Medium-sized sand, depending on the extraction method, can be natural, crushed and fractionated, and depending on the extraction method: quarry, alluvial and sea, its fineness determines the size of the sand grains. For medium sand it is 2.0 – 2.5 mm.

In accordance with the Interstate standard GOST 8736-2014 “Sand for construction work. Technical conditions”, the “medium size” category includes sand with a fineness modulus (Mk) ranging from 2.0 to 2.5 units.

Medium sand is of class I and II, depending on the percentage of the content of grains of different sizes, to the value of the main batch size. For various classes, it looks like this:

When separating by size, sieving is performed, during which the total residue is determined, characterized by the filtration coefficient. For medium sand, the total residue, when sifted on sieve No. 063, should be in the range from 30.0 to 40.0%.

The composition of sand is regulated by the content of clay, dust and clay particles. For different classes, this ratio, in percentage terms, must correspond to the following parameters:

Material characteristics

All the main characteristics of sand are regulated by GOST and are given above, these are:

• Size module.
• Grain composition.
• Content of clay, dust and clay particles.

In addition to the characteristics regulated by GOST, important indicators of properties are:

• Density, measured in kg per m3, depends on:

• degree of compaction, characterized by the method of extraction and storage;
• humidity, which varies depending on the extraction method and storage conditions;

• porosity and structure of the material;
• presence of impurities.

Density is 1300 – 1800 kg/m3.

• Specific gravity characterizes the amount of material in dry form per unit volume, and is also measured in kg per m3.

The specific gravity is 2.55 – 2.65 kg/m3.

• Volumetric weight characterizes the material in natural state and differs from specific gravity indicators. Depends on:

• specific gravity of a specific batch of material;
• the presence and quantity of voids in a batch of material;
• humidity in each individual batch of material.

Volumetric weight is 1.5 – 1.8 kg/m3.

• Bulk density – characterizes the parameters of sand in bulk and is measured in kg per m3.

Bulk density – 1500 – 1700 kg/m3.

• Porosity coefficient – ​​divides sand according to the degree of porosity into: dense, medium density and loose, which correspond to the following values:

• Dense – K, less than 0.55;
• Medium density – K, ranges from 0.55 to 0.65;
• Loose – K, more than 0.65.

• Deformation modulus - characterizes the ability of sand to compress under the influence of external loads. This indicator depends on the porosity of the material and corresponds to the following parameters:

• Elastic modulus - characterizes the strength and ability to restore the previous volume after applying an external load and removing it.

Elastic modulus – 120 MPa.

• The compaction coefficient is an important indicator when performing construction and installation work.

The compaction coefficient is 0.95 – 0.98.

• Specific adhesion - characterizes the strength to move under the influence of external force, measured in Newtons per m2. The specific adhesion of medium sand depends on its porosity and corresponds to the following parameters:

Extraction methods

Under natural conditions, the most common sand is medium-sized sand without significant inclusions of clay and other impurities.

There are several methods of extraction, these are:

• Open method.

With this method, mining is carried out in quarries located above sea level, in areas with deep deposits. groundwater. To perform the work, heavy equipment is used (excavators, bulldozers, dump trucks, etc.), as well as special equipment, through which the extracted raw materials are cleaned and divided into fractions and classes.

• Underwater method.

When organizing mining from the bottom of reservoirs (seas, lakes, rivers and other large water bodies), are used special means, dredgers (dredge pumps), which are installed on watercraft or pontoons, where they are fixed at a certain point in a water body. During operation, soil (sand) is sucked in with water, after which it is crushed and supplied to storage areas. Water pumped together with raw materials flows into the reservoir.

In addition to the two main methods, depending on technical capabilities enterprises engaged in mining, as well as natural conditions, a method can be used when sand is washed in an open quarry with special equipment, or the quarry is filled with water, after which mining is carried out underwater.

With the open mining method, depending on the equipment used, you get the following types sand:

• Seeded - when during the production process separation is carried out according to grain size (separation into fractions):
• Alluvial – the most pure material, which is due to several degrees of flushing during the extraction process.
• Ground – obtained by direct shipment of material, without processing. The most “dirty” material, the presence of various impurities, can reach 40.0% of the total volume of mined rock.

Control, rules of acceptance and shipment

Every sand mining enterprise must carry out acceptance inspections and periodic testing.

When carrying out acceptance control, the values ​​of the main characteristics and their compliance with the values ​​obtained as a result of the inspection are determined: grain composition, content of various impurities.

When conducting periodic tests, bulk density and the presence of organic impurities are determined (once a quarter), and additionally, grain density and radionuclide efficiency - once a year.

The check is carried out for each specific batch of shipped material: train, cargo barge, etc. GOST requirements regulate the number of samples that need to be taken in accordance with the volume of the shipment: with a volume of up to 350 m3 - 10 samples, with a volume of 350 - 700 m3 - 15 samples and with a volume of more than 700 m3 - 20 samples.

