Ready-made finishing cement mortar 1 2. Characteristics of mortars

Plaster cement-lime-sand mixture.

When performing construction and very often used plaster cement-lime-sand mixture for brick, concrete and wooden walls. And although the popularity of gypsum plaster mixtures is huge, many customers still choose cement-lime mortars for plastering. Lime cement mortar for wall plastering has many positive characteristics, but its main advantage is its relatively low price. This material is flexible and also very durable. Cement-lime plaster has excellent adhesion to the surface and is usually used for finishing internal walls premises with high humidity.

Cement-lime mortar composition.

AT composition of cement-lime mortar includes three components: binder (cement and lime), filler (sand) and water. To make the mortar, you need fresh cement grade 400 or 500. With long-term storage of cement under conditions far from ideal, the grade of cement decreases, and properties deteriorate accordingly. After a month of such storage, M 500 will turn out to be M 450, and in six months, cement can lose a quarter of its properties.

River or quarry sand must be sifted through a mesh with a cell of 3-5 mm. For the preparation of plaster, quarry sand is usually used, since it contains a small amount, so the solution is a little softer and more plastic. Also, to increase plasticity, you can add PVA glue (0.5 liters per 20 liters of solution), liquid soap(approximately 0.2 liters per 20 liters of solution) or add plasticizers.

If the lime is not slaked, then it must be slaked. Lime is poured into a barrel and filled with water, observing elementary rules safety precautions and using goggles and gloves for protection, as a huge amount of heat is generated due to the chemical reaction.

Cement-lime mortar proportion.

The proportions for plastering with cement-lime mortar in the manufacture differ depending on the type of construction finishing works ah planned to use given material. One of the most common options for finishing walls with plaster: 1:1:6 or 1:2:9 (one part cement: one part milk of lime: six parts sand).

Consumption of cement-lime plaster per 1 m2

The consumption of cement-lime plaster per 1 m2 with a layer thickness of 5 mm is approximately 7 kg. By volume, the consumption of the solution per 1 sq. meter with a layer thickness of 5 mm is approximately 5-6 liters or 0.005-0.006 m3. It is recommended to apply the layer thickness from 5 mm to 30 mm. In practice, take 1 bag of cement weighing 50 kg. and 40 kg. slaked lime, 550 kg of sand and 100 liters of water. With the proper preparation of a plaster mixture from a lime-cement mortar, it is possible to achieve high-quality wall decoration and several times reduce

Cement-lime mortar is used for masonry and plaster work. Its composition is the same as that of a mixture with cement, but with the addition of slaked lime. Depending on the proportions of the introduced components, its characteristics and purpose change, it is used for finishing work both outside and inside the premises. You can make it yourself or buy ready-made.

Lime mortar has an increased degree of adhesion. It adheres well to almost any surface, including wood and concrete. Due to the bactericidal properties of lime, the likelihood of mold or fungi is eliminated. Such a composition is able to pass moisture without disturbing the microclimate in the room. Withstands temperature fluctuations from -50°С to +65°С.

Unlike cement mixture, lime is more elastic. It perfectly fills all the cracks and cavities. The applied plaster can be corrected within 1-3 hours. Mortar with cement is only up to one hour. Due to this long drying, the likelihood of cracking is minimal.

To distinguish compositions with lime and cement, there is such a technical characteristic of the solution as fat content. It is on it that the scope of its application is determined.

There are the following degrees of fat content:

• normal;
• skinny;
• oily.

Most often, a solution with a normal level of fat content is used, since it has the most optimal plasticity, rarely shrinks and does not crack. Skinny ones are suitable for surface cladding and have minimal shrinkage. Fats are made up of a large number binder component, therefore highly elastic. They are used for laying bricks or other block material.

The characteristic of fat content depends on the ratio of the components of the solution. To get lean, add more sand, greasy - more lime. They also differ in density: low (up to 1500 kg / m3) and medium (from 1500). The ratio of components affects the scope of the solution. The most commonly used grades are M50 (for plastering) and M75 (for bricklaying).

Also, cement-lime plaster mortars are divided into the following types:

• basic;
• decorative;
• special purpose.

