Ready-made heavy lime finishing mortar 1 3. Lime mortar and features of its use. In factory conditions

In this article we will look at what types of mortars there are for brick and stone masonry, plaster, as well as for decorative and terrazite finishing layers. As well as methods for preparing them.

Compositions of solutions

For brick and stone masonry

The following types of mortars are known:

• by purpose - masonry mortars, plaster and special
• by appearance binding materials- cement mortars, lime, gypsum and mixed (cement-lime, cement-gypsum, etc.)
• by volumetric mass - ordinary (heavy) with a volumetric mass of 1500 kg/m3 or more (on dense aggregates), light with a volumetric mass 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 primarily with lime. The strength of the solution depends on the hardening temperature. At a hardening temperature different from 18-22°C, the strength of the solution is taken according to Table 1 or determined by laboratory tests.

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

Notes:

1. This table applies to solutions that harden at a relative air 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 increase in 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 hardening temperature T=0oC; 0.7 - at hardening temperature T=5oC; 0.9 - at hardening temperature T=9oC; 1.0 - at hardening temperature T=15oC and above.
3. For intermediate values ​​of the hardening temperature and age of the solution, its strength is determined by interpolation.

Compositions of solutions

Determination of the composition of the mortar is carried out in accordance with SN 290-(..), guided by the house construction project and depending on local construction conditions and the area of ​​application of the mortars.

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

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

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

Table 5. Solutions for terrazite finishing layers and plasters (in parts by volume)

Methods for preparing solutions

Solutions are prepared using 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:

• serve water
• then fill in the aggregate (natural and artificial sand)
• binders (lime, clay, gypsum, cement)
• plasticizer

The duration of mixing all components is at least 1 minute for heavy solutions and 2 minutes for light solutions. To prepare solutions with organic plasticizers, add water and a plasticizer to the mortar mixer and mix them 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 solutions obtained by mixing colored cements with dry filler in a mortar mixer.

Then the mixture is mixed with water and further stirred. 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 dry mixed with dye powder, is added, and this mixture is mixed for 2-3 minutes.

Then add filler and mix until a homogeneous mixture is obtained.

Mortars made from a mixture of sand, lime and cement are used for niches on wooden, concrete and stone surfaces. For plastering works ready-made finishing heavy lime mortar is used in accordance with GOST 28013-98.

Characteristics

The main parameters that determine the properties of the prepared solution are:

1. water retention capacity;
2. mobility;
3. degree of delamination;
4. average density;
5. temperature conditions of use.

Freshly prepared mixtures are tested for water retention ability by factory laboratories. These figures should not be less than 95% in winter and less than 90% in summer.

Important. As a result of transportation to construction sites, the water-holding capacity of the finished solution may decrease, but should not become less than 75% of the value that was established by the laboratory. It is strictly forbidden to add water to already set solutions.

The low degree of stratification of the finished compositions is very important, as it reduces the possibility of separating it into liquid and solid fractions during transportation and pumping through hoses.

The main properties of the composition in hardened form are:

1. frost resistance;
2. its compressive strength;
3. density.

All these properties must be acquired by the hardened composition at the design age, which is determined at 28 days. The only exceptions are mixtures with gypsum binders.

Ready-made lime finishing heavy mortar according to GOST 28013-98 must have an average density of at least 1500 kg/m3.

The strength of finishing ready-mixes is much lower than that of concrete or masonry mixtures. The fact is that plaster compositions carry virtually no load.

Preparation

There are a few possible options preparation of lime mortar mixtures for finishing work. The necessary mixtures can be ordered from mortar factories or special mortar units. They can also be made directly on the construction site ().

In factory conditions

The process of factory preparation of solutions consists of precise dosing of the initial components, loading them into the container of the mortar mixer and high-quality mixing there. The purpose of mixing is to obtain a homogeneous mass in the drum.

Structurally, mortar mixers differ in whether they have a vertical or horizontal blade shaft. They come in various volumes from 30 to 900 liters.

Important. In order for the prepared solution to have the desired properties, it is necessary to achieve homogeneity of the composition by stirring. For this purpose, the minimum kneading time is limited. For heavy lime mortars, the mixing time cannot be less than 3 minutes.

Ready-made solutions are delivered from factories to construction sites by dump trucks or vehicles specially equipped for this purpose. During transportation, it is necessary to exclude the possibility of loss of material, its moistening by precipitation, sudden change temperature.