The amount of sand shipped is measured by its volume and weight. When determining the volume, the volume of the body, hold or wagon is calculated vehicle, to determine the mass - use special scales, when shipping by road and rail, and by the draft of the vessel - when shipping water means delivery.

Upon shipment, the organization selling the goods is obliged to provide documents indicating the manufacturer, the characteristics of the product being shipped, the batch number and the quantity of products being shipped. If the product is certified, then a certificate of conformity of the established form is attached.

Transportation and storage

Transportation is carried out by all modes of transport: road, rail and water, in accordance with the Rules for transportation on these modes of transport. Sand of different fractions is transported separately.

Storage of different fractions is also carried out separately; if necessary, storage is carried out in special rooms or containers to prevent contamination and strong wetting of the material.

Use in industries

Depending on the extraction method and the type of material obtained, its use also differs.

Ground sand, used for filling roads and others transport routes. IN agriculture it is used for drainage and improvement of soil composition.

Clean, sifted sand is used in various areas of construction, namely, medium-sized sand is the main filler in the production of concrete of all grades and reinforced concrete products. In addition, this fraction is used in the manufacture of masonry and plaster mixtures, foundation arrangement for various purposes and construction of concrete pavements.

GOST 8736-2014

Group Zh17

INTERSTATE STANDARD

SAND FOR CONSTRUCTION WORK

Specifications

Sand for construction works. Specifications

MKS 91.100.15

Date of introduction 2015-04-01

Preface

The goals, basic principles and basic procedure for work on interstate standardization are established by the "Interstate standardization system. Basic provisions" and "Interstate standardization system. Interstate standards, rules and recommendations for interstate standardization. Rules for development, adoption, application, updating and cancellation"

Standard information

1 DEVELOPED by the Federal State unitary enterprise"Research and design and survey institute on the problems of mining, transport and processing of mineral raw materials in the construction materials industry" (FSUE "VNIPIIstromsyrye")

2 INTRODUCED Technical Committee on standardization TC 465 "Construction"

3 ADOPTED by the Interstate Council for Standardization, Metrology and Certification (protocol dated September 30, 2014 N 70-P)

4 By order Federal agency By technical regulation and metrology dated November 18, 2014 N 1641-st interstate standard GOST 8736-2014 came into force as a national standard of the Russian Federation on April 1, 2015.

5 INSTEAD GOST 8736-93

Information about changes to this standard is published in the annual information index " National standards", and the text of changes and amendments - in the monthly information index "National Standards". In case of revision (replacement) or cancellation of this standard, the corresponding notification will be published in the monthly information index "National Standards". The relevant information, notification and texts are also posted in information system common use- on the official website of the Federal Agency for Technical Regulation and Metrology on the Internet

1 area of ​​use

This standard applies to natural sands with a true grain density of 2.0 to 2.8 g/cm 3 and mixtures of natural sands and sands from crushing screenings intended for use as aggregates for heavy, light, fine-grained, cellular and silicate concretes, mortars, dry building mixtures, for the installation of bases and coverings highways and bases of runways and airfield aprons, roadsides, production of roofing and ceramic materials, reclamation, improvement and planning of territories and other types of construction work. This standard does not apply to sands from dense crushing screenings rocks.

2 Normative references

This standard uses normative references to the following interstate standards:

4.2.18 Sands should not contain foreign contaminants.

4.2.19 Delivery of mixtures is allowed natural sand and sand from crushing screenings in accordance with GOST 31424-2010 with the latter content not exceeding 20% ​​by weight, and the mixtures must comply with the requirements of this standard.

(Amendment. IUS N 10-2015).

It is allowed to supply mixtures of natural sand and sand from crushing screenings in accordance with GOST 31424-2010 if the latter content is more than 20% by weight, and the mixtures must comply with the requirements of GOST 31424-2010. Sand from crushing screenings as part of mixtures, having true density grains more than 2.8 g/cm 3 or containing grains of rocks and minerals classified as harmful components in quantities exceeding their permissible content, or containing several different harmful components, are released for specific types construction work according to regulatory and technical documents, developed in in the prescribed manner and agreed with laboratories specialized in the field of corrosion.

4.2.20 The manufacturer, at the request of the consumer, must indicate the following characteristics of sand, established by geological exploration: - mineralogical and petrographic composition indicating rocks and minerals classified as harmful components and impurities; - content of organic impurities; - true density of sand grains.

4.3 Radiation-hygienic assessment The sand must be given a radiation-hygienic assessment, based on the results of which the area of ​​its application is determined. Sand depending on the specific effective activity values natural radionuclides A eff apply:

A eff up to 370 Bq/kg - in newly constructed residential and public buildings;

A eff St. 370 to 740 Bq/kg - for road construction within the territory settlements and areas of promising development, as well as during the construction industrial buildings and structures;

A eff St. 740 to 1500 Bq/kg - in road construction outside populated areas. If necessary, in national standards in force on the territory of the state, the value of the specific effective activity of natural radionuclides can be changed within the limits specified above.

