Plaster solutions - types, proportions and methods of preparation. Cement mortar Mortars where used

Solutions are a homogeneous mass or mixture consisting of two or more substances, in which one substance acts as a solvent, and the other as soluble particles.

There are two theories of interpretation of the origin of solutions: chemical, the founder of which is D. I. Mendeleev, and physical, proposed by the German and Swiss physicists Ostwald and Arrhenius. According to Mendeleev's interpretation, the components of the solvent and the solute become participants in a chemical reaction with the formation of unstable compounds of these same components or particles.

The physical theory denies chemical interaction between the molecules of the solvent and the dissolved substances, explaining the process of formation of solutions as a uniform distribution of particles (molecules, ions) of the solvent between the particles of the dissolved substance due to physical phenomenon called diffusion.

Classification of solutions according to various criteria

Not for today unified system classification of solutions, however, conventionally, the types of solutions can be grouped according to the most significant criteria, namely:

I) According to the state of aggregation, they distinguish: solid, gaseous and liquid solutions.

II) By the size of the particles of the dissolved substance: colloidal and true.

III) According to the degree of concentration of the particles of the dissolved substance in the solution: saturated, unsaturated, concentrated, diluted.

IV) According to the ability to conduct electricity: electrolytes and non-electrolytes.

V) By purpose and scope: chemical, medical, building, special solutions, etc.

Types of solutions by state of aggregation

The classification of solutions according to the state of aggregation of the solvent is given in the broad sense of the meaning of this term. It is customary to consider liquid substances as solutions (moreover, both a liquid and a solid element can act as a solute), but if we take into account the fact that a solution is a homogeneous system of two or more substances, then it is quite logical to recognize also solid solutions, and gaseous. Solid solutions are considered to be mixtures of, for example, several metals, better known in everyday life as alloys. Gaseous types of solutions are mixtures of several gases, an example is the air around us, which is presented as a combination of oxygen, nitrogen and carbon dioxide.

Solutions by size of dissolved particles

The types of solutions in terms of the size of the dissolved particles include true (ordinary) solutions and B. The solute breaks up into small molecules or atoms, which are close in size to the molecules of the solvent. At the same time, the true types of solutions retain the original properties of the solvent, only slightly transforming it under the influence of the physicochemical properties of the element added to it. For example: when salt or sugar is dissolved in water, the water remains in the same state of aggregation and the same consistency, almost the same color, only its taste changes.

Colloidal solutions differ from conventional ones in that the added component does not completely decompose, retaining complex molecules and compounds, the dimensions of which are much larger than the solvent particles, exceeding the value of 1 nanometer.

Types of concentration solutions

In the same amount of solvent, you can add different amount dissolved element, we will have solutions with different concentrations at the output. We list the main ones:

1. Saturated solutions are characterized by the degree at which the dissolved component under the influence constant value temperature and pressure no longer decomposes into atoms and molecules, and the solution reaches phase equilibrium. Saturated solutions can also be conditionally divided into concentrated ones, in which the dissolved component is comparable to the solvent, and dilute ones, where the solute is several times less than the solvent.
2. Unsaturated are those solutions in which the solute can still decompose into small particles.
3. Supersaturated solutions are obtained when the parameters of the influencing factors (temperature, pressure) change, as a result of which the process of "crushing" of the dissolved substance continues, it becomes more than it was under normal (usual) conditions.

Electrolytes and non-electrolytes

Some substances in solution decompose into ions that can conduct electricity. Such homogeneous systems are called electrolytes. This group includes acids, most salts. And solutions that do not conduct electric current are commonly called non-electrolytes (almost all organic compounds).

Groups of solutions by purpose

Solutions are indispensable in all industries National economy, the specificity of which created such types special solutions like medical, construction, chemical and others.

Medical solutions are a set of drugs in the form of ointments, suspensions, mixtures, solutions for infusions and injections and other dosage forms used for medical purposes for the treatment and prevention of various diseases.

Kinds chemical solutions include a huge variety of homogeneous compounds used in chemical reactions: acids, salts. These solutions can be of organic or inorganic origin, aqueous (sea water) or anhydrous (based on benzene, acetone, etc.), liquid (vodka) or solid (brass). They have found their application in the most various industries national economy: chemical, food, textile industry.

