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 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

State name	Name of body government controlled construction
Republic of Armenia	Ministry of Urban Development of the Republic of Armenia
The Republic of Kazakhstan	Committee on Housing and Construction Policy under the Ministry of Energy, Industry and Trade of the Republic of Kazakhstan
Republic of Kyrgyzstan	State Inspectorate for Architecture and Construction under the Government of the Kyrgyz Republic
The Republic of Moldova	Ministry of Territorial Development, Construction and Communal Services of the Republic of Moldova
Russian Federation	Gosstroy of Russia
The Republic of Tajikistan	State Construction Committee of the Republic of Tajikistan
The Republic of Uzbekistan	State Committee for Architecture and Construction of the Republic of Uzbekistan

3 INSTEAD GOST 28013-89

4 ENTERED INTO EFFECT on July 1, 1999 as a state standard of the 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 website of the Federal Agency for 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 Properties mortars 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

Mobility grade P	Norm of mobility for cone immersion, cm

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 at a minimum outside temperature, °C, not less than:

	from 5 and above

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

	from 5 and above

table 2

Average daily outside air temperature, °C	Temperature of the mortar mixture, °C, not less
	Masonry material
	at wind speed, m/s
Up to minus 10
From minus 10 to minus 20
Below minus 20
Note - For masonry mortar mixtures during installation work, the temperature of the mixture should be 10°C higher than indicated in the table

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.

The design age of a mortar, unless otherwise specified in the design documentation, should be taken as 28 days for mortars made with 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 mortars.

4.11 The frost resistance of solutions is characterized by grades.

The following frost resistance grades are 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:

	Heavy solutions	1500 or more
	Light solutions	less than 1500.

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 for a specific type of binder.

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:

	Masonry (except rubble masonry)
	Rubble masonry
	Plaster (except for the covering layer)
	Plaster covering layer
	Facing

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

	Cement binder
	Cement-lime, cement-clay and clay binders
	Lime, clay-lime, gypsum and lime-gypsum binders

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 dosing 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 plastic film bags in accordance with GOST 10354 weighing up to 8 kg or paper bags in accordance with 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 of 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 by the manufacturer’s official 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 quality indicators 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 Mortar mixtures delivered to the construction site, ready for use, must be reloaded into mixer loaders 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

Main purpose of the solution	Cone immersion depth, cm	Mobility grade P
A Masonry:
For rubble masonry:
vibrated
unvibrated
For masonry made of hollow bricks or ceramic stones
For masonry made of solid bricks; ceramic stones; concrete stones or light rock stones
For filling voids in masonry and supplying with a mortar pump
For making a bed when installing walls made of large concrete blocks and panels; jointing horizontal and vertical joints in walls made of panels and large concrete blocks
B Facing:
For fastening slabs natural stone And ceramic tiles on a finished brick wall
For fastening cladding products of lightweight concrete panels and blocks in the factory
In Plastering:
soil solution
spray solution:
with manual application
with a mechanized application method
coating solution:
without the use of gypsum
using gypsum

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

Under dry and normal room conditions

In humid conditions

In wet room conditions

UDC 666.971.001.4:006.354	ISS 91.100.10
Key words: mortars, mineral binders, masonry, installation of building structures; masonry, facing, plastering mortars

Electronic document text

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

), fine aggregate (sand), sealer (water) and, if necessary, special additives. This mixture before hardening begins is called a mortar mixture. A dry mortar mixture is a mixture of dry components - binder, filler and additives, dosed and mixed at the factory - mixed with water before use. The binder in the solution envelops the aggregate particles, reducing friction between them, as a result of which the mortar mixture acquires the mobility necessary for work. During the hardening process, the binder material firmly binds the individual aggregate particles together. Cement, clay, gypsum, lime or mixtures thereof are used as a binder, and sand is used as a filler. Construction mortars are classified depending on a number of factors: the binder used, the properties of the binder, the ratio between the amount of binder material and aggregate, density and purpose.

Depending on the type of binder used, mortars can be simple using one binder(cement, lime, gypsum, etc.) and complex using mixed binders(cement-lime, lime-gypsum, lime-ash, etc.).

The compositions of simple solutions are designated by two numbers. The first number (usually one) shows that there is one volume (or mass) part of the binder material in the solution. The last number, in relation to the first, shows how many volumetric (or mass) parts of the filler are per part of the binder material. For example, a lime mortar with a composition of 1:3 means that in this solution there are 3 parts of aggregate for 1 part of lime. For complex solutions, the ratio consists of three numbers, of which the first number (unit) expresses the volumetric part of the main binder material, and the second number shows how much additional binder needs to be taken per part. Depending on the properties of the binder, a distinction is made between air solutions, which harden in air-dry conditions (for example, gypsum), and hydraulic solutions, which begin to harden in air and continue to harden in water or in wet conditions (cement).

Depending on the ratio between the amount of binder material and filler, fatty, normal and lean mortars and mortar mixtures are distinguished. Solutions with excess binder material are called greasy. Their mixtures are very plastic, but during hardening they shrink greatly; greasy solutions applied in a thick layer will crack. Lean mortars contain a relatively small amount of binder material. However, they give very little shrinkage, which is very valuable for facing work.

Based on density, mortars are divided into heavy - medium density in a dry state 1500 kg/m3 or more, prepared on ordinary sand, and light - with an average density of up to 1500 kg/m3, which are prepared on light porous sand from pumice, tuff, expanded clay, etc. According to their intended purpose, mortars are masonry (for stone ordinary and fireproof masonry, installation of walls from large-sized elements), finishing (for plastering rooms, applying decorative layers to wall blocks and panels), special ones with special properties (waterproofing, acoustic, X-ray protective).

Links

Wikimedia Foundation. 2010.

See what “mortar” is in other dictionaries:

Building mixture- – cement/lime/gypsum, sand and water mixed in a certain proportion. Mortar is used in the construction of stone (brick) masonry, finishing works as a binder. Mortar is divided: according to the type of binders... ... Builder's Dictionary

MORTAR, in construction, a substance used to hold bricks, stones, tiles or concrete blocks together in a structure. Modern mortar consists of a mixture of cement, sand and water. To improve the properties of the solution can... ... Scientific and technical encyclopedic dictionary

A hardened mixture of binder, fine aggregate (sand) and water. In terms of its composition, the mortar is fine-grained concrete, and it has all the regularities inherent in concrete. Construction mortars according to the type of binder... ... Encyclopedia of technology

Building mixture- when building. buildings made of cut stone or brick were not required. S. r. Original builders, use S. r. As a binding material, marble chips were mixed with adhesives. Gypsum S. r., used. in an era of more... Ancient world. encyclopedic Dictionary

Building mixture- When constructing buildings made of cut stone or brick, the use of Sr. was not required. Initially, builders who used C p as a binder material mixed marble chips with adhesives Gypsum C p, used... ... Dictionary of Antiquity

Cement, sand and water mixed in a certain proportion. It is used in the construction of stone (brick) masonry as a binder.

There are the following types mortars: lime, clay, clay-lime, lime-gypsum and clay-cement. Before adding clay to the mortar, it must be thoroughly sifted through a thick sieve.

One of the main requirements for mortar is its homogeneity. the mixture must be stirred for a long time with tools so that the ingredients in the total mass cannot be distinguished. The quantitative ratio of the components is also of great importance. Depending on the purpose (plaster, masonry, sealing cracks, etc.), the composition of the solution changes. Online calculation of the composition of cement mortar.

With a high binder content, building mixture turns out greasy. As a result, cracks form on the plaster after drying. If sand predominates in the total mass, then such solutions are called lean. They make fragile and weak plaster.