5 Acceptance rules

5.1 Sand, enriched sand and graded sand must be accepted by the technical control service of the manufacturer.

5.2 To verify compliance of the quality of sand, enriched and fractionated sand with the requirements of this standard, acceptance control and periodic tests are carried out.

5.3 Acceptance control at the manufacturer is carried out daily by testing a combined replacement sample of sands selected in accordance with. During acceptance control the following is determined:

• grain composition;
• content of dust and clay particles;
• clay content in lumps;
• presence of contaminants.

5.4 When periodic testing sands are determined:

once a quarter bulk density (bulk density at humidity during shipment is determined if necessary) and the presence of organic impurities (humic substances);

once a year and with each change in the properties of the rock being mined, the true density of grains, the content of rocks and minerals classified as harmful components and impurities, the specific effective activity of natural radionuclides.

Periodic monitoring of the specific effective activity of natural radionuclides is carried out in specialized laboratories duly accredited for the right to conduct gamma spectrometric tests or in radiation metric laboratories of supervisory authorities. In the absence of geological survey data on the radiation-hygienic assessment of the deposit and a conclusion on the class of sand, the manufacturer carries out a radiation-hygienic assessment of the developed rock sections using the express method directly at the mine face or in warehouses finished products(according to the alluvial map) in accordance with the requirements.

5.5 Acceptance and delivery of sand, enriched sand and fractionated sand is carried out in batches. A batch is considered to be the amount of sand established in the supply contract and simultaneously shipped to one consumer in one train or in one vessel. Upon shipment by car A batch is considered to be the amount of sand shipped to one consumer during the day.

(Amendment. IUS N 10-2015).

5.6 Selection and preparation of sand samples for quality control at the manufacturing plant is carried out in accordance with the requirements.

5.7 When checking the quality of sand, the consumer must use the sampling procedure given in 5.8-5.11. If the results of the control check on the grain composition, the content of dust and clay particles and clay in lumps are unsatisfactory, the batch of sand will not be accepted.

5.8 The number of spot samples taken to control the quality of sands in each tested batch, depending on the volume of the batch, must be at least:

From the spot samples, a combined sample is obtained that characterizes the controlled batch. Averaging, reduction and sample preparation are carried out according to.

5.9 To control the quality of sand shipped by rail, spot samples are taken when unloading cars from the flow of sand on belt conveyors used to transport it to the consumer’s warehouse. When unloading the car, five spot samples are taken at equal time intervals. The number of cars is determined taking into account the receipt of the required number of spot samples in accordance with 5.8. Cars are selected according to the instructions of the consumer. If the batch consists of one wagon, five spot samples are taken during unloading, from which a combined sample is obtained.

If conveyor transport is not used for unloading, spot samples are taken directly from the cars. To do this, the surface of the sand in the car is leveled and holes 0.2-0.4 m deep are dug at the sampling points. The sampling points should be located in the center and in the four corners of the car, and the distance from the sides of the car to the sampling points should be not less than 0.5 m. Samples are taken from the holes with a scoop, moving it from bottom to top along the walls of the hole.

5.10 To control the quality of sand supplied by water transport, spot samples are taken when unloading ships. When used during unloading belt conveyors spot samples are taken at regular intervals from the flow of sand on conveyors. When unloading a vessel with grab cranes, point samples are taken with a scoop at regular intervals as unloading proceeds, directly from the newly formed sand surface in the vessel, and not from the holes.

For control testing of sand unloaded from ships and placed on alluvial maps using hydromechanization, spot samples are taken in accordance with paragraph 2.9.

5.11 To control the quality of sand shipped by road transport, spot samples are taken when unloading vehicles.

If belt conveyors are used for unloading sand, point samples are taken from the flow of sand on the conveyor. When unloading each vehicle, one spot sample is taken. The number of cars is determined taking into account the receipt of the required number of spot samples according to 5.8. Cars are selected according to the instructions of the consumer. If the batch consists of less than ten cars, sand samples are taken from each car.

If conveyor transport is not used when unloading cars, spot samples are taken directly from the cars. The surface of the sand in the car is leveled, a hole 0.2-0.4 m deep is dug in the center of the body. Sand samples are taken from the hole with a scoop, moving it from bottom to top along the wall of the hole.

5.12 The quantity of sand supplied is determined by volume or weight. Sand measurements are carried out in wagons, ships or cars.

Sand shipped in wagons or cars is weighed on truck scales. The mass of sand shipped in ships is determined by the vessel's draft.

The amount of sand from units of mass to units of volume is recalculated according to the values bulk density sand, determined by its moisture content at the time of shipment. The supply contract specifies the calculated sand moisture content accepted by agreement of the parties.