To protect the composition from hypothermia in winter, car bodies must be insulated or heated. At construction sites, the finished finishing mortar is delivered to the site of application through pipes or unloaded into special tubs, which are lifted to the floors by a crane.

Under construction conditions

The finishing solution required for plastering work can be prepared directly at the construction site.

This is beneficial when:

1. the concrete mortar plant is located at a very considerable distance from the construction site, the price of one cube of mortar, including delivery, is too high;
2. The volume of plastering work is small, so buying a whole machine of mortar is not profitable.

In this case, you can prepare the lime mortar with your own hands, following the necessary technology.

Step-by-step instructions for preparing heavy cement-lime mortar:

1. first of all, the day before cooking, you need to slak the lime, quicklime put it in a metal bucket, fill it with water and close the lid, pressing the lid with a weight;
2. after the end of the chemical reaction in the bucket, filter the resulting composition through gauze;
3. sift the sand through a metal mesh with 3x3 mm cells;
4. prepare a box or trough, the depth of which will be approximately 20 cm;
5. pour sand in a heap in the center of the trough, taking into account that 1 part of cement will be 3 parts of sand and 1 part of lime milk;
6. pour cement on top of the sand and mix;
7. add 1 part lime milk and mix until smooth.

You can use your own prepared solution only on the day of production. It is clear that when dosing components you can make a mistake and not get the material of the desired quality.

Optimal results can be obtained by using ready-made building mixtures factory made. All the components have already been selected and mixed, all that remains is to add water.

The use of dry plaster mixtures for the production of finishing solutions increases labor productivity and improves the quality of work performed. Kneading can be done in small portions, using a drill with a special attachment - a mixer - to better mix the composition.

Summary

Lime-cement mortars are prepared by mixing cement-sand mixture lime milk and are used for plastering work inside and outside buildings (). In the video presented in this article you will find Additional information on this topic.

GOST 28013-98

Group Zh13

INTERSTATE STANDARD

BUILDING SOLUTIONS

General technical conditions

General specifications

ISS 91.100.10
OKSTU 5870

Date of introduction 1999-07-01

Preface

Preface

1 DEVELOPED by the State Central Research and Design Institute of Complex Problems building structures and structures named after V.A. Kucherenko (TsNIISK named after V.A. Kucherenko), Research, Design and Technological Institute of Concrete and Reinforced Concrete (NIIZhB), with the participation of JSC "Pilot Plant of Dry Mixes" and JSC "Roskonitstroy" " Russian Federation

INTRODUCED by the State Construction Committee of Russia

2 ADOPTED by the Interstate Scientific and Technical Commission for Standardization, Technical Regulation and Certification in Construction (MNTKS) on November 12, 1998.

Voted for acceptance

3 INSTEAD GOST 28013-89

4 ENTERED INTO EFFECT on July 1, 1999 as state standard Russian Federation by Decree of the State Construction Committee of Russia dated November 29, 1998 N 30

5 EDITION (July 2018), with Amendment No. 1 (IUS 11-2002)


Information about changes to this standard is published in the annual information index "National Standards", and the text of changes and amendments is published in the monthly information index "National Standards". In case of revision (replacement) or cancellation of this standard, the corresponding notice will be published in the monthly information index "National Standards". Relevant information, notices and texts are also posted in the information system common use- on the official site Federal agency on technical regulation and metrology on the Internet (www.gost.ru)

1 area of ​​use

This standard applies to mortars with mineral binders used for masonry and installation of building structures during the construction of buildings and structures, fastening cladding products, and plaster.

The standard does not apply to special solutions (heat-resistant, chemical-resistant, fire-resistant, heat- and waterproofing, grouting, decorative, tensile, etc.).

The requirements set out in 4.3-4.13, 4.14.2-4.14.14, sections 5-7, appendices B and D of this standard are mandatory.

2 Normative references

The normative documents used in this standard are given in Appendix A.

3 Classification

3.1 Construction mortars are classified according to:

- main purpose;

- the binder used;

- medium density.

3.1.1 According to their main purpose, solutions are divided into:

- masonry (including for installation work);

- facing;

- plastering.

3.1.2 According to the binders used, solutions are divided into:

- simple (on one type of binder);

- complex (on mixed binders).