Kinds mortars differ in a viscous and thick consistency, which is why the name of the mixture is more suitable for them.

Due to their ability to quickly harden, they are successfully used as masonry for walls, ceilings, load-bearing structures, as well as for finishing works. They are aqueous solutions, most often three-component (solvent, cement various markings, aggregate), where sand, clay, crushed stone, lime, gypsum and other building materials are used as a filler.

Depending on the type of structure (wall, foundation, etc.) and the conditions in which it will work, based on the requirements of SNiP, the basic requirements for solutions (grade, water resistance, frost resistance) for the construction or installation of this structure are established.

Masonry mortars are used depending on the design stresses and operating conditions of the masonry. The laying of elevated structures operating at low voltage is recommended to be carried out on mortars containing cheap local binders: lime-slag, lime-pozzolanic, lime. In mortars for laying foundations with aggressive sulfate waters, sulfate-resistant cements are used, for the installation of large-block and large-panel walls - Portland cement, Portland slag cement, as well as Portland cement with organic additives. The mobility of the mortar mixture is chosen taking into account the purpose of the solution. When laying walls made of hollow bricks or ceramic stones mobility is assigned 7 ... 8 cm, with rubble masonry -4 ... 6 cm, for masonry from solid brick and concrete stones- 8 ... 12 cm, for mounting walls from panels and large blocks -5 ... .7 cm, for filling voids in the masonry and supplying with a mortar pump -12 ... 14 cm.

Mounting solutions. When installing walls, horizontal seams between panels made of heavy concrete fill with a solution of grade not lower than Ml00; from lightweight concrete- not lower than M50. When installing walls from large blocks, the brand of mortar for filling horizontal joints is indicated in the project (usually M10 ... M50). For jointing vertical joints of panel and large-block walls, the brand of mortar must be at least M50.

For carrier mounting reinforced concrete structures the brand of cement mortar must not be lower than the brand of concrete of this design.

As a filler for heavy masonry and installation mortars, quartz sand is used according to GOST 8736-93, which should not contain particles larger than 5 mm, and the particle size modulus should be 1.5 ... .2.5.

When laying mortars in winter, the hardening rate slows down. For example, at the age of 28 days. the strength of solutions hardening at a temperature of 1 °C is half that at a hardening temperature of 20 °C. Therefore, in winter, for masonry and sealing joints in prefabricated elements, a mortar with a grade one or two steps higher than for a mortar used for the same purposes in summer is used. Solutions for winter work may be served warm. The temperature of the solution at the time of its application should be at least 10 °C at an outside air temperature of minus 10 ... 15 °C and not less than 20 °C - at an air temperature below minus 20 °C.

The temperature of mixtures for the installation of structures should be 10 ° C higher than for masonry.

In construction, monolithic plaster obtained from plaster solutions. The plaster coating consists of two or more layers. Adhesion to the base surface is provided by a preparatory layer, or spray, not more than 5 mm thick on brick and concrete surfaces and 9 mm - for wood. The main layer (ground) with a thickness of 5 ... 7 mm serves to obtain a flat surface. An improved appearance is achieved due to the covering layer with a thickness of not more than 2 mm.

As a filler for plaster mortars, natural sand of the "very fine", "fine" and "medium" groups is used (size modulus - up to 2.0).

Maximum allowable size grains of sand for the preparatory layers of spray and soil should not exceed 2.5 mm, for the finishing layer (covering) - 1.2 mm.

Properties of different layers plaster system must be coordinated with each other in such a way that no stresses arise on the interfaces between the layers and the base due to shrinkage and thermal expansion. For this, it is necessary that the strength of the upper layer be less than the strength of the lower one, or that both layers have the same strength.

Solutions for conventional plasters subdivided into cement, lime, gypsum, cement-lime, lime-gypsum, gypsum and clay-lime. The binder for solutions of conventional plasters is chosen depending on the humidity conditions of operation.

Cement mortars are used for external plasters subjected to systematic moistening (external walls, cornices, etc.), and internal - in rooms with a relative humidity of more than 60%. To increase their water resistance, it is desirable to use water-repellent additives, such as organosilicon fluids.

Cement-lime mortars are used for plastering both building facades (structures that are not subjected to systematic moisture) and interior spaces. The introduction of lime sharply increases the plasticity of solutions. The content of the lime paste depends on the purpose of the layer.