5.13 The manufacturer must accompany each batch of supplied sand with a quality document indicating:

• name of the manufacturer and its address;
• number and date of issue of the document;
• name and address of the consumer;
• batch number, name and quantity of material;
• numbers of invoices and vehicles;
• grain composition of sand, enriched sand;
• grain composition of a mixture of fractions or the size of narrow fractions (for fractionated sand);
• content of dust and clay particles, clay in lumps;
• content of harmful components and impurities;
• presence of contaminants;
• bulk density and filtration coefficient (at the consumer’s request) in sand and enriched sand;
• specific effective activity of natural radionuclides;
• designation of this standard.

6 Test methods

6.1 Sand tests are carried out according to.

6.2 The filtration coefficient of sand and enriched sand used in road construction is determined by.

6.4 The specific effective activity of natural radionuclides is determined by.

6.5 The resistance of sand to harmful components and impurities is determined by the mineralogical and petrographic composition and content of harmful components and impurities.

7 Transportation and storage

7.1 Transportation

7.1.1 Sand, enriched sand and fractionated sand are transported by rail, water and road transport in accordance with the rules for the carriage of goods in force for a particular type of transport.

7.1.2 Dry fractionated sand is transported in the form of separate fractions or mixtures thereof by specialized vehicles (cement trucks, capsules and other means of transportation that provide protection from moisture and the ingress of contaminants). The permissible moisture content of the sand is established by the consumer, and the range of permissible humidity must be within from 0.1% to 0.5% by weight, unless a different value is specified in other regulatory documents.

7.2 Storage

7.2.1 Sand and enriched sand are stored in the warehouse of the manufacturer and consumer under conditions that protect them from contamination.

7.2.2 Dry graded sand should be stored in dry indoors or closed bunkers (silos) that prevent the ingress of moisture and contaminants.

7.2.3 When shipping and storing sand and enriched sand in winter time the manufacturer should take measures to prevent freezing (shovelling, processing special solutions and so on.).

Appendix A (mandatory). Permissible content of harmful components and impurities

The permissible content of rocks and minerals classified as harmful components and impurities in sand used as a filler for concrete and mortars should not exceed the following values:

• amorphous varieties of silicon dioxide, soluble in alkalis (chalcedony, opal, flint, etc.) - no more than 50 mmol/l;
• sulfur, sulfides, except pyrite (marcasite, pyrrhotite, etc.), and sulfates (gypsum, anhydrite, etc.) in terms of SO 3- no more than 1.0%; pyrite in terms of SO 3- no more than 4% by weight;
• mica - no more than 2% by weight;
• halogen compounds (halite, sylvite, etc.), including water-soluble chlorides, in terms of chlorine ion - no more than 0.15% by weight;
• coal - no more than 1% by weight;
• organic impurities (humic acids) - less than the amount that gives the sodium hydroxide solution (colorimetric test) a color corresponding to the color of the standard or darker than this color. The use of sand that does not meet this requirement is permitted only after receipt positive results testing sand in concrete or mortar for durability characteristics.

The permissible content of zeolite, graphite, and oil shale is established based on studies of the effect of sand on the durability of concrete or mortar.

End of document

For concrete, it is recommended to use coarse and medium sand with a fineness modulus of 2...3.25. In sand intended for the production of concrete, grains of gravel or crushed stone larger than 10 mm are allowed in an amount of up to 0.5% (by weight); grains measuring 5-10 mm are allowed in an amount of no more than 5% by weight; the content of grains passing through a sieve with mesh No. 016 should not exceed 10%.

Grain Density quartz sand 2600-2700 kg/m 3, bulk density of sand 1400-1600 kg/m 3; it depends on the degree of compaction, the moisture content of the sand, as well as on the grain and mineralogical composition (the lowest bulk density of quartz sands corresponds to a moisture content of 5-7% by weight).

Large aggregate. The coarse aggregate for preparing heavy concrete is gravel or crushed stone that meets the requirements of GOST 8267-93.

Gravel – inorganic granular bulk material with a particle size of over 5 mm, obtained by sieving natural gravel-sand mixtures.

Gravel grains have a round shape and a smooth surface. It may contain grains of high strength (granite) and weak grains (porous limestone).

Gravel according to bedding conditions divided by:

• mountain (ravine).

Mountain gravel usually has many impurities, river and sea - much less. Constant exposure to water gave the grains of river and sea gravel a rounded shape and a smooth surface. The grains of gully gravel have a crushed stone shape (slightly rounded), which improves its adhesion to the cement-sand mortar.

Advantages (compared to crushed stone):

found in nature in a crushed state, and only large pieces have to be crushed;

concrete mixture on gravel has greater mobility due to less friction between the aggregate grains and the cement mortar.

Crushed stone – inorganic granular bulk material with grains larger than 5 mm, obtained by crushing rocks, gravel and boulders or substandard waste from mining enterprises. A crushed mixture of grains of various sizes (5...70 mm) is scattered into separate fractions: screened particles less than 3 mm in size are used as sand. Crushed stone is crushed using stone crushers from granite, diabase and other igneous rocks, as well as from dense sedimentary rocks - limestone, dolomite and modified rocks - quartzite. The pieces of crushed stone have an acute-angled shape and a rough surface, so its adhesion to the cement-sand mortar is stronger than that of gravel. The content of harmful organic impurities in crushed stone is insignificant.