3.1.3 Based on average density, solutions are divided into:

- heavy;

- lungs.

3.2 The designation of a mortar when ordering must consist of an abbreviated designation indicating the degree of readiness (for dry mortar mixtures), purpose, type of binder used, grades for strength and mobility, average density (for light mortars) and the designation of this standard.

An example of a symbol for a heavy mortar, ready-to-use, masonry, on lime-gypsum binder, grade M100 for strength, P2 for mobility:

Masonry mortar, lime-gypsum, M100, P2, GOST 28013-98 .

For a dry mortar mixture, light, plaster, on a cement binder, grade M50 for strength and mobility - P3, medium density D900:

Dry mortar plaster mixture, cement, M50, P3, D900, GOST 28013-98 .

4 General technical requirements

4.1 Construction mortars are prepared in accordance with the requirements of this standard according to the technological regulations approved by the manufacturer.

4.2 Mortar properties include the properties of mortar mixtures and hardened mortar.

4.2.1 Basic properties of mortar mixtures:

- mobility;

- water holding capacity;

- delamination;

- application temperature;

- average density;

- humidity (for dry mortar mixtures).

4.2.2 Basic properties of the hardened solution:

- compressive strength;

- frost resistance;

- average density.

If necessary, additional indicators can be established in accordance with GOST 4.233.

4.3 Depending on the mobility, mortar mixtures are divided in accordance with Table 1.


Table 1

4.4 The water-holding capacity of mortar mixtures must be at least 90%, for clay-containing solutions - at least 93%.

4.5 The stratification properties of freshly prepared mixtures should not exceed 10%.

4.6 The mortar mixture should not contain fly ash more than 20% of the cement mass.

4.7 The temperature of mortar mixtures at the time of use should be:

a) masonry mortars for external work - in accordance with the instructions in Table 2;

b) facing mortars for facing with glazed tiles when minimum temperature outside air, °C, not less than:

c) plaster solutions at a minimum outside temperature, °C, not less than:

table 2

4.8 The moisture content of dry mortar mixtures should not exceed 0.1% by weight.

4.9 The standardized quality indicators of the hardened mortar must be ensured at the design age.

For the design age of the solution, unless otherwise specified in project documentation, should be taken for 28 days for solutions based on all types of binders, except gypsum and gypsum-containing ones.

The design age of solutions based on gypsum and gypsum-containing binders is 7 days.

(Changed edition, Amendment No. 1).

4.10 The compressive strength of mortars at design age is characterized by the following grades: M4, M10, M25, M50, M75, M100, M150, M200.

The compressive strength grade is assigned and controlled for all types of solutions.

4.11 The frost resistance of solutions is characterized by grades.

The following frost resistance grades have been established for the solutions: F10, F15, F25, F35, F50, F75, F100, F150, F200.

For mortars of compressive strength grades M4 and M10, as well as for mortars prepared without the use of hydraulic binders, frost resistance grades are not assigned or controlled.

4.12 The average density, , of hardened solutions at design age should be, kg/m:

The normalized value of the average density of solutions is set by the consumer in accordance with the work project.

4.13 Deviation of the average density of the solution towards an increase is allowed no more than 10% of that established by the design.

4.14 Requirements for materials for the preparation of mortars

4.14.1 Materials used for the preparation of mortars must comply with the requirements of standards or technical specifications for these materials, as well as the requirements of this standard.

4.14.2 The following should be used as binding materials:

- gypsum binders according to GOST 125;

- building lime according to GOST 9179;

- Portland cement and Portland slag cement according to GOST 10178;

- pozzolanic and sulfate-resistant cements according to GOST 22266;

- cements for mortars in accordance with GOST 25328;

- clay according to Appendix B;

- others, including mixed binders, according to regulatory documents on specific type knitting.

4.14.3 Cementing materials for preparing solutions should be selected depending on their purpose, type of structures and conditions of their operation.

4.14.4 The consumption of cement per 1 m of sand in mortars based on cement and cement-containing binders must be at least 100 kg, and for masonry mortars, depending on the type of structure and their operating conditions, no less than that given in Appendix D.

4.14.6 Lime binder is used in the form of hydrated lime (fluff), lime dough, and milk of lime.

Lime milk must have a density of at least 1200 kg/m and contain at least 30% lime by weight.

