The usual winter cold not only causes discomfort to people, it is a real test for buildings, roads and embankments.
The frost resistance of crushed stone depends on its resistance to repeated freezing and thawing.
The thing is that crushed stone, which is widely used in the construction of embankments, construction, and road construction, quickly loses its properties under the influence of frost.
Frost resistance of crushed stone is one of its most important characteristics.
Crushed stone is an inorganic bulk granular material with grains whose dimensions are greater than 5 mm. It is classified as a non-metallic mineral. Crushed stone is obtained by crushing rocks or by weathering them. In addition, it can be obtained as an accompanying material during processing and mining of non-metallic and ore minerals.
Main characteristics
Processing granite crushed stone.
Crushed stone and its properties, which you need to pay attention to when choosing a material:
- fraction;
- flakiness;
- frost resistance;
- strength;
- radioactivity;
- water saturation and water absorption;
- content of dust and clay particles;
- adhesion.
Characteristics of crushed stone for road work
Crushed stone is a granular building material of natural or artificial origin. The main production method is crushing and separating rocks into fractions.
Construction of roads using crushed stone
When laying roads, different types of crushed stone are used:
- Granite, the most durable material. It is used for laying roads with heavy traffic.
- Gravel, less durable than granite. It has the advantages of affordable price and low level of radioactivity. It has found application in laying roads, repairing road surfaces, and producing asphalt.
- Limestone is used in the construction of secondary roads as a road base.
- Concrete has low strength and wear resistance; it is used for filling temporary roads.
Crushed stone is used at all stages of laying, operating and repairing highways.
When choosing a building material, its characteristics are taken into account:
- strength;
- flakiness;
- frost resistance;
- grain size;
- radioactivity.
These parameters are fundamental when choosing the area of use - for preparing different types of asphalt, creating a base or top layer of road surfaces.
Application area
Technology for the production of colored crushed stone.
Crushed stone is used quite extensively, in almost all types of construction work. Since the surface of the grains is rough and can adhere remarkably to cement, crushed stone, as well as gravel similar in properties to it, are used for the production of concrete, reinforced concrete products and structures. Filling the bases for the foundation, creating drainage whirlpools - and here you cannot do without crushed stone, which does not allow water to stagnate. In the construction of highways, the material is used as a cushion under asphalt pavement; low strength characteristics are suitable here. The properties of crushed stone make it possible to use it in large fractions to create a ballast layer under the railway track.
Crushed stone is also used in landscaping, landscape design and the gardening industry for arranging paths and platforms, in the design of flower beds and lawns. Walking paths are sprinkled with small pebbles in winter to combat ice. In the sports industry, fine crushed stone is used to produce tennis court surfaces.
Kinds
Types of crushed stone can be classified according to various criteria. The origin of crushed stone allows us to distinguish a significant number of varieties, some of which are of particular interest:
- granite;
- gravel;
- dolomite;
- limestone;
- marble;
- slag;
- foam glass;
- expanded clay and agloporite, which are visually similar, but differ in properties;
- basaltic;
- quartz and slate.
Expanded clay crushed stone 5-10. Photos of Soil Trucks
Depending on the type of post-processing, after production the material can be subject to additional processing, distinguished between black, colored, washed, galvanized. All types have the characteristics presented below, but each has its own specific indicators, values, which determine the scope of application.
Determination of frost resistance
Full cycle of crushed stone production.
Frost resistance is the ability of rocks in a state of water saturation to withstand repeated alternating thawing and freezing . When water freezes, it increases in volume by approximately 10%, and the resulting ice puts pressure on the walls of the material, causing its strength to decrease over time and the material to collapse.
In particularly severe conditions, stone material ends up in road surfaces. In the fall, as a rule, it is thoroughly saturated with water, and in the winter and spring seasons it alternately freezes and thaws. To calculate the specific frost resistance of crushed stone, several samples should be tested. This test is carried out on small cubic samples 5x5x5 cm or cylindrical with a diameter and height of 5 cm. The test is carried out as follows: water-saturated samples are alternately frozen and thawed at temperatures of -20°C, +20°C. The number of thawing and freezing cycles can be up to 200 or more, depending on the class of the structure and the purpose of the stone material in this structure. The rock is considered to have passed the frost resistance test when the prototypes show no damage such as delamination, cracks, rounding of corners or edges.
Use of crushed stone in road construction.
For rock that has passed frost resistance tests, the degree of strength reduction is determined. Thus, frost-resistant rocks have a frost resistance coefficient close to unity. In those samples that could not pass the frost resistance test, the weight loss is determined for greater clarity.
The safety test using sodium sulfate solution is the saturation of stone pores with such a solution. Sodium sulfate gradually increases in volume, thereby creating pressure on the pore walls. Approximately the same thing happens with frozen water when determining frost resistance.
Where can I buy
A large number of enterprises sell wholesale and retail crushed stone with various characteristics to solve a whole range of problems; the companies are presented here.
Characteristics of crushed stone · 02/09/2021 · 0
Useful tips
When purchasing building materials, crushed stone should be selected especially carefully and attention should be paid to its characteristics such as frost resistance. As a rule, in such cases there is a loss of strength of the entire structure, and this can lead to the collapse of the building. To prevent such troubles, the use of crushed stone with a grade less than F300 is prohibited. In the northern and central regions it is better to stay on the F400. As for the relatively warm center, frost resistance is assessed by the number of thawing and freezing cycles, and there are quite a lot of such cycles in the warm central zone in one winter. Therefore, you should purchase F400 brand crushed stone - this material will last much longer than others.