The first option is used to level any surfaces and is used as a rough layer. Decorative dry up long time, making them easy to handle and apply desired shape and patterns. Special-purpose mixtures have increased moisture-proof characteristics, absorb noise well and provide thermal insulation.

Do-it-yourself solution preparation

Compared to cement-sand mortar, lime mortar has a lower price. For 1 m2 with an application layer thickness of 1 mm, about one and a half kg will be required. For kneading, you will need to buy sand, lime and cement. The ratios of the components depend on the required grade of the mixture. To get a solution of M75, you need to mix everything in the following proportions - 1: 0.8: 7 (M500 cement, lime, sand) or 1: 0.5: 5.5 if M400 cement. To mix the M50 brand, Portland cement M400 is required. The proportions of the components are 1:0.9:8 (cement, lime, sand).

Also, the proportions of the solution depend on the thickness of the application layer. For rough work (spray), knead in the following ratios - 6.7: 1.5: 1: 2.2 (sand, lime, Portland cement, water). For a layer of medium thickness - 9:2.2:1:2.8, as a top coat - 13.5:3:1:4.

Mixing a lime mixture usually requires no more than 0.8 parts of water to one part of Portland cement. This ratio is also affected by the dryness of the components. The main thing is that the cement mortar should be similar in consistency to thick sour cream.

Before kneading, lime must be extinguished. If this is not done in advance, then swelling will appear in the solution due to a chemical reaction. A separate container is used for extinguishing. The slaking technology depends on the type of lime. It can be fast-extinguishing, medium and slow. The first type is quenched as follows: powder is poured into a container filled with water. As soon as the chemical reaction begins, water is added and everything is mixed. The extinguishing process will end in 8 minutes.

Lime average speed quenching is quenched in the same way, but it takes longer - about half an hour. Slow-extinguishing lime powder is not poured with water, but only sprinkled. Quenching lasts until the entire volume increases by 3 times. The reaction takes more than half an hour.

In order for the lime mortar to turn out to be of high quality, the main thing is to observe the proportions, since all its characteristics and the final result depend on the ratio of the components. Portland cement is recommended for mixing, rather than conventional cement, as it has better strength.

If the mixture is mixed for laying a large amount of bricks, it is recommended to use a concrete mixer. She will make it absolutely homogeneous. First, water is poured in, after which Portland cement, lime powder and sand are poured. Once everything is thoroughly mixed, water is added again and everything is brought to the desired consistency.

• Slaked lime is filtered through a sieve with a mesh diameter of up to 3 mm. Sand and Portland cement are poured into the resulting milk of lime. All components are thoroughly mixed, and the mixture is brought to the required degree of fat content.
• In dry form, sand is mixed with Portland cement until smooth. Strained water is slowly poured slaked lime. Bring to the desired consistency with water.

To improve the technical characteristics, plasticizers are added, additives that make the solution frost-resistant, hardening time accelerators or retarders, and so on.

Overview of manufacturers and prices

Most well-known manufacturers lime mortars are Besto, Osnovit, Knauf and Henkel.

Cement-plaster composition Besto brand M100 is available in paper bags weighing 25 and 50 kg. It includes Portland cement M500d0, slaked lime, water-retaining components, sand of different fractions - 1 and 0.6 mm and polypropylene fiber, which increases the strength properties of the solution, or rather, reinforces it. Used by Besto for internal and external works. It can be applied both manually and with the help of equipment. The finished powder must be diluted with the amount of water indicated in the instructions. With a layer thickness of 1 cm, 18 kg of the mixture per 1 m2 will be required.

Dry Osnovit PC21 Startwell is packed in 25 kg bags. Contains components that increase the frost resistance of lime mortar. It also has moisture-retaining additives, so it can be used for finishing rooms with high humidity or for facades. Strength grade - B10. Consumption is the same as that of Besto - 18 kg/m2 with a thickness of 10 mm. The diluted solution can be used for two hours at a temperature of +5 to +30°C.

Moment Henkel is intended for surface treatment indoors only. Henkel Powder can be used as an intermediate layer, which is subsequently topcoated. The closed mixture must be applied within an hour. The layer thickness for one application should not be more than 2 cm. Packed in packages weighing 25 kg.