It is easy to determine which solution is obtained by mixing. If the mass sticks strongly to the instrument, then the solution is greasy. If it doesn't stick, then building mixture turned out to be lean. A properly made solution should stick slightly to the instrument.

Fine sand is poured onto a solid surface and leveled. Then the required amount of lime is poured on top. The layers are first mixed with a shovel and then thoroughly mixed with a hoe. A crater is made in the middle of the resulting mixture into which water is poured.

After this, the mixture is stirred so that the crater is gradually filled with the mixture, but at the same time its edges should be higher than the solution to avoid possible overflow. A correctly made solution is a homogeneous thick mixture.

Clay mortar used in secondary or accessory buildings for plastering and masonry. This mortar is made in the same way as lime mortar, but clay mortar is not as strong. To increase the strength of the solution, cement, lime or gypsum is added to it. To prepare a clay-cement mortar, materials are taken in the following proportions: for 1 part of clay there are 0.15-0.2 parts of cement and 3-5 parts of sand.

To prepare a clay-lime mortar, for 1 part of clay you need to take 0.3-0.4 parts of slaked lime and 3-6 parts of sand. The amount of sand required depends on the purpose of the mortar. In order to make a clay-gypsum solution for 1 part of clay, you should take 0.25 parts of gypsum and 3-5 parts of sand.

Preparation of construction cement mortar.

Cement is one of the main materials in construction. Cement is a mixture of limestone and clay. This mixture is first sintered and then ground into powder. gray, which consists of CaO, Al2O3 and SiO2. If you add water to this mixture and mix it into the dough, the resulting mass will harden after a while. By adding sand and crushed stone to cement, concrete is obtained. When reinforcement (a frame made of iron rods or mesh) is placed inside a concrete product, the result is a durable material called reinforced concrete. Cement mortar differs from other binding materials in that after it is mixed with water it hardens, and in the solid state it is resistant to water. In order to do quality material 24-28% water is required. In case of more or less added water, the quality of the solution decreases.

Cement mortar begins to harden about an hour after it is mixed with water. In about 12 hours building mixture loses its plasticity and stops hardening. With more high temperature Cement sets faster, so cement mortar hardens faster in warmer months. In order to speed up the drying process when preparing the solution, you can use certain additives.

Mortar is a mixture of mineral components mixed with water. of various origins, intended 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 of construction site occupied by cement and gypsum mortars. To prepare them, different proportions of components are taken, depending on the required properties of the finished stone or joint. Basic composition of the mixture:

• Binder (gypsum, cement of various brands);
• Water.

The composition of the mortar is regulated by GOST 5802-78. The main task of such a material is to harden, adhering to work 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 construction mortars. It defines the classification, basic parameters and application of working compositions; for special ones there are separate regulatory documents.

The main construction mixtures 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).

Special and basic solutions are based on a basic composition; only the brand of cement and the quantity and quality of impurities - fillers and improvers - change.

Construction mortars are classified according to the type of binder:

• Cement;
• Plaster;
• Calcareous;
• Combined.

According to the properties of the main binder component:

• Air (on gypsum, lime. The mixtures are light);
• Hydraulic (on cement different types and strength).

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

Classification of mortars by weight:

• Heavy with dense filler (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 uses of mortars

The main type of cement material is masonry. It is used for the construction of walls and structures made of bricks and building blocks. In the classic version, it is lime binder and sand; for the construction of critical structures, water is added to 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.

Plaster mortar does not require the use of a strong binder, so hydraulic lime is usually used as it. exterior finishing or air for interior cladding 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.

Cement mortar is used to plaster surfaces to obtain a durable coating for many years. It is prepared from cement and water in a ratio of 1:2 or 1:3.

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

The material is sold in bags in the form of dry construction mixtures, sealed at the construction site immediately before production.