Lime binder for plastering and facing mortars should not contain unslaked lime particles.

Lime dough must have a temperature of at least 5°C.

4.14.7 The following should be used as a filler:

- sand for construction work according to GOST 8736;

- fly ash according to GOST 25818;

- ash and slag sand according to GOST 25592;

- porous sands according to GOST 25820;

- sand from slag of thermal power plants according to GOST 26644;

- sand from ferrous and non-ferrous metallurgy slags for concrete according to GOST 5578.

4.14.8 The largest grain size of the filler should be, mm, no more than:

4.14.9 When heating aggregates, their temperature, depending on the binder used, should not be higher, °C, when using:

4.14.11 The specific effective activity of natural radionuclides of materials used for the preparation of mortar mixtures should not exceed the limit values ​​depending on the area of ​​application of the mortar mixtures according to GOST 30108.

4.14.12 Chemical additives must comply with the requirements of GOST 24211.

Additives are introduced into ready-to-use mortar mixtures in the form of aqueous solutions or aqueous suspensions, and into dry mortar mixtures - in the form of water-soluble powder or granules.

4.14.13 Water for mixing mortar mixtures and preparing additives is used in accordance with GOST 23732.

4.14.14 Bulk starting materials for mortar mixtures are dosed by weight, liquid components are dosed by weight or volume.

The dosage error should not exceed ±1% for binders, water and additives, and ±2% for aggregates.

For mortar mixing plants with a capacity of up to 5 m3/h, volumetric dosing of all materials is allowed with the same errors.

4.15 Labeling, packaging

4.15.1 Dry mortar mixtures are packaged in bags made of polyethylene film according to GOST 10354 weighing up to 8 kg or paper bags according to GOST 2226 weighing up to 50 kg.

4.15.2 Packaged dry mortar mixtures should be labeled on each package. The markings must be clearly marked on the packaging with indelible paint.

4.15.3 Mortar mixtures must have a quality document.

The manufacturer must accompany the dry mortar mixture with a label or marking applied to the packaging, and the ready-to-use mortar mixture dispensed into the vehicle with a quality document, which must contain the following data:

- name or trademark and address of the manufacturer;

- symbol mortar according to 3.2;

- class of materials used to prepare the mixture, according to the specific effective activity of natural radionuclides and digital value;

- grade for compressive strength;

- mobility grade (P);

- volume of water required to prepare the mortar mixture, l/kg (for dry mortar mixtures);

- type and amount of added additive (% of binder mass);

- shelf life (for dry mortar mixtures), months;

- weight (for dry mortar mixtures), kg;

- quantity of mixture (for ready-to-use mortar mixtures), m;

- date of preparation;

- application temperature, °C;

- designation of this standard.

If necessary, the labeling and quality document may contain additional data.

The quality document must be signed official manufacturer responsible for technical control.

5 Acceptance rules

5.1 Mortar mixtures must be accepted by the manufacturer's technical control.

5.2 Mortar mixtures and solutions are accepted in batches through acceptance and periodic control.

A batch of mortar mixture and mortar is taken to be the quantity of a mixture of the same nominal composition with the same quality of its constituent materials, prepared using a single technology.

The volume of the batch is established by agreement with the consumer - no less than the output of one shift, but no more than the daily output of the mortar mixer.

5.3 All mortar mixtures and solutions are subject to acceptance control according to all standardized quality indicators.

5.4 When accepting each batch, at least five spot samples are taken from the mortar mixture.

5.4.1 Spot samples are taken at the place of preparation of the mortar mixture and/or at the place of its use from several batches or places in the container into which the mixture is loaded. Sampling points from the tank should be located at different depths. With a continuous supply of the solution mixture, point samples are taken at irregular intervals for 5-10 minutes.

5.4.2 After selection, spot samples are combined into a total sample, the mass of which must be sufficient to determine all controlled indicators of the quality of mortar mixtures and solutions. The selected sample is thoroughly mixed before testing (with the exception of mixtures containing air-entraining additives).

Mortar mixtures containing air-entraining, foaming and gas-forming additives are not additionally mixed before testing.

5.4.3 Testing of the mortar mixture, ready for use, should begin during the period when the normalized mobility is maintained.

5.5 The mobility and average density of the mortar mixture in each batch is monitored at least once per shift by the manufacturer after unloading the mixture from the mixer.

The humidity of dry mortar mixtures is controlled in each batch.

The strength of the solution is determined in each batch of the mixture.

Standardized technological indicators of the quality of mortar mixtures provided for in the supply contract (average density, temperature, delamination, water-holding capacity) and frost resistance of the solution are monitored within a time frame agreed with the consumer, but at least once every 6 months, as well as when the quality of the initial ones changes materials, composition of the solution and technology for its preparation.

5.6 Radiation-hygienic assessment of materials used for the preparation of mortar mixtures is carried out according to quality documents issued by enterprises that supply these materials.

In the absence of data on the content of natural radionuclides, the manufacturer determines the specific effective activity of natural radionuclides of materials in accordance with GOST 30108 once a year, as well as with each change of supplier.

5.7 Mortar mixtures, ready for use, are dispensed and taken by volume. The volume of the mortar mixture is determined by the output of the mortar mixer or by the volume of the transport or measuring container.

Dry mortar mixtures are released and taken by weight.

5.8 If, when checking the quality of the mortar, a discrepancy is revealed in at least one of the technical requirements of the standard, this batch of mortar is rejected.

5.9 The consumer has the right to carry out a control check of the quantity and quality of the mortar mixture in accordance with the requirements of this standard according to the methods of GOST 5802.

5.10 The manufacturer is obliged to inform the consumer, upon his request, the results of control tests no later than 3 days after their completion, and if the standardized indicator is not confirmed, notify the consumer immediately.

6 Control methods

6.1 Samples of mortar mixtures are taken in accordance with the requirements of 5.4, 5.4.1 and 5.4.2.

6.2 Materials for preparing mortar mixtures are tested in accordance with the requirements of standards and technical specifications for these materials.

6.3 The quality of chemical additives is determined by the effectiveness of their effect on the properties of mortars according to GOST 30459.

6.4 The concentration of the working solution of additives is determined with a hydrometer according to GOST 18481 in accordance with the requirements of standards and technical specifications for specific types of additives.

6.5 The specific effective activity of natural radionuclides in materials for the preparation of mortar mixtures is determined according to GOST 30108.

6.6 Mobility, average density, water-holding capacity and stratification of mortar mixtures are determined according to GOST 5802.

6.7 The volume of entrained air in mortar mixtures is determined according to GOST 10181.

6.8 The temperature of freshly prepared mortar mixtures is measured with a thermometer, immersing it in the mixture to a depth of at least 5 cm.

6.9 Compressive strength, frost resistance and average density of hardened solutions are determined according to GOST 5802.

6.10 The moisture content of dry mortar mixtures is determined according to GOST 8735.

7 Transportation and storage

7.1 Transportation

7.1.1 Mortar mixtures, ready for use, should be delivered to the consumer in vehicles, specially designed for their transportation.

With the consent of the consumer, transportation of mixtures in bunkers (tubs) is allowed.

7.1.2 The methods used for transporting mortar mixtures must exclude the loss of binder dough, the ingress of atmospheric precipitation and foreign impurities into the mixture.

7.1.3 Packaged dry mortar mixtures are transported by road, rail and other modes of transport in accordance with the rules for the transportation and securing of goods in force for this type of transport.

7.2 Storage

7.2.1 Delivered to construction site mortar mixtures, ready for use, must be reloaded into loader-mixers or other containers, provided that the specified properties of the mixtures are maintained.

7.2.2 Packaged dry mortar mixtures are stored in covered, dry rooms.

Bags of dry mixture must be stored at a temperature not lower than 5°C under conditions that ensure the safety of the packaging and protection from moisture.

7.2.3 The shelf life of the dry mortar mixture is 6 months from the date of preparation.

At the end of the storage period, the mixture must be checked for compliance with the requirements of this standard. If compliant, the mixture can be used for its intended purpose.

APPENDIX A (for reference). List of regulatory documents

APPENDIX A
(informative)

GOST 4.233-86 SPKP. Construction. Construction solutions. Nomenclature of indicators

GOST 125-79 Gypsum binders. Specifications

GOST 2226-2013 Bags made of paper and combined materials. General technical conditions

GOST 2642.5-2016 Refractories and refractory raw materials. Methods for determining iron (III) oxide

GOST 2642.11-97 Refractories and refractory raw materials. Methods for determining potassium and sodium oxides

GOST 3594.4-77 Molding clays. Methods for determining sulfur content

GOST 5578-94 Crushed stone and sand from ferrous and non-ferrous metallurgy slags for concrete. Specifications

GOST 5802-86 Construction mortars. Test methods

GOST 8735-88 Sand for construction work. Test methods

GOST 8736-2014 Sand for construction work. Specifications

GOST 9179-77 Construction lime. Specifications

GOST 10178-85 Portland cement and Portland slag cement. Specifications

GOST 10181-2014 Concrete mixtures. Test methods

GOST 10354-82 Polyethylene film. Specifications

GOST 18481-81 Hydrometers and glass cylinders. Specifications

GOST 21216-2014

GOST 21216-2014 Clay raw materials. Test methods

GOST 22266-2013 Sulfate-resistant cements. Specifications

GOST 23732-2011 Water for concrete and mortars. Specifications

GOST 24211-2008 Additives for concrete and mortars. General technical conditions

GOST 25328-82 Cement for mortars. Specifications

GOST 25592-91 Ash and slag mixtures from thermal power plants for concrete. Specifications

GOST 25818-2017 Fly ash from thermal power plants for concrete. Specifications

GOST 25820-2000 Lightweight concrete. Specifications

GOST 26633-2015 Heavy and fine-grained concrete. Specifications

GOST 26644-85 Crushed stone and sand from thermal power plant slag for concrete. Specifications

GOST 30108-94 Construction materials and products. Determination of specific effective activity of natural radionuclides

GOST 30459-2008 Additives for concrete. Methods for determining effectiveness

SNiP II-3-79* Construction heating engineering

APPENDIX B (recommended). Mobility of the mortar mixture at the site of application depending on the purpose of the solution

Table B.1

APPENDIX B (mandatory). Clay for mortars. Technical requirements

APPENDIX B
(required)

These technical requirements apply to clay intended for the preparation of mortars.

B.1 Technical requirements for clay

B.1.3 The content of chemical components by weight of dry clay should not be more than %:

- sulfates and sulfides in terms of - 1;

- sulfide sulfur in terms of - 0.3;

- mica - 3;

- soluble salts (causing efflorescence and efflorescence):

total iron oxides - 14;

the sum of potassium and sodium oxides is 7.

B.1.4 Clay should not contain organic impurities in quantities that impart a dark color.

B.2 Clay testing methods

B.2.1 The granulometric composition of clay is determined according to GOST 21216.2 and GOST 21216.12. B.2.4 The mica content is determined by the petrographic method according to

Operating conditions of enclosing structures, humidity conditions of premises according to SNiP II-3-79*

Minimum consumption of cement in masonry mortar per 1 m of dry sand, kg

In dry and normal room conditions

In humid conditions

In wet room conditions

Electronic document text

prepared by Kodeks JSC and verified against:
official publication
M.: Standartinform, 2018

Cement-lime mortar is a mixture with high adhesion, strength and elasticity. Has proven itself as masonry mortar for building blocks and bricks, as well as for plastering various surfaces indoors and outdoors. The scope of application is not limited finishing works, this also includes laying pipes, processing reinforcing mesh, and pouring monolithic floors. One of the most important advantages This composition is reliable and moisture resistant.

In addition to the above properties, lime is also characterized by its bactericidal properties, which prevent the formation of fungi and molds. It is worth noting, unlike cement mortar, the material’s ability to transmit moisture, which has a positive effect on the level of humidity inside the room. Hence, it is resistant to temperature changes up to 65 °C and frost-resistant to -50 °C.

Good adhesive properties make it possible to work with any materials, even wood. The mixture is easy to apply, filling even the smallest cracks and irregularities. The increased plasticity of lime mortar allows you to extend the drying time to three hours, thereby avoiding cracking.

According to the characteristics of fat content, the following lime compositions are distinguished:

1. normal – with an optimal degree of ductility, practically no cracking or shrinkage when drying;

2. skinny - used for any facing work, as they have minimal shrinkage;

3. fatty – highly plastic material with a large amount of binders, therefore it is well used in the form of masonry mortar.

Fat content can be adjusted by adding various components. So, to reduce the value, porous sand is added, and lime increases the fat content back.

Based on density ratio, solutions are divided into:

• low density – up to 1500 kg/m3;
• medium density – from 1500 kg/m3.