Types of crushed stone and frost resistance values
The material obtained from granite is one of the most durable grades of crushed stone in terms of frost resistance (F300, F400). As for crushed gravel, it is inferior to granite in all respects, including frost resistance, which corresponds to F150, F200, and less often reaches F300.
The frost resistance of crushed slag varies and depends on the chemical composition and structure. The porous version of the slag has a low grade of F15, and the product obtained from copper smelting waste is characterized by an index of F300.
The frost resistance parameter of crushed limestone is low - F100.
3 Definitions
The following terms are used in this standard.
3.1 crushed
rock:
Inorganic granular bulk material with grains of coarseness. 5 mm, obtained by crushing suitable rocks, gravel and boulders, incidentally mined overburden and host rocks or substandard waste from mining enterprises for processing ores (ferrous, non-ferrous and rare metals in the metallurgical industry) and non-metallic minerals from other industries and subsequent sieving of crushed products.
3.2 rock gravel:
Inorganic granular bulk material with grains of coarseness. 5 mm, obtained by sieving natural gravel-sand mixtures.
GOSTs for construction • GOSTs crushed stone • GOST 8267-93
3. Instead of GOST 8267-82, GOST 8268-82, GOST 10260-82, GOST 23254-78, GOST 26873-86.
4. Entered into force on January 1, 1995 as a state standard of the Russian Federation by Decree of the State Construction Committee of Russia dated June 17, 1994 No. 18-43.
1 AREA OF USE
This standard applies to crushed stone and gravel from rocks with an average grain density of 2.0 to 3.0 g/cm³, used as aggregates for heavy concrete, as well as for road and other types of construction work. The standard does not apply to crushed stone and gravel for the ballast layer of railway tracks and decorative crushed stone. The requirements set out in paragraphs 4.2 - 4.9, sections 5 and 6 are mandatory.
2. REGULATORY REFERENCES
This standard uses references to the following standards: GOST 3344-83 Crushed stone and slag sand for road construction. Technical specifications GOST 8269.0-97 Crushed stone and gravel from dense rocks and industrial waste for construction work. Methods of physical and mechanical testing GOST 8269.1-97 Crushed stone and gravel from dense rocks and industrial waste for construction work. Methods of chemical analysis GOST 30108-94 Construction materials and products. Determination of specific effective activity of natural radionuclides.
3. DEFINITIONS
The following terms are used in this standard. Crushed rock is an inorganic granular bulk material with grains of coarseness. 5 mm, obtained by crushing rocks, gravel and boulders, incidentally mined overburden and host rocks or substandard waste from mining enterprises for processing ores (ferrous, non-ferrous and rare metals of the metallurgical industry) and non-metallic minerals from other industries and subsequent sieving of crushed products. Rock gravel is an inorganic granular bulk material with grains of coarse grain size. 5 mm, obtained by sieving natural gravel-sand mixtures.
4. TECHNICAL REQUIREMENTS
4.1. Crushed stone and gravel must be manufactured in accordance with the requirements of this standard according to technological documentation approved by the manufacturer. 4.2. Main parameters and dimensions 4.2.1. Crushed stone and gravel are produced in the form of the following main fractions: from 5 (3) to 10 mm; St. 10 to 15 mm; St. 10 to 20 mm; St. 15 to 20 mm; St. 20 to 40 mm; St. 40 to 80 (70) mm and mixtures of fractions from 5 (3) to 20 mm. By agreement between the manufacturer and the consumer, crushed stone and gravel are produced in the form of other mixtures composed of individual fractions, as well as fractions from 80 (70) to 120 mm, St. 120 to 150 mm. 4.2.2. Complete residues on control sieves when sifting crushed stone and gravel of fractions from 5 (3) to 10 mm, St. 10 to 15 mm, St. 10 to 20 mm, St. 15 to 20 mm, St. 20 to 40 mm, St. 40 to 80 (70) mm and mixtures of fractions from 5 (3) to 20 mm must correspond to those indicated in Table 1, where d and D are the smallest and largest nominal grain sizes.
Table 1
| Diameter of test sieves holes, mm | d | 0.5(d+D) | D | 1.25 D |
| Total residues on sieves,% by weight | From 90 to 100 | From 30 to 60 | To 10 | Up to 0.5 |
Notes.
| ||||
4.2.3. For crushed stone and gravel fractions of St. 80 (70) to 120 mm and St. 120 to 150 mm, as well as for a mixture of fractions produced by agreement between the manufacturer and the consumer, the total residues on control sieves with diameters d, D, 1.25 D must satisfy those indicated in Table 1, and the ratio of fractions in the mixtures is established by agreement between the manufacturer and the consumer in accordance with regulatory documents for the use of these mixtures for construction work. 4.3. Content of crushed grains in crushed stone from gravel and boulders and shape of grains 4.3.1. Crushed stone from gravel and boulders must contain crushed grains in an amount of at least 80% by weight. It is allowed, by agreement between the manufacturer and the consumer, to produce crushed stone from gravel containing at least 60% crushed grains. 4.3.2 The shape of crushed stone and gravel grains is characterized by the content of lamellar (flaky) and needle-shaped grains. Crushed stone, depending on the grain content of lamellar and needle-shaped forms, is divided into five groups, which must correspond to those indicated in Table 2.