Dry powder MP Leight Cement contains perlite and polymer additives. Used as a leveling layer. Can be used both outdoors and indoors. Packed in bags of 30 kg. For 1 m2 with a layer thickness of 1 cm, 13.4 kg will be required. Applied either by hand or by machine.

The cost of cement mortar with lime depends on the volume of the bag, the purpose and the manufacturer.

Table with prices at which you can buy ready-made dry lime mixtures:

Lime mortar is sold in paper bags with different weights. When purchasing it, you should check the integrity of the bag, it should not have holes or glued places. You also need to pay attention to storage conditions. It should not be stored in a damp room, as cement quickly loses its strength characteristics. In addition, the powder seizes and lumps form. If you use such material for masonry or plaster, then cracks will appear in it after drying. To increase the degree of adhesion of the finished surface, it is necessary to clean it from dirt, old finish coatings and greasy oil stains. It can also be treated with a primer or concrete contact.

mounting -for filling and sealing joints between large elements during the installation of buildings and structures from prefabricated structures and parts;

special -waterproof, acid-resistant, heat-resistant, acoustic, heat-insulating, injectable, X-ray protective and pipelined.

There is no coarse aggregate in the composition of the mortars, therefore, in essence, they are fine-grained concretes. General patterns, which characterize the properties of concrete, are in principle applicable to mortars. However, when using solutions, two features must be taken into account. First, they are placed thin layers(1 ... 2 cm), without applying a mechanical seal. Secondly, solutions are often applied to porous substrates (brick, concrete, light stones and blocks of porous rocks), capable of absorbing water strongly. As a result, the properties of the solution change, which must be taken into account when determining its composition.

Selection of the composition, preparation and transportation of solutions

The compositions of mortar mixtures are selected or selected depending on the purpose of the solution, the required brand and mobility, and the conditions for the production of work. The selected composition of mortar mixtures must have the necessary mobility (without delamination and water separation during laying) when minimum flow binder and ensure that the required hardened strength is obtained.

Lineups mortars are selected according to tables and by calculation, in both cases they are refined experimentally in relation to specific materials.

The calculation-experimental method for selecting the composition of the solution is based on the preliminary calculation of the consumption of components (binder, aggregates, water and additives) on the basis of scientifically substantiated and experimentally verified dependencies given below. It is used to select the composition of heavy masonry and installation mortars.

The composition of solutions grades 25 ... 200 is selected as follows.To obtain a given brand of solution in the case of using binders that differ in grade M vf from those given in 5.8 (table 4 ) SP 82-101-98 Preparation and application of mortars, binder consumption per 1 m 3 of sand is determined byformula

where Q c - binder consumption with activity according to the table 4 per 1 m 3 sand, kg;

Q vf - the consumption of a binder with a different activity;

R in Q in - taken according to the table 4 for this brand of solution.

Amount of inorganic plasticizers (lime or clay dough) V d per 1 m 3 of sand is determined by the formula

V d = 0,17(1 — 0,002Q in),

where V e - inorganic additive per 1 m 3 of sand, m.

The calculation of the composition of the solution should be preceded by the determination of activity (brand) and average bulk density cement, grain composition and sand size modulus, average density of inorganic plasticizer (lime or clay).

Preparation of solutions. Solutions are produced in the form of ready-to-use or dry mixtures, mixed with water before use.

The process of preparing the mortar mixture consists of dosing the starting materials, loading them into the drum of the mortar mixer and mixing until a homogeneous mass is obtained in mortar mixers periodical action with forced mixing. By design, mortar mixers with a horizontal or vertical paddle shaft are distinguished. The latter are called turbulent mixers.

Mortar mixers with a horizontal paddle shaft are produced with a capacity of 30; 65; 80; 250 and 900 l. All these mixers, with the exception of the last one, are mobile. Capacity for the finished batch of turbulent mixers, the working body of which is fast-rotating rotors - 65; 500 and 800 l.