Advantages:· provides good adhesion to cement mortar during hardening, which ensures the required strength of concrete and less contamination with harmful impurities.

Crushed stone and gravel are produced in the following forms: main factions :

from 5 to 10 mm;

over 10 to 20 mm;

over 20 to 40 mm;

over 40 to 70 mm;

mixtures of fractions from 5 to 20 mm.

For the preparation of concrete, extremely coarse gravel or crushed stone is more economical, since due to its smaller total grain surface, less cement is required to obtain durable concrete.

The grain composition of each fraction or mixture of fractions must be within the limits specified in Table 6.3.

The standard applies to natural sand and sand from rock crushing screenings with a true grain density of 2.0 to 2.8 g/cm3, intended for use as a filler for heavy, light, fine-grained, cellular and silicate concrete, mortars, and the preparation of dry mixtures for the construction of bases and coatings of highways and airfields.
The requirements of the standard do not apply to fractionated and crushed sands

GOST 8736-93

INTERSTATE STANDARD

SAND FOR CONSTRUCTION WORK

TECHNICAL CONDITIONS

INTERSTATE SCIENTIFIC AND TECHNICAL COMMISSION
ON STANDARDIZATION AND TECHNICAL REGULATION
IN CONSTRUCTION (MNTKS)

Preface

1 DEVELOPED by the VNIPIIstromsyryo Institute with the participation of SoyuzDorNII, NIIZhB, TsNIIOMTP of the Russian Federation

INTRODUCED by the Ministry of Construction of Russia

2 ADOPTED by the Interstate Scientific and Technical Commission for Standardization and Technical Regulation in Construction (INTKS) November 10, 1993

3 ENTERED INTO EFFECT on July 1, 1995 as a state standard of the Russian Federation by Resolution of the Ministry of Construction of Russia dated November 28, 1994 No. 18-29

4 INSTEAD GOST 8736-85, GOST 26193-84

INTERSTATE STANDARD

SAND FOR CONSTRUCTION WORK

Technicalconditions

Sand for construction works.
Specifications

Date of introduction 1995-07-01

1 AREA OF USE

This standard applies to natural sand and sand from screenings of crushing rocks with a grain density of 2.0 to 2.8 g/cm 3, intended for use as a filler for heavy, light, fine-grained, cellular and silicate concrete, mortars, preparation of dry mixtures, for the construction of foundations and coverings of highways and airfields.

The requirements of this standard do not apply to graded and crushed sands.

The requirements of this standard, set out in paragraphs , , , , sections and , are mandatory.

2 REGULATORY REFERENCES

GOST 8269.0 Crushed stone and gravel from dense rocks and industrial waste for construction work. Methods of physical and mechanical tests

GOST 8735-88 Sand for construction work. Test methods.

GOST30108-94 Construction materials and products. Determination of specific effective activity of natural radionuclides

(Changed edition. Amendment No. 2).

3 DEFINITIONS

The following terms are used in this standard.

Natural sand- inorganic bulk material with a grain size of up to 5 mm, formed as a result of the natural destruction of rocks and obtained during the development of sand and sand-gravel deposits without use or using special processing equipment.

(Changed edition. Amendment No. 1).

Crushed sand- sand with a grain size of up to 5 mm, made from rocks and gravel using special crushing and grinding equipment.

Fractionated sand - sand divided into two or more fractions using special equipment.

Sand from crushing screenings - inorganic bulk material with a grain size of 5 mm, obtained from screenings of crushing rocks during the production of crushed stone and from waste from the enrichment of ores of ferrous and non-ferrous metals and non-metallic minerals and other industries.

4 TECHNICAL REQUIREMENTS

4.1 Sand must be manufactured in accordance with the requirements of this standard according to technological documentation approved by the manufacturer.

4.2 Sand, depending on the values ​​of standardized quality indicators (grain composition, content of dust and clay particles), is divided into two classes.

4.3 Main parameters and dimensions

4.3.1 Depending on the grain composition, sand is divided into groups according to size:

I class - very coarse (sand from crushing screenings), increased size, large, medium and small;

Class II - very coarse (sand from crushing screenings), increased coarseness, coarse, medium, fine, very fine, fine and very fine.

4.3.2 Each group of sand is characterized by the value of the particle size modulus indicated in the table.

Table 1

4.3.3 The total sand residue in the sieve with mesh No. 063 must correspond to the values ​​indicated in the table.

table 2

Percentage by weight

4.3.4 Content of grains coarseness. 10.5 and less than 0.16 mm should not exceed the values ​​​​specified in the table.

Table 3

Percentage by weight, no more

4.4Characteristics

in natural sand

in sand from crushing screenings

in natural sand

in sand from crushing screenings

I class

Very large

0,35

Increased size. large and medium

0,25

0,35

Small

0,35

0,50

II class

Very large

Extra fine, large and medium

Small and very small

Thin and very thin

Not standardized

0,1*

Note - In very fine natural sand of class II, in agreement with the consumer, the content of dust and clay particles up to 7% by weight is allowed.