Solutions based on airborne lime and gypsum are used for plastering indoor surfaces with relative humidity up to 60%. The main disadvantage of lime mortars is slow hardening. To speed up their hardening, building gypsum is added. The most convenient lime-gypsum solutions for plastering wooden surfaces indoors. To increase their water resistance, hydraulic additives are introduced into the solution: tripoli, diatomite, slag, ash, etc.

All types of plaster mortars must have a given mobility (9 ... 14 cm - for spraying with mechanized application, 7 ... .8 cm - for soil and covering); not delaminate during the production process; provide the specified strength and adhesion to the base.

Protective and decorative solutions and compositions are intended for outdoor and interior decoration various porous surfaces, performing plastering and filling works. Depending on the type, dry and mortar mixtures, as well as paste compositions, and depending on the composition of the incoming components - mineral, polymer-mineral and polymer compositions.

Protective and finishing plasters must meet a number of specific requirements related to their purpose and operating conditions. The most important are the strength of adhesion to the base and frost resistance. The main indicators of the quality of protective and finishing plasters according to STB 1263-2001 are given in Table. 22.

The stability of these indicators over time depends mainly on the properties of the components of the solutions. Binders for decorative mortars and compositions applied to the exterior surfaces of buildings include white and colored Portland cement, Portland cement with organic additives. In addition, for protective coating often use solutions on a polymeric binder. Lime, gypsum, gypsum-polymer-cement and polymer-cement binders are more often used for interior decoration.

Coloring additives are light, alkali and acid resistant pigments of natural or artificial origin, such as chromium oxide, red lead, graphite, ultramarine, ocher. Of the white pigments, the most commonly used are lime, marble flour, white Portland cement, and titanium dioxide.

Fillers for decorative mortars are washed natural and artificial sands, ceramic, glass, plastic and crushed rocks with a particle size of 2...5 mm. In necessary cases, to obtain sparkling surfaces, mica or crushed

High physical and mechanical properties, comparable with foreign analogues, are possessed by a polymeric protective and finishing acrylic plaster produced by Apimiks. Decorative plasters"Apimix-Sh" are produced on the basis of 100% copolymer of acrylic, quartz sand or marble chips and additives (antistatic, antifungal and anti-mould) and are colored with inorganic pigments. Acrylic plasters do not contain cement and have increased water resistance compared to mineral or polymer-mineral plasters, while maintaining vapor permeability within the required limits; can be applied to any prepared substrate. Plasters "Apimix-Sh" are very resistant to abrasion, resistant to impact and scratching, hardly flammable. They are recommended for finishing wall surfaces on stairwells, in lobbies, cash halls, for prestigious decoration office buildings and façade decorations.

Solutions for special purposes. Waterproofing (waterproof) solutions - conventional greasy solutions with a composition of 1: 1-1: 3.5, into which sealing agents (aluminum sulfate, calcium nitrate, iron chloride, bitumen emulsion, water-soluble resins) or water-reducing (plasticizing) additives are introduced. Solutions with the addition of water glass or sodium aluminate quickly set, which allows them to be used to seal cracks from which water oozes.

For waterproofing mortars, Portland cement, pozzolanic, sulfate-resistant and hydrophobic Portland cement, aluminous and expanding cements of at least M400 grades are used. As a fine aggregate in waterproofing solutions for screeds, sand with a fineness modulus of 2 ... 3 is used.

Especially reliable are the waterproofing mortars applied by shotcrete, the sand particle size modulus of which should be 2.5 ... 3.5. Such solutions are used to cover the walls of pools, pipelines, tunnels, basements exposed to aggressive environments.

Heat-insulating and acoustic solutions are used instead of conventional plaster solutions in order to increase heat-shielding properties enclosing structures or giving them sound-absorbing properties.

Porous sands are used as fillers for heat-insulating and acoustic solutions: perlite - grades 100, 150 and 200, expanded clay - grades 500 ... ,16 and larger than 2.5 mm - no more than 15%, agloporite and expanded clay sand - respectively less than 0.16 and larger than 5 mm - no more than 5%.

For acoustic solutions, one-fraction sands with a grain size of 3 ... 5 mm are used.

