonal preferences is not only favorable weather conditions for outdoor work, but also the fact that at low temperatures the masonry mortar hardens very quickly. However, if you still have to work at an air temperature below 5 ° C, then special additives are added to the solution. But even such "antifreeze" impurities do not save the masonry from a decrease in strength.

The heat-saving mixture provides a more homogeneous masonry wall, despite the fact that the amount of mortar in it is only 4% of the total area! Warm masonry mortar allows you to save heat as much as possible, reduces the weight of wall structures, and also reduces the consumption of building materials.

Didn't find the answer in the article? More information

Many customers and builders are wondering whether it is worth buying a special warm mix for laying ceramic blocks or limiting themselves to the usual CFC mortar? Undoubtedly, the cement-sand mixture is cheaper, but at the same time it does not have some important technical characteristics.

Benefits of a warm solution

• Specially designed for porous ceramic blocks to reduce heat loss through mortar joints
• Due to the special composition with perlite, the mixture is very convenient to use, it is plastic and does not fall into voids.
• Thermal insulation properties are 4 times better than conventional mortar
• The output of the finished mixture from 1 kg is 1.6 times greater than that of a conventional solution
• Easy to mix - just add water

Warm solution consumption

What problem does warm masonry mortar solve? According to statistics, about 15% of the heat in the house goes through mortar joints. By choosing a warm mixture for laying ceramic blocks, you will improve the thermal properties by 15%, respectively. Since the thermal conductivity of the solution is almost identical to the thermal conductivity of the ceramic block, the wall can be called monolithic.

In addition to the original Porotherm TM mortar, there have long been analogues on the market that are not inferior in quality to the original, for example, Perel masonry mixtures.

Heat-insulating heat-saving masonry mortar

But, the use of glue for filling joints when laying single-layer walls made of ceramic, expanded clay concrete, wood concrete blocks, and blocks of other materials is only possible when using blocks with size deviation in height no more than +/- 1 mm. (category 1 according to the deviation of geometric parameters).

Not all manufacturers produce such blocks. Yes and at a price, blocks with a height deviation of no more than +/- 3 are more affordable mm. (category 2). These blocks must be placed in the wall on a mortar with a joint thickness of 8-12 mm.

The use of a conventional cement-sand mortar for laying external single-layer walls from blocks significantly reduces their heat-shielding properties. The coefficient of thermal conductivity of the masonry increases up to 30% compared to the masonry with glue (for blocks D400-500). It's too much.

So, for laying external single-layer walls from blocks, heat-insulating light warm mortars with a dry density of less than 1500 should be used kg / m 3.

How to prepare a heat-insulating masonry mortar

Warm light masonry mortar is prepared using cement and light aggregates - expanded clay or perlite sand, expanded polystyrene granules.

Perlite is a rock of volcanic origin, hardened stone foam.

D adding lime to the composition of the mixture increases the plasticity of the solution.

Warm light masonry mortar is convenient to prepare fromdry masonry mix. On the construction market, you can find ready-made dry mixes of various compositions for the preparation of heat-insulating masonry mortar.

For example, a dry masonry mix of one of the manufacturers based on cement, mineral aggregate - perlite and plasticizing additives has the following characteristics:

Name of the mixture - Dry masonry heat-insulating mixture.
The compressive strength grade is M50.
Coefficient of thermal conductivity ( W/m°C) — 0,21 / 0,93
Average density ( kg / m 3) — 1000 / 1800
Solution yield from 20 kg. dry mix - 34 l.
Frost resistance - 25 cycles
Shelf life - 12 months.

(A slash (/) indicates the value for a conventional cement-sand mortar).

From the above data it can be seen that more than 4 times more heat is lost through a seam from a conventional solution than through a seam from a heat-insulating solution.

The method of preparing the solution is usually indicated on the packaging of the finished dry mix. The exact implementation of the recommendations indicated on the packaging guarantees a mortar with good plasticity and adhesion to masonry blocks.

When choosing a ready-made dry mix, one should be guided not only by price, but also by consider how much of the finished solution is obtained from one package. For example, from a 25-kilogram bag of dry mix from one manufacturer, 40 liters of ready-made mortar are obtained, and the same weight packaging from another manufacturer will only allow 18 liters of mortar to be prepared.

The amount of ready-made mortar that can be prepared from a dry mix must be indicated on the product packaging.

When buying a dry mix, also pay attention to the coefficient of thermal conductivity - the lower the better.

The composition of the cement light mortar for laying blocks

For self-preparation of a warm light masonry mortar of the M50 brand, several recipes are given in the table:

note – the dosage of the binder, aggregates and additives should be made by weight.

To improve the plasticity of the solution, hydrophobic or air-entraining additives are used in an amount of up to 0.2% by weight of cement.

With a decrease in the density of the solution, the coefficient of thermal conductivity also decreases.

When preparing the mortar, 50-70% of water, aggregate and cement are first loaded into the container, which are mixed for 1-2 minutes. After that, the composition is mixed with the rest of the water and additives.

Perlite grains are very fragile. With prolonged mixing in a concrete mixer, they are crushed, which reduces the heat-saving properties of the solution. Do not stir the solution with perlite for longer than necessary.

When laying, the block is lowered onto the mortar from above, avoiding horizontal movement of more than 5 mm. Squeezed out excess solution is removed immediately, preventing them from setting. Blocks can be straightened by rocking or tamping with a tool that excludes mechanical damage.

It is recommended to moisten the surfaces of the block with water before applying the solution.

In the process of masonry work, it is necessary to provide for the protection of masonry joints from too rapid drying and atmospheric influences - sun, rain, frost.

Consumption of mortar for laying blocks

For masonry 1 m 2 single layer wall from smooth blocks with a thickness of 30 - 40 cm. tentatively 20 - 30 liters of solution are needed with a seam thickness of 10-12 mm.

For buildings with a height of 1-2 floors it is possible to further reduce heat loss through the mortar joint, as well as reduce its consumption. To do this, during laying, the mortar is applied in two strips along the outer and inner surfaces of the wall, leaving an air gap in the middle of the wall in a joint 1/3 - 1/4 of the block width wide. This measure reduces the thermal conductivity of the seam, but at the same time reduces the bearing capacity of the masonry - therefore, it is used only for buildings of low height.

A smaller amount of mortar will be needed if blocks with a tongue-and-groove connection of vertical joints are used for masonry. Vertical seams in this case are not filled with mortar.

The use of a warm light masonry mortar can significantly improve the thermal conductivity of the wall compared to a conventional mortar, but not so much as to be on an equal footing with the adhesive joint. In addition, the consumption of glue is several times less than that of a light mortar, and the price of ready-made dry mixtures of glue and mortar is almost the same.

Next article:

Previous article: