GOST test of building mortar evaluation of results. Selection of the composition and testing of mortar. Determination of the average density of the solution

Decree State Committee USSR on construction affairs dated December 11, 1985 No. 214, the deadline for introduction is set

01.07.86

This standard applies to mortar mixtures and building mortars made with mineral binders (cement, lime, gypsum, soluble glass) used in all types of construction, except for hydraulic engineering.

The standard establishes methods for determining the following properties of the mortar mixture and solution:

mobility, medium density, stratification, water-holding capacity, water separation of the mortar mixture;

This standard does not apply to heat-resistant, chemically resistant and straining mortars.

1. GENERAL REQUIREMENTS

1.8. Before forming the samples, the inner surfaces of the molds are covered with a thin layer of lubricant.

1.9. All samples must be labelled. The marking must be indelible and must not damage the sample.

1.10. The fabricated samples are measured with a caliper with an error of up to 0,1 mm.

1.11. IN winter conditions to test the solution with and without antifreeze additives, sampling and sample preparation should be carried out at the place of its application or preparation, and the samples should be stored in the same temperature and humidity conditions in which the solution placed in the structure is located.

Samples should be stored on the shelf of a lockable inventory box with mesh walls and a waterproof roof.

1.12. All measuring instruments and parameters of the vibration platform should be checked within the time limits specified by the metrological services of the State Standard.

1.13. The temperature of the room in which the tests are carried out should be (20 ± 2) ° C, relative humidity 50-70%.

The temperature and humidity of the room are measured with an MV-4 aspiration psychrometer.

1.14. For testing mortar mixtures and solutions, vessels, spoons, and other devices must be made of steel, glass or plastic.

The use of products made of aluminum or galvanized steel and wood is not allowed.

1.15. The compressive strength of the solution taken from the masonry joints is determined by the method given in the appendix.

The tensile strength of the solution in bending and compression is determined according to GOST 310.4-81.

The tensile strength of the solution during splitting is determined according to GOST 10180-90.

Adhesion strength is determined according to GOST 24992-81.

Shrinkage deformation is determined according to GOST 24544-81.

The water separation of the mortar mixture is determined according to GOST 10181.0-81.

1.16. The results of testing samples of mortar mixtures and mortar samples are recorded in a journal, on the basis of which a document is drawn up that characterizes the quality of the mortar.

2. DETERMINATION OF MOBILITY OF SOLUTION MIXTURE

2.1. The mobility of the mortar mixture is characterized by the depth of immersion of the reference cone into it, measured in centimeters.

2.2. Equipment

2.2.1. For testing use:

a device for determining mobility (damn);

steel rod diameter 12 mm, length 300 mm;

trowel.

2.2.2. The reference cone of the device is made of sheet steel or plastic with a steel tip. The corner at the top should be 30° ± 30".

The mass of the reference cone with the rod must be (300 ± 2) g.

Device for determining the mobility of the mortar mixture

1- tripod; 2 - scale; 3 - reference cone; 4 - rod; 5 - holders;

8 - locking screw

laboratory scales according to GOST 24104-88;

steel rod with a diameter of 12 mm, length 300 mm;

steel ruler 400 mm according to GOST 427-75.

3.3.

3.3.1. Before testing, the vessel is preliminarily weighed with an error of up to 2 d. Then fill with an excess of mortar mixture.

3.3.2. The mortar mixture is compacted by baying with a steel rod 25 times and 5-6 multiple light tapping on the table.

3.3.3. After compaction, the excess mortar mixture is cut off with a steel ruler. The surface is carefully aligned flush with the edges of the vessel. The walls of the measuring vessel are cleaned with a damp cloth from the solution that has fallen on them. Then the container with the mortar mixture is weighed to the nearest 2 G.

3.4. Results processing

3.4.1. Mortar densityr, g / cm 3, calculated by the formula

(1)

where m - mass of a measuring vessel with a mortar mixture, g;

m 1 is the mass of the measuring vessel without mixture, g.

3.4.2. The density of the mortar mixture is determined as the arithmetic mean of the results of two determinations of the density of a “mixture from one sample, which differ by no more than 5% from the lower value.

With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

3.4.3. The test results must be recorded in the log in the form according to the appendix.

4. DETERMINATION OF THE SEPARATION OF A SOLUTION MIXTURE

4.1. The stratification of the mortar mixture, which characterizes its cohesion under dynamic action, is determined by comparing the mass content of the aggregate in the lower and upper parts of the freshly molded sample with the dimensions 150x150x150 mm.

4.2. Equipment

4.2.1. For testing use: molds with steel dimensions 150x150x150 mm according to GOST 2 2685-89;

laboratory shaker type 435 BUT;

laboratory scales according to GOST 24104-88;

sieve with cells 0,14 mm;

baking sheet;

steel rod diameter 12 mm, length 300 mm.

4.2.2. The laboratory vibratory platform in the loaded state must provide vertical vibrations with a frequency 2900±100 per minute and amplitude ( 0.5±0.05) mm. The vibrating platform must have a device that ensures, when vibrating, a rigid fastening of the form with a solution to the table surface.

4.3. Testing

4.3.1. The mortar mixture is placed and compacted in a form for control samples with dimensions 150x150x150 mm. After that, the compacted mortar mixture in the form is subjected to vibration impact on a laboratory vibration platform for 1 min.

4.3.2. After vibrating, the upper layer of the solution with a height ( 7.5±0.5) mm is taken from the mold onto a baking sheet, and the lower part of the sample is unloaded from the mold by tipping onto the second baking sheet.

4.3.3. The selected samples of the mortar mixture are weighed with an error of up to 2 g and subjected to wet sieving on a sieve with holes 0,14 mm.

In wet sieving, the individual parts of the sample placed on the sieve are washed with a jet clean water until complete removal of the binder. The washing of the mixture is considered complete when clean water flows out of the sieve.

4.3.4. The washed portions of the aggregate are transferred to a clean baking sheet, dried to constant weight at a temperature 105-110°C and weighed with an error up to 2 G.

4.4. Results processing

4.4.1. Aggregate content in the upper (lower) parts of the compacted mortar V in percent is determined by the formula

(2)

where t 1 - mass of washed dried aggregate from the upper (lower) part of the sample, g;

m 2 - mass of the mortar mixture taken from the upper (lower) part of the sample, g.

4.4.2. Mortar mix exfoliability index P in percent is determined by the formula

where D V- the absolute value of the difference between the content of aggregate in the upper and lower parts of the sample,%;

å V- total content of filler in the upper and lower parts of the sample, %.

4.4.3. The stratification index for each sample of the mortar mixture is determined twice and calculated with rounding up to 1% as the arithmetic mean of the results of two determinations that differ from each other by no more than 20% from the smaller value. With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

4.4.4. The test results must be recorded in a log, which indicates:

date and time of the test;

sampling site;

brand and type of solution;

results of particular definitions;

average result.

5. DETERMINATION OF THE WATER-HOLDING CAPABILITY OF A MORTAR MIXTURE

5.1. The water-holding capacity is determined by testing a 12 mm thick layer of mortar laid on blotting paper.

5.2. Equipment and materials

5.2.1. For testing use:

sheets of blotting paper 150 ´ 150 mm according to TU 13-7308001-758-88;

gauze pads size 250 ´ 350 mm according to GOST 11109-90;

metal ring inner diameter 100 mm, height 12 mm and wall thickness 5 mm;

glass plate size 150x150 mm, 5 mm thick;

laboratory scales according to GOST 24104-88;

a device for determining the water-holding capacity of a mortar mixture (damn).

5.3. Preparing for testing and conducting tests

5.3.1. Before the test 10 sheets of blotting paper are weighed with an error of up to 0,1 g, placed on a glass plate, a gauze pad is placed on top, a metal ring is installed and weighed again.

5.3.2. The thoroughly mixed mortar mixture is placed flush with the edges of the metal ring, leveled, weighed and left for 10 min.

5.3.3. The metal ring with the solution is carefully removed along with the gauze.

The blotting paper is weighed with an error up to 0,1 G.

Scheme of the device for determining the water-retaining capacity of the mortar mixture

1 - a metal ring with a solution; 2 - 10 layers of blotting paper;

3 - glass plate; 4 - gauze layer

hydraulic press according to GOST 28840-90;

kernel steel diameter 12 mm, length 300 mm;

6.4. Preparing for the test

6.4.1. Mortar samples with mobility up to 5 cm must be made in molds with a pallet.

The form is filled with a solution in two layers. The compaction of the layers of the solution in each compartment of the mold is carried out 12 spatula pressure: 6 pressing along one side in 6 - in the perpendicular direction.

The excess solution is cut flush with the edges of the form with a steel ruler moistened with water and the surface is smoothed.

6.4.2. Mobility mortar samples 5 cm and more are made in molds without a pallet.

The form is set on a brick covered with newsprint moistened with water or other non-glued paper. The size of the paper should be such that it covers the side faces of the brick. Bricks before use must be hand-lapped one against the other to eliminate sharp irregularities. The brick is used ordinary clay brick with a moisture content of not more than 2 % and water absorption 10-15 % by weight. Bricks with traces of cement on the edges cannot be reused.

6.4.3. The molds are filled with a mortar mixture at one time with some excess and compacted by baying with a steel rod. 25 times in a concentric circle from the center to the edges.

6.4.4. In conditions of winter masonry for testing mortars with and without antifreeze additives antifreeze additives for each test period and each controlled area, 6 samples are made, three of which are tested within the time required for floor-by-floor control of the mortar strength after 3-hour thawing at a temperature not lower than ( 20±2) °C, and the remaining three samples are tested after thawing and subsequent 28 - daily hardening at a temperature not lower than ( 20 ± 2) °C. The defrosting time must correspond to that indicated in the table. .

6.4.5. Forms filled with a mortar mixture on hydraulic binders are kept until demoulding in a normal storage chamber at a temperature ( 20 ± 2) °С and relative air humidity of 95-100%, and molds filled with mortar mixture on air binders, - indoors at a temperature ( 20 ± 2) °С and relative humidity ( 65±10) %.

6.4.6. Samples are released from forms via ( 24 ± 2) hours after laying the mortar.

Samples made from mortar mixtures prepared on Portland slag cements, pozzolanic Portland cements with additions of setting retarders, as well as samples of winter masonry stored on outdoors, are released from the forms via 2-3 day

6.4.7. After being released from the molds, the samples should be stored at a temperature ( 20±2) °С. At the same time, the following conditions: samples from solutions prepared with hydraulic binders during the first 3 days. should be stored in a normal storage chamber at relative humidity 95-100 %, and the time remaining before the test - indoors at relative humidity ( 65±10) % (from solutions hardening in air) or in water (from solutions hardening in a humid environment); samples from solutions prepared with air binders should be stored indoors at relative humidity ( 65 ± 10)%.

6.4.8. In the absence of a normal storage chamber, it is allowed to store samples prepared with hydraulic binders in wet sand or sawdust.

6.4.9. When stored indoors, specimens must be protected from drafts, heating from heating appliances, etc.

6.4.10 Before the compression test (for the subsequent determination of density), the samples are weighed with an error up to 0,1 % and measured with a caliper with an error up to 0,1 mm.

6.4.11. Samples stored in water should be removed from it no earlier than 10 minutes before testing and wiped clean. damp cloth.

Samples stored indoors should be cleaned with a broom.

drying cabinet according to OST 16.0.801.397-87;

steel rulers according to GOST 427-75;

desiccator according to GOST 25336-82;

anhydrous calcium chloride according to GOST 450-77 or sulfuric acid with a density 1,84 g / cm 3 according to GOST 2184-77;

7.4. Preparing for the test

7.4.1. The density of the solution is determined by testing samples in a state of natural humidity or a normalized moisture state: dry, air-dry, normal, water-saturated.

7.4.2. When determining the density of a solution in a state of natural humidity, the samples are tested immediately after they are taken or stored in a vapor-tight package or sealed container, the volume of which exceeds the volume of the samples placed in it by no more than 2 times.

7.4.3. The density of the solution in a normalized moisture state is determined by testing samples of the solution that have a normalized moisture content or an arbitrary moisture content, followed by recalculation of the results obtained for the normalized moisture content using the formula ().

7.4.4. When determining the density of a solution in a dry state, the samples are dried to constant weight in accordance with the requirements of p.

7.4.5. When determining the density of a solution in an air-dry state, the samples withstand at least 28 days indoors at a temperature ( 25±10) °С and relative air humidity ( 50 ± 20) %.

7.4.6. When determining the density of the solution under normal humidity conditions, the samples are stored 28 days in a normal hardening chamber, desiccator or other sealed container at a relative humidity of at least 95% and a temperature ( 20±2) °С.

7.4.7. When determining the density of a solution in a water-saturated state, the samples are saturated with water in accordance with the requirements of paragraph.

7.5. Conducting a test

7.5.1. The volume of the samples is calculated from their geometric dimensions. The dimensions of the samples are determined with a caliper with an error of not more than 0,1 mm.

7.5.2. The mass of samples is determined by weighing with an error of no more than 0.1%.

7.6. Results processing

drying cabinet according to OST 16.0.801.397-87;

desiccator according to GOST 25336-82;

baking sheets;

calcium chloride according to GOST 450-77.

8.5. Testing

Gypsum solutions are dried at a temperature of 45-55 °C.

The constant is the mass at which the results of two successive weighings differ by no more than 0.1%. In this case, the time between weighings should be at least 4 hours.

8.5.2. Before reweighing, the samples are cooled in a desiccator with anhydrous calcium chloride or together with drying cabinet up to room temperature.

8.5.3. Weighing is carried out with an error up to 0,1 G.

8.6. Results processing

8.6.1. Humidity of the solution by weightW m as a percentage is calculated with an error of up to 0.1% according to the formula

(8)

where T in - mass of the solution sample before drying, g;

t s - weight of the solution sample after drying, g

8.6.2. Humidity of the solution by volumeW o as a percentage is calculated with an error of up to 0.1% according to the formula

(9)

where r about- the density of the dry solution, determined by p.;

r in- the density of water, taken equal to 1 g/cm 3 .

8.6.3. The moisture content of a solution of a series of samples is determined as the arithmetic mean of the results of determining the moisture content of individual samples of the solution.

8.6.4. The test results must be recorded in a log, which indicates:

place and time of sampling;

moisture state of the solution;

the age of the solution and the date of testing;

sample marking;

moisture content of the solution of samples (samples) and series by weight;

humidity of the solution of samples (samples) and series by volume.

9. DETERMINATION OF SOLUTION WATER ABSORPTION

9.1. The water absorption of the solution is determined by testing samples. The dimensions and number of samples are taken according to clause 7.1.

9.2. Equipment and materials

9.2.1. For testing use:

laboratory scales according to GOST 24104-88;

drying cabinet according to OST 16.0.801.397-87;

container for saturating samples with water;

wire brush or abrasive stone.

9.3. Preparing for the test

9.3.1. The surface of the samples is cleaned of dust, dirt and traces of grease using a wire brush or abrasive stone.

9.3.2. Samples are tested in a state of natural moisture or dried to constant weight.

10.6. Preparing for the test

10.6.1. The samples to be tested for frost resistance (basic) should be numbered, inspected and any defects noticed (minor edges or corners, chipping, etc.) should be recorded in the test log.

10.6.2. The main samples should be tested for frost resistance at 28 days of age after exposure to a normal curing chamber.

10.6.3. Control samples intended for compression testing should be stored in a normal hardening chamber at a temperature of (20 ± 2) ° C and a relative humidity of at least 90%.

10.6.4. The main samples of the solution intended for testing for frost resistance, and control samples intended for determining the compressive strength at 28 days of age, must be saturated with water before testing without prior drying by keeping them for 48 hours in water at a temperature of 15-20 ° FROM. In this case, the sample must be surrounded on all sides by a layer of water with a thickness of at least 20 mm. The saturation time in water is included in the total age of the solution.

10.7. Conducting a test

10.7.1. Water-saturated base samples should be placed in the freezer in special containers or placed on wire racks. The distance between the samples, as well as between the samples and the walls of the containers and overlying shelves, must be at least 50 mm.

10.7.2. Samples should be frozen in a freezer that provides the possibility of cooling the chamber with samples and maintaining the temperature in it at minus 15-20 °C. The temperature should be measured at half the height of the chamber.

10.7.3. Samples should be loaded into the chamber after the air in it has cooled to a temperature not higher than minus 15 °C. If, after loading the chamber, the temperature in it is higher than minus 15 °C, then the beginning of freezing should be considered the moment the air temperature reaches minus 15 °C.

10.7.4. The duration of one freezing should be at least 4 hours.

10.7.5. Samples after unloading from freezer should be thawed in a bath of water at a temperature of 15-20 ° C for 3 hours.

10.7.6. A control inspection of the samples should be carried out in order to terminate the frost resistance test of a series of samples in which the surface of two out of three samples has visible damage (delamination, through cracks, chipping).

10.7.7. After alternate freezing and thawing of the samples, the main samples should be tested for compression.

10.7.8. Compression specimens should be tested in accordance with the requirements of Sec. of this standard.

10.7.9. Before the compression test, the main samples are inspected and the area of ​​damage to the faces is determined.

If there are signs of damage to the supporting faces of the samples (peeling, etc.), before testing, they should be leveled with a layer of fast-hardening compound no more than 2 mm thick. Samples in this case should be tested 48 hours after gravy, and the first day the samples should be stored in a humid environment, and then in water at a temperature of 15-20 °C.

10.7.10. Control samples should be tested for compression in a water-saturated state before freezing the main samples. Before mounting on the press, the supporting surfaces of the specimens must be wiped with a damp cloth.

10.7.11. When assessing frost resistance by weight loss after the required number of freezing and thawing cycles, the samples are weighed in a state saturated with water with an error of not more than 0.1%.

10.7.12. When assessing frost resistance according to the degree of damage, the samples are inspected every 5 cycles of alternate freezing and thawing. Samples are inspected after they are thawed every 5 cycles.

10.8. Results processing

10.8.1. Frost resistance in terms of loss of compressive strength of samples during alternate freezing and thawing is evaluated by comparing the strength of the main and control samples in a state saturated with water.

Loss of strength samplesDas a percentage is calculated by the formula

(12)

where Rcounter- arithmetic mean value of the compressive strength of control samples, MPa (kgf / cm 2);

Rmain - the arithmetic mean value of the compressive strength of the main samples after testing them for frost resistance, MPa (kgf / cm 2).

Permissible value of sample strength loss during compression after their alternate freezing and thawing - no more than 25 %.

10.8.2. Weight loss of samples tested for frost resistance, M as a percentage is calculated by the formula

(13)

where m 1 - mass of the sample saturated with water before testing it for frost resistance, g;

m 2 - the mass of the sample saturated with water after testing it for frost resistance, g.

The weight loss of the samples after the frost resistance test is calculated as the arithmetic mean of the test results of three samples.

Permissible weight loss of samples after alternate freezing and thawing - no more 5 %.

10.8.3. The following data should be indicated in the test log of samples for frost resistance:

type and composition of the solution, design mark for frost resistance;

marking, date of manufacture and date of testing;

the dimensions and weight of each sample before and after the test and the percentage weight loss;

curing conditions;

a description of the defects found in the specimens prior to testing;

description external signs destruction and damage after testing;

ultimate compressive strength of each of the main and control samples and the percentage change in strength after the frost resistance test;

number of freeze and thaw cycles.

APPENDIX 1

Mandatory

DETERMINATION OF THE STRENGTH OF A SOLUTION TAKEN FROM THE SEAMS,

FOR COMPRESSION

1. The strength of the mortar is determined by compressive testing of cubes with ribs 2-4 cm, made of two plates taken from horizontal masonry joints or joints of large-panel structures.

2. The plates are made in the form of a square, the side of which is 1,5 times must exceed the thickness of the plate, equal to the thickness of the seam.

3. Gluing the solution plates to obtain cubes with ribs of 2-4 cm and leveling their surfaces is carried out using a thin layer of gypsum dough ( 1-2 mm).

4. It is allowed to cut sample-cubes from plates in the case when the thickness of the plate provides the required size of the rib.

5. Samples should be tested one day after their manufacture.

6. Sample cubes from a solution with ribs of length 3-4 see tested according to clause of this standard.

7. For testing sample cubes from a solution with ribs 2 cm, as well as thawed solutions, a small-sized desktop press of the PS type is used. The normal load range is 1,0-5,0 kN ( 100-500 kgf).

8. The strength of the solution is calculated according to paragraph of this standard. The mortar strength shall be determined as the arithmetic mean of the test results of five specimens.

9. To determine the strength of the solution in cubes with ribs 7,07 cm should be the test results of cubes of summer and winter solutions that have hardened after thawing, multiplied by the coefficient given in the table.

APPENDIX2

tests to determine the mobility, average density

mortar and compressive strength, medium density

solution samples

Laboratory manager _____________ _______________________________

Responsible for manufacturing

and sample testing ________________________________________________

_____________

* In the "Notes" column, the defects of the samples should be indicated: shells, foreign inclusions and their locations, the special nature of the destruction, etc.

BUILDING SOLUTIONS

TEST METHODS

GOST 5802-86

MINSTROY OF RUSSIA

STATE STANDARD OF THE UNION OF THE SSR

BUILDING SOLUTIONS GOST

Test Methods 5802* 86

Mortars. test methods. Instead

GOST 580278

Decree of the State Committee of the USSR for Construction of December 11, 1985 No. 214, the deadline for the introduction is set

01.07.86

This standard applies to mortar mixtures and building mortars made with mineral binders (cement, lime, gypsum, soluble glass) used in all types of construction, except for hydraulic engineering.

The standard establishes methods for determining the following properties of the mortar mixture and solution:

mobility, medium density, stratification, water-holding capacity, water separation of the mortar mixture;

This standard does not apply to heat-resistant, chemically resistant and straining mortars.

1. GENERAL REQUIREMENTS

1.1. Determination of the mobility, density of the mortar mixture and the compressive strength of the mortar is mandatory for all types of mortar. Other properties of mortar mixtures and mortar are determined in cases provided for by the project or the rules for the production of work.

1.2. Samples for testing the mortar mixture and making samples are taken before the mortar mixture begins to set.

1.3. Samples should be taken from the mixer at the end of the mixing process, at the place of application of the solution from vehicles or a working box.

Samples are taken from at least three places at different depths.

The volume of the sample must be at least 3 liters.

1.4. The sample taken before testing must be additionally mixed for 30 s.

1.5. The test of the mortar mixture should be started no later than 10 minutes after sampling.

1.6. The test of hardened solutions is carried out on samples. The shape and dimensions of the samples, depending on the type of test, must correspond to those indicated in Table. one.

1.7. The deviation of the dimensions of the molded samples along the length of the edges of the cubes, sides cross section prisms listed in table. 1 should not exceed 0.7 mm.

Table 1

Note. In the production control of solutions, which are simultaneously subject to requirements for tensile strength in bending and compressive strength, it is allowed to determine the compressive strength of the solution by testing the halves of the prism samples obtained after the bending test of the prism samples according to GOST 310.481.

1.8. Before sample molding internal surfaces molds are coated with a thin layer of grease.

1.9. All samples must be labelled. The marking must be indelible and must not damage the sample.

1.10. The fabricated samples are measured with a caliper with an error of up to 0.1 mm.

1.11. In winter conditions, to test the solution with and without antifreeze additives, sampling and sample preparation should be carried out at the place of its application or preparation, and the samples should be stored in the same temperature and humidity conditions in which the solution is placed in the structure.

Samples should be stored on the shelf of a lockable inventory box with mesh walls and a waterproof roof.

1.12. All measuring instruments and parameters of the vibration platform should be checked within the time limits specified by the metrological services of the State Standard.

1.13. The temperature of the room in which the tests are carried out should be (20 ± 2) ° C, relative humidity 5070%.

The temperature and humidity of the room are measured with an MV-4 aspiration psychrometer.

1.14. For testing mortar mixtures and solutions, vessels, spoons, and other devices must be made of steel, glass or plastic.

The use of products made of aluminum or galvanized steel and wood is not allowed.

1.15. The compressive strength of the mortar taken from the masonry joints is determined according to the method given in Appendix 1.

The tensile strength of the solution in bending and compression is determined according to GOST 310.481.

The tensile strength of the mortar during splitting is determined according to GOST 1018090.

Adhesion strength is determined according to GOST 2499281.

Shrinkage deformation is determined according to GOST 2454481.

The water separation of the mortar mixture is determined according to GOST 10181.081.

1.16. The results of testing samples of mortar mixtures and mortar samples are recorded in a journal, on the basis of which a document is drawn up that characterizes the quality of the mortar.

2. DETERMINATION OF MOBILITY OF SOLUTION MIXTURE

2.1. The mobility of the mortar mixture is characterized by the depth of immersion of the reference cone into it, measured in centimeters.

2.2. Equipment

2.2.1. For testing use:

a device for determining mobility (Fig. 1);

2.2.2. The reference cone of the device is made of sheet steel or plastic with a steel tip. The corner at the top should be 30° ± 30".

The mass of the reference cone with the rod must be (300 ± 2) g.

Device for determining the mobility of the mortar mixture

1 tripod; 2 scale; 3 reference cone; 4 barbell; 5 holders;

6 guides; 7 a vessel for the mortar mixture;

8 lock screw

2.3. Test preparation

2.3.1. All surfaces of the cone and vessel in contact with the mortar mixture should be cleaned of dirt and wiped with a damp cloth.

2.4. Testing

2.4.1. The immersion value of the cone is determined in the sequence below.

The device is installed on a horizontal surface and the free sliding of the rod is checked. 4 in guides 6.

2.4.2. Vessel 7 fill with a mortar mixture 1 cm below its edges and compact it by baying with a steel rod 25 times and 56 times lightly tapping on the table, after which the vessel is placed on the platform of the device.

2.4.3. cone point 3 bring into contact with the surface of the solution in the vessel, fix the cone rod with a locking screw 8 and make the first reading on the scale. Then the locking screw is released.

2.4.4. The cone must be immersed in the mortar mixture freely. The second reading is taken on a scale 1 min after the start of the cone immersion.

2.4.5. The immersion depth of the cone, measured with an error of up to 1 mm, is determined as the difference between the first and second readings.

2.5. Results processing

2.5.1. The immersion depth of the cone is estimated from the results of two tests on different samples of the mortar mixture of one batch as the arithmetic mean of them and rounded off.

2.5.2. The difference in the performance of private tests should not exceed 20 mm. If the difference is more than 20 mm, then the tests should be repeated on a new sample of the mortar mixture.

2.5.3. The test results are recorded in the log in the form according to Appendix 2.

3. DETERMINATION OF THE DENSITY OF THE SOLUTION MIXTURE

3.1. The density of the mortar mixture is characterized by the ratio of the mass of the compacted mortar mixture to its volume and is expressed in g/cm 3 .