table 2
Percentage by weight
| Crushed stone group | Content of lamellar (flaky) and needle-shaped grains |
| Up to 10 incl. | |
| St. 10 to 15 | |
| » 15 » 25 | |
| » 25 » 35 | |
| » 35 » 50 | |
| Note. By agreement between the manufacturer and the consumer, it is allowed to produce crushed stone from igneous rocks containing St. 50%, but not more than 65% of grains are lamellar (flaky) and needle-shaped. | |
4.3.3. Gravel should not contain lamellar and needle-shaped grains of more than 35% by weight. 4.4. Strength 4.4.1. The strength of crushed stone and gravel is characterized by a grade based on its crushability when compressed (crushed) in a cylinder. Crushed stone and gravel intended for the construction of highways are characterized by a grade based on crushability when compressed (crushed) in a cylinder and a grade based on abrasion, determined by testing in a shelf drum. 4.4.2. Grades for crushability of crushed stone from sedimentary and metamorphic rocks must meet the requirements specified in Table 3, and grades for crushability of crushed stone from igneous rocks - in Table 4.
Table 3
| Grade for crushability of crushed stone from sedimentary and metamorphic rocks | Weight loss when testing crushed stone, % | |
| dry | saturated with water | |
| 1200 | Up to 11 incl. | Up to 11 incl. |
| 1000 | St. 11 to 13 | St. 11 to 13 |
| 800 | » 13 » 15 | » 13 » 15 |
| 600 | » 15 » 19 | » 15 » 20 |
| 400 | » 19 » 24 | » 20 » 28 |
| 300 | » 24 » 28 | » 28 » 38 |
| 200 | » 28 » 35 | » 38 » 54 |
>Table 4
| Grade for crushability of crushed stone from igneous rocks | Weight loss when testing crushed stone, % | |
| from intrusive rocks | from effusive rocks | |
| 1400 | Up to 12 incl. | Up to 9 incl. |
| 1200 | St. 12 to 16 | St. 9 to 11 |
| 1000 | » 16 » 20 | » 11 » 13 |
| 800 | » 20 » 25 | » 13 » 15 |
| 600 | » 25 » 34 | » 15 » 20 |
It is allowed to determine the grade of crushed stone from sedimentary and metamorphic rocks both in a dry and in a water-saturated state. If the grades do not match in terms of crushability, the strength is assessed based on the test results in a water-saturated state. The crushability grades of crushed stone and gravel must meet the requirements specified in Table 5.
Table 5
| Grade for crushability of crushed stone and gravel | Weight loss during testing,% | |
| crushed gravel | gravel | |
| 1000 | Up to 10 incl. | Up to 8 incl. |
| 800 | St. 10 to 14 | St. 8 to 12 |
| 600 | » 14 » 18 | » 12 » 16 |
| 400 | » 18 » 26 | » 16 » 24 |
To establish the grade for crushability of crushed stone from boulders, consisting of rocks of different genetic types, an intermediate grade for crushability is determined according to GOST 8269.0 as a weighted average of the grades obtained separately for crushed stone of these types of rocks, taking into account their content in crushed stone from boulders. Based on the weighted average grade, the grade is determined according to the crushability of crushed stone from boulders according to Table 5a.
Table 5a
| Intermediate weighted average grade for crushability of crushed stone from boulders | Grade for crushability of crushed stone from boulders |
| 1200 and above | 1200 |
| St. 1000 to 1200 | 1000 |
| St. 800 to 1000 | 800 |
| St. 600 to 800 | 600 |
| St. 400 to 600 | 400 |
| St. 300 to 400 | 300 |
.
4.4.3. The abrasion grades of crushed stone and gravel must meet the requirements specified in Table 6.
Table 6
| Grade for abrasion of crushed stone and gravel | Weight loss during testing,% | |
| crushed stone | gravel | |
| I1 | Up to 25 incl. | Up to 20 incl. |
| AND 2 | St. 25 to 35 | St. 20 to 30 |
| I3 | » 35 » 45 | » 30 » 40 |
| I4 | » 45 » 60 | » 40 » 50 |
4.5. Content of soft rock grains The content of soft rock grains in crushed stone and gravel, depending on the type of rock and grade of crushability, should not be more than indicated in Table 7.
Table 7
Percentage by weight
| Type of rock and grade for crushability of crushed stone and gravel | Content of weak rock grains |
| Crushed stone from igneous, metamorphic and sedimentary rocks grades: | |
| 1400; 1200; 1000 | 5 |
| 800; 600; 400 | 10 |
| 300 | 15 |
| Crushed stone from gravel and boulders and gravel grades: | |
| 1000; 800; 600 | 10 |
| 400 | 15 |
4.6. Frost resistance 4.6.1. Frost resistance of crushed stone and gravel is characterized by the number of freezing and thawing cycles, during which the percentage loss by weight of crushed stone and gravel does not exceed the established values. It is possible to evaluate the frost resistance of crushed stone and gravel by the number of cycles of saturation in a solution of sodium sulfate and drying. If the brands do not match, frost resistance is assessed based on the results of the freezing and thawing test. 4.6.2. Crushed stone and gravel are divided into the following grades based on frost resistance: F15; F25; F50; F100; F150; F200; F300; F400. The frost resistance indicators of crushed stone and gravel when tested by freezing and thawing or saturation in a solution of sodium sulfate and drying must correspond to those indicated in Table 8.
