Sand extracted from the quarry is a very popular material today. As is already clear, it is mined using open-pit mining. For this, special equipment is used, but despite this, the cost of quarry sand is low.
In addition, the popularity of this material is influenced by its widespread use. The presented product is used in the production of concrete mortars, which are used when arranging the foundation or plastering surfaces.
Characteristics
Quarry sand is a material that is of natural origin. This is due to the fact that it is extracted directly from the quarry. In most cases, the material deposit is not located on great depth under the soil layer.
Where and how to use quarry construction sand can be found in this
Taking into account the amount of space between the granules, specific gravity may differ many times for different fractions of the same type of material. For example, the parameter under consideration for quarry sand with small granules will reach 1700-1800 kg/m3. For sand with medium and coarse grains, the specific gravity will be 1500-1600 kg/m3.
How much river sand, indicated in this
The next parameter is the density of the material in question. This value is equal to the specific gravity. In the field of construction, the concept of bulk density has been established for bulk products. In this case, we are talking about the density of the product in its uncompacted form.
The presented parameter can change its values when exposed to the most various factors. For example, the level of humidity and mechanical influence greatly influence the parameter under consideration. The reason is that each particle is enveloped in a film of water, as a result of which the distance between the grains increases. By applying pressure, the density increases, reducing the space between the grains.
The density of the product is directly dependent on quality composition. If it contains clay components in large quantities, then the sand density will be greater. In addition, the characteristic under consideration is influenced by the size of the grains, as well as its belonging to the fractions. The larger the fraction, the lower the density indicators.
If we consider the radioactivity of sand, it depends on the deposit of the material. Since it is extracted from mining, this product is characterized by an increased radioactive background. During construction residential buildings and agricultural structures, it is necessary to use sand with the first class of environmental friendliness. During construction road surfaces it is necessary to use sand of classes 2 and 3.
In the photo - quarry sand:
The level of humidity depends on the mass of the material. The higher this parameter, the greater the weight. For sand extracted from a quarry, the moisture level should not exceed 5-7%.
The amount of clay components and organic substances in the presented product should not be more than 3%, sulfites and sulfur - up to 1%.
The specific gravity of crushed stone 20 40 is indicated
Varieties
In the construction field, quarry sand is classified according to the size of the sand grains and the processing method. Taking into account the grain size, the material in question takes the following forms:
- small
- average
- large grains of sand
For material with fine grains, their size cannot be more than 2 mm. Medium-grained sand is characterized by dimensions of 2-2.8 mm. Granules of a large product can reach 5 mm. In addition, the material is classified according to the processing method into seeded and alluvial. 
To obtain seeded quarry sand, a sifting method is used using a system of special sieves. As a result, stones and other large inclusions are removed from it. Alluvial is obtained by the method of washing. In this case, hydromechanical equipment is used. As a result of this treatment, clay and soil impurities are removed from the composition of quarry sand, which improves the chemical composition. 
Based on grain composition, they are divided into the following types:
- quartz;
- mica-quartz;
- feldspar;
- limestone;
- dolomite.
What does crushed limestone of fraction 40-70 look like?
In the field of construction, quarry stone, which arose during the destruction of mountain quartz, is in great demand.
Price
The main advantage of quarry sand remains its low price. If you purchase the material in question in a volume of 1 m3, its price will be 500 rubles. The presented product can be sold in pure form or already processed. Of course, when purchasing the second option, you will need to spend a little more, because such a product is characterized by high quality indicators.
Quarry sand is considered the most popular material in the field of construction. The reason for such demand is that it is not expensive and can be used everywhere. But it cannot be used in its pure form in all cases, since it contains foreign impurities that negatively affect the quality characteristics.
Sand is a bulk material. It is difficult to measure its true density - it is almost impossible to remove gaps between grains of sand. For this reason, the concept of bulk density of sand is more applicable to sand. This is the average value of the weight of the material per unit volume.
Concept and meanings
The determination of the bulk density of sand hides the value of the dry mass of the material per unit volume, measured in cubic meters or cubic centimeters.