X-ray protective solutions. These are heavy mortars with a density of more than 2200 kg/m3, used for plastering X-ray rooms and rooms where work is carried out related to X-ray or y-radiation. Such plaster replaces the sheathing with lead sheets. Portland cement or Portland slag cement and special heavy aggregates (barite), iron ores (magnesite, limonite) and others in the form of sand and dust with a particle size of not more than 1.25 mm are used as binders. The following composition of the barite solution (may hours) can be recommended: ground barite concentrate - 4; fast-hardening Portland cement - 1; polyvinyl acetate dispersion - 0.1; water - to the required mobility.

acid resistant solutions. These are solutions on an acid-resistant liquid glass binder used for the device anti-corrosion coatings structures that are exposed to acids during operation.

Liquid glass is used as a binder in these solutions: sodium glass with a silicate module of 2.4 ... 2.8 and a density of 1.38 ... 1.40 g / cm3 and potassium glass with a silicate module of 3 ... 3.2 and with a density of 1.30 ... 1.32 g / cm3 (paragraph 9.6). The filler is natural quartz or artificial sand obtained by crushing acid-resistant rocks (andesite, beshtaunit, granite). The sand should not contain clay impurities, grains of carbonate rocks and impurities of organic substances.

In acid-resistant solutions, in addition to sand, a finely ground filler is introduced - powder from acid-resistant rocks (andesite, diabase). The filler must contain at least 70% of grains up to 0.075 mm in size.

To increase water resistance, special finely ground additives are used containing reactive silica - silica gel, diatomite, tripoli, agloporite, acid ash from thermal power plants. The acid resistance of fillers should be at least 96%, while the active silica (capable of interacting with alkali) should be 84 ... 97%. The consumption of the active additive is approximately 5...22% by weight of the finely ground filler.

To improve the water resistance of acid-resistant, polymeric additives are used, for example, furyl alcohol.

Mortar is a mixture of mineral components mixed with water various origins designed for leveling walls, laying bricks or finishing interior and exterior spaces. There are many of them, the main varieties and their application will be discussed below.

Basic composition

The main share at the construction site is occupied by cement and gypsum mortars. For their preparation, different proportions of the components are taken, depending on the necessary properties of the finished stone or joint. The basic composition of the mixture:

• Binder (gypsum, cement of different grades);
• Water.

The composition of the mortar is regulated by GOST 5802-78. The main task of such a material is to harden, adhering to working surface and masonry components (tiles, bricks, concrete blocks, etc.).

Regulatory documents and classification

The composition and use of the material is regulated by GOST 28013-98 for mortars. It determines the classification, basic parameters and the use of working compositions; for special ones, there are separate regulatory documents.

The main building mixes include:

• Masonry for bricks and blocks;
• Mounting for structures;
• Facing for tiles.

SP 82-101-98 defines the composition, application and features of special solutions:

• Heat resistant;
• Injectable;
• Acid-resistant;
• Frost-resistant;
• Decorative (facing).

At the heart of special and basic solutions is the basic composition, only the brand of cement and the quantity and quality of impurities - aggregates and improvers change.

According to the type of binder, mortars are distinguished:

• Cement;
• Gypsum;
• lime;
• Combined.

According to the properties of the main binder component:

• Air (on gypsum, lime. Mixtures are light);
• hydraulic (on cement different types and strength).

The composition of the solutions can be simple (with basic components) or complex (several binders, for example, gypsum + lime).

Classification of mortars by weight:

• Heavy with dense aggregate (sand, crushed stone), their density exceeds 1500 kg / m 3;
• Lightweight with porous fillers (expanded clay, polystyrene, etc.) with a density of up to 1500 kg / m 3.

Types and application of mortars

main view cement material- masonry. It is used for the construction of walls and structures made of bricks, building blocks. In the classic version, this is a lime binder and sand, for the construction of critical structures, water is introduced into the mixture. The ratio of sand to lime is 3 (4): 1, 1-2 full scoops of cement are added to the volume. To more accurately calculate its amount, use the ratio of sand to cement (3 ... 6): 1, a more accurate amount is determined by the brand of binder and the required properties of the material. calculated constructively.

The plaster mortar does not require the use of a strong binder, therefore hydraulic lime is usually used as it for exterior finish or air for internal lining of walls and ceilings.