Table 8
| Type of test | Frost resistance grade for crushed stone and gravel | |||||||
| F15 | F25 | F50 | F100 | F150 | F200 | F300 | F400 | |
| Freeze-thaw: | ||||||||
| number of cycles | 15 | 25 | 50 | 100 | 150 | 200 | 300 | 400 |
| weight loss after testing,%, no more | 10 | 10 | 5 | 5 | 5 | 5 | 5 | 5 |
| Saturation in sodium sulfate solution - drying: | ||||||||
| number of cycles | 3 | 5 | 10 | 10 | 15 | 15 | 15 | 15 |
| weight loss after testing,%, no more | 10 | 10 | 10 | 5 | 5 | 3 | 2 | 1 |
4.7. Content of dust and clay particles 4.7.1. The content of dust and clay particles (less than 0.05 mm in size) in crushed stone and gravel, depending on the type of rock and grade of crushability, must correspond to that indicated in Table 9.
Table 9
.
| Type of rock and grade for crushability of crushed stone and gravel | Content of dust and clay particles, % by weight, no more |
| Crushed stone from igneous and metamorphic rocks grades: | |
| St. 800 | 1 |
| St. 600 to 800 incl. | 1 |
| Crushed stone from sedimentary rocks grades: | |
| from 600 to 1200 incl. | 2 |
| 200, 400 | 3 |
| Crushed gravel and gravel grades: | |
| 1000 | 1 |
| 800 | 1 |
| 600 | 2 |
| 400 | 3 |
| Crushed stone from boulders brands: | |
| 1200 | 1 |
| 1000 | 1 |
| 800 | 1 |
| 600 | 2 |
| 400 | 3 |
4.7.2. The clay content in lumps should not exceed that specified in Table 10.
Table 10
| Grade for crushability of crushed stone and gravel | Clay content in lumps, % by weight, no more |
| Crushed stone from igneous, sedimentary and metamorphic rocks grades: | |
| 400 and above | 0,25 |
| 300, 200 | 0,5 |
| Crushed gravel and gravel grades: | |
| 1000, 800, 600, 400 | 0,25 |
| Crushed stone from boulders brands: | |
| 1200, 1000, 800, 600 | 0,25 |
4.8. Presence of harmful components and impurities 4.8.1. Crushed stone from incidentally mined overburden and host rocks and substandard waste from mining enterprises for processing ores (ferrous, non-ferrous and rare metals of the metallurgical industry) and non-metallic minerals from other industries must be resistant to all types of decay. The stability of the crushed stone structure against all types of decay must meet the requirements specified in Table 11.
Table 11
| Grade for crushability of crushed stone | Weight loss during decay, %, no more |
| 1000 and above | 3 |
| 800, 600 | 5 |
| 400 and below | 7 |
4.8.2. Crushed stone and gravel must be resistant to environmental influences. Crushed stone and gravel intended for use as aggregates for concrete must be resistant to the chemical effects of cement alkalis. The durability of crushed stone and gravel is determined by the mineralogical and petrographic composition of the original rock and the content of harmful components and impurities that reduce the durability of concrete and cause corrosion of the reinforcement of reinforced concrete products and structures. The list of harmful components and their maximum permissible contents are given in Appendix A. 4.9 During the production of crushed stone and gravel, their radiation-hygienic assessment must be carried out, based on the results of which the scope of application is established. Crushed stone and gravel, depending on the values of the total specific effective activity of natural radionuclides, are used: - at up to 370 Bq/kg - in newly constructed residential and public buildings; - at 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 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. 4.10. Crushed stone and gravel should not contain foreign contaminants. 4.11. The provision of the standard values for the quality indicators of crushed stone and gravel in terms of grain composition (content of grains smaller than the smallest nominal size d and larger than the largest nominal size D) and the content of dust and clay particles must be at least 95%.
5. ACCEPTANCE RULES
5.1. Crushed stone and gravel must be accepted by the technical control of the manufacturer. 5.2. Acceptance and delivery of crushed stone and gravel is carried out in batches. A batch is considered to be the amount of crushed stone (gravel) of one fraction (mixture of fractions), established in the supply contract and simultaneously shipped to one consumer in one train or one vessel. When shipping by road, a batch is considered to be the amount of crushed stone (gravel) of one fraction (mixture of fractions) shipped to one consumer during the day. 5.3. To verify compliance of the quality of crushed stone (gravel) with the requirements of this standard, acceptance inspection and periodic testing are carried out. Acceptance control at the manufacturer is carried out daily by testing a combined sample of crushed stone (gravel) taken from each production line. During acceptance control, the following is determined: - grain composition; — content of dust and clay particles; — clay content in lumps; — content of grains of weak rocks. 5.4. During periodic tests, the following is determined: - once every 10 days - the content of lamellar and needle-shaped grains and the content of crushed grains in crushed stone from gravel and boulders and the content of free asbestos fiber in crushed stone from asbestos-containing rocks; - once a quarter - strength and bulk density, stability of the structure against decay; - once a year - frost resistance and class of crushed stone (gravel) according to the specific effective activity of natural radionuclides, as well as the content of harmful components and impurities at the request of consumers. The value of the specific effective activity of natural radionuclides is determined, and the class of crushed stone and gravel is established in specialized laboratories on gamma spectrometric installations certified in the prescribed manner or in radiation metric laboratories of supervisory authorities. In the absence of geological survey data on radiation-hygienic assessment of the deposit and a conclusion on the class of crushed stone and gravel, the manufacturer carries out a preliminary assessment of the developed rock areas directly in the quarry or crushed stone (gravel) in the finished product warehouse in accordance with GOST 30108. Strength, frost resistance of crushed stone and gravel, as well as the stability of the crushed stone structure against all types of decay are determined in each case by changes in the properties of the feedstock (rock, associated rocks and industrial waste). In the absence of geological survey data on the content of harmful components and impurities, the enterprise conducts tests in specialized or accredited laboratories and centers to determine the content of reactive rocks in products, the content of weak grains and metal impurities in crushed stone from slags of ferrous and non-ferrous metallurgy, the activity of slags and electrical insulating materials. properties of crushed stone for the ballast layer of railway tracks. 