3.2. Equipment

3.2.1. For testing use:

steel cylindrical vessel with a capacity of 1000 +2 ml (Fig. 2);

Steel cylindrical vessel

steel rod 12 mm in diameter, 300 mm long;

steel ruler 400 mm according to GOST 42775.

3.3. Preparing for testing and conducting tests

3.3.1. Before testing, the vessel is preliminarily weighed with an error of up to 2 g. Then it is filled with an excess of the mortar mixture.

3.3.2. The mortar mixture is compacted by baying with a steel rod 25 times and 56 times lightly tapping on the table.

3.3.3. After compaction, the excess mortar mixture is cut off with a steel ruler. The surface is carefully aligned flush with the edges of the vessel. The walls of the measuring vessel are cleaned with a damp cloth from the solution that has fallen on them. The vessel containing the mortar mixture is then weighed to the nearest 2 g.

3.4. Results processing

3.4.1. The density of the mortar mixture r, g / cm 3, is calculated by the formula

where m mass of a measuring vessel with a mortar mixture, g;

m 1 mass of measuring vessel without mixture, g.

3.4.2. The density of the mortar mixture is determined as the arithmetic mean of the results of two determinations of the density of a "mixture from one sample, which differ from each other by no more than 5% from the lower value.

With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

3.4.3. The test results must be recorded in the log in the form in accordance with Appendix 2.

4. DETERMINATION OF THE SEPARATION OF A SOLUTION MIXTURE

4.1. The stratification of the mortar mixture, which characterizes its cohesion under dynamic action, is determined by comparing the mass content of the aggregate in the lower and upper parts of the freshly molded sample with dimensions of 150x150x150 mm.

4.2. Equipment

4.2.1. For testing, the following are used: steel molds with dimensions of 150x150x150 mm according to GOST 2268589;

laboratory vibration platform type 435A;

laboratory scales according to GOST 2410488;

drying cabinet according to OST 16.0.801.39787;

sieve with cells 0.14 mm;

baking sheet;

steel rod with a diameter of 12 mm, a length of 300 mm.

4.2.2. The laboratory vibratory platform in the loaded state should provide vertical oscillations with a frequency of 2900 ± 100 per minute and an amplitude of (0.5 ± 0.05) mm. The vibrating platform must have a device that ensures, when vibrating, a rigid fastening of the form with a solution to the table surface.

4.3. Testing

4.3.1. The mortar mixture is placed and compacted in a mold for control samples with dimensions of 150x150x150 mm. After that, the compacted mortar mixture in the form is subjected to vibration on a laboratory vibration platform for 1 min.

4.3.2. After vibrating, the upper layer of the solution with a height of (7.5 ± 0.5) mm is taken from the mold onto a baking sheet, and the lower part of the sample is unloaded from the mold by tipping onto the second baking sheet.

4.3.3. The selected samples of the mortar mixture are weighed with an error of up to 2 g and subjected to wet sieving on a sieve with 0.14 mm holes.

During wet sieving, individual parts of the sample placed on a sieve are washed with a stream of clean water until complete removal binder. The washing of the mixture is considered complete when clean water flows out of the sieve.

4.3.4. The washed portions of the filler are transferred to a clean baking sheet, dried to constant weight at a temperature of 105-110 ° C and weighed with an error of up to 2 g.

4.4. Results processing

where T 1 mass of washed dried aggregate from the upper (lower) part of the sample, g;

m 2 mass of the mortar mixture taken from the upper (lower) part of the sample, g.

4.4.2. Mortar mix exfoliability index P in percent is determined by the formula

where D V the absolute value of the difference between the content of aggregate in the upper and lower parts of the sample,%;

e V total content of filler in the upper and lower parts of the sample, %.

4.4.3. The stratification index for each sample of the mortar mixture is determined twice and calculated with rounding up to 1% as the arithmetic mean of the results of two determinations that differ from each other by no more than 20% from the smaller value. With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

4.4.4. The test results must be recorded in a log, which indicates:

date and time of the test;

sampling site;

brand and type of solution;

results of particular definitions;

average result.

5. DETERMINATION OF THE WATER-HOLDING CAPABILITY OF A MORTAR MIXTURE

5.1. The water-holding capacity is determined by testing a 12 mm thick layer of mortar laid on blotting paper.

5.2. Equipment and materials

5.2.1. For testing use:

sheets of blotting paper measuring 150x150 mm according to TU 13-7308001-75888;

pads made of gauze fabric measuring 250X350 mm according to GOST 1110990;

a metal ring with an inner diameter of 100 mm, a height of 12 mm and a wall thickness of 5 mm;

a glass plate measuring 150x150 mm, 5 mm thick;

laboratory scales according to GOST 2410488;

a device for determining the water-holding capacity of the mortar mixture (Fig. 3).

5.3. Preparing for testing and conducting tests

5.3.1. Before testing, 10 sheets of blotting paper are weighed with an error of up to 0.1 g, placed on a glass plate, a gauze pad is placed on top, a metal ring is installed and weighed again.

5.3.2. The thoroughly mixed mortar mixture is placed flush with the edges of the metal ring, leveled, weighed and left for 10 minutes.

5.3.3. The metal ring with the solution is carefully removed along with the gauze.

The blotting paper is weighed to the nearest 0.1 g.

Scheme of the device for determining water-retaining

mortar ability

1 a metal ring with a solution; 2 10 layers of blotting paper;

3 glass plate; 4 gauze layer

5.4. Results processing

5.4.1. The water-holding capacity of the mortar mixture is determined by the percentage of water in the sample before and after the experiment according to the formula

where T 1 mass of blotting paper before testing, g;

T 2 mass of blotting paper after the test, g;

m 3 unit weight without mortar mixture, g;

T 4 weight of the installation with mortar mixture, g.

5.4.2. The water-holding capacity of the mortar mixture is determined twice for each sample of the mortar mixture and is calculated as the arithmetic mean of the results of two determinations that differ by no more than 20% from the lower value.

5.4.3. The test results must be recorded in a log, which indicates:

date and time of testing;

sampling site;

brand and type of mortar;

results of particular determinations and the arithmetic mean result.

6. DETERMINATION OF THE COMPRESSION STRENGTH OF SOLUTION

6.1. The compressive strength of the solution should be determined on cube samples with dimensions of 70.7x70.7x70.7 mm at the age specified in the standard or specifications on the this species solution. Three specimens are made for each test period.

6.2. Sampling and general technical requirements to the method for determining the compressive strength according to paragraphs. 1.11.14 of this standard.

6.3. Equipment

6.3.1. For testing use:

detachable steel molds with and without pallet according to GOST 2268589;

hydraulic press according to GOST 2884090;

calipers according to GOST 16689;

steel rod with a diameter of 12 mm, a length of 300 mm;

spatula (Fig. 4).

Spatula for compacting the mortar mixture

6.4. Preparing for the test

6.4.1. Mortar samples with a mobility of up to 5 cm should be made in molds with a pallet.

The form is filled with a solution in two layers. Compaction of the mortar layers in each mold compartment is carried out with 12 spatula pressures: 6 pressures along one side, 6 in the perpendicular direction.

The excess solution is cut flush with the edges of the form with a steel ruler moistened with water and the surface is smoothed.

6.4.2. Samples from the mortar mixture with a mobility of 5 cm or more are made in molds without a pallet.

The form is set on a brick covered with newsprint moistened with water, or other non-glued paper. The size of the paper should be such that it covers the side faces of the brick. Bricks before use must be hand-lapped one against the other to eliminate sharp irregularities. The brick is used ordinary clay with a moisture content of not more than 2% and a water absorption of 10-15% by weight. Bricks with traces of cement on the edges cannot be reused.

6.4.3. The molds are filled with a mortar mixture at one time with some excess and compacted by baying with a steel rod 25 times along a concentric circle from the center to the edges.

6.4.4. In the conditions of winter masonry, for testing mortars with antifreeze additives and without antifreeze additives, for each test period and each controlled area, 6 samples are made, three of which are tested within the time limits necessary for floor-by-floor control of the mortar strength after 3-hour thawing at a temperature not lower than (20 ± 2) °С, and the remaining three samples are tested after thawing and subsequent 28-day hardening at a temperature not lower than (20 ± 2) °С. The defrosting time must correspond to that indicated in the table. 2.

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INTERSTATE STANDARD

BUILDING SOLUTIONS

TEST METHODS

INTERSTATE STANDARD

Date of introduction 01.07.86

This standard applies to mortar mixtures and building mortars made with mineral binders (cement, lime, gypsum, soluble glass) used in all types of construction, except for hydraulic engineering.

The standard establishes methods for determining the following properties of the mortar mixture and solution:

Mobility, medium density, stratification, water-holding capacity, water separation of the mortar mixture;

This standard does not apply to heat-resistant, chemically resistant and straining mortars.

1. GENERAL REQUIREMENTS

1.1. Determination of the mobility, density of the mortar mixture and the compressive strength of the mortar is mandatory for all types of mortar. Other properties of mortar mixtures and mortar are determined in cases provided for by the project or the rules for the production of work.

1.2. Samples for testing the mortar mixture and making samples are taken before the mortar mixture begins to set.

1.3. Samples should be taken from the mixer at the end of the mixing process, at the place of application of the solution from Vehicle or work box.

Samples are taken from at least three places at different depths.

The volume of the sample must be at least 3 liters.

1.4. The sample taken before testing must be additionally mixed for 30 s.

1.5. The test of the mortar mixture should be started no later than 10 minutes after sampling.

1.6. The test of hardened solutions is carried out on samples. The shape and dimensions of the samples, depending on the type of test, must correspond to those indicated in Table. one.

Table 1

Note. In the production control of solutions that are simultaneously subject to requirements for tensile strength in bending and compressive strength, it is allowed to determine the compressive strength of the solution by testing the halves of the prism samples obtained after the bending test of the prism samples according to GOST 310.4.

1.7. The deviation of the dimensions of the molded samples along the length of the edges of the cubes, the sides of the cross section of the prisms indicated in table. 1 should not exceed 0.7 mm.

1.8. Before forming the samples, the inner surfaces of the molds are covered with a thin layer of lubricant.

1.9. All samples must be labelled. The marking must be indelible and must not damage the sample.

1.10. The fabricated samples are measured with a caliper with an error of up to 0.1 mm.

1.11. In winter conditions, to test the solution with and without antifreeze additives, sampling and sample preparation should be carried out at the place of its application or preparation, and the samples should be stored in the same temperature and humidity conditions in which the solution placed in the structure is located.

Samples should be stored on the shelf of a lockable inventory box with mesh walls and a waterproof roof.

1.12. All measuring instruments and parameters of the vibration platform should be checked within the time limits specified by the metrological services of the State Standard.

1.13. The temperature of the room in which the tests are carried out should be (20 ± 2) ° C, relative humidity 50 - 70%.

The temperature and humidity of the room are measured with an MV-4 aspiration psychrometer.

1.14. For testing mortar mixtures and solutions, vessels, spoons, and other devices must be made of steel, glass or plastic.

The use of products made of aluminum or galvanized steel and wood is not allowed.

1.15. The compressive strength of the mortar taken from the masonry joints is determined according to the method given in Appendix 1.

The tensile strength of the solution in bending and compression is determined according to GOST 310.4.

The tensile strength of the solution during splitting is determined according to GOST 10180.

Adhesion strength is determined according to GOST 24992.

Shrinkage deformation is determined according to GOST 24544.

The water separation of the mortar mixture is determined according to GOST 10181.

1.16. The results of testing samples of mortar mixtures and mortar samples are recorded in a journal, on the basis of which a document is drawn up that characterizes the quality of the mortar.

2. DETERMINATION OF MOBILITY OF SOLUTION MIXTURE

2.1. The mobility of the mortar mixture is characterized by the depth of immersion of the reference cone into it, measured in centimeters.

2.2 . Equipment

2.2.1. For testing use:

Device for determining mobility (Fig. 1);

2.2.2. The reference cone of the device is made of sheet steel or plastic with a steel tip. The apex angle should be 30° ± 30′.

The mass of the reference cone with the rod must be (300 ± 2) g.

Device for determining the mobility of the mortar mixture

1 - tripod; 2 - scale; 3 - reference cone; 4 - rod; 5 - holders;
6 - guides; 7 - vessel for the mortar mixture; 8 - locking screw

2.3 . Test preparation

2.3.1. All surfaces of the cone and vessel in contact with the mortar mixture should be cleaned of dirt and wiped with a damp cloth.

2.4 . Testing

2.4.1. The immersion value of the cone is determined in the sequence below.

The device is installed on a horizontal surface and the free sliding of the rod is checked. 4 in guides 6 .

2.4.2. Vessel 7 fill with a mortar mixture 1 cm below its edges and compact it by baying with a steel rod 25 times and 5-6 times lightly tapping on the table, after which the vessel is placed on the platform of the device.

2.4.3. cone point 3 bring into contact with the surface of the solution in the vessel, fix the cone rod with a locking screw 8 and make the first reading on the scale. Then the locking screw is released.

2.4.4. The cone must be immersed in the mortar mixture freely. The second reading is taken on a scale 1 min after the start of the cone immersion.

2.4.5. The immersion depth of the cone, measured with an error of up to 1 mm, is determined as the difference between the first and second readings.

2.5 . Results processing

2.5.1. The immersion depth of the cone is estimated from the results of two tests on different samples of the mortar mixture of one batch as the arithmetic mean of them and rounded off.

2.5.2. The difference in the performance of private tests should not exceed 20 mm. If the difference is more than 20 mm, then the tests should be repeated on a new sample of the mortar mixture.

2.5.3. The test results are recorded in the log in the form according to Appendix 2.

3. DETERMINATION OF THE DENSITY OF THE SOLUTION MIXTURE

3.1. The density of the mortar mixture is characterized by the ratio of the mass of the compacted mortar mixture to its volume and is expressed in g/cm 3 .

3.2 . Equipment

3.2.1. For testing use:

Steel cylindrical vessel with a capacity of 1000 +2 ml (Fig. 2);

Steel cylindrical vessel

Steel rod 12 mm in diameter, 300 mm long;

* Within the territory of Russian Federation valid GOST R 53228-2008.

3.3

3.3.1. Before testing, the vessel is preliminarily weighed with an error of up to 2 g. Then it is filled with an excess of the mortar mixture.

3.3.2. The mortar mixture is compacted by baying with a steel rod 25 times and 5-6 times lightly tapping on the table.

3.3.3. After compaction, the excess mortar mixture is cut off with a steel ruler. The surface is carefully aligned flush with the edges of the vessel. The walls of the measuring vessel are cleaned with a damp cloth from the solution that has fallen on them. The vessel containing the mortar mixture is then weighed to the nearest 2 g.

3.4 . Results processing

3.4.1. The density of the mortar mixture r, g / cm 3, is calculated by the formula

where m- mass of a measuring vessel with a mortar mixture, g;

m 1 - mass of the measuring vessel without mixture, g.

3.4.2. The density of the mortar mixture is determined as the arithmetic mean of the results of two determinations of the density of the mixture from one sample, which differ from each other by no more than 5% from the smaller value.

With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

3.4.3. The test results must be recorded in the log in the form in accordance with Appendix 2.

4. DETERMINATION OF THE SEPARATION OF A SOLUTION MIXTURE

4.1. The stratification of the mortar mixture, which characterizes its cohesion under dynamic action, is determined by comparing the mass content of the filler in the lower and upper parts of the freshly molded sample with dimensions of 150 × 150 × 150 mm.

4.2 . Equipment

4.2.1. For testing use:

Steel molds with dimensions 150 × 150 × 150 mm according to GOST 22685;

Laboratory vibration platform type 435A;

Sieve with cells 0.14 mm;

baking sheet;

Steel rod 12 mm in diameter, 300 mm long.

4.2.2. The laboratory vibratory platform in the loaded state should provide vertical oscillations with a frequency of 2900 ± 100 per minute and an amplitude of (0.5 ± 0.05) mm. The vibrating platform must have a device that ensures, when vibrating, a rigid fastening of the form with a solution to the table surface.

4.3 . Testing

4.3.1. The mortar mixture is placed and compacted in a mold for control samples with dimensions of 150×150×150 mm. After that, the compacted mortar mixture in the form is subjected to vibration on a laboratory vibration platform for 1 min.

4.3.2. After vibrating, the upper layer of the solution with a height of (7.5 ± 0.5) mm is taken from the mold onto a baking sheet, and the lower part of the sample is unloaded from the mold by tipping onto the second baking sheet.

4.3.3. The selected samples of the mortar mixture are weighed with an error of up to 2 g and subjected to wet sieving on a sieve with 0.14 mm holes.

During wet sieving, individual parts of the sample placed on a sieve are washed with a stream of clean water until the binder is completely removed. The washing of the mixture is considered complete when clean water flows out of the sieve.

4.3.4. The washed portions of the filler are transferred to a clean baking sheet, dried to constant weight at a temperature of 105 - 110 ° C and weighed with an error of up to 2 g.

4.4 . Results processing

where D V- the absolute value of the difference between the content of aggregate in the upper and lower parts of the sample,%;

å V- total content of filler in the upper and lower parts of the sample, %.

4.4.3. The stratification index for each sample of the mortar mixture is determined twice and calculated with rounding up to 1% as the arithmetic mean of the results of two determinations that differ from each other by no more than 20% from the smaller value. With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

4.4.4. The test results must be recorded in a log, which indicates:

date and time of the test;

Sampling location;

Brand and type of solution;

Results of particular definitions;

Average result.

5. DETERMINATION OF THE WATER-HOLDING CAPABILITY OF A MORTAR MIXTURE

5.1. The water-holding capacity is determined by testing a 12 mm thick layer of mortar laid on blotting paper.

5.2 . Equipment and materials

5.2.1. For testing use:

Sheets of blotting paper measuring 150×150 mm according to TU 13-7308001-758;

Gaskets made of gauze fabric measuring 250 × 350 mm in accordance with GOST 11109;

Metal ring with an inner diameter of 100 mm, a height of 12 mm and a wall thickness of 5 mm;

Glass plate 150×150 mm in size, 5 mm thick;

A device for determining the water-holding capacity of the mortar mixture (Fig. 3).

5.3 . Preparing for testing and conducting tests

5.3.1. Before testing, 10 sheets of blotting paper are weighed with an error of up to 0.1 g, placed on a glass plate, a gauze pad is placed on top, a metal ring is installed and weighed again.

5.3.2. The thoroughly mixed mortar mixture is placed flush with the edges of the metal ring, leveled, weighed and left for 10 minutes.

5.3.3. The metal ring with the solution is carefully removed along with the gauze.

The blotting paper is weighed to the nearest 0.1 g.

Scheme of the device for determining the water-retaining capacity of the mortar mixture

1 - a metal ring with a solution; 2 - 10 layers of blotting paper;
3 - glass plate; 4 - gauze layer

5.4 . Results processing

5.4.1. Water-holding capacity of the mortar V determined by the percentage of water in the sample before and after the experiment according to the formula

where T 1 - mass of blotting paper before testing, g;

T 2 - mass of blotting paper after testing, g;

m 3 - mass of the installation without mortar mixture, g;

T 4 - mass of the installation with mortar mixture, g.

5.4.2. The water-holding capacity of the mortar mixture is determined twice for each sample of the mortar mixture and is calculated as the arithmetic mean of the results of two determinations that differ by no more than 20% from the lower value.

5.4.3. The test results must be recorded in a log, which indicates:

Date and time of testing;

Sampling location;

Brand and type of mortar;

The results of particular definitions and the arithmetic mean result.

6. DETERMINATION OF THE COMPRESSION STRENGTH OF SOLUTION

6.1. The compressive strength of the solution should be determined on cube samples with dimensions of 70.7 × 70.7 × 70.7 mm at the age specified in the standard or technical specifications for this type of solution. Three specimens are made for each test period.

6.2. Sampling and general technical requirements for the method for determining compressive strength - according to paragraphs. 1.1 - 1.14 of this standard.

6.3 . Equipment

6.3.1. For testing use:

Detachable steel molds with and without pallet according to GOST 22685;

Steel rod with a diameter of 12 mm, a length of 300 mm;

Spatula (Fig. 4).

Spatula for compacting the mortar mixture

6.4 . Preparing for the test

6.4.1. Mortar samples with a mobility of up to 5 cm should be made in molds with a pallet.

The form is filled with a solution in two layers. The compaction of the layers of the solution in each compartment of the mold is carried out with 12 spatula pressures: six pressures along one side and six - in the perpendicular direction.

The excess solution is cut flush with the edges of the form with a steel ruler moistened with water and the surface is smoothed.

6.4.2. Samples from the mortar mixture with a mobility of 5 cm or more are made in molds without a pallet.

The form is set on a brick covered with newsprint moistened with water, or other non-glued paper. The size of the paper should be such that it covers the side faces of the brick. Bricks before use must be hand-lapped one against the other to eliminate sharp irregularities. The brick is used ordinary clay with a moisture content of not more than 2% and a water absorption of 10 - 15% by weight. Bricks with traces of cement on the edges cannot be reused.

6.4.3. The molds are filled with a mortar mixture at one time with some excess and compacted by baying with a steel rod 25 times along a concentric circle from the center to the edges.

6.4.4. In the conditions of winter masonry, for testing mortars with antifreeze additives and without antifreeze additives, for each test period and each controlled area, 6 samples are made, three of which are tested within the time limits necessary for floor-by-floor control of the mortar strength after 3-hour thawing at a temperature not lower than (20 ± 2) °С, and the remaining three samples are tested after thawing and subsequent 28-day hardening at a temperature not lower than (20 ± 2) °С. The defrosting time must correspond to that indicated in the table. 2.

table 2

6.4.5. Molds filled with a mortar mixture on hydraulic binders are kept until stripping in a normal storage chamber at a temperature of (20 ± 2) ° C and relative humidity of 95 - 100%, and molds filled with a mortar mixture on air binders are kept indoors at a temperature ( 20 ± 2) °С and relative humidity (65 ± 10)%.

6.4.6. The samples are released from the molds after (24 ± 2) hours after laying the mortar mixture.

Samples made from mortar mixtures prepared on Portland slag cements, pozzolanic Portland cements with setting retarder additives, as well as winter masonry samples stored in the open air, are released from molds after 2–3 days.

6.4.7. After being released from the molds, the samples should be stored at a temperature of (20 ± 2) °C. In this case, the following conditions must be observed: samples from solutions prepared with hydraulic binders should be stored in a normal storage chamber at a relative air humidity of 95–100% for the first 3 days, and the remaining time before the test should be stored indoors at a relative air humidity of (65 ± 10)% (from solutions hardening in air) or in water (from solutions hardening in a humid environment); samples from solutions prepared with air binders should be stored indoors at a relative humidity of (65 ± 10)%.

6.4.8. In the absence of a normal storage chamber, it is allowed to store samples prepared with hydraulic binders in wet sand or sawdust.

6.4.9. When stored indoors, specimens must be protected from drafts, heating from heating appliances, etc.

6.4.10. Before the compression test (for the subsequent determination of density), the samples are weighed with an error of up to 0.1% and measured with a caliper with an error of up to 0.1 mm.

6.4.11. Samples stored in water should be removed from it no earlier than 10 min before testing and wiped with a damp cloth.

Samples stored indoors should be cleaned with a broom.

6.5 . Conducting a test

6.5.1. Before installing the sample on the press, the particles of the solution remaining from the previous test are carefully removed from the support plates of the press in contact with the faces of the sample.

6.5.2. The sample is mounted on the lower plate of the press centrally relative to its axis so that the base is the faces that were in contact with the walls of the mold during its manufacture.

6.5.3. The scale of the force meter of the testing machine or press is selected from the condition that the expected value of the breaking load should be in the range of 20 - 80% of the maximum load allowed by the selected scale.

The type (brand) of the testing machine (press) and the selected scale of the force meter are recorded in the test log.

6.5.4. The load on the sample must increase continuously at a constant rate of (0.6 ± 0.4) MPa [(6 ± 4) kgf/cm 2 ] per second until it fails.

The maximum force achieved during the testing of the sample is taken as the value of the breaking load.

6.6 . Results processing

6.6.1. Mortar compressive strength R calculated for each sample with an error of up to 0.01 MPa (0.1 kgf / cm 2) according to the formula

BUT- working cross-sectional area of ​​the sample, cm 2 .

6.6.2. The working cross-sectional area of ​​the samples is determined from the measurement results as the arithmetic mean of the areas of two opposite faces.

6.6.3. The compressive strength of the solution is calculated as the arithmetic mean of the test results of three samples.

6.6.4. The test results are recorded in the log in the form according to Appendix 2.

7. DETERMINATION OF THE AVERAGE DENSITY OF THE SOLUTION

7.1. The density of the solution is determined by testing samples-cubes with an edge of 70.7 mm, made from a mortar mixture of the working composition, or plates measuring 50 × 50 mm, taken from the joints of structures. The thickness of the plates must correspond to the thickness of the seam.

During production control, the density of solutions is determined by testing samples intended to determine the strength of the solution.

7.2. Samples are made and tested in batches. The series should consist of three samples.

7.3 . Equipment, materials

7.3.1. For testing use:

Drying cabinet according to OST 16.0.801.397;

Anhydrous calcium chloride according to GOST 450 or sulfuric acid with a density of 1.84 g / cm 3 according to GOST 2184;

7.4 . Preparing for the test

7.4.1. The density of the solution is determined by testing samples in a state of natural moisture or a normalized moisture state: dry, air-dry, normal, water-saturated.

7.4.2. When determining the density of a solution in a state of natural humidity, the samples are tested immediately after they are taken or stored in a vapor-tight package or sealed container, the volume of which exceeds the volume of the samples placed in it by no more than 2 times.

7.4.3. The density of the solution in a normalized moisture state is determined by testing solution samples having a normalized moisture content or an arbitrary moisture content, followed by recalculation of the results obtained for the normalized moisture content according to formula (7).

7.4.4. When determining the density of a solution in a dry state, the samples are dried to constant weight in accordance with the requirements of clause 8.5.1.

7.4.5. When determining the density of a solution in an air-dry state, the samples are kept for at least 28 days in a room at a temperature of (25 ± 10) °C and relative humidity of (50 ± 20)% before testing.

7.4.6. When determining the density of the solution under normal humidity conditions, the samples are stored for 28 days in a normal hardening chamber, desiccator or other sealed container at a relative humidity of at least 95% and a temperature of (20 ± 2) °C.

7.4.7. When determining the density of a solution in a water-saturated state, the samples are saturated with water in accordance with the requirements of clause 9.4.

7.5 . Conducting a test

7.5.1. The volume of the samples is calculated from their geometric dimensions. The dimensions of the samples are determined with a caliper with an error of not more than 0.1 mm.

7.5.2. The mass of samples is determined by weighing with an error of not more than 0.1%.

7.6 . Results processing

7.6.1. The density of the solution sample r w is calculated with an error of up to 1 kg / m 3 according to the formula

where r w is the density of the solution at humidity W m, kgf / m 3;

W n is the normalized moisture content of the solution, %;

W m is the moisture content of the solution at the time of testing, determined according to Sec. 8.

7.6.4. The test results must be recorded in the log in the form in accordance with Appendix 2.

8. DETERMINATION OF SOLUTION HUMIDITY

8.1. The moisture content of the solution is determined by testing samples or samples obtained by crushing samples after their strength test or extracted from finished products or structures.

8.2. The largest size of the crushed pieces of the solution should be no more than 5 mm.

8.3. Samples are crushed and weighed immediately after sampling and stored in a vapor-tight package or sealed container, the volume of which exceeds the volume of the samples placed in it by no more than two times.

8.4 . Equipment and materials

8.4.1. For testing use:

Drying cabinet according to OST 16.0.801.397;

baking sheets;

8.5 . Testing

8.5.1. The prepared samples or samples are weighed and dried to constant weight at a temperature of (105 ± 5) °C.

Gypsum solutions are dried at a temperature of 45 - 55 °C.

A constant is the mass at which the results of two successive weighings differ by no more than 0.1%. In this case, the time between weighings should be at least 4 hours.

8.5.2. Before reweighing, the samples are cooled in a desiccator with anhydrous calcium chloride or together with an oven to room temperature.

8.5.3. Weighing is carried out with an error of up to 0.1 g.

8.6 . Results processing

8.6.1. Humidity of the solution by weight W m as a percentage is calculated with an error of up to 0.1% according to the formula

where r o is the density of the dry solution, determined according to clause 7.6.1;

8.6.3. The moisture content of a solution of a series of samples is determined as the arithmetic mean of the results of determining the moisture content of individual samples of the solution.

8.6.4. The test results must be recorded in a log, which indicates:

Place and time of sampling;

Moisture state of the solution;

The age of the solution and the date of testing;

Sample marking;

Humidity of the solution of samples (samples) and series by weight;

Humidity of the solution of samples (samples) and series by volume.

9. DETERMINATION OF SOLUTION WATER ABSORPTION

9.1. The water absorption of the solution is determined by testing samples. The dimensions and number of samples are taken according to clause 7.1.

9.2 . Equipment and materials

9.2.1. For testing use:

Drying cabinet according to OST 16.0.801.397;

Tank for saturating samples with water;

Wire brush or abrasive stone.

9.3 . Preparing for the test

9.3.1. The surface of the samples is cleaned of dust, dirt and traces of grease using a wire brush or abrasive stone.

9.3.2. Samples are tested in a state of natural moisture or dried to constant weight.

9.4 . Conducting a test

9.4.1. The samples are placed in a container filled with water in such a way that the water level in the container is approximately 50 mm higher than the top level of the stacked samples.

Samples are placed on spacers so that the height of the sample is minimal.

The temperature of the water in the container must be (20 ± 2) °C.

9.4.2. Samples are weighed every 24 hours of water absorption on a conventional or hydrostatic balance with an error of no more than 0.1%.

When weighing on a conventional balance, the samples removed from the water are preliminarily wiped with a wrung out damp cloth.

9.4.3. The test is carried out until the results of two successive weighings differ by no more than 0.1%.

9.4.4. Samples tested in a state of natural humidity, after the end of the water saturation process, are dried to constant weight according to clause 8.5.1.

9.5 . Results processing

9.5.1. Water absorption of a single sample solution by mass W m as a percentage is determined with an error of up to 0.1% according to the formula

where r o is the density of the dry solution, kg/m 3 ;

r in - the density of water, taken equal to 1 g / cm 3.

9.5.3. The water absorption of a solution of a series of samples is determined as the arithmetic mean of the test results of individual samples in a series.

9.5.4. In the journal in which the test results are entered, the following columns should be provided:

Sample marking;

Age of the solution and date of testing;

Water absorption of sample solution;

Water absorption of the sample series solution.

10. DETERMINATION OF THE FROST RESISTANCE OF THE SOLUTION

10.1. The frost resistance of the mortar is determined only in cases specified in the project.

Solutions grades 4; 10 and solutions prepared with air binders are not tested for frost resistance.

10.2. The solution is tested for frost resistance by repeated alternate freezing of samples-cubes with an edge of 70.7 mm in a state of saturation with water at a temperature of minus 15 - 20 ° C and thawing them in water at a temperature of 15 - 20 ° C.

10.3. For the test, six sample cubes are prepared, of which three samples are frozen, and the remaining samples are control.

10.4. For the brand of solution in terms of frost resistance, the largest number of cycles of alternate freezing and thawing is taken, which the samples withstand during the test.

Mortar grades for frost resistance should be accepted in accordance with the requirements of the current regulatory documentation.

10.5 . Equipment

10.5.1. For testing use:

freezer with forced ventilation and automatic temperature control within minus 15 - 20 °С;

Tank for saturating samples with water with a device that maintains the water temperature in the vessel within plus 15 - 20 °C;

Forms for the manufacture of samples in accordance with GOST 22685.

10 .6. Preparing for the test

10.6.1. The samples to be tested for frost resistance (basic) should be numbered, inspected and any defects noticed (minor edges or corners, chipping, etc.) should be recorded in the test log.

10.6.2. The main samples should be tested for frost resistance at 28 days of age after exposure to a normal curing chamber.

10.6.3. Control samples intended for compression testing should be stored in a normal hardening chamber at a temperature of (20 ± 2) ° C and a relative humidity of at least 90%.

10.6.4. The main samples of the solution, intended for testing for frost resistance, and control samples, intended for determining the compressive strength at 28 days of age, must be saturated with water before testing without prior drying by keeping them for 48 hours in water at a temperature of 15 - 20 ° FROM. In this case, the sample must be surrounded on all sides by a layer of water with a thickness of at least 20 mm. The saturation time in water is included in the total age of the solution.

10.7 . Conducting a test

10.7.1. Water-saturated base samples should be placed in the freezer in special containers or placed on wire racks. The distance between the samples, as well as between the samples and the walls of the containers and overlying shelves, must be at least 50 mm.

10.7.2. Samples should be frozen in a freezer that provides the possibility of cooling the chamber with samples and maintaining the temperature in it at minus 15 - 20 °C. The temperature should be measured at half the height of the chamber.

10.7.3. Samples should be loaded into the chamber after the air in it has cooled to a temperature not higher than minus 15 °C. If, after loading the chamber, the temperature in it is higher than minus 15 °C, then the beginning of freezing should be considered the moment the air temperature reaches minus 15 °C.

10.7.4. The duration of one freezing should be at least 4 hours.

10.7.5. Samples after unloading from the freezer should be thawed in a bath of water at a temperature of 15 - 20 ° C for 3 hours.

10.7.6. A control inspection of the samples should be carried out in order to terminate the frost resistance test of a series of samples in which the surface of two out of three samples has visible damage (delamination, through cracks, chipping).

10.7.7. After alternate freezing and thawing of the samples, the main samples should be tested for compression.

10.7.8. Compression specimens should be tested in accordance with the requirements of Sec. 6 of this standard.

10.7.9. Before the compression test, the main samples are inspected and the area of ​​damage to the faces is determined.

If there are signs of damage to the supporting faces of the samples (peeling, etc.), before testing, they should be leveled with a layer of fast-hardening compound no more than 2 mm thick. Samples in this case should be tested 48 hours after gravy, and the first day the samples should be stored in a humid environment, and then in water at a temperature of 15-20 °C.

10.7.10. Control samples should be tested for compression in a water-saturated state before freezing the main samples. Before mounting on the press, the supporting surfaces of the specimens must be wiped with a damp cloth.

10.7.11. When assessing frost resistance by weight loss after the required number of freezing and thawing cycles, the samples are weighed in a state saturated with water with an error of no more than 0.1%.

10.7.12. When assessing frost resistance according to the degree of damage, the samples are inspected every five cycles of alternate freezing and thawing. Samples are inspected after they have been thawed every five cycles.

10.8 . Results processing

10.8.1. Frost resistance in terms of loss of compressive strength of samples during alternate freezing and thawing is evaluated by comparing the strength of the main and control samples in a state saturated with water.

The strength loss of samples D in percent is calculated by the formula

where m 1 - mass of the sample saturated with water before testing it for frost resistance, g;

m 2 - mass of the sample saturated with water after testing it for frost resistance, g.

The weight loss of the samples after the frost resistance test is calculated as the arithmetic mean of the test results of three samples.

Permissible weight loss of samples after alternate freezing and thawing - no more than 5%.

10.8.3. The following data should be indicated in the test log of samples for frost resistance:

Type and composition of the solution, design mark for frost resistance;

Marking, date of manufacture and date of testing;

Dimensions and weight of each sample before and after testing and percentage weight loss;

curing conditions;

Description of the defects found in the specimens prior to testing;

Description of external signs of destruction and damage after the test;

The ultimate compressive strength of each of the main and control samples and the percentage change in strength after the frost resistance test;

Number of freeze and thaw cycles.

ATTACHMENT 1
Mandatory

DETERMINATION OF THE STRENGTH OF A SOLUTION TAKEN FROM THE SEAMS FOR COMPRESSION

1. The strength of the solution is determined by testing the compression of cubes with ribs of 2 - 4 cm, made of two plates, taken from horizontal masonry joints or joints of large-panel structures.

2. The plates are made in the form of a square, the side of which should be 1.5 times the thickness of the plate, equal to the thickness of the seam.

3. Gluing the solution plates to obtain cubes with ribs of 2 - 4 cm and leveling their surfaces is carried out using a thin layer of gypsum dough (1 - 2 mm).

4. It is allowed to cut sample-cubes from plates in the case when the thickness of the plate provides the required size of the rib.

5. Samples should be tested one day after their manufacture.

6. Sample cubes from a solution with ribs 3 - 4 cm long are tested according to paragraph 6.5 of this standard.

7. To test sample cubes from a solution with ribs of 2 cm, as well as thawed solutions, a small-sized desktop press of the PS type is used. The normal load range is 1.0 - 5.0 kN (100 - 500 kgf).

8. The strength of the solution is calculated according to clause 6.6.1 of this standard. The mortar strength shall be determined as the arithmetic mean of the test results of five specimens.

9. To determine the strength of the solution in cubes with ribs of 7.07 cm, the results of testing cubes of summer and winter solutions that have hardened after thawing should be multiplied by the coefficient given in the table.

JOURNAL
tests to determine the mobility, average density
mortar and compressive strength, medium density
solution samples

Laboratory manager _________________________________________________

Responsible for manufacturing

and testing of samples ______________________________________________________________

* In the "Notes" column, the defects of the samples should be indicated: shells, foreign inclusions and their locations, the special nature of the destruction, etc.

INFORMATION DATA 7.3.1, 8.4.1

OST 16.0.801.397-87

4.2.1, 7.3.1, 8.4.1, 9.2.1

TU 13-7308001-758-88

5. REPUBLICATION. October 2010

GOST 5802-86

UDC 666.971.001.4:006.354 Group Zh19

INTERSTATE STANDARD

BUILDING SOLUTIONS
TEST METHODS

Mortars. test methods.

OKP 57 4500
Date of introduction 01.07.86

INFORMATION DATA

1. DEVELOPED AND INTRODUCED by the Central Research Institute building structures(TsNIISK named after Kucherenko) Gosstroy of the USSR

2. APPROVED AND INTRODUCED BY Decree No. 214 of the USSR State Committee for Construction Affairs of December 11, 1985

3. REPLACE GOST 5802-78

4. REFERENCE REGULATIONS AND TECHNICAL DOCUMENTS

Designation of the NTD to which the link is given Item number
GOST 166-89 6.3.1, 7.3.1
GOST 310.4-81 1.7, 1.15
GOST 427-75 3.2.1
GOST 450-77 7.3.1, 8.4.1
GOST 2184-77 7.3.1
GOST 10180-90 1.15
GOST 10181-2000 1.15
GOST 11109-90 5.2.1
GOST 21104-2001 3.2.1, 4.2.1, 5.2.1, 7.3.1, 8.4.1, 9.2.1
GOST 22685-89 4.2.1, 10.5.1
GOST 23683-89 7.3.1, 10.5.1
GOST 24544-81 1.15
GOST 24992-81 1.15
GOST 25336-82 7.3.1, 8.4.1
GOST 28840-90 6.3.1
OST 16.0.801.397-87 4.2.1, 7.3.1, 8.4.1, 9.2.1
TU 13-7308001-758-88 5.2.1

5. REPUBLICATION. October 2002

This standard applies to mortar mixtures and building mortars made with mineral binders (cement, lime, gypsum, soluble glass) used in all types of construction, except for hydraulic engineering.
The standard establishes methods for determining the following properties of the mortar mixture and solution:
- mobility, average density, stratification, water-holding capacity, water separation of the mortar mixture;
- tensile strength (hereinafter referred to as strength) in compression, tensile splitting, flexural tensile strength, shrinkage, average density, humidity, water absorption, frost resistance of the hardened solution.
This standard does not apply to heat-resistant, chemically resistant and straining mortars.

1. GENERAL REQUIREMENTS

1.1. Determination of the mobility, density of the mortar mixture and the compressive strength of the mortar is mandatory for mortars of all types. Other properties of mortar mixtures and mortar are determined in cases provided for by the project or the rules for the production of work.
1.2. Samples for testing the mortar mixture and making samples are taken before the mortar mixture begins to set.
1.3. Samples should be taken from the mixer at the end of the mixing process, at the place of application of the solution from vehicles or a working box.
Samples are taken from at least three places at different depths.
The volume of the sample must be at least 3 liters.
1.4. The sample taken before the test must be additionally moved for 30 s.
1.5. The test of the mortar mixture should be started no later than 10 minutes after sampling.
1.6. The test of hardened solutions is carried out on samples. The shape and dimensions of the samples, depending on the type of test, must correspond to those indicated in Table. one.