Clay is introduced into the lime-cement or pure cement mortar as a moisture-retaining component. It increases the density of the mass, improves the grain composition, and the solution is conveniently placed. This mixture is used for lining stoves and surfaces that can be heated. It is worth noting: cement-clay coatings and layers are much stronger than cement-lime ones.

Fat content of 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 compounds are solutions with a large amount of binder. They are viscous, easy to lay on the surface, but have a tendency to crack.

Normal - universal masses for masonry and plastering of 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 experimentally by examining a sample of frozen material in the form of a cube or bar 28 days old under pressure. Strength grades of mortars: 10, 25, 50, 75, 100, 150, 200, 300. The latter are used only in industrial construction; compositions of grades 10-150 are most widespread. The table shows the proportions for their preparation:

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

To lay bricks, it is necessary to determine the mobility of the mortar using a standard cone:

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

Summarize

Construction mortars in most cases are mixtures of the same type with different numbers of components. They can be easily prepared on the construction site immediately before use. To obtain the material of the required strength, refer to the table presented earlier. In general, you can choose the composition yourself, based on the approximate proportions of the components.

It is recommended to knead using a construction mixer or a drill with an attachment. The consistency is determined individually by adding the required amount of water. Construction stores offer plasticizers that can be used to improve the properties of future stone (frost or heat resistance, strength, etc.).

K category: Selection of building materials

Mortars

Mortars are mineral mixtures that harden and bond firmly to the stone. The solution must contain a binder (cement, gypsum or lime), aggregate (gravel or sand) and clean water.

Depending on the purpose and use of mortar additives, the following solutions are prepared:
1. Construction, for bricklaying.
2. Plastering.
3. Plaster.
4. Cement.

The mortar for masonry should consist of sand and lime in a ratio of 3: 1 or 4: 1. 1 or 2 shovels of cement can be added to the mortar. This is especially necessary when constructing walls that bear a special load. Sand and cement in this case are mixed in a ratio of 3:1 -6:1.

To prepare the plaster mortar, you can use both hydraulic lime and air lime. It also contains sand. There is a difference between plaster mortar for external work and plaster mortar for internal work.

In the first case, hydraulic lime and sand are taken in a ratio of 1:3; air and lime - 1: 2. In the second case, hydraulic lime and sand are mixed in a ratio of 1: 5, and air lime - 1: 3.

Gypsum mortar differs from cement and lime mortar in its high strength and ease of preparation. To do this, all you need to do is take a container, pour it into water, pour in the plaster and mix everything thoroughly so that there are no lumps, which could later cause cracks to appear. Dilute the plaster with water immediately before working with it, because it may thicken ahead of time, then you will not be able to work with it. To prevent this from happening, you can mix a little sifted sand (2:1) into the plaster, but be aware that this will significantly reduce the strength of the gypsum.

Cement mortar is necessary for the preparation of durable plaster. To do this, take pure cement and water in a ratio of 1: 2 (1: 3).

Mortar additives are necessary to improve the quality of solutions. They significantly improve the physical and mechanical properties of solutions, their color, and frost resistance.

When coloring solutions, in addition to the usual additives, you can only use paints of bright colors that do not contain gypsum and barite impurities. Frost resistance is achieved by adding chlorides to the solution. They allow you to work with the solution at fairly low sub-zero temperatures. Chlorides and other means of protecting against exposure to low temperatures are used with the utmost caution, because an overdose of substances, as a rule, leads to the formation of unsightly smudges.

Construction mortars are characterized by three main parameters: density, type of binder and its purpose.

Depending on the density (in a dry state), heavy (density 1500 kg/m3 or more) and light (density less than 1500 kg/m3) solutions are distinguished. To make heavy solutions, heavy quartz or other sands are used; fillers in light solutions are light porous sands made from pumice, tuff, slag, expanded clay, etc. Light solutions are also obtained using foaming additives - porous solutions.