5.5. Selection and preparation of crushed stone (gravel) samples for quality control at the manufacturing enterprise is carried out in accordance with the requirements of GOST 8269.0, GOST 8269.1. Control points for preliminary assessment of rocks and the class of crushed stone and gravel are selected according to GOST 30108. 5.6. When checking the compliance of crushed stone (gravel) with the requirements of this standard, the consumer must apply the information given in paragraphs. 5.7 - 5.10 sampling procedure. 5.7. The number of spot samples taken by the consumer to control the quality of crushed stone (gravel) in each batch, depending on the volume of the batch, must be at least:
| up to 350 m³ | 10 |
| St. 350 to 700 m³ | 15 |
| 700 m³ | 20 |
From the spot samples, a combined sample is formed that characterizes the controlled batch. Averaging, reduction and sample preparation for testing are carried out in accordance with GOST 8269.0, GOST 8269.1. 5.8. To control the quality of crushed stone and gravel supplied by rail, spot samples are taken when unloading cars from the flow of crushed stone (gravel) on belt conveyors used to transport it to the consumer’s warehouse. When unloading each wagon being tested, 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 according to clause 5.8. The 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 when unloading wagons, then spot samples are taken directly from the wagons. To do this, the surface of the crushed stone (gravel) in the car is leveled and holes with a depth of 0.2 - 0.4 m are made 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 be at least 0.5 m. Crushed stone samples are taken from the holes with a scoop, moving it from bottom to top along the wall of the hole. 5.9. To control the quality of crushed stone (gravel) supplied by water transport, spot samples are taken when unloading ships. When used for unloading belt conveyors, point samples are taken at regular intervals from the flow of crushed stone (gravel) on the conveyors. When unloading ships with grab cranes, point samples are taken with a scoop at regular intervals as unloading proceeds directly from the newly formed surface of crushed stone (gravel) in the ship, and not from holes. 5.10. To control the quality of crushed stone (gravel) shipped by road, spot samples are taken when unloading vehicles. If belt conveyors are used for unloading crushed stone (gravel), point samples are taken from the flow of crushed stone on the conveyors. When unloading each vehicle, one spot sample is taken. The number of cars is taken into account obtaining the required number of spot samples according to 5.7. Cars are selected according to the consumer's instructions. If the batch consists of less than ten cars, then crushed stone samples are taken from each car. If conveyor transport is not used when unloading cars, spot samples are taken directly from the cars. To do this, the surface of the crushed stone (gravel) in the car is leveled, a hole 0.2 - 0.4 m deep is opened in the center of the body. A sample of crushed stone (gravel) is taken from the hole with a scoop, moving it from bottom to top along the hole. 5.11. The amount of crushed stone (gravel) supplied is determined by volume or weight. Measurement of crushed stone (gravel) is carried out in carriages and cars. Crushed stone (gravel) shipped in wagons or cars is weighed on railway or truck scales. The mass of crushed stone (gravel) shipped in ships is determined by the vessel's draft. The amount of crushed stone (gravel) from units of mass to units of volume is recalculated according to the value of the bulk density of crushed stone (gravel), determined by its moisture content during shipment. The volume of crushed stone (gravel) supplied in a carriage or car is determined by its measurement, the resulting volume is multiplied by the compaction coefficient of crushed stone (gravel) during transportation, which depends on the loading method, transportation distance, and grain composition. The maximum permissible value of humidity and compaction coefficient, which should not exceed 1.10, is established in the supply contract. 5.13. The results of acceptance inspection and periodic testing are given in a quality document, which indicates: - the name of the manufacturer and its address; — number and date of issue of the document; — name and address of the consumer; — batch number and quantity of crushed stone (gravel); — wagon number or vessel number and invoice numbers; — grain composition of crushed stone (gravel); — content of lamellar (flaky) and needle-shaped grains; — content of crushed grains in crushed gravel; — clay content in lumps; — content of dust and clay particles; — grade of crushed stone (gravel) by strength (crudibility); — content of grains of weak rocks; — frost resistance of crushed stone (gravel); — bulk density of crushed stone (gravel); — specific effective activity of natural radionuclides of crushed stone (gravel); — stability of the crushed stone structure against decay; — content of harmful components and impurities; — designation of this standard. In addition, at the request of the consumer, the document indicates the mineralogical and petrographic characteristics of the gravel and rock from which crushed stone is produced, as well as the true and average density, porosity, hollowness and water absorption.