The ratio of the components of the solution determines the scope of its application. The most popular brands are M75 and M50. For example, the M75 mixture has proven itself best as a reliable masonry mortar for bricks. Whereas for a wider area of ​​use, as well as for plastering work, M50 is suitable.

Applied to plaster mixtures they are conventionally divided into:

1. basic – for rough leveling the surfaces of walls and ceilings;

2. decorative – having decorative elements in the structure or due to prolonged drying, they are easily subjected to texture processing followed by painting;

3. special – are of a technical nature to improve moisture-proof properties, sound insulation and insulation.

Manufacturers and prices

Another advantage is the affordable cost of the material compared to cement-sand mortar. Its low consumption (1 m2 layer of 1 mm - 1.5 kg of mixture) causes economic benefits. Mortar You can buy it from manufacturers ready-made or in the form of a dry mixture packaged in bags. Construction manipulations indoors can be carried out with powder compositions, while for outdoor work, especially under the condition high humidity, it is recommended to entrust the preparation to professionals.

The cost depends on the quality of the raw materials used and the ratio of ingredients. The approximate price range is shown in the table below.

The range of manufacturers of ready-made dry mixes is quite extensive. All of them have their own characteristics, features in composition and scope of application. Below are the most accessible and common ones.

Making your own solution

In addition to ready-made production options, it is possible to make lime mortar yourself. Buy everything you need quality elements and carefully observe the proportions to achieve quality results saving money. The main ingredients used are cement, sand, lime and water.

The ratio of ingredients determines the brand and specifications.

Water consumption during preparation is usually 0.8 parts per 1 hour of cement. In practice, the amount of liquid is determined visually by the consistency of the solution - normally the mixture should resemble thick sour cream.

Lime, as a building material, is used only in quenched form, otherwise as a result of a chemical reaction ready material may swell or rupture altogether. For preparation you will need a separate container. The process varies depending on the rate of extinction.

1. Quick-quenching lime is poured into a barrel of water until completely immersed. After steam appears, more water is added and mixed. Extinguishing takes an average of 8 minutes.

2. Medium-slaking lime is poured into a container and filled with water in double volume. When steaming, water is also added and mixed. The process lasts approximately 25 minutes.

3. Slow slaking lime is only moistened with water. The reaction is accompanied by a threefold increase in volume and an increase in temperature. Takes more than 25 minutes.

The prepared material is diluted with water in a 1:1 ratio to the state of lime milk. Often, to carry out the final extinguishing, it is poured into a special pit, sprinkled with a layer of sand and earth and kept in this way for 15-20 days. The composition acquires a creamy consistency and is now called lime dough or paste.

For cement-lime plaster mortar The most commonly used binder cement is:

• Portland cement type I with a minimum amount of additives and a high setting speed;
• Portland cement type II grades M500-400 with additive content up to 35%.

As practice shows, on construction sites Three-layer plastering is most often used. The proportions of the solution (water-sand-lime-cement) in this case will depend on the layer of plaster.

• rough layer – spray – 2.2:6.7:1.5:1;
• middle layer – soil – 2.8:9:2.2:1;
• finishing layer – covering – 4:13.5:3:1.

To prepare masonry cement mortar, it is more advisable to use a concrete mixer, since in practice more of it is required than plaster. The latter, in turn, is prepared in improvised containers using a construction mixer.

Part of the water is poured into the concrete mixer, then cement, lime and sand are added alternately required proportion. After thorough mixing, the mixture is mixed with the remaining water.

In the case of manual cooking, there are two types of procedures:

1. Lime dough is passed through a sieve with a cell diameter of no more than 3 mm. Then sand and cement are added to it in portions, everything is thoroughly mixed until the required fat content of the solution is obtained.

2. A dry mixture of sand and cement is prepared in the required ratio. Lime milk is gradually poured into it, if necessary, diluted with water to achieve the required consistency.

To increase the solution’s resistance to factors external environment, slowing down the hardening process in ready mixture contribute:

• plasticizers;
• frost-resistant additives;
• retarders and others.