Table 1

Test type Sample shape Geometrical dimensions, mm
Determination of compressive and tensile splitting strength Cube Rib length 70.7
Determination of tensile strength in bending Square prism 40x40x160
Determination of shrinkage The same 40x40x160
Determination of density, humidity, water absorption, frost resistance Cube Rib length 70.7

Note. In the production control of solutions, which are simultaneously subject to requirements for tensile strength in bending and in compression, it is allowed to determine the compressive strength of the solution by testing the halves of the prism samples obtained after the bending test of the prism samples according to GOST 310.4.

1.7. The deviation of the dimensions of the molded samples along the length of the edges of the cubes, the sides of the cross section of the prisms indicated in table. 1 should not exceed 0.7 mm.
1.8. Before forming the samples, the inner surfaces of the molds are covered with a thin layer of lubricant.
1.9. All samples must be labelled. The marking must be indelible and must not damage the sample.
1.10. The fabricated samples are measured with a caliper with an error of up to 0.1 mm.
1.11. In winter conditions, to test the solution with and without antifreeze additives, sampling and sample preparation should be carried out at the place of its application or preparation, and the samples should be stored in the same temperature and humidity conditions in which the solution is placed in the structure.
Samples should be stored on the shelf of a lockable inventory box with mesh walls and a waterproof roof.
1.12. All measuring instruments and parameters of the vibration platform should be checked within the time limits specified by the metrological services of the State Standard.
1.13. The temperature of the room in which the tests are carried out should be (20 ± 2) ° C, relative humidity 50-70%.
The temperature and humidity of the room are measured with an MV-4 aspiration psychrometer.
1.14. For testing mortar mixtures and solutions, vessels, spoons, and other devices must be made of steel, glass or plastic.
The use of products made of aluminum or galvanized steel and wood is not allowed.
1.15. The compressive strength of the mortar taken from the masonry joints is determined according to the method given in Appendix 1.
The tensile strength of the solution in bending and compression is determined according to GOST 310.4.
The tensile strength of the mortar during splitting is determined according to GOST 10180.
Adhesion strength is determined according to GOST 24992.
Shrinkage deformation is determined according to GOST 24544.
The water separation of the mortar mixture is determined according to GOST 10181.
1.16. The results of testing samples of mortar mixtures and mortar samples are recorded in a journal, on the basis of which a document is drawn up that characterizes the quality of the mortar.

2. DETERMINATION OF MOBILITY OF SOLUTION MIXTURE

2.1. The mobility of the mortar mixture is characterized by the depth of immersion of the reference cone into it, measured in centimeters.
2.2. Equipment
2.2.1. For testing use:
a device for determining mobility (Fig. 1);
trowel.

Device for determining the mobility of the mortar mixture

1 - tripod; 2 - scale; 3 - reference cone; 4 - rod; 5 - holders;
6 - guides; 7 - vessel for the mortar mixture; 8 - lock screw

2.2.2. The reference cone of the device is made of sheet steel or plastic with a steel tip. The corner at the top should be 30° ± 30".
The mass of the reference cone with the rod must be (300 ± 2) g.
2.3. Test preparation
2.3.1. All surfaces of the cone and vessel in contact with the mortar mixture should be cleaned of dirt and wiped with a damp cloth.
2.4. Testing
2.4.1. The immersion value of the cone is determined in the sequence below.
The device is installed on a horizontal surface and the freedom of sliding of the rod 4 in the guides 6 is checked.
2.4.2. Vessel 7 is filled with the mortar mixture 1 cm below its edges and sealed by baying with a steel rod 25 times and lightly tapping on the table 5-6 times, after which the vessel is placed on the platform of the device.
2.4.3. The tip of the cone 3 is brought into contact with the surface of the solution in the vessel, the rod of the cone is fixed with a locking screw 8 and the first reading is made on the scale. Then the locking screw is released.
2.4.4. The cone must be immersed in the mortar mixture freely. The second reading is taken on a scale 1 min after the start of the cone immersion.
2.4.5. The immersion depth of the cone, measured with an error of up to 1 mm, is determined as the difference between the first and second readings.
2.5. Results processing
2.5.1. The immersion depth of the cone is estimated from the results of two tests on different samples of the mortar mixture of one batch as the arithmetic mean of them and rounded off.
2.5.2. The difference in the performance of private tests should not exceed 20 mm. If the difference is more than 20 mm, then the tests should be repeated on a new sample of the mortar mixture.
2.5.3. The test results are recorded in the log in the form according to Appendix 2.

3. DETERMINATION OF THE DENSITY OF THE SOLUTION MIXTURE

3.1. The density of the mortar mixture is characterized by the ratio of the mass of the compacted mortar mixture to its volume and is expressed in g/cm3.
3.2. Equipment
3.2.1. For testing use:
a steel cylindrical vessel with a capacity of 1000 + 2 ml (Fig. 2);
steel rod 12 mm in diameter, 300 mm long;
steel ruler 400 mm according to GOST 427.

Steel cylindrical vessel

3.3. Preparing for testing and conducting tests
3.3.1. Before testing, the vessel is preliminarily weighed with an error of up to 2 g. Then it is filled with an excess of the mortar mixture.
3.3.2. The mortar mixture is compacted by baying with a steel rod 25 times and 5-6 times lightly tapping on the table.
3.3.3. After compaction, the excess mortar mixture is cut off with a steel ruler. The surface is carefully aligned flush with the edges of the vessel. The walls of the measuring vessel are cleaned with a damp cloth from the solution that has fallen on them. The vessel containing the mortar mixture is then weighed to the nearest 2 g.
3.4. Results processing
3.4.1. The density of the mortar mixture, g / cm3, is calculated by the formula
(1)
where m is the mass of the measuring vessel with the mortar mixture, g;
m1 - mass of measuring vessel without mixture, g.
3.4.2. The density of the mortar mixture is determined as the arithmetic mean of the results of two determinations of the density of the mixture from one sample, which differ from each other by no more than 5% from the smaller value.
With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.
3.4.3. The test results must be recorded in the log in the form in accordance with Appendix 2.

4. DETERMINATION OF THE SEPARATION OF A SOLUTION MIXTURE

4.1. The stratification of the mortar mixture, which characterizes its cohesion under dynamic action, is determined by comparing the mass content of the aggregate in the lower and upper parts of the freshly molded sample with dimensions of 150x150x150 mm.
4.2. Equipment
4.2.1. For testing use:
steel molds with dimensions 150x150x150 mm according to GOST 22685;
laboratory vibration platform type 435A;
laboratory scales according to GOST 24104;
drying cabinet according to OST 16.0.801.397;
sieve with cells 0.14 mm;
baking sheet;
steel rod with a diameter of 12 mm, a length of 300 mm.
4.2.2. The laboratory vibratory platform in the loaded state should provide vertical oscillations with a frequency of 2900 ± 100 per minute and an amplitude of (0.5 ± 0.05) mm. The vibrating platform must have a device that ensures, when vibrating, a rigid fastening of the form with a solution to the table surface.
4.3. Testing
4.3.1. The mortar mixture is placed and compacted in a mold for control samples with dimensions of 150x150x150 mm. After that, the compacted mortar mixture in the form is subjected to vibration on a laboratory vibration platform for 1 min.
4.3.2. After vibrating, the upper layer of the solution with a height of (7.5 ± 0.5) mm is taken from the mold onto a baking sheet, and the lower part of the sample is unloaded from the mold by tipping onto the second baking sheet.
4.3.3. The selected samples of the mortar mixture are weighed with an error of up to 2 g and subjected to wet sieving on a sieve with 0.14 mm holes.
During wet sieving, individual parts of the sample placed on a sieve are washed with a stream of clean water until the binder is completely removed. The rinsing of the mixture is considered complete when

GOST 5802-86

Group G19

STATE STANDARD OF THE UNION OF THE SSR

BUILDING SOLUTIONS

Test Methods

Mortars. Test methods

OKP 57 4500

Introduction date 1986-07-01

* DEVELOPED by the Central Research Institute of Building Structures (TsNIISK named after Kucherenko) of the USSR State Construction Committee

* PERFORMERS:

V.A.Kameiko, Ph.D. tech. sciences (topic leader); I.T.Kotov, Ph.D. tech. sciences; N.I. Levin, Ph.D. tech. sciences; B.A. Novikov, Ph.D. tech. sciences; G.M.Kirpichenko, Ph.D. tech. sciences; V.S. Martynov; V.E. Budreyka; V.M. Kosarev, M.P. Zaitsev; N.S. Statkevich; E.B. Madorsky, Ph.D. tech. sciences; Yu.B.Volkov, Ph.D. tech. sciences; D.I. Prokofiev

* INTRODUCED by the Central Research Institute of Building Structures (TsNIISK named after Kucherenko) of the USSR State Construction Committee

_________________

* Information about the developers and performers is given from the publication: Gosstandart of the USSR - Standards Publishing House, 1986. Note "CODE".

APPROVED AND INTRODUCED BY Decree of the State Committee of the USSR for Construction of December 11, 1985 N 214

REPUBLICATION. June 1992

This standard applies to mortar mixtures and building mortars made with mineral binders (cement, lime, gypsum, soluble glass) used in all types of construction, except for hydraulic engineering.

The standard establishes methods for determining the following properties of the mortar mixture and solution:

mobility, medium density, stratification, water-holding capacity, water separation of the mortar mixture;

This standard does not apply to heat-resistant, chemically resistant and straining mortars.

1. GENERAL REQUIREMENTS

1.1. Determination of the mobility, density of the mortar mixture and the compressive strength of the mortar is mandatory for all types of mortar. Other properties of mortar mixtures and mortar are determined in cases provided for by the project or the rules for the production of work.

1.2. Samples for testing the mortar mixture and making samples are taken before the mortar mixture begins to set.

1.3. Samples should be taken from the mixer at the end of the mixing process, at the place of application of the solution from vehicles or a working box.

Samples are taken from at least three places at different depths.

The volume of the sample must be at least 3 liters.

1.4. The sample taken before testing must be additionally mixed for 30 s.

1.5. The test of the mortar mixture should be started no later than 10 minutes after sampling.

1.6. The test of hardened solutions is carried out on samples. The shape and dimensions of the samples, depending on the type of test, must correspond to those indicated in Table. one.

1.7. The deviation of the dimensions of the molded samples along the length of the edges of the cubes, the sides of the cross section of the prisms indicated in table. 1 should not exceed 0.7 mm.

Table 1

Note. In the production control of solutions, which are simultaneously subject to requirements for tensile strength in bending and compressive strength, it is allowed to determine the compressive strength of the solution by testing the halves of the prism samples obtained after the bending test of the prism samples according to GOST 310.4-81.

1.8. Before forming the samples, the inner surfaces of the molds are covered with a thin layer of lubricant.

1.9. All samples must be labelled. The marking must be indelible and must not damage the sample.

1.10. The fabricated samples are measured with a caliper with an error of up to 0.1 mm.

1.11. In winter conditions, to test the solution with and without antifreeze additives, sampling and sample preparation should be carried out at the place of its application or preparation, and the samples should be stored in the same temperature and humidity conditions in which the solution is placed in the structure.

Samples should be stored on the shelf of a lockable inventory box with mesh walls and a waterproof roof.

1.12. All measuring instruments and parameters of the vibration platform should be checked within the time limits specified by the metrological services of the State Standard.

1.13. The temperature of the room in which the tests are carried out should be (20 ± 2) ° C, relative humidity 50-70%.

The temperature and humidity of the room are measured with an MV-4 aspiration psychrometer.

1.14. For testing mortar mixtures and solutions, vessels, spoons, and other devices must be made of steel, glass or plastic.

The use of products made of aluminum or galvanized steel and wood is not allowed.

1.15. The compressive strength of the mortar taken from the masonry joints is determined according to the method given in Appendix 1.

The tensile strength of the solution in bending and compression is determined according to GOST 310.4-81.

The tensile strength of the solution during splitting is determined according to GOST 10180-90.

Adhesion strength is determined according to GOST 24992-81.

Shrinkage deformation is determined according to GOST 24544-81.

The water separation of the mortar mixture is determined according to GOST 10181.0-81.

1.16. The results of testing samples of mortar mixtures and mortar samples are recorded in a journal, on the basis of which a document is drawn up that characterizes the quality of the mortar.

2. DETERMINATION OF MOBILITY OF SOLUTION MIXTURE

2.1. The mobility of the mortar mixture is characterized by the depth of immersion of the reference cone into it, measured in centimeters.

2.2. Equipment

2.2.1. For testing use:

a device for determining mobility (Fig. 1);

trowel.

2.2.2. The reference cone of the device is made of sheet steel or plastic with a steel tip. The apex angle must be 30° ± .

The mass of the reference cone with the rod must be (300 ± 2) g.

Device for determining the mobility of the mortar mixture

1 - tripod; 2 - scale; 3 - reference cone; 4 - rod; 5 - holders; 6 - guides;

7 - vessel for the mortar mixture; 8 set screw

Heck. one

2.3. Test preparation

2.3.1. All surfaces of the cone and vessel in contact with the mortar mixture should be cleaned of dirt and wiped with a damp cloth.

2.4. Testing

2.4.1. The immersion value of the cone is determined in the sequence below.

The device is installed on a horizontal surface and the freedom of sliding of the rod 4 in the guides 6 is checked.