6. CONTROL METHODS
6.1. Tests of crushed stone and gravel are carried out in accordance with GOST 8269.0, GOST 8269.1. When determining the grain composition of crushed stone and gravel, it is allowed to use a sieve with 70 mm holes before equipping enterprises with sieves with 80 mm holes. 6.2. The stability of the crushed stone structure against all types of decay is determined according to GOST 8269.0. 6.3. The specific effective activity of natural radionuclides in crushed stone and gravel is determined by the gamma spectrometric method according to GOST 30108. 6.4. The provision of the standard values for the content in crushed stone and gravel of grains smaller than the smallest nominal size d and larger than the largest nominal size D and the content of dust and clay particles is characterized by the ratio of the number of replacement samples, the quality indicators of which exceed standard values, to the total number of replacement samples taken and tested within one quarter.
7. TRANSPORTATION AND STORAGE
7.1. Crushed stone and gravel are transported in bulk in vehicles of any type in accordance with the current rules for the transportation of goods and technical conditions for loading and securing goods, approved by the Ministry of Railways, rules for the transportation of goods by road and water transport. When transporting crushed stone and gravel by rail, wagons should be loaded taking into account the full use of their carrying capacity. 7.2. Crushed stone and gravel are stored separately into fractions and mixtures of fractions under conditions that protect them from clogging and contamination.
Appendix A (mandatory)
CONTENT OF HARMFUL COMPONENTS AND IMPURITIES
1. The main components that reduce the strength and durability of concrete include inclusions: - clay minerals (montmorillonite, kaolinite, etc.); - mica and hydromicas and other layered silicates; — asbestos; — organic substances (coal, lignite, oil shale, humic acids, etc.); — minerals that are not resistant to weathering processes (chlorite, zeolite, apatite, nepheline, phosphorite). 2. The main components that cause deterioration in surface quality and internal corrosion of concrete include inclusions of: - rocks and minerals containing amorphous varieties of silicon dioxide (chalcedony, opal, etc.); — sulfur-containing rocks and minerals (pyrite, marcasite, pyrrhotite and other sulfides, as well as gypsum, anhydrite and other sulfates); — rocks and minerals containing iron oxides and hydroxides (magnetite, goethite, etc.); - mica, hydromicas and other layered silicates. 3. The main components that cause corrosion of reinforcement in concrete include inclusions: - halogen-containing minerals (pyrite, marcasite, pyrrhotite and other sulfides, gypsum, anhydrite and other sulfates). 4. Crushed stone and gravel are used in concrete without restrictions, if the content of rocks and minerals classified as harmful components is no more than: - 50 mmol/l of amorphous varieties of silicon dioxide, soluble in alkalis; - 1.5% by weight of sulfates (gypsum, anhydrite) and sulfides, except pyrite (marcasite, pyrrhotite, gypsum, anhydrite, etc.) in terms of; — 4% by weight of pyrite; - 15% by volume of layered silicates, if mica, hydromicas, chlorites and others are rock-forming minerals; — 0.1% by weight of halogen compounds (halite, sylvite, etc., including water-soluble chlorides) calculated as chlorine ion; - 0.25% by weight of free asbestos fibers; — 1.0% by weight of coal and wood residues; - 10% by volume of each of the listed rock-forming minerals (magnetite, goethite, hematite, etc., apatite, nepheline, phosphorite) or their sum in an amount of no more than 15%.
| GOST construction standards: | |
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Flakiness of crushed stone
In crushed stone, the content of grains of lamellar (flaky - derived from the word “bream”, i.e. flat like bream) and needle-shaped forms is normalized. Lamellar and needle-shaped grains include grains whose thickness or width is three times or more less than their length. According to the shape of the grains, crushed stone is divided into four groups (content of grains of lamellar and needle-shaped forms, % by weight):
- Group I “cuboidal” up to 15%,
- Group II “improved” from 15% to 25%,
- Group III “normal” from 25% to 35%,
- Group IV “normal” from 35% to 50%.
Grain composition of crushed stone
The grain composition of each fraction must meet the requirements of GOST 8267-93 “Crushed stone and gravel from dense rocks for construction work.”
Based on the requirements of the specified GOST, it follows that in the fraction of crushed stone supplied for construction, for example, 20-40 mm, the number of grains smaller than 20 mm in size should not exceed 10%, and grains larger than 1.25 * D (50 mm) - no more than 0, 5%. These requirements are necessary for strict compliance with the grain composition of individual fractions. Compliance with these requirements is reflected in the sieving.
4 Technical requirements
4.1 Crushed stone and gravel must be manufactured in accordance with the requirements of this standard according to technological documentation approved by the manufacturer.
4.2
Main parameters and dimensions
4.2.1 Crushed stone and gravel are produced in the form of the following main fractions: from 5(3) to 10 mm; St. 10 to 15 mm; St. 10 to 20 mm; St. 15 to 20 mm; St. 20 to 40 mm; St. 40 to 80(70) mm and mixtures of fractions from 5(3) to 20 mm.
By agreement between the manufacturer and the consumer, crushed stone and gravel are produced in the form of other mixtures composed of individual fractions, as well as fractions from 80 (70) to 120 mm, St. 120 to 150 mm.
4.2.2 Complete residues on control sieves when sifting crushed stone and gravel of fractions from 5(3) to 10 mm, St. 10 to 15 mm; St. 10 to 20 mm, St. 15 to 20 mm; St. 20 to 40 mm, St. 40 to 80(70) mm and mixtures of fractions from 5(3) to 20 mm must correspond to those indicated in the table, where d
and
D
are the smallest and largest nominal grain sizes.