* For sands obtained during the enrichment of ores of ferrous and non-ferrous metals and non-metallic minerals from other industries.

4.4.2 Sands from screenings are divided into grades depending on the strength of the rock and gravel. Igneous and metamorphic rocks must have a compressive strength of at least 60 MPa, sedimentary rocks - at least 40 MPa.

The grade of sand from crushing screenings must correspond in strength to that indicated in the table.

Table 5

The durability of sand is determined by its mineralogical and petrographic composition and the content of harmful components and impurities. The list of rocks and minerals classified as harmful components and impurities and their maximum permissible contents are given in the Appendix.

4.4.4 Sand from screening crushed rocks, having a true grain density of more than 2.8 g/cm 3 or containing grains of rocks and minerals classified as harmful components in an amount exceeding their permissible content, or containing several different harmful components, is produced for specific types construction work according to technical documents developed in accordance with the established procedure and agreed with laboratories specialized in the field of corrosion.

4.4.5 It is allowed to supply a mixture of natural sand and sand from crushing screenings with a content of the latter of at least 20% by weight, and the amount of the mixture must meet the requirements of this standard for the quality of sand from crushing screenings.

4.4.6 The manufacturer must inform the consumer of the following characteristics established by geological exploration:

Mineralogical and petrographic composition indicating rocks and minerals attributed to harmful components and impurities;

Emptiness;

The true density of sand grains.

At A eff up to 370 Bq/kg - in newly constructed residential and public buildings;

At A eff St. 370 to 740 Bq/kg - for road construction within the territory of settlements and areas of prospective development, as well as during the construction of industrial buildings and structures;

At A eff St. 740 to 1500 Bq/kg - in road construction and populated areas.

If necessary, in the national standards in force on the territory of the state, the value of the specific effective activity of natural radionuclides can be changed within the limits of the standards specified above.

(Changed edition. Amendment No. 1, 2).

4.4.9 Sand should not contain foreign contaminants.

5 ACCEPTANCE RULES

5.1 Sand must be accepted by the technical control service of the manufacturer.

5.2 To verify the compliance of sand quality with the requirements of this standard, acceptance and periodic tests are carried out.

5.3 Acceptance tests at the manufacturer are carried out daily by testing one shift sample taken in accordance with GOST 8735 from each production line.

During acceptance control the following is determined:

Grain composition;

Once a quarter - bulk density (bulk density at humidity during shipment is determined as necessary), as well as the presence of organic impurities (humic substances) in natural sand;

Once a year and in each case, changes in the properties of the rock being mined - the true density of grains, the content of rocks and minerals classified as harmful components and impurities, the strength grade of sand from crushing screenings, the specific effective activity of natural radionuclides.

Periodic monitoring of the specific effective activity of natural radionuclides is carried out in specialized laboratories accredited in accordance with the established procedure for conducting gamma spectrometric tests or in radiation metric laboratories of supervisory authorities.

In the absence of geological survey data on the radiation-hygienic assessment of the deposit and a conclusion on the class of sand, the manufacturer carries out a radiation-hygienic assessment of the developed rock sections using the express method directly at the face or in finished product warehouses (alluvium map) in accordance with the requirements of GOST 30108.

5.5 Selection and preparation of sand samples for quality control at the manufacturer is carried out in accordance with the requirements of GOST 8735.

5.6 Delivery and acceptance of sand is carried out in batches. A batch is considered to be a quantity of material simultaneously supplied to one consumer in one train or in one vessel. When shipping by road, a batch is considered to be the amount of sand shipped to one consumer per day.

5.7 When checking the quality of sand, the consumer must use the sampling procedure given in -. If the results of the control check on the grain composition and the content of dust and clay particles are unsatisfactory, the batch of sand will not be accepted.

Batch size Number of point samples

Up to 350 m................................................... ...................................10

St. 350 to 700 m............................................ ..........................15

St. 700 m................................................... ....................................10

From spot samples, a combined sample is formed that characterizes the controlled batch. Averaging, reduction and sample preparation are carried out according to GOST 8735.

5.9 To control the quality of sand shipped by rail, spot samples are taken when unloading cars from the flow of sand on belt conveyors used to transport it to the consumer’s warehouse. When unloading the car, five spot samples are taken at equal time intervals. The number of cars is determined taking into account the receipt of the required number of spot samples in accordance with.

Cars are selected according to the instructions of the consumer. If the batch consists of one wagon, five spot samples are taken during unloading, from which a combined sample is obtained.