In order for the solution to have the required properties, it is necessary to achieve uniformity of its composition. To do this, limit the minimum mixing time. Average mixing cycle time for heavy solutions must be at least 3 minutes. Light solutions are stirred longer. To facilitate this process, lime and clay are introduced into the solution in the form of lime or clay milk. Lime paste and lump clay cannot be used for mixed mortars, since in this case it is almost impossible to achieve a homogeneous mortar mixture.

For the preparation of cement mortars with inorganic plasticizers, lime (clay) milk of such a consistency is poured into the mortar mixer so that it is not necessary to add additional water, and then the aggregate and cement are poured. Organic plasticizers are first mixed in a mortar mixer with water for 30–45 s, and then the remaining components are loaded. Solutions, as a rule, are prepared at centralized concrete mixing plants or mortar units, which ensures high quality products. In winter, to obtain solutions with a positive temperature, the components of the solution - sand and water - are heated to a temperature of no more than 60 ° C. The binder must not be heated.

Transportation. Mortar mixtures from factories are transported by dump trucks or specially equipped vehicles, which exclude the loss of laitance, environmental pollution, moisture from precipitation, and temperature reduction. The transportation distance depends on the type of solution, the condition of the road and the air temperature. To protect the solution from hypothermia and freezing in winter, car bodies are insulated or heated with engine exhaust gases.

At construction sites, the mortar mixture is fed to the place of use through pipes using mortar pumps.

The shelf life of mortar mixtures depends on the type of binder and is limited by the time of its setting. lime mortars retain their properties for a long time (until water evaporates from them), and water can be added to the dried lime mortar and mixed again. Cement mortars must be used within 2…4 hours; dilution with water and re-mixing of set cement mortars is not allowed, as this leads to a sharp decrease in its quality, i.e., a drop in the brand of mortar.

Mortars for laying foundations and plinths below the waterproofing layer

Grade of cement	Soil type
	low humidity		Wet	Saturated with water
	Cement-lime mortar M10 (cement: lime paste: sand)	Cement-clay mortar M25 (cement: clay dough: sand)	Cement-lime and cement-clay mortar M25 (cement: lime or clay: sand)	Cement mortar M50 (cement: sand)
50	1:0,1:2,5	1:0,1:2,5	—	—
100	1:0,5:5	1:0,5:5	1:0,1:2	—
150	1:1,2:9	1:1,7	1:03:3,5	—
200	1:1,7:12	1:1:8	1:0,5:5	1:2,5
250	1:1,7:12	1:1:9	1:0,7:5	1:3
300	1:2,1:15	1:1:11	1:0,7:8	1:6

Note: Solution compositions are given in volume ratios. Sand is accepted with medium size and moisture content of 2% or more. When using dry sand, its dosage is reduced by 10%.

The cement mortar is prepared in this way: first, a dry mixture is prepared, which is then mixed with water and mixed. Dry cement mortars shut with water, mix and use within 1-1.5 hours. Water is also carefully dosed. From excess water, a more liquid solution will be obtained; after drying, it becomes less durable than a thick solution of the same composition.

Cement-lime mortar is prepared in proportions. These are the so-called complex solutions, designed to work under normal conditions. Therefore, for masonry located below the level ground water such solutions should not be used. Cement-lime mortars are most often used for interior masonry or for plastering. basements. Prepare it in this order.

The lime dough is diluted to the density of milk and filtered on a clean sieve. A dry mixture is prepared from cement and sand, mixed with lime milk and thoroughly mixed until a homogeneous mass is obtained. The addition of milk of lime increases the plasticity of the solution and makes it more “warm” (Tables 2, 3).

The composition of the solution for above-ground masonry with indoor humidity less than 60%

Grade of cement	Solution grade
	100	75	50	25
600	1:0,4:4,5	1:0,7:6	—	—
500	1:0,3:4	1:0,5:5	1:1:8	—
400	1:0,2:3	1:0,3:4		1:1,7:1,2
300	—	1:0,2:3	1:0,4:4,5	1:1,2:9
Cement-clay mortars
600	1:0,4:4,5	1:0,7:6	—	—
500	1:0,4:4,5	1:0,7:6	1:1:3	—
400	1:0,2:3	1:0,3:4	1:0,7:6	1:1:11
300	—	1:0,2:3	1:0,4:4,5	1:1:9