Table 1
| Diameter of test sieves holes, mm | d | 0,5(d + | D | 1,25D |
| Total residues on sieves, % by weight | From 90 to 100 | From 30 to 60 | To 10 | Up to 0.5 |
| Notes 1 For crushed stone and gravel of fractions from 5(3) to 10 mm and a mixture of fractions from 5(3) to 20 mm, additionally use: lower sieves 2.5 mm (1.25 mm), the total residue on which should be from 95 % up to 100 + | ||||
4.2.3 For crushed stone and gravel fractions St. 80(70) to 120 mm and St. 120 to 150 mm, as well as for a mixture of fractions produced by agreement between the manufacturer and the consumer, complete residues on test sieves with diameter d
,
D
, 1.15
D
must satisfy those indicated in the table, and the ratio of fractions in the mixtures is established by agreement between the manufacturer and the consumer in accordance with regulatory documents for the use of these mixtures for construction work.
4.2.1 — 4.2.3. (Changed edition, Amendment No. 3).
4.2.4 (Deleted, Change. No. 3).
4.3
Content of crushed grains in crushed stone from gravel and boulders and shape of grains
4.3.1 Crushed stone from gravel and boulders must contain crushed grains in an amount of at least 80% by weight. It is allowed, by agreement between the manufacturer and the consumer, to produce crushed stone from gravel containing at least 60% crushed grains.
(Changed edition, Amendment No. 4).
4.3.2 The shape of crushed stone and gravel grains is characterized by the content of lamellar (flaky) and needle-shaped grains.
Crushed stone, depending on the content of lamellar and needle-shaped grains, is divided into five groups, which must correspond to those indicated in the table.
table 2
| Crushed stone group | Content of lamellar (flaky) and needle-shaped grains, % by weight | Crushed stone group | Content of lamellar (flaky) and needle-shaped grains, % by weight |
| 1 | Up to 10 incl. | 4 | Over 25 to 35 inclusive. |
| 2 | St. 10 to 15 | 5 | » 35 » 50 |
| 3 | » 15 » 25 | ||
| Note - By agreement between the manufacturer and the consumer, it is allowed to produce crushed stone from igneous rocks containing St. 50 % , but not more than 65 | |||
(Changed edition, Amendment No. 3).
4.3.3 Gravel should not contain lamellar and needle-shaped grains of more than 35% by weight.
4.4 Strength
4.4.1 The strength of crushed stone and gravel is characterized by the grade according to its crushability when compressed (crushed) in a cylinder.
Crushed stone and gravel intended for the construction of highways are characterized by a grade based on crushability when compressed (crushed) in a cylinder and a grade based on abrasion, determined by testing in a shelf drum.
(Changed edition, Amendment No. 4).
4.4.2 Grades for crushability of crushed stone from sedimentary and metamorphic rocks must comply with the requirements specified in table, and grades for crushability of crushed stone from igneous rocks - in table.
Table 3
| Grade for crushability of crushed stone from sedimentary and metamorphic rocks | Weight loss when testing crushed stone, % | |
| dry | saturated with water | |
| 1200 | Up to 11 incl. | Up to 11 incl. |
| 1000 | St. 11 to 13 | St. 11 to 13 |
| 800 | » 13 » 15 | » 13 » 15 |
| 600 | » 15 » 19 | » 15 » 20 |
| 400 | » 19 » 24 | » 20 » 28 |
| 300 | » 24 » 28 | » 28 » 38 |
| 200 | » 28 » 35 | » 38 » 54 |
Table 4
| Grade for crushability of crushed stone from igneous rocks | Mass loss when testing crushed stone, % | |
| from intrusive rocks | from effusive rocks | |
| 1400 | Up to 12 incl. | Up to 9 incl. |
| 1200 | St. 12 to 16 | St. 9 to 11 |
| 1000 | » 16 » 20 | » 11 » 13 |
| 800 | » 20 » 25 | » 13 » 15 |
| 600 | » 25 » 34 | » 15 » 20 |
It is allowed to determine the grade of crushed stone from sedimentary and metamorphic rocks both in a dry and in a water-saturated state.
If the grades do not match in terms of crushability, the strength is assessed based on the test results in a water-saturated state.
Grades for crushability of crushed stone and gravel must meet the requirements specified in the table.
Table 5
| Grade for crushability of crushed stone and gravel | Weight loss during testing,% | |
| crushed gravel | gravel | |
| 1000 | Up to 10 incl. | Up to 8 incl. |
| 800 | St. 10 to 14 | St. 8 to 12 |
| 600 | » 14 » 18 | » 12 » 16 |
| 400 | » 18 » 26 | » 16 » 24 |
To establish the grade for crushability of crushed stone from boulders, consisting of rocks of different genetic types, an intermediate grade for crushability is determined according to GOST 8269.0 as a weighted average of the grades obtained separately for crushed stone of these types of rocks, taking into account their content in crushed stone from boulders. Based on the weighted average grade, the grade is determined according to the crushability of crushed stone from boulders according to the table.
Table 5a
| Intermediate weighted average grade for crushability of crushed stone from boulders | Grade for crushability of crushed stone from boulders |
| 1200 and above | 1200 |
| St. 1000 to 1200 | 1000 |
| » 800 » 1000 | 800 |
| » 600 » 800 | 600 |
| » 400 » 600 | 400 |
| » 300 » 400 | 300 |
(Changed edition, Amendment No. 4).