The Portland cement used in the composition also brings a number of positive characteristics to the material:

1. in combination with the action of hydraulic additives, it provides resistance to leaching, and therefore to long-term exposure to ground and sea waters;

2. provides cement with a high level of anti-corrosion protection;

3. lime mixtures with Portland cement are not prone to destruction even with seasonal changes in freezing and thawing regimes.

installation -for filling and sealing seams between large elements during the installation of buildings and structures from ready-made prefabricated structures and parts;

special -waterproof, acid-proof, heat-resistant, acoustic, heat-insulating, injection, X-ray-proof and pipeable.

The mortars do not contain coarse aggregate, so they are essentially fine-grained concrete. General laws characterizing the properties of concrete are, in principle, applicable to mortars. However, when using solutions, two features must be taken into account. First, they are laid thin layers(1...2 cm), without using a mechanical seal. Secondly, solutions are often applied to porous substrates (brick, concrete, light stones and blocks made of porous rocks), capable of strongly sucking water. As a result, the properties of the solution change, which must be taken into account when determining its composition.

Selection of composition, preparation and transportation of solutions

The compositions of mortar mixtures are selected or selected depending on the purpose of the solution, the required grade and mobility and the conditions of work. The selected composition of mortar mixtures must have the necessary mobility (without delamination and water separation during installation) with a minimum consumption of binder and ensure the required strength in the hardened state.

The compositions of mortars are selected according to tables and by calculation, in both cases they are clarified experimentally in relation to specific materials.

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

The composition of solutions of grades 25...200 is selected as follows.To obtain a given grade of mortar 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 use of construction mortars, the consumption of binder per 1 m 3 of sand is determined byformula

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

Q vf — consumption of binder with other activity;

R V Q V - accepted according to the table 4 for a given 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 d - inorganic additive per 1 m 3 of sand, m.

Calculation of the composition of the solution should be preceded by determining the activity (grade) and average bulk density of cement, grain composition and sand fineness modulus, average density of inorganic plasticizer (lime or clay).

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

The process of preparing a 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 batch mortar mixers with forced mixing. By design, mortar mixers are distinguished with a horizontal or vertical blade shaft. The latter are called turbulent mixers.

Mortar mixers with a horizontal blade shaft are produced with a finished batch capacity of 30; 65; 80; 250 and 900 l. All of 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. The average duration of the mixing cycle for heavy solutions should be at least 3 minutes. Light solutions take longer to mix. For relax 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 uniformity of the mortar mixture.

For cooking cement mortars with inorganic plasticizers, lime (clay) milk is poured into a mortar mixer of such a consistency that there is no need to add additional water, and then filler 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. Mortars, as a rule, are prepared at centralized concrete mortar plants or mortar units, which ensures the production of High Quality. 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 astringent cannot be heated.

Transportation. Mortar mixtures from factories are transported by dump trucks or specially equipped transport, which eliminates the loss of cement laitance, environmental pollution, moisture from precipitation, and a decrease in temperature. The transportation distance depends on the type of solution, road condition and 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 supplied 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 its setting time. Lime mortars retain their properties for a long time (until the 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 repeated mixing of hardened cement mortars is not allowed, as this leads to a sharp decrease in its quality, i.e., a drop in the grade of the mortar.

Mortars for laying foundations and plinths below the waterproofing layer

Note: The compositions of the solutions are given in volumetric ratios. The sand is of medium size with a 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 prepare a dry mixture, which is then mixed with water and mixed. Dry cement mortars are mixed with water, mixed and used for 1-1.5 hours. Water is also carefully dosed. Excess water will result in a thinner solution; after drying, it becomes less durable than a thick solution of the same composition.

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

Lime dough is diluted to the consistency 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 lime milk increases the plasticity of the solution and makes it “warmer” (Tables 2, 3).

Composition of mortar for above-ground masonry with room humidity less than 60%

Table 3. Composition of mortar for above-ground masonry with room humidity more than 60%

Lime mortar is prepared by mixing clean sand with lime milk without the inclusion of cement. Typically these are low grade mortars and are mostly used for interior plastering of residential premises. Such solutions are characterized by ease of installation and good adhesion to the masonry material. Lime mortars harden slowly and to speed up this process, gypsum is often added to the solution. The need to introduce gypsum especially increases when plastering ceilings and slopes, where increased demands are placed on the speed of hardening of the solution.

To obtain a clay-lime mortar, clay and lime are mixed and then filled with water. The resulting mixture is mixed 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.

Plastering solutions and for fastening facing tiles