Table 3

Grade of cement	Solution grade
	100	75	50	25
Cement-lime mortars
600	1:0,4:4,5	1:0,7:6	—	—
500	1:0,3:4	1:0,5:5	1:0,7:8	—
400	1:0,2:3	1:0.3:4	1:0,7:6	—
300	—	1:0,2:3	1:0,4:4,5	1:0,7:9
Cement-clay mortars
600	1:0.4:4,5	1:0,7:6	—	—
500	1:0,3:4	1:0,5:5	1:0,7:6	1:0,7:8,5
400	1:0,2:3	1:0,3:4	1:0,7:6	1:0,7:8,5
300	—	1:0,2:3	1:0,4:5	—
cement mortars
600	1:4,5	1:6	—	—
500	1:4	1:5	—	—
400	1:3	1:4	1:6	—
300	—	1:3	1:4,5	—

Lime mortar is obtained by mixing clean sand with milk of lime without the inclusion of cement. Usually these are solutions of low grades and are mostly used for interior plastering of residential premises. Such solutions are characterized by workability, good adhesion to the masonry material. Lime mortars harden slowly and gypsum is often added to the mortar to speed up this process. Especially the need for the introduction of gypsum increases when plastering ceilings and slopes, where increased requirements are placed on the rate of hardening of the solution.

To obtain a clay-lime mortar, clay and lime are mixed, and then poured with water. The resulting mixture is closed with sand in the required proportion. Such solutions are used in summer conditions for above-ground masonry, mainly in dry climates with normal humidity indoor air.

Compositions of cement-lime, cement-clay and cement mortars
brand solution	Compositions in the volumetric dosage of solutions with a brand of binder
	500	400	300	200	150
Compositions of cement-lime and cement-clay mortars for above-ground structures with a relative humidity of indoor air up to 60% and for foundations in low-moisture soils
300	1: 0,15: 2,1	1: 0,07: 1,8
200	1: 0,2: 3	1: 0,1: 2,5
150	1: 0,3: 4	1: 0,2: 3	1: 0,1: 2,5
100	1: 0,5: 5,5	1: 0,4: 4,5	1: 0,2: 3,5
75	1: 0,8: 7	1: 0,5: 5,5	1: 0,3: 4	1: 0,1: 2,5
50		1: 0,9: 8	1: 0,6: 6	1: 0,3: 4
25			1: 1,4: 10,5	1: 0,8: 7	1: 0,3: 4
10					1: 1,2: 9,5
Compositions of cement-lime and cement-clay mortars for above-ground structures with relative humidity of indoor air over 60% and for foundations in wet soils
300	1: 0,15: 2,1	1: 0,07: 1,8
200	1: 0,2: 3	1: 0,1: 2,5
150	1: 0,3: 4	1: 0,2: 3	1: 0,1: 2,5
100	1: 0,5: 5,5	1: 0,4: 4,5	1: 0,2: 3,5
75	1: 0,8: 7	1: 0,5: 5,5	1: 0,3: 4	1: 0,1: 2,5
50		1: 0,9: 8	1: 0,6: 6	1: 0,3: 4
25			1: 1: 10,5 / 1: 1: 9*	1: 0,8: 7	1: 0,3: 4
10					1: 1: 9 / 1: 0,8: 7*
Compositions of cement mortars for foundations and other structures located in water-saturated soils and below the groundwater level
300	1: 0: 2,1	1: 0: 1,8
200	1: 0: 3	1: 0: 2,5
150	1: 0: 4	1: 0: 3	1: 0: 2,5
100	1: 0: 5,5	1: 0: 4,5	1: 0: 3,0
75	1: 0: 6	1: 0: 5,5	1: 0: 4	1: 0: 2,5
50			1: 0: 6	1: 0: 4
* Above the line - compositions of cement-lime mortars, below the line - cement-clay. Cement: Lime (Clay) : Sand. Sand is accepted according to GOST 8736