4.4.3 The abrasion grades of crushed stone and gravel must meet the requirements specified in the table.
Table 6
| Grade for abrasion of crushed stone and gravel | Weight loss during testing,% | |
| crushed stone | gravel | |
| I1 | Up to 25 incl. | Up to 20 incl. |
| AND 2 | St. 25 to 35 | St. 20 to 30 |
| I3 | » 35 » 45 | » 30 » 40 |
| I4 | » 45 » 60 | » 40 » 50 |
4.5
Content of soft rock grains
The content of soft rock grains in crushed stone and gravel, depending on the type of rock and crushability grade, should not be more than indicated in the table.
Table 7
| Type of rock and grade for crushability of crushed stone and gravel | Content of soft rock grains, % by weight |
| Crushed stone from igneous, metamorphic and sedimentary rocks grades: | |
| 1400; 1200; 1000 | 5 |
| 800; 600; 400 | 10 |
| 300 | 15 |
| Crushed stone from gravel and boulders and gravel grades: | |
| 1000; 800; 600 | 10 |
| 400 | 15 |
4.6
Frost resistance
4.6.1 Frost resistance of crushed stone and gravel is characterized by the number of freezing and thawing cycles, during which the percentage loss by weight of crushed stone and gravel does not exceed the established values.
It is possible to evaluate the frost resistance of crushed stone and gravel by the number of cycles of saturation in a solution of sodium sulfate and drying. If the brands do not match, frost resistance is assessed based on the results of the freezing and thawing test.
4.6.2 Crushed stone and gravel are divided into the following grades based on frost resistance: F15; F25; F50; F100; F150; F200; F300; F400.
The frost resistance indicators of crushed stone and gravel when tested by freezing and thawing or saturation in a solution of sodium sulfate and drying must correspond to those indicated in the table.
Table 8
| Type of test | Frost resistance grade for crushed stone and gravel | |||||||
| F15 | F25 | F50 | F100 | F150 | F200 | F300 | F400 | |
| Freezing - thawing: — number of cycles | 15 | 25 | 50 | 100 | 150 | 200 | 300 | 400 |
| - weight loss after testing, % , no more | 10 | 10 | 5 | 5 | 5 | 5 | 5 | 5 |
| Saturation in sodium sulfate solution - drying: number of cycles | 3 | 5 | 10 | 10 | 15 | 15 | 15 | 15 |
| weight loss after testing,%, no more | 10 | 10 | 10 | 5 | 5 | 3 | 2 | 1 |
4.7
Content of dust and clay particles
4.7.1 The content of dust and clay particles (less than 0.05 mm in size) in crushed stone and gravel, depending on the type of rock and grade of crushability, must correspond to that indicated in the table.
Table 9
| Type of rock and grade for crushability of crushed stone and gravel | Content of dust and clay particles, % by weight, no more |
| Crushed stone from igneous and metamorphic rocks grades: | |
| over 800. | 1 |
| St. 600 to 800 incl. | 1 |
| Crushed stone from sedimentary rocks grades: | |
| from 600 to 1200 incl. | 2 |
| 200, 400 | 3 |
| Crushed gravel and gravel grades: | |
| 1000 | 1 |
| 800 | 1 |
| 600 | 2 |
| 400 | 3 |
| Crushed stone from boulders brands: | |
| 1200 | 1 |
| 1000 | 1 |
| 800 | 1 |
| 600 | 2 |
| 400 | 3 |
(Changed edition, Amendment No. 4).
4.7.2. The clay content in the lumps should not exceed that indicated in the table.
Table 10
| Grade for crushability of crushed stone and gravel | Clay content in lumps, % by weight, no more |
| Crushed stone from igneous, sedimentary and metamorphic rocks grades: | |
| 400 and above | 0,25 |
| 300, 200 | 0,5 |
| Crushed gravel and gravel grades: | |
| 1000, 800, 600, 400 | 0,25 |
| Crushed stone from boulders brands: | |
| 1200, 1000, 800, 600 | 0,25 |
(Changed edition, Amendment No. 4).
4.8 Presence of harmful components and impurities
4.8.1 Crushed stone from incidentally mined overburden and host rocks and substandard waste from mining enterprises for processing ores (ferrous, non-ferrous and rare metals of the metallurgical industry) and non-metallic minerals from other industries must be resistant to all types of decay.
The stability of the crushed stone structure against all types of decay must meet the requirements specified in the table.
Table 11
| Grade for crushability of crushed stone | Mass loss during decay, %, no more |
| 1000 and above | 3 |
| 800, 600 | 5 |
| 400 and below | 7 |
4.8.2 Crushed stone and gravel must be resistant to environmental influences. Crushed stone and gravel intended for use as aggregates for concrete must be resistant to the chemical effects of cement alkalis.
The durability of crushed stone and gravel is determined by the mineralogical and petrographic composition of the original rock and the content of harmful components and impurities that reduce the durability of concrete and cause corrosion of the reinforcement of reinforced concrete products and structures.
The list of harmful components and their maximum permissible contents are given in the appendix.
4.9. When producing crushed stone and gravel, their radiation-hygienic assessment must be carried out, based on the results of which the scope of application is established. Crushed stone and gravel depending on the values of the total specific effective activity of natural radionuclides A
eff is used:
- 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 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.
(Changed edition, Amendment No. 1, 2).
4.10 Crushed stone and gravel must not contain foreign contaminants.
4.11 Provision of the standard values of crushed stone and gravel quality indicators in terms of grain composition (content of grains smaller than the smallest nominal size d
and more than the largest nominal size
D
) and the content of dust and clay particles must be at least 95%.