2.4.2. Vessel 7 is filled with the mortar mixture 1 cm below its edges and sealed by baying with a steel rod 25 times and lightly tapping on the table 5-6 times, after which the vessel is placed on the platform of the device.

2.4.3. The tip of the cone 3 is brought into contact with the surface of the solution in the vessel, the rod of the cone is fixed with a locking screw 8 and the first reading is made on the scale. Then the locking screw is released.

2.4.4. The cone must be immersed in the mortar mixture freely. The second reading is taken on a scale 1 min after the start of the cone immersion.

2.4.5. The immersion depth of the cone, measured with an error of up to 1 mm, is determined as the difference between the first and second readings.

2.5. Results processing

2.5.1. The immersion depth of the cone is estimated from the results of two tests on different samples of the mortar mixture of one batch as the arithmetic mean of them and rounded off.

2.5.2. The difference in the performance of private tests should not exceed 20 mm. If the difference is more than 20 mm, then the tests should be repeated on a new sample of the mortar mixture.

2.5.3. The test results are recorded in the log in the form according to Appendix 2.

3.DETERMINATION OF THE DENSITY OF THE MORTAR MIXTURE

3.1. The density of the mortar mixture is characterized by the ratio of the mass of the compacted mortar mixture to its volume and is expressed in g/cm.

3.2. Equipment

3.2.1. For testing use:

a steel cylindrical vessel with a capacity of 1000 ml (Fig. 2);

Steel cylindrical vessel

Heck. 2

steel rod 12 mm in diameter, 300 mm long;

steel ruler 400 mm according to GOST 427-75.

3.3. Preparing for testing and conducting tests

3.3.1. Before testing, the vessel is preliminarily weighed with an error of up to 2 g. Then it is filled with an excess of the mortar mixture.

3.3.2. The mortar mixture is compacted by baying with a steel rod 25 times and 5-6 times lightly tapping on the table.

3.3.3. After compaction, the excess mortar mixture is cut off with a steel ruler. The surface is carefully aligned flush with the edges of the vessel. The walls of the measuring vessel are cleaned with a damp cloth from the solution that has fallen on them. The vessel containing the mortar mixture is then weighed to the nearest 2 g.

3.4. Results processing

3.4.1. The density of the mortar mixture, g / cm, is calculated by the formula

, (1)

where is the mass of the measuring vessel with the mortar mixture, g;

Weight of measuring vessel without mixture, g

3.4.2. The density of the mortar mixture is determined as the arithmetic mean of the results of two determinations of the density of the mixture from one sample, which differ from each other by no more than 5% from the lower value.

With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

3.4.3. The test results must be recorded in the log in the form in accordance with Appendix 2.

4. DETERMINATION OF THE SEPARATION OF A SOLUTION MIXTURE

4.1. The stratification of the mortar mixture, which characterizes its cohesion under dynamic action, is determined by comparing the mass content of the aggregate in the lower and upper parts of the freshly molded sample with dimensions of 150x150x150 mm.

4.2. Equipment

4.2.1. For testing use:

steel molds with dimensions 150x150x150 mm according to GOST 22685-89;

laboratory vibration platform type 435A;

laboratory scales according to GOST 24104-88;

sieve with cells 0.14 mm;

baking sheet;

steel rod with a diameter of 12 mm, a length of 300 mm.

4.2.2. The laboratory vibrating platform in the loaded state should provide vertical oscillations with a frequency of 2900 ± 100 per minute and an amplitude of (0.5 ± 0.05) mm. The vibrating platform must have a device that ensures, when vibrating, a rigid fastening of the form with a solution to the table surface.

4.3. Testing

4.3.1. The mortar mixture is placed and compacted in a mold for control samples with dimensions of 150x150x150 mm. After that, the compacted mortar mixture in the form is subjected to vibration on a laboratory vibration platform for 1 min.

4.3.2. After vibrating, the upper layer of the solution with a height of (7.5 ± 0.5) mm is taken from the mold onto a baking sheet, and the lower part of the sample is unloaded from the mold by tipping onto the second baking sheet.

4.3.3. The selected samples of the mortar mixture are weighed with an error of up to 2 g and subjected to wet sieving on a sieve with 0.14 mm holes.

During wet sieving, individual parts of the sample placed on a sieve are washed with a stream of clean water until the binder is completely removed. The washing of the mixture is considered complete when clean water flows out of the sieve.

4.3.4. The washed portions of the filler are transferred to a clean baking sheet, dried to a constant weight at a temperature of 105-110 ° C and weighed with an error of up to 2 g.

4.4. Results processing

4.4.1. The content of the filler in the upper (lower) parts of the compacted mortar mixture in percent is determined by the formula.

, (2)

where is the mass of the washed dried aggregate from the upper (lower) part of the sample, g;

Mass of the mortar mixture taken from the upper (lower) part of the sample, g

4.4.2. The index of stratification of the mortar mixture in percent is determined by the formula

, (3)

where is the absolute value of the difference between the content of aggregate in the upper and lower parts of the sample,%;

The total content of aggregate in the upper and lower parts of the sample, %.

4.4.3. The stratification index for each sample of the mortar mixture is determined twice and calculated with rounding up to 1% as the arithmetic mean of the results of two determinations that differ from each other by no more than 20% from the lower value. With a greater discrepancy between the results, the determination is repeated on a new sample of the mortar mixture.

4.4.4. The test results must be recorded in a log, which indicates:

date and time of the test;

sampling site;

brand and type of solution;

results of particular definitions;

average result.

5. DETERMINATION OF THE WATER-HOLDING CAPABILITY OF A MORTAR MIXTURE

5.1. The water-holding capacity is determined by testing a 12 mm thick layer of mortar laid on blotting paper.

5.2. Equipment and materials

5.2.1. For testing use:

sheets of blotting paper measuring 150x150 mm according to TU 13-7308001-758 - 88;

gauze pads 250x350 mm in size according to GOST 11109-90;

a metal ring with an inner diameter of 100 mm, a height of 12 mm and a wall thickness of 5 mm;

a glass plate measuring 150x150 mm, 5 mm thick;

laboratory scales according to GOST 24104-88;

a device for determining the water-holding capacity of the mortar mixture (Fig. 3).

5.3. Preparing for testing and conducting tests

5.3.1. Before testing, 10 sheets of blotting paper are weighed with an error of up to 0.1 g, placed on a glass plate, a gauze pad is placed on top, a metal ring is installed and weighed again.

5.3.2. The thoroughly mixed mortar mixture is placed flush with the edges of the metal ring, leveled, weighed and left for 10 minutes.

5.3.3. The metal ring with the solution is carefully removed along with the gauze.

The blotting paper is weighed to the nearest 0.1 g.

Scheme of the device for determining the water-retaining capacity of the mortar mixture

1 - metal ring with a solution; 2 - 10 layers of blotting paper; 3 - glass plate; 4 - layer of gauze fabric

Heck. 3

5.4. Results processing

5.4.1. The water-holding capacity of the mortar mixture is determined by the percentage of water in the sample before and after the experiment according to the formula

, (4)

where is the mass of blotting paper before testing, g;

Mass of blotting paper after testing, g;

Unit weight without mortar mixture, g;

Mass of the installation with the mortar mixture, g

5.4.2. The water-holding capacity of the mortar mixture is determined twice for each sample of the mortar mixture and is calculated as the arithmetic mean of the results of two determinations that differ from each other by no more than 20% from the lower value.

5.4.3. The test results must be recorded in a log, which indicates:

date and time of testing;

sampling site;

brand and type of mortar;

results of particular determinations and the arithmetic mean result.

6. DETERMINATION OF THE COMPRESSION STRENGTH OF SOLUTION

6.1. The compressive strength of the mortar should be determined on cube samples measuring 70.7x70.7x70.7 mm at the age specified in the standard or technical specifications for this type of mortar. Three specimens are made for each test period.

6.2. Sampling and general technical requirements for the method for determining compressive strength - according to paragraphs. 1.1-1.14 of this standard.

6.3. Equipment

6.3.1. For testing use:

detachable steel molds with and without pallet according to GOST 22685-89;

hydraulic press according to GOST 28840-90;

calipers according to GOST 166-89;

steel rod with a diameter of 12 mm, a length of 300 mm;

spatula (Fig. 4).

Spatula for compacting the mortar mixture

Heck. 4

6.4. Preparing for the test

6.4.1. Mortar samples with a mobility of up to 5 cm should be made in molds with a pallet.

The form is filled with a solution in two layers. Compaction of the layers of the solution in each compartment of the form is carried out with 12 spatula pressures: 6 pressures along one side, 6 - in the perpendicular direction.

The excess solution is cut flush with the edges of the form with a steel ruler moistened with water and the surface is smoothed.

6.4.2. Samples from the mortar mixture with a mobility of 5 cm or more are made in molds without a pallet.

The form is set on a brick covered with newsprint moistened with water, or other non-glued paper. The size of the paper should be such that it covers the side faces of the brick. Bricks before use must be hand-lapped one against the other to eliminate sharp irregularities. The brick is used ordinary clay with a moisture content of not more than 2% and a water absorption of 10-15% by weight. Bricks with traces of cement on the edges cannot be reused.

6.4.3. The molds are filled with a mortar mixture at one time with some excess and compacted by baying with a steel rod 25 times along a concentric circle from the center to the edges.

6.4.4. In the conditions of winter masonry, for testing mortars with antifreeze additives and without antifreeze additives, for each test period and each controlled area, 6 samples are made, three of which are tested within the time limits necessary for floor-by-floor control of the mortar strength after 3-hour thawing at a temperature not lower than (20 ± 2) ° C, and the remaining three samples are tested after thawing and subsequent 28-day hardening at a temperature not lower than (20 ± 2) ° C. The thawing time should correspond to that indicated in table. 2.

table 2

6.4.5. Forms filled with a mortar mixture on hydraulic binders are kept until demoulding in a normal storage chamber at a temperature of (20 ± 2) ° C and a relative humidity of 95-100%, and forms filled with a mortar mixture on air binders are kept indoors at a temperature ( 20±2)° С and relative humidity (65±10)%.

6.4.6. The samples are released from the forms after (24±2) hours after laying the mortar mixture.

Samples made from mortar mixtures prepared on Portland slag cements, pozzolanic Portland cements with setting retarder additives, as well as winter masonry samples stored outdoors, are released from molds after 2-3 days.

6.4.7. After release from molds, specimens should be stored at (20 ± 2)°C. In this case, the following conditions must be observed: samples from solutions prepared with hydraulic binders must be stored in a normal storage chamber at a relative air humidity of 95-100% for the first 3 days, and the remaining time before the test - indoors at a relative air humidity of (65 ±10)% (from solutions hardening in air) or in water (from solutions hardening in a humid environment); samples from solutions prepared with air binders should be stored indoors at a relative humidity of (65 ± 10)%.

6.4.8. In the absence of a normal storage chamber, it is allowed to store samples prepared with hydraulic binders in wet sand or sawdust.

6.4.9. When stored indoors, specimens must be protected from drafts, heating from heating appliances, etc.

6.4.10. Before the compression test (for the subsequent determination of density), the samples are weighed with an error of up to 0.1% and measured with a caliper with an error of up to 0.1 mm.

6.4.11. Samples stored in water should be removed from it no earlier than 10 min before testing and wiped with a damp cloth.

Samples stored indoors should be cleaned with a broom.

6.5. Conducting a test

6.5.1. Before installing the sample on the press, the particles of the solution remaining from the previous test are carefully removed from the support plates of the press in contact with the faces of the sample.

6.5.2. The sample is mounted on the lower plate of the press centrally relative to its axis so that the base is the faces that were in contact with the walls of the mold during its manufacture.

6.5.3. The scale of the force meter of the testing machine or press is chosen from the condition that the expected value of the breaking load should be in the range of 20-80% of the maximum load allowed by the selected scale.

The type (brand) of the testing machine (press) and the selected scale of the force meter are recorded in the test log.

6.5.4. The load on the sample must increase continuously at a constant rate of (0.6 ± 0.4) MPa [(6 ± 4) kgf / cm ] per second until it fails.

The maximum force achieved during the testing of the sample is taken as the value of the breaking load.

6.6. Results processing

6.6.1. The compressive strength of the solution is calculated for each sample with an error of up to 0.01 MPa (0.1 kgf / cm ) according to the formula

, (5)

Working cross-sectional area of ​​the sample, cm.

6.6.2. The working cross-sectional area of ​​the samples is determined from the measurement results as the arithmetic mean of the areas of two opposite faces.

6.6.3. The compressive strength of the solution is calculated as the arithmetic mean of the test results of three samples.

6.6.4. The test results are recorded in the log in the form according to Appendix 2.

7. DETERMINATION OF THE AVERAGE DENSITY OF THE SOLUTION

7.1. The density of the solution is determined by testing samples-cubes with an edge of 70.7 mm, made from a mortar mixture of the working composition, or plates measuring 50x50 mm, taken from the joints of structures. The thickness of the plates must correspond to the thickness of the seam.

During production control, the density of solutions is determined by testing samples intended to determine the strength of the solution.

7.2. Samples are made and tested in batches. The series should consist of three samples.

7.3. Equipment, materials

7.3.1. For testing use:

technical scales according to GOST 24104-88;

drying cabinet according to OST 16.0.801.397-87;

caliper according to GOST 166-89;

steel rulers according to GOST 427-75;

desiccator according to GOST 25336-82;

anhydrous calcium chloride according to GOST 450-77 or sulfuric acid with a density of 1.84 g/cm according to GOST 2184-77;

paraffin according to GOST 23683-89.