Based on the type of binder, construction mortars are divided into cement (based on Portland cement or its varieties), lime (based on air or hydraulic lime), gypsum (based on gypsum binders) and mixed (based on cement-lime, cement-clay, lime-gypsum binders) . Solutions prepared with one binder are called simple, and solutions prepared with several binders are called mixed (complex).

According to their intended purpose, mortars can be masonry (for masonry, installation of walls from large-sized elements), finishing (for plastering rooms, applying decorative layers to wall blocks and panels), special ones with special properties (waterproofing, acoustic, X-ray protective).

The choice of binder depends on the purpose of the solution, the requirements for it, the temperature and humidity conditions of hardening and the operating conditions of the building. Portland cements, pozzolanic Portland cements, slag Portland cements, special low-grade cements, lime, and gypsum binders are used as binders. To save hydraulic binders and improve the technological properties of mortars, mixed binders are widely used. Lime in mortars is used in the form of lime paste or milk. Gypsum is mainly used in plaster solutions as an additive to lime.

Water used for solutions should not contain impurities that have an impact bad influence for hardening of the binder. Tap water is suitable for these purposes.

If the solution is used in winter conditions, hardening accelerators are added to its composition, as well as additives that reduce the freezing point of water (calcium chloride, sodium chloride, potash, sodium nitrate, etc.).

The composition of a mortar is indicated by the quantity (by mass or volume) of materials per 1 m3 of mortar or by the relative ratio (by mass or volume) of the original dry materials. In this case, the consumption of the binder is taken as 1. For simple solutions consisting of a binder (cement or lime) and not containing mineral additives, the composition is designated 1: 4, that is, for 1 mass part of cement there are 4 mass parts of sand. Mixed solutions, consisting of two binders or containing mineral supplements, denoted by three numbers, for example 1:3:4 (cement: lime: sand).

The quality of mortar mixtures is characterized by their workability - the ability to be laid without special compaction on the base in a thin layer, filling all its unevenness. Workability is determined by the mobility and water-holding capacity of mortar mixtures.

Mobility is the ability of a mortar mixture to spread under the influence of its own mass. Mobility is determined (in cm) by the depth of immersion in the mortar mixture of a standard cone weighing 300 g with an apex angle of 30° and a height of 15 cm. The deeper the cone is immersed in the mortar mixture, the greater mobility it has.

The degree of mobility of the mixture depends on the amount of water, the composition and properties of the starting materials. To increase the mobility of mortar mixtures, plasticizing additives and surfactants are added to them.

The mobility of mortars, depending on their purpose and method of installation, should be as follows.

Laying walls made of bricks, concrete stones, light rock stones: 9-11

Laying walls made of hollow bricks, ceramic stones: 7-8.

Filling horizontal joints when installing walls made of concrete blocks and panels; Joining vertical and horizontal seams: 5-7.

Rubble masonry: 4-6.

Filling voids in rubble masonry: 13-15.

Water retention capacity is the ability of a solution to retain water when laid on a porous base. If the mortar has good water-holding capacity, partial suction of water compacts it in the masonry, which increases the strength of the mortar. Water holding capacity depends on the ratio of the components of the mortar mixture. It increases with increasing cement consumption and frequent replacement! cement, the introduction of additives (ash, clay, etc.), as well as some surfactants. The strength of the hardened mortar depends on the activity of the binder, the water-cement ratio, the duration and conditions of hardening (temperature and humidity environment). When laying mortar mixtures n; a porous base capable of intensively sucking out water, the hardening strength of solutions is significantly higher than the same solutions laid on a dense base.

The strength of the mortar depends on its brand, which is determined by the compressive strength after 28 days of hardening at air temperature; 5-25° C. The following brands of solutions are available: 4, 10, 15, 50, 75, 100, 150, 2t)0 and 300

The frost resistance of solutions is determined by the number of cycles of alternating freezing and thawing until the loss of 15% of the original strength (or 5% of the mass). PS frost resistance solutions are divided into Mrz grades from 10 to 300.

- Construction solutions