If continuous transport is not used during unloading, point samples are taken directly from the cars. To do this, the surface of the sand in the car is leveled and holes 0.2-0.4 m deep are dug at the sampling points. Sampling points should be located in the center and in the four corners of the car, in this case, the distance from the sides of the car to the sampling points must be at least 0.5 m. Samples from the holes are taken with a scoop, moving it from bottom to top along the walls of the hole.

5.10 To control the quality of sand supplied by water transport, spot samples are taken when unloading ships. When belt conveyors are used for unloading, spot samples are taken at regular intervals from the sand flow on the conveyors. When unloading a vessel with grab cranes, spot samples are taken with a scoop at regular intervals as unloading proceeds, directly from the newly formed sand surface in the vessel, and not from the holes.

For control testing of sand unloaded from ships and placed on alluvial maps using hydromechanization, spot samples are taken in accordance with 2.9 GOST 8735.

If belt conveyors are used for sand unloading, point samples are taken from the sand flow on the conveyors. When unloading each car, one spot sample is taken. The number of cars is determined taking into account the receipt of the required number of spot samples. Cars are selected according to the instructions of the consumer.

If the lot consists of less than ten cars, sand samples are taken from each car.

If conveyor transport is not used for unloading cars, spot samples are taken directly from the cars. To do this, the surface of the sand in the car is leveled, a hole 0.2-0.4 m deep is dug in the center of the body. Sand samples are taken from the hole with a scoop, moving it from bottom to top along the wall of the hole.

5.12 The quantity of sand supplied is determined by volume or weight. Sand measurements are carried out in carriages, ships or cars.

Sand shipped in wagons or cars is weighed on truck scales. The mass of sand shipped to vessels is determined by the vessel's draft.

The amount of sand from units of mass to units of volume is recalculated based on the bulk density of sand, determined by its moisture content during shipment. The supply contract specifies the calculated sand moisture content accepted by agreement of the parties.

5.13 The manufacturer is obliged to accompany each batch of sand supplied with a document on its quality in the established form, which must indicate:

Name of the manufacturer and its address;

Number and date of issue of the document;

Batch number and amount of sand;

Numbers of wagons and vessel numbers, invoice numbers;

Class, fineness module, total residue on sieve No. 063;

Specific effective activity of natural radionuclides in sand in accordance with;

Designation of this standard.

6 CONTROL METHODS

6.1 Sand tests are carried out according to GOST 8735.

6.2 The specific effective activity of natural radionuclides in sand is determined according to GOST 30108.

7 TRANSPORTATION AND STORAGE

7.1 Sand is transported open railway carriages and ships, as well as cars in accordance with the rules for the carriage of goods by the appropriate mode of transport, approved in the established manner, and stored in the warehouse of the manufacturer and consumer under conditions that protect the sand from contamination.

When transporting sand by rail, compliance with the requirements of the Technical Conditions for Loading and Securing Cargo, approved by the Ministry of Railways, must also be ensured.

7.2 When shipping and storing sand in winter, the manufacturer must take measures to prevent freezing (shovelling, treatment with special solutions, etc.).

APPENDIX A

(required)

The permissible content of rock minerals classified as harmful components and impurities in sand used as a filler for concrete and mortars should not exceed the following values:

Amorphous varieties of silicon dioxide, soluble in alkalis (chalcedony, opal, flint, etc.) - no more than 50 mmol/l;

Sulfur, sulfides, except pyrite (marcasite, pyrrhotite, etc.) and sulfates (gypsum, anhydrite, etc.) are converted into SO 3 - no more than 1.0%, pyrite in terms of SO 3 - no more than 4% by weight;

Mica - no more than 2% by weight:

Halide compounds (halite, sylvite, etc.), including water-soluble chlorides, are converted to chlorine ion - no more than 0.15% by weight;

Coal - no more than 1% by weight;

Organic impurities (humic acids) - less than the amount that gives a solution of sodium hydroxide (colorimetric test according to GOST 8267) a color corresponding to the color of the standard or darker than this color. The use of sand that does not meet this requirement is allowed only after receiving positive test results of sand in concrete or mortar with characteristics durability.

The permissible content of zeolite, graphite, and oil shale is established based on studies of the influence of sand on the durability of concrete or mortar.

APPENDIXB

(informational)

(Excluded. Amendment No. 2).

Keywords:natural sand, construction work, sand from crushed screenings, fractionated sand, crushed sand, grain composition

Sand- a loose mixture of grains of various minerals (quartz, feldspar, mica, etc.) with dimensions of 0.14 - 5 mm, formed as a result of weathering of rocks.
Sands distinguished by deposit and mineralogical composition. Depending on the location, there are mountain, river, sea, barchan, dune sands, as well as career.
According to mineralogical composition sands subdivided into quartz, feldspar, limestone and dolomite.
From the quality of the used sands The strength of many cement-based building materials depends on it. Their production requires enriched sands, i.e. washed, sorted both by grain size and mineralogical composition. Sand used as an iron additive in cement factories, the production of heavy, light, fine-grained, cellular and silicate concrete, in the preparation of mortars, dry mixtures, for the construction of bases and coatings of highways, airfields, in the full cycle of construction and many other types of construction work.