The choice of binders in the preparation of mortars for masonry
Operating conditions of structures	Type of binder
1 For above-ground structures with a relative humidity of indoor air up to 60% and for foundations erected in low-moisture soils	Portland cement, plasticized and hydrophobic Portland cements, slag Portland cement, pozzolanic Portland cement, mortar cement, lime-slag binder
2 For above-ground structures with a relative humidity of more than 60% and for foundations erected in wet soils	Pozzolanic Portland cement, plasticized and hydrophobic Portland cement, Portland slag cement, Portland cement, mortar cement, lime-slag binder
3 For foundations with aggressive sulphate waters	Sulfate-resistant Portland cements, Pozzolanic Portland cement

Estimated binder costs per 1 m³ of sand or 1 m³ of mortar
Astringents	Brand of solution Mr	Binder brand MV	Binder consumption, kg
			per 1 m³ of sand	per 1 m³ solution
GOST 10178 GOST 25328 GOST 22266
The consumption of binders is indicated for mixed cement-lime and cement-clay mortars and sand in a loosely poured state at a natural moisture content of 3–7%.

Mortars for plastering and fixing facing tiles

Type and composition of the mortar for the preparatory layers of external and internal plasters (spray and primer)
Type of plastered surface	Type and composition of the solution
	cement	cement-lime	lime	lime-gypsum
For spraying
Stone and concrete	from 1:2.5 up to 1:4	from 1:0.3:3 up to 1:0.5:5
For ground
Stone and concrete	from 1:2 up to 1:3	from 1:0.7:2.5 up to 1:1.2:4>
External plastering of walls not subject to systematic moisture, and internal plaster in rooms with relative air humidity up to 60%
For spraying
		from 1:0.5:4 up to 1:0.7:6	from 1:2.5 up to 1:4	from 1:0.3:2 up to 1:1:3
For ground
Stone and concrete. Wood and plaster		from 1:0.7:3 up to 1:1:5	from 1:2 up to 1:3	from 1:0.5:1.5 up to 1:1.5:2

Type and composition of the mortar for the finishing layer (coating) of external and internal plasters
Type of soil of plastered surfaces	Type and composition of the solution
	cement	cement-lime	lime	lime-gypsum
External plastering of walls, plinths, cornices, etc. subjected to systematic moisture, as well as internal plastering in rooms with a relative humidity of more than 60%
	from 1:1 up to 1:1.5	from 1:1:1.5 up to 1:1.5:2
External plaster of walls that are not subject to systematic moisture, and internal plaster in rooms with relative humidity up to 60%
Cement and cement-lime		from 1:1:2 up to 1:1.5:3
Lime and lime-gypsum			from 1:1 up to 1:2	from 1:1:0 up to 1:1.5:0
Binder1: Binder2: Sand. Sand is accepted according to GOST 8736 with natural humidity 3–7%

Ready-made finishing heavy cement mortar - a mortar that, for ordinary person is no different from styling, but in fact they are completely different and have different physical properties.

Conventional cement mortar is an integral part of any modern construction, despite huge technological breakthroughs and innovations in the manufacturing industry of modern building materials. Only at first glance, it seems that there is nothing complicated in the preparation of the cement composition, but in practice every little thing is important, from the brand of cement to the right technology kneading.

What is cement mortar made of?

The mortar is a special mixture of several constituent components, which is used for reliable connection of elements, as well as a filler for technological voids in order to create a monolithic block. The price of the mixture depends on the components included in its composition, which endow it with special physical characteristics.

In most cases, cement is the link between the other components of the solution. Sand, expanded clay, pumice crumbs can be used as these components. After adding water and a binder, which reduces friction between the particles of other components, a building mixture of the required consistency and mobility is formed.

Classification of solutions

Mortars are classified according to their physical characteristics, methods of application and purpose.

For each type of work

• dry density;
• type of binder;
• appointment;
• physical and mechanical indicators.

Density in dry state

• light (density below 1500 kg/m3);
• heavy (density over 1500 kg/m3).

By type of binder

• cement, mixed with various types Portland cement;

• lime, made on hydraulic or air lime;
• plaster;

• anhydrite, are a mixture of cement and lime.