To prepare the mass take:

• Lime and sand in a ratio of 3:1 (for hydraulics);
• For an air solution, sand and lime are mixed in a ratio of 1:2.

For plastering surfaces to obtain durable coating on the long years cement mortar is used. It is prepared from cement and water in a ratio of 1:2 or 1:3.

Gypsum plaster compositions designed for interior decoration: leveling, plastering, finishing and base coating of walls, flows. They are distinguished by a short development and setting time, high aesthetic properties, safety and affordable price materials. The gypsum layer begins to set after 20 minutes. To delay the moment, up to 20% of borax, lime paste or skin glue are added to the mass.

The material is sold in bags in the form of dry building mixtures, closes at the construction site immediately before working out.

Clay is introduced into lime-cement or pure cement mortar as a moisture-retaining component. It increases mass density, improves grain composition, the solution fits comfortably. Such a mixture is used for lining furnaces, surfaces that can be heated. It should be noted: cement-clay coatings and layers are much stronger than cement-lime.

Fat content of the solution

The proportions of the solution may differ even within the same type of mixture. There are 3 types of material:

• fatty solutions;
• Normal;
• Skinny.

Fatty formulations are solutions with large quantity binder. They are viscous, fit comfortably on the surface, but have a tendency to crack.

Normal - universal masses for laying and plastering surfaces.

Basic properties

The main parameter that is taken into account when choosing the type and composition of the solution is strength. It is determined empirically by examining a sample of the solidified material in the form of a cube or bar of age 28 days under pressure. Brands of mortars for strength: 10, 25, 50, 75, 100, 150, 200, 300. The latter are used only in industrial construction, the most common compositions of grades 10-150. The table shows the proportions for their preparation:

Frost resistance grades assigned to solutions: F10, 15, 25, 35, 50, 100, 150, 200, 300.

For laying bricks, it is necessary to determine the mobility of the mortar with a reference cone:

• For an ordinary clay brick - 9-13 cm;
• For rubble masonry - 13-15 cm;
• For hollow brick - 7-8 cm;
• Plastering solution - 5-7 cm.

Summarize

Mortars in most cases are mixtures of the same type with different amounts of components. They are easy to prepare on the construction site immediately before use. To obtain the material of the desired strength, refer to the table presented earlier. In general, you can choose the composition yourself, based on the approximate proportions of the components.

Mixing is recommended to be done with a construction mixer or a drill with a nozzle. The consistency is determined individually by adding right amount water. AT construction stores plasticizers are presented, which can improve the tedious properties of the future stone (frost or heat resistance, strength, etc.).

Liquid dosage forms(Formae medicamentorum fluidae) are free dispersed systems in which medicinal substances are distributed in a liquid dispersion medium. Medicinal substances in these forms can be in three states of aggregation: liquid, solid and gaseous. Depending on the size of the particles of the dispersed phase and the nature of its connection with the dispersion medium, liquid dosage forms can be true solutions of low and high molecular weight substances, colloidal solutions, suspensions, emulsions and combined systems- usually mixtures of the above systems, most often - extraction dosage forms.

For medical purposes, liquid dosage forms are divided into dosage forms for internal, external and parenteral (dosage forms for injection) use.

Solutions

Solution (Solutio, Genitive - solutions) - liquid dosage form obtained by dissolving a solid drug substance or liquid in a solvent. Solutions are used for external and internal use, as well as for injections.

As a solvent use:

• distilled water ( Aqua destillata);
• ethanol ( Spiritus aethylicus 70%, 90%, 95%);
• glycerin ( Glycerinurn);
• liquid oils (Oleum Vaselini, Oleum Olivarum, Oleum Persicorum and etc.).

Accordingly, aqueous, alcohol, glycerin and oil solutions are isolated. True solutions are always transparent, they should not contain suspended particles and sediment. Use solutions for external and internal use, as well as for injection.

Solutions for external use are solutions that are used as eye and ear drops, drops for instillation into the nose, as well as for lotions, washes, douches.

A solution in drops is prescribed in a volume of 5-10 ml, solutions for other purposes - in an amount of 50-100 ml or more. Issued in the recipe in an abbreviated or expanded form.

When using the abbreviated form after the letters Rp.: indicate the name dosage form, then the name of the medicinal substance, the concentration of the solution and its amount in milliliters. The concentration of a solution is:

• as a percentage (most often);
• in relationships (1:1000; 1:5000);
• in mass-volume ratios (0.1 - 200 ml).