River sand

River sand extracted from the river bottom using a hydro-mechanized method. It is universal building material, since it practically does not contain stones and clay particles. river sand usually has a grain size modulus of 1.6 to 1.8 mm.
river sand Widely used in the following construction fields:
- in concrete production,
- in housing and road construction - for laying roads and preparing asphalt concrete mixtures,
- for decorative purposes,
- in the glass industry.
river sand suitable for all types of construction work, but since its cost is comparatively more expensive quarry sand, the latter is usually often used instead of the river one.

Quarry sand

Quarry sand mined in quarries open method. It is formed during the destruction of hard rocks and has a grain size modulus from 0.15 to 4.5 mm.
Quarry sand It has low cost compared to other types of sand due to the content of clay and dust particles in it and, therefore, is widely used in zero-cycle works, road and housing construction, as well as in many other types of construction work.

Natural sand and sand from rock crushing screenings with a true grain density from 2.0 to 2.8 g/cm 3 , intended for use as a filler for heavy, light, fine-grained, cellular and silicate concrete, mortars, preparation of dry mixtures, for the construction of bases and coatings, highways and airfields, are manufactured according to GOST 8736-93. GOST 8736-93 does not apply to fractionated and crushed sands.

Depending on the grain composition sand divided into groups according to size:

I class - very coarse (sand from crushing screenings), increased size, large, medium and small;

II class - very coarse (sand from crushing screenings), increased coarseness, large, medium, fine, very fine, fine and very fine.

Each sand group is characterized by the particle size modulus value indicated in Table 1.

Note.

By agreement between the manufacturer and the consumer, in class II sand, deviation of the total residue on sieve No. 063 from the above is allowed, but not more than ±5%.

The total sand remaining on the sieve with mesh No. 063 must correspond to the values ​​​​indicated in table 2.

Sands crushing screenings are divided into grades depending on the strength of rock and gravel. Igneous and metamorphic rocks must have a compressive strength of at least 60 MPa, sedimentary rocks - at least 40 MPa.

Sand brand from crushing screenings, the strength must correspond to that indicated in Table 5.

Note.

It is allowed, by agreement between the manufacturer and the consumer, to supply sand class II from sedimentary rocks with a compressive strength of less than 40 MPa, but not less than 20 MPa.

Sand, intended for use as a filler for concrete, must be resistant to chemical exposure cement alkalis.

Sand resistance determined by the mineralogical and petrographic composition and content of harmful components and impurities.

Sand from screenings of rock crushing, having a true grain density of more than 2.8 g/cm 3 or containing grains of rocks and minerals classified as harmful components in an amount exceeding their permissible content, or containing several different harmful components, produced for specific types of construction works according to technical documents developed in accordance with the established procedure and agreed upon with laboratories specialized in the field of corrosion.

Mix supply allowed natural sand and sand from screenings crushing with a content of the latter of at least 20% by weight, while the quality of the mixture must meet the requirements of this standard for sand quality from crushing screenings,

Natural sand when treated with a sodium hydroxide solution (colorimetric test for organic impurities according to GOST 8735), it should not give the solution a color that matches or is darker than the color of the standard.

Sand a radiation-hygienic assessment must be given, based on the results of which the scope of its application is established. Sand depending on the values ​​of the specific effective activity of natural radionuclides A EFF is used:

at A EFF up to 370 B K /kg - in newly constructed residential and public buildings;

at A EFF St. 370 to 740 B K /kg - for road construction within the territory of settlements and areas of prospective development, as well as during the construction of industrial buildings and structures;

at A EFF St. 740 to 2800 B K / kg - in road construction outside populated areas.

Sand must not contain foreign contaminants.

The manufacturer is obliged to accompany each batch of supplied sand with a document on its quality in the established form, which must indicate:

name of the manufacturer and its address;

number and date of issue of the document;

batch number and amount of sand;

wagon numbers and vessel number, invoice numbers;

class, fineness module, total residue on sieve No. 063;

specific effective activity natural radionuclides in sand;

designation of this standard.

Permissible content of rocks and minerals classified as harmful components and impurities in the sand used as a filler for concrete and mortars, should not exceed the following values:

amorphous varieties of silicon dioxide, soluble in alkalis (chalcedony, opal, flint, etc.) - no more than 50 mmol/l;

sulfur, sulfides, except pyrite (marcasite, pyrrhotite, etc.) and sulfates (gypsum, anhydrite, etc.), in terms of SO 3 - no more than 1.0%; pyrite in terms of SO 3 - no more than 4% by weight;

mica - no more than 2% by weight;

halide compounds (halite, sylvite, etc.), including water-soluble chlorides, in terms of chlorine ion - no more than 0.15% by weight;

coal - no more than 1% by weight.

Based on materials from the site: http://www.baurum.ru/