There are many types of sand by origin and fraction. Small grains of sand fit more tightly into the volume than large ones, therefore their mass is much greater. And vice versa.
Thus, sand extracted from the river is usually smooth and polished and has a dense structure. Its weight per cube averages 1500-1600 kg/m 3 according to GOST 8736-93. Sand grains from a quarry are often porous with sharp corners and edges; these weigh much less - about 1300 kg/m3.
Factors determining density
The bulk weight of sand depends on several factors:
- The fraction and shape of sand grains determines the density of the bulk material to a greater extent. The larger the fragments, the greater the distance between them and vice versa. Round and square grains of sand take up more space than flat ones.
- Breed of origin. The denser the mineral from which the sand is formed, the greater the mass.
- Remains of soil and organic impurities also affect the bulk mass of sand. The technology for preparing mortars involves the use of purified fine filler, so this parameter can be adjusted by washing or sifting the embankment.
- Humidity after washing or sand mining. Water penetrates the pores of sand grains and increases their weight. The bulk density of dry sand is up to 30% less than wet sand. As it dries, the mass decreases and the volume increases.
- Sand compacted during placement has much more high density per unit volume than poured in the normal state.
The value of mass per cubic meter can be clearly seen in the table of bulk density of natural sand:
Calculation of changes in volume and mass
Sand is delivered to the construction site in in different forms: dry or wet, river or quarry. It may not be used immediately: the material is used as needed. If the embankment is stored under open air, grains of sand constantly change humidity depending on weather conditions. Technologists have to take these factors into account before preparing working solutions and backfilling pits.
Since the bulk density of fine and coarse sand is constantly changing, compaction coefficients are used to determine the actual mass of the volume without weighing. Some of them are reflected in the table:
The average density of the material is multiplied by the coefficient to obtain the desired result. The table shows the most popular values of kу.
The bulk compaction coefficient of sand does not guarantee an accurate result - the error can be 5 percent or more. The only reliable way to determine the mass of a unit volume of material is weighing, which is not always possible or convenient. Professionals can use any of available methods determining density on site.
Construction or renovation work are often produced using various sand-cement mortars prepared independently. The quality of any mixture depends on the condition of its components. While all parameters are known for cement, the situation with sand is more complicated. Density of dry sand - important parameter, which largely determines the quality and consistency of the solution. The ability to calculate this value is just as necessary for the builder as the ability to calculate the amount of materials.
Why is it necessary to determine the density of dry sand?
Types of sand
Sand is a dry bulk material consisting of finely crushed rocks. The fraction size ranges from 0.05 to 5 mm, which creates problems in calculations. Compound building mixtures requires fairly careful adherence to proportions, otherwise the strength of the materials will not meet the requirements of SNiP.
Determining the density of sand in practice is very difficult task. The gaps between individual grains of sand are practically impossible to measure, since the shape of the grains of sand obtained by different conditions crushing rocks, has a complex and irregular configuration. There may be gaps between the corners and edges of individual particles that are significantly larger than the gaps between natural grains of sand, whose shape is closer to spherical.
Dry sand of natural origin (river) has a denser structure, so using the same volume of material of different origin or fraction size will result in mixtures that differ from each other in their parameters. Therefore, it is very important to have the most correct knowledge of all parameters of the components of the mixture, the mass of the material, its density and other indicators.
Main types and parameters of sand
The difficulty in definition forced the introduction of the concept of bulk density of sand, which determines the amount of mass per unit volume. There are three types of density:
- True. This is an indicator of extremely compressed sand, which has no voids between the grains.
- Bulk. Value in weighed and dry form.
- Average. This is a value that takes into account the presence of moisture and the porous structure of the grain. The average density is higher than the bulk density, but less than the true density.
Humidity is one of the the most important factors, constantly changing state and bulk weight. Sand is stored, as a rule, in the open air, as a result of which the degree of humidity begins to depend on weather conditions. The compositions of all mortars assume the presence of dry material, and the sand in the mixture has other, non-ideal parameters. The change in density forces the use of compaction factors that correct the value that dry sand has.