The abbreviated form of prescription solutions is used in cases where

when the choice of solvent is determined by factory technology or provided to a pharmacy worker. If the solution is aqueous, then the type of solvent in the abbreviated prescription is not indicated. If the solution is oily or alcohol, then after the name of the medicinal substance, the designations follow - oleosae(oil) or spirituosae(alcohol).

Solutions in construction - necessary material for the construction of any buildings: both overall and light. These mixtures are divided into several types: mortars are prepared on cement, lime or plaster base also these substances can be combined.

There is a gradation according to quality indicators, according to the proportions of the binder component and aggregate, as well as other characteristics.

Types of mortars and their composition

Mortar (GOST 5802-78) is a mixture of binder and aggregate (sand) with water. Such a mixture has the main property of hardening after laying. With the help of the mortar, individual bricks, blocks, stones, etc. are bound together.

The strength of such a bond depends on the quality of the mortar used. The use of mortars in construction depends on the building material used: a certain type of mortar must be used for each material.

When building a shower and toilet, they use various solutions. Depending on the binder included in the mortar, they can be divided into several groups. The main types of mortars in construction are cement, gypsum, lime and combined.

Cement mortars are prepared on the basis of cement or Portland cement. main component gypsum solutions is gypsum. The composition of lime mortars includes air or hydraulic lime.

Combined solutions can be prepared on the basis of gypsum and lime, cement and clay, cement and lime, etc.

Lime has more pronounced astringent properties, so all other components equate to its volume.

For the use of mortars in construction and prepare quality material, guided only by the quantitative ratio of binders and filler, is not always possible, since in addition to similar ratio it is also necessary to take into account the main properties of the components, i.e. fat content, brand, amount of impurities, etc.

Simple and complex mortars for construction and their proportions

The durability of the structure largely depends on the quality of the prepared solution. summer shower and toilets and their finishes. There are simple and complex solutions for construction: a simple one consists of one binder component and an aggregate (lime, clay, cement), and a complex one consists of two binder components and an aggregate (cement-lime).

For simple solutions, designations are used, where the mass part of the binder component is indicated in the first place, and the mass part of the aggregate (1: 5, etc.) is indicated in the second place.

In complex solutions, mass parts are indicated in the following sequence: binder, lime paste, aggregate. The optimal proportions of complex mortars for construction are 1:1:6. The introduction of several binders affects the structure and properties of the solution. The addition of clay gives greater plasticity to the cement mortar, that is, it acts as a plasticizer.

In complex solutions, the volume of the main binder component is conventionally taken as a unit. The remaining substances are indicated by numbers that indicate how many parts by volume are needed for one part of the main binder component. The main binder component has more pronounced astringent properties compared to other substances included in this solution. Therefore, the name of the solutions is given according to the name of the main binder. So, for example, in the composition of the lime-clay-mortar there are two binders - lime and clay.

Grease and lean mortars

There are greasy, thin, and normal building mortars: each has properties that make them suitable or unsuitable for building work. Greasy solutions are more plastic, but prone to cracking.

Lean mortars are too rigid, therefore they do not have sufficient strength. When building a summer shower and toilet, it is recommended to use normal mortars, since they have sufficient plasticity and do not crack when dried, and their shrinkage is minimal. To determine the fat content of the solution, it is enough to look at the paddle with which it is mixed. If the solution only stained the paddle, then the solution is lean. A lightly adherent solution is normal, while a strongly adherent solution is oily.

Solutions can be divided into heavy ones, the density of which in the dry state is more than 1500 kg/m3, and light ones, the density of which does not exceed 1500 kg/m3.

According to their purpose, mortars are divided into masonry (intended directly for laying bricks, stone and stove blocks), finishing (for finishing stoves) and special.

Brands of mortars for strength and mobility

Like brick, cement and others used in construction, mortars differ in brand. It is determined depending on the ability of the solution to withstand the compressive load. There are the following grades of mortars for masonry: 0, 2, 10, 25, 50, 75, 100, 150, 200. Only grades 150 and 200 are suitable for the construction of a summer shower and toilet. testing a cube of it with a size of 70 X 70 mm on the 25th day at a temperature of about 20 ° C. To do this, samples must be taken at different stages of the batch (at the beginning, middle and end).