By appointment

• masonry, for laying bricks, stone and other structures;

• finishing - ready-made finishing heavy cement mortar 1:3 or 1:2, used for plastering and modeling decorative elements building; (See also the article.)
• special, with non-standard properties for specific work (photo).

According to the physical and mechanical parameters, the strength of cement and frost resistance are taken into account, since it is these indicators that characterize its durability.

Characteristics and application

Each composition, depending on its purpose, must have a number of special characteristics that make it possible to use it for its intended purpose. For example, to fill structural voids or shallow foundations, workers use a liquid mixture with large quantity water, so that it spreads and equalizes under its own weight, while penetrating into all the small holes.

Important: A ready-made finishing heavy cement mortar 1: 2 is used for plastering surfaces and correcting structural irregularities; it has a pasty consistency that cannot be used to fill voids.

For brickwork or pouring the foundation with their own hands, workers use high-strength cement of a grade not lower than M400, since it will need to withstand a lot of weight for a long time, while for finishing work they use grade M300 and lower, since special strength is not required here. As you can see, for each type of work is used different types cement, with different proportions and components.

Finishing mortar

Finishing mixtures are used by workers for plastering in order to smooth the surface and eliminate irregularities made during the construction of a building or its individual parts. Plaster is also used to cultivate slopes after installing or replacing windows or making decorative elements with your own hands inside or on the outside of the building.

Important!
For the implementation of such work, it is very important that the composition has good mobility and does not dry out for a long time.
For accurate layer correction and polishing, this is important.
Finishing mortars for use inside and outside the building must have different properties, as they are made from different binders.

For outdoor work, the following compositions are used:

• cement;
• lime;

• cement-lime.

For internal works use:

• plaster;
• lime-gypsum.

If you need a composition with decorative glitter, then the cooking instructions provide for such additional components as mica or glass, crushed to a state of sand.

For the preparation of decorative plaster, special colored cement or ordinary cement with the addition of dye is used. the right amount. Also, the composition of decorative plaster includes quartz sand, marble, granite, tuff, limestone, dolomite and many other types of colored rocks crushed to a sandy state can be used.

For coloring finishing compositions special pigments of natural or artificial origin can be used, which, according to GOST, must be resistant to alkalis and light.

Such dyes can be red lead, ocher, ultramarine or chromium oxide. Craft decorative plaster you can do it yourself, selecting components and dyes empirically to create a unique color and texture.

Conclusion

For all kinds building mixtures there is GOST. This is a list normative documents, which clearly indicate what characteristics mixtures must have in order to be used for their intended purpose. GOST for finished finishing heavy cement-lime mortar also defines special physical indicators, which the composition must comply with at the time of its application.

Get Additional information about ready-made mixtures, you can watch the video in this article.

In this article, we will consider what mortars are for laying brick and stone, plaster, as well as for decorative and terrazitic finishing layers. As well as how to prepare them.

Solution compositions

For brick and masonry

The following types of mortars are known:

• by appointment - masonry mortars, plasters and special
• by type of binder materials - cement mortars, lime, gypsum and mixed (cement-lime, cement-gypsum, etc.)
• by volumetric weight - ordinary (heavy) with a bulk density of 1500 kg / m3 and more (on dense aggregates), light with a bulk density of less than 1500 kg / m3, on light aggregates
• in terms of compressive strength - grade M-4; M-10; M-25; M-75; M-100; M-150; M-200

Solutions of grades M-4 and M-10 are made mainly on lime. The strength of the solution depends on the curing temperature. At a hardening temperature that differs from 18-22 ° C, the strength of the solution is taken according to table 1 or determined by laboratory tests.