7.4. Preparing for the test

7.4.1. The density of the solution is determined by testing samples in a state of natural moisture or a normalized moisture state: dry, air-dry, normal, water-saturated.

7.4.2. When determining the density of a solution in a state of natural humidity, the samples are tested immediately after they are taken or stored in a vapor-tight package or sealed container, the volume of which exceeds the volume of the samples placed in it by no more than 2 times.

7.4.3. The density of the solution in a normalized moisture state is determined by testing solution samples having a normalized moisture content or an arbitrary moisture content, followed by recalculation of the results obtained for the normalized moisture content according to formula (7).

7.4.4. When determining the density of a solution in a dry state, the samples are dried to constant weight in accordance with the requirements of clause 8.5.1.

7.4.5. When determining the density of a solution in an air-dry state, the samples are kept for at least 28 days in a room at a temperature of (25 ± 10) ° C and relative humidity of (50 ± 20)% before testing.

7.4.6. When determining the density of the solution under normal humidity conditions, the samples are stored for 28 days in a normal hardening chamber, desiccator or other sealed container at a relative humidity of at least 95% and a temperature of (20 ± 2) ° C.

7.4.7. When determining the density of a solution in a water-saturated state, the samples are saturated with water in accordance with the requirements of clause 9.4.

7.5. Conducting a test

7.5.1. The volume of the samples is calculated from their geometric dimensions. The dimensions of the samples are determined with a caliper with an error of not more than 0.1 mm.

7.5.2. The mass of samples is determined by weighing with an error of not more than 0.1%.

7.6. Results processing

7.6.1. The density of the solution sample is calculated with an error of up to 1 kg / m according to the formula

, (6)

where is the mass of the sample, g;

Sample volume, see .

7.6.2. The solution density of a series of samples is calculated as the arithmetic mean of the test results of all samples in the series.

Note. If the determination of the density and strength of the solution is carried out by testing the same samples, then the samples rejected when determining the strength of the solution are not taken into account when determining its density.

7.6.3. The density of the solution at a normalized humidity state, kg / m, is calculated by the formula

, (7)

where is the density of the solution at humidity, kgf / m;

Normalized moisture content of the solution, %;

The moisture content of the solution at the time of the test, determined according to Sec. 8.

7.6.4. The test results must be recorded in the log in the form in accordance with Appendix 2.

8. DETERMINATION OF SOLUTION HUMIDITY

8.1. The moisture content of the solution is determined by testing samples or samples obtained by crushing samples after their strength test or extracted from finished products or structures.

8.2. The largest size of the crushed pieces of the solution should be no more than 5 mm.

8.3. Samples are crushed and weighed immediately after sampling and stored in a vapor-tight package or sealed container, the volume of which exceeds the volume of the samples placed in it by no more than two times.

8.4. Equipment and materials

8.4.1. For testing use:

laboratory scales according to GOST 24104-88;

drying cabinet according to OST 16.0.801.397-87;

desiccator according to GOST 25336-82;

baking sheets;

calcium chloride according to GOST 450-77.

8.5. Testing

8.5.1. Prepared samples or samples are weighed and dried to constant weight at a temperature of (105 ± 5) ° C.

Gypsum solutions are dried at a temperature of 45-55 ° C.

A constant is the mass at which the results of two successive weighings differ by no more than 0.1%. In this case, the time between weighings should be at least 4 hours.

8.5.2. Before reweighing, the samples are cooled in a desiccator with anhydrous calcium chloride or together with an oven to room temperature.

8.5.3. Weighing is carried out with an error of up to 0.1 g.

8.6. Results processing

8.6.1. The moisture content of the solution by weight in percent is calculated with an error of up to 0.1% according to the formula

, (8)

where is the mass of the solution sample before drying, g;

Weight of solution sample after drying, g

8.6.2. The moisture content of the solution by volume in percent is calculated with an error of up to 0.1% according to the formula

= , (9)

where is the density of the dry solution, determined according to clause 7.6.1;

Density of water taken equal to 1 g/cm.

8.6.3. The moisture content of a solution of a series of samples is determined as the arithmetic mean of the results of determining the moisture content of individual samples of the solution.

8.6.4. The test results must be recorded in a log, which indicates:

place and time of sampling;

moisture state of the solution;

the age of the solution and the date of testing;

sample marking;

moisture content of the solution of samples (samples) and series by weight;

humidity of the solution of samples (samples) and series by volume.

9. DETERMINATION OF SOLUTION WATER ABSORPTION

9.1. The water absorption of the solution is determined by testing samples. The dimensions and number of samples are taken according to clause 7.1.

9.2. Equipment and materials

9.2.1. For testing use:

laboratory scales according to GOST 24104-88;

drying cabinet according to OST 16.0.801.397-87;

container for saturating samples with water;

wire brush or abrasive stone.

9.3. Preparing for the test

9.3.1. The surface of the samples is cleaned of dust, dirt and traces of grease using a wire brush or abrasive stone.

9.3.2. Samples are tested in a state of natural moisture or dried to constant weight.

9.4. Conducting a test

9.4.1. The samples are placed in a container filled with water in such a way that the water level in the container is approximately 50 mm higher than the top level of the stacked samples.

Samples are placed on spacers so that the height of the sample is minimal.

The temperature of the water in the tank should be (20±2)°C.

9.4.2. The samples are weighed every 24 hours of water absorption on a conventional or hydrostatic balance with an error of no more than 0.1%.

When weighing on a conventional balance, the samples removed from the water are preliminarily wiped with a wrung out damp cloth.

9.4.3. The test is carried out until the results of two successive weighings differ by no more than 0.1%.

9.4.4. Samples tested in a state of natural humidity, after the end of the water saturation process, are dried to constant weight according to clause 8.5.1.

9.5. Results processing

9.5.1. The water absorption of a solution of an individual sample by weight in percent is determined with an error of up to 0.1% according to the formula

, (10)

where is the mass of the dried sample, g.

Weight of water-saturated sample, g

9.5.2. The water absorption of a solution of an individual sample by volume in percent is determined with an error of up to 0.1% according to the formula

= , (11)

where is the density of the dry solution, kg/m;

Density of water taken equal to 1 g/cm.

9.5.3. The water absorption of a solution of a series of samples is determined as the arithmetic mean of the test results of individual samples in a series.

9.5.4. The log in which the test results are recorded should include the following columns:

sample marking;

the age of the solution and the date of testing;

water absorption of the sample solution;

water absorption solution sample series.

10. DETERMINATION OF THE FROST RESISTANCE OF THE SOLUTION

10.1. The frost resistance of the mortar is determined only in cases specified in the project.

Solutions grades 4; 10 and solutions prepared with air binders are not tested for frost resistance.

10.2. The solution is tested for frost resistance by repeated alternate freezing of samples-cubes with an edge of 70.7 mm in a state of saturation with water at a temperature of minus 15-20 ° C and thawing them in water at a temperature of 15-20 ° C.

10.3. For the test, 6 sample cubes are prepared, of which 3 samples are subjected to freezing, and the remaining 3 samples are control.

10.4. For the brand of solution in terms of frost resistance, the largest number of cycles of alternate freezing and thawing is taken, which the samples withstand during the test.

Mortar grades for frost resistance should be accepted in accordance with the requirements of the current regulatory documentation.

10.5. Equipment

10.5.1. For testing use:

freezer with forced ventilation and automatic temperature control within minus 15-20°C;

a container for saturating samples with water with a device that maintains the temperature of the water in the vessel within plus 15-20 ° C;

molds for making samples according to GOST 22685-89.

10.6. Preparing for the test

10.6.1. The samples to be tested for frost resistance (basic) should be numbered, inspected and any defects noticed (minor edges or corners, chipping, etc.) should be recorded in the test log.

10.6.2. The main samples should be tested for frost resistance at 28 days of age after exposure to a normal curing chamber.

10.6.3. Control samples intended for compression testing should be stored in a normal hardening chamber at a temperature of (20 ± 2) ° C and a relative humidity of at least 90%.

10.6.4. The main samples of the solution intended for testing for frost resistance, and control samples intended for determining the compressive strength at 28 days of age, must be saturated with water before testing without prior drying by keeping them for 48 hours in water at a temperature of 15-20 ° C. In this case, the sample must be surrounded on all sides by a layer of water with a thickness of at least 20 mm. The saturation time in water is included in the total age of the solution.

10.7. Conducting a test

10.7.1. Water-saturated base samples should be placed in the freezer in special containers or placed on wire racks. The distance between the samples, as well as between the samples and the walls of the containers and overlying shelves, must be at least 50 mm.

10.7.2. Samples should be frozen in a freezer capable of cooling the sample chamber and keeping it at minus 15-20°C. The temperature should be measured at half the height of the chamber.

10.7.3. Samples should be loaded into the chamber after the air in it has cooled to a temperature not higher than minus 15°C. If, after loading the chamber, the temperature in it is higher than minus 15°C, then the beginning of freezing should be considered the moment the air temperature reaches minus 15°C.

10.7.4. The duration of one freezing should be at least 4 hours.

10.7.5. Samples after unloading from the freezer should be thawed in a bath of water at a temperature of 15-20 ° C for 3 hours.

10.7.6. A control inspection of the samples should be carried out in order to terminate the frost resistance test of a series of samples in which the surface of two out of three samples has visible damage (delamination, through cracks, chipping).

10.7.7. After alternate freezing and thawing of the samples, the main samples should be tested for compression.

10.7.8. Compression specimens should be tested in accordance with the requirements of Sec. 6 of this standard.

10.7.9. Before the compression test, the main samples are inspected and the area of ​​damage to the faces is determined.

If there are signs of damage to the supporting faces of the samples (peeling, etc.), before testing, they should be leveled with a layer of fast-hardening compound no more than 2 mm thick. Samples in this case should be tested 48 hours after gravy, and the first day the samples should be stored in a humid environment, and then in water at a temperature of 15-20 ° C.

10.7.10. Control samples should be tested for compression in a water-saturated state before freezing of the main samples. Before mounting on the press, the supporting surfaces of the specimens must be wiped with a damp cloth.

10.7.11. When assessing frost resistance by weight loss after the required number of freezing and thawing cycles, the samples are weighed in a state saturated with water with an error of not more than 0.1%.

10.7.12. When assessing frost resistance according to the degree of damage, the samples are inspected every 5 cycles of alternate freezing and thawing. Samples are inspected after they are thawed every 5 cycles.

10.8. Results processing

10.8.1. Frost resistance in terms of loss of compressive strength of samples during alternate freezing and thawing is evaluated by comparing the strength of the main and control samples in a state saturated with water.

The strength loss of samples in percent is calculated by the formula

, (12)

where is the arithmetic mean value of the compressive strength of control samples, MPa (kgf / cm );

The arithmetic mean value of the compressive strength of the main samples after testing them for frost resistance, MPa (kgf / cm ).

The permissible value of the loss of strength of samples during compression after their alternate freezing and thawing is not more than 25%.

10.8.2. The weight loss of samples tested for frost resistance, as a percentage, is calculated by the formula

, (13)

where is the mass of the sample saturated with water before testing it for frost resistance, g;

The mass of the sample saturated with water after testing it for frost resistance, g.

The weight loss of the samples after the frost resistance test is calculated as the arithmetic mean of the test results of three samples.

Permissible weight loss of samples after alternate freezing and thawing - no more than 5%.

10.8.3. The following data should be indicated in the test log of samples for frost resistance:

type and composition of the solution, design mark for frost resistance;

marking, date of manufacture and date of testing;

the dimensions and weight of each sample before and after the test and the percentage weight loss;

curing conditions;

a description of the defects found in the specimens prior to testing;

description of external signs of destruction and damage after the test;

ultimate compressive strength of each of the main and control samples and the percentage change in strength after the frost resistance test;

number of freeze and thaw cycles.

ATTACHMENT 1

Mandatory

DETERMINATION OF THE STRENGTH OF A SOLUTION TAKEN FROM THE SEAMS FOR COMPRESSION

1. The strength of the solution is determined by testing the compression of cubes with ribs of 2-4 cm, made of two plates, taken from horizontal masonry joints or joints of large-panel structures.

2. The plates are made in the form of a square, the side of which should be 1.5 times the thickness of the plate, equal to the thickness of the seam.

3. Gluing the solution plates to obtain cubes with ribs of 2-4 cm and leveling their surfaces is carried out using a thin layer of gypsum dough (1-2 mm).

4. It is allowed to cut sample-cubes from plates in the case when the thickness of the plate provides the required size of the rib.

5. Samples should be tested one day after their manufacture.

6. Sample cubes from a solution with ribs 3-4 cm long are tested according to paragraph 6.5 of this standard.

7. To test sample cubes from a solution with ribs of 2 cm, as well as thawed solutions, a small-sized desktop press of the PS type is used. The normal load range is 1.0-5.0 kN (100-500 kgf).

8. The strength of the solution is calculated according to clause 6.6.1 of this standard. The mortar strength shall be determined as the arithmetic mean of the test results of five specimens.

9. To determine the strength of the solution in cubes with ribs of 7.07 cm, the results of testing cubes of summer and winter solutions that have hardened after thawing should be multiplied by the coefficient given in the table.

APPENDIX 2

JOURNAL

tests to determine the mobility, the average density of the mortar mixture and the compressive strength, the average density of the mortar samples

Head of the laboratory _______________________________________________________________

Responsible for manufacturing

and testing of samples _____________________________________________________________

____________________

* In the "Notes" column, the defects of the samples should be indicated: shells, foreign inclusions and their locations, the special nature of the destruction, etc.

The text of the document is verified by:

official publication

Ministry of Construction of Russia -

M.: Publishing house of standards, 1992