For uniform filling of vertical and horizontal joints with masonry mortar, it is necessary that it be sufficiently mobile and able to retain moisture. It is clear that these properties depend on the characteristics and ratio of the components. For various works different brands of mortars are used in terms of mobility: it can be measured by the depth of immersion in a solution of a reference cone with certain parameters. The deeper the immersion of the cone, the more mobile the solution is considered. masonry mortar has a mobility of 9-13 cm for ordinary clay bricks, 7-8 cm for hollow bricks, 13-15 cm for rubble masonry and 5-7 cm for plastering.

Composition of lime mortar for construction

Such a solution is prepared from lime dough (1 part), obtained from lime and water, and river sand (2-4 parts). Pour sand into the lime dough with constant stirring. Mix everything well until a homogeneous mass is obtained. In the event that the solution sticks to the spatula, this means that it is too greasy.

You can reduce the degree of fat content by introducing an additional amount of sand. If the resulting solution cannot be kept on the spatula when scooping, then lime is added. Mortar used for and and internal plastering works, because it is a low grade solution. In work, it does not create problems, since it is characterized by ease of installation and good adhesion.

Cement mortar: composition, properties and preparation

Due to their composition and properties, cement mortars are the most durable, they are able to harden both in air and at high humidity and even in water. The beginning of the setting of cement mortars begins after about 30-40 minutes, and the final hardening occurs after 10-12 hours. Due to the high strength properties of cement mortars and their moisture resistance, these materials are used for the construction of main walls, laying foundations, erecting elements of street buildings, most often located in conditions of high humidity or in the zone of its strong drops.

When laying the foundation on wet ground and erecting the walls of the summer shower, it is recommended to use mixed cement mortars. They most often consist of two binders and a filler. An example of such a mortar would be a mixture of cement, lime paste and sand. When solidified, such a solution has high strength and moisture resistance. To prepare it, you will need 1 part of cement, 2 parts of lime paste and from 6 to 12 parts of sand.

To prepare a standard cement mortar, you need to take cement (1 part), river sand(2-5 parts) and water. The ingredients must be combined and then thoroughly mixed. The solution obtained in this way should be used for its intended purpose within an hour. If it is necessary to obtain a particularly plastic mass, it is recommended to reduce the amount of sand to 2-3 parts.

cement mortar used for building walls winter conditions by freezing, erecting walls, the thickness of which does not exceed 25 cm, and foundations. In addition, cement mortar is recommended for the construction of walls with lightweight brickwork and walls in rooms with high level humidity.

To obtain a cement mortar, cement and sand must be mixed in a dry form, and then closed with water.

Cement-lime and clay mortars: composition, application and how to prepare

The composition of the cement-lime mortar includes cement (1 part), river sand (6-8 parts) and lime paste (2 parts). To prepare it, you first need to combine and mix sand and cement, then add lime dough to the resulting mixture and mix everything thoroughly again until a viscous mass of a homogeneous consistency is obtained. The use of a complex cement-lime mortar is recommended for use when construction work in normal conditions, it is mainly suitable for plastering the yard toilet.

The composition of the lime-clay mortar includes clay dough (1 part) and lime dough (0.4 parts), as well as river sand (4-5 parts). Lime dough must be mixed with clay, and then dry sand is added to the resulting mixture with constant stirring. After that, you should mix everything and use the solution for its intended purpose.

Compared to cement-lime mortar, cement-clay mortar is considered to be stronger and faster setting. In addition, it is easy to transport, as it does not delaminate when shaken.

Cement-clay mortar can be used when working in winter conditions, since clay retains moisture, which, when defrosted, increases the strength of the mortar. Clay should have a finely ground texture. It should be added in equal proportions with cement.

How to prepare a clay solution for the construction of light structures? To prepare a lime-gypsum-clay mortar, you will need gypsum (1 part), clay-lime composition (3-4 parts) and water. Large and deep dishes should be filled with water, then pour gypsum into it and mix quickly, then add the clay-gypsum mixture. After that, everything should be thoroughly mixed until a homogeneous mass without lumps is obtained.

Lime-gypsum mortar has higher strength characteristics than lime mortar.

Depending on the type of work, a different amount of solution will be required.