Table 1. The strength of the solution,% strength at the age of 28 days

The age of the solution days	Curing temperature, o C
	0	5	10	15	20	25	30	35	40	45	50
1	1	4	6	10	13	18	23	27	32	38	43
2	3	8	12	18	23	30	38	45	54	63	76
3	5	11	18	24	33	47	49	58	66	75	85
5	10	19	28	37	45	54	61	70	78	85	95
7	15	25	37	47	55	64	72	79	87	94	99
10	23	35	48	58	68	75	82	89	95	100	—
14	31	45	60	71	80	85	92	96	100	—	—
21	42	58	74	85	92	96	100	103	—	—	—
28	52	68	83	96	100	104	—	—	—	—	—

Notes:

1. This table refers to solutions that harden at a relative humidity of 50-60%.
2. When using solutions based on slag Portland cement and pozzolanic Portland cement, one should take into account the slowdown in the growth of their strength at a hardening temperature below 15 ° C. The strength of these solutions is determined by multiplying the values ​​given in table 1 by the coefficients:
   0.3 - at a hardening temperature T=0oC; 0.7 - at a hardening temperature T=5oC; 0.9 - at a hardening temperature T=9oC; 1.0 - at a hardening temperature T=15oC and higher.
3. For intermediate values ​​of the hardening temperature and the age of the solution, its strength is determined by interpolation.

Solution compositions

Determination of the composition of the solution is carried out in accordance with CH 290-(..), guided by the project for building a house and depending on local building conditions and the scope of the solutions.

Table 2. Compositions of mortars (by volume) for brick (stone) masonry

Solution type	Grade of cement	Brand of solutions
		100	75	50	25
Cement-lime mortar	400	1:0,3:4	1:0,5:5	1:1:8	—
	300	1:0,2:3	1:0,3:4	1:0,7:6	1:1,7:12
	200	—	1:0,2:3	1:0,4:4,5	1:1,2:9
cement mortar	400	1:4	1:5	—	—
	300	1:3	1:4	1:6	—
	200	—	1:3	1:4,5	—

Table 3. Approximate consumption of cement grade M-300 in plaster mortars

Solution type	The composition of the solution by volume	Consumption of cement per 1 m3 of mortar, kg
Finishing - heavy:
cement	1:4	300
cement	1:3	400
cement-lime	1:2,5	450
cement-lime	1:2,9	135
Decorative - with stone chips:
cement	—	450
cement-lime	—	200
light cement-lime	—	250

Table 4. Solutions for stone-like (decorative) plasters

Components	The number of components, in parts by volume, when simulating under:
	white marble	yellow marble	red granite	gray granite
Portland cement:
white	1	1	—	—
grey	—	—	1	1
lime dough	0,5	0,25	0,1	0,1
marble flour	0,5	0,25	—	—
Marble chips	3	3	3	3
Mica (from the volume of cement)	0,5	0,5	0,5	0,5
Pigment (% by weight of cement)	—	Ocher 3-5%	Minium iron 5-10%	Manganese peroxide 1-5%

Table 5. Mortars for terrasite finish coats and plasters (parts by volume)

materials	Plaster color
	white	yellow	brown	light gray
Portland cement:	1	1,5	1,5	1
Fluffy lime	3	4	3	2,5
Sand quartz	—	9	11	—
Marble chips	6	4	—	9
marble powder	1,5	1	—	3
Mica (from the volume of cement)	0,5	0,5	0,5	—
Pigment (mass fraction of the entire dry mixture), %	—	Ocher 2%	Umber 0.5%	—

Methods for preparing solutions

Solutions are prepared on mechanized on-site installations (concrete mixers or mortar mixers). In order to prepare mixed mortars with inorganic plasticizers (lime, clay, etc.), as well as cement, lime and clay mortars, in a mortar mixer:

• supply water
• then load the aggregate (natural and artificial sand)
• binders (lime, clay, gypsum, cement)
• plasticizer

The duration of mixing of all components is at least 1 minute for heavy solutions and 2 minutes for light solutions. To prepare solutions with organic plasticizers, water and a plasticizer are supplied to the mortar mixer and mixed for 30-45 seconds.

Then load the remaining materials and mix them until a homogeneous mixture is obtained, but not less than 1 minute. Decorative mortars are obtained by mixing colored cements with filler in dry form in a mortar mixer.

Then the mixture is closed with water and further mixed. To obtain solutions for stone-like decorative finishing layers and plasters, lime paste is loaded into the mortar mixer, colored cement or Portland cement, previously thoroughly mixed in a dry state with dye powder, is poured into the mortar mixer, and this mixture is stirred for 2-3 minutes.

The filler is then added and mixed until a homogeneous mixture is obtained.