The most common options for correction factors are shown in the table:
The average sand density is multiplied by the compaction coefficient, and the result is a value close to the real one. However, it is necessary to take into account the presence of an error (about 5%) arising from the impossibility of establishing with absolute accuracy the value of the correction for each specific case. A more accurate result is provided by the weighing method, but it is not available under construction site conditions, so calculated indicators are most often used.
Calculation of sand density
Independent calculation of indicators can be done using the weighing method. To do this, you will need a scale or a steelyard with a capacity of 20–25 kg, and a dry container (an ordinary bucket can be used). The procedure is as follows:
- Weighs in empty container(container), the result is recorded separately.
- The container is completely filled with sand. The best option- pour it in a heap, then carefully remove the excess with an even strip and leave it flush with the edges.
- The full container is weighed.
- The tare weight is subtracted from the resulting value.
- The resulting value is divided by the volume of the container, the result is converted into standard units - kg/m3.
More accurate indicators can be obtained by weighing several times, collecting material from different areas. It must be remembered that construction sand is stored in conditions that do not allow maintaining the same degree of humidity, so you should use it as quickly as possible, or periodically take repeated measurements and adjust the calculations.
Bulk density values for different types of sand
Sand mined in different places has different structure, composition and particle size. To correctly calculate the number of components in different mixtures or concrete, it is necessary to take into account the bulk density of sand of one type or another.
| View | Extraction method | Dry density (bulk) | |
| g/cm 3 | kg/m 3 | ||
| River | Mined from the bottom of the river | 1,5–1,52 | 1500–1520 |
| River with grain size 1.6–1.8 | 1,5 | 1500 | |
| River compacted | Washed, without clay fractions | 1,59 | 1590 |
| River alluvium | Extracted from the river bottom using the alluvial method | 1,65 | 1650 |
| Career | From quarries, alluvial | 1,50 | 1500 |
| Quarry, fine grain | Seeded, dry | 1,7–1,8 | 1700–1800 |
| Building | Complies with GOST 8736-93. Mined during mining | 1,68 | 1680 |
| Loose | 1,44 | 1440 | |
| Quartz | Obtained by crushing white quartz | 1,4–1,9 | 1400–1900 |
| Nautical | Drawn from the bottom of the sea | 1,62 | 1,62 |
| Ovrazhny | Mined open method, may contain many impurities | 1,4 | 1400 |
| gravelly | Mixed with gravel | 1,7–1,9 | 1700–1900 |
| Perlite | Obtained from expanded rocks | 0,075–0,4 | 75–400 |
| Slag | Obtained as a result of crushing sieving metallurgical waste | 0,7–1,2 | 700–1200 |
The indicated values are valid for dry raw materials, so when calculating, you will need to take into account the actual condition and use compaction factors. If they are neglected, excessive consumption will occur, and the composition of the mortar or concrete will be changed, which can reduce the strength of the pouring or connection of building structures.
Density is a physical quantity characterized by a certain amount of substance, expressed in grams or kilograms, per unit volume. This indicator, characteristic of bulk substances, including sand, cannot be determined unambiguously. This is due to the fact that the volume in which the same amount can fit may be different. The indicator is influenced by several factors, including:
- degree of compaction;
- humidity percentage;
- faction structure;
- porosity;
- the presence of all kinds of inclusions.
Determining density level
The density of sand acts as the main parameter, the level of which determines the scope of its application and the final strength of buildings and structures. The described characteristic is required to calculate sand consumption when it is necessary to obtain a certain volume of building mixture.
In addition, in some cases it becomes necessary to convert the mass of sand into volume or vice versa. If you need to determine the mass of 1 m 3 of sand or calculate the volume of a ton of the mentioned material, then you need to perform the following steps.
The density of sand or any other material can be determined by dividing the mass (M) by the volume (V) that it occupied. So, ρ=M/V. The mass of the material that occupies a certain volume can be determined using the following formula: M=ρ*V. But the volume can be calculated if the ρ index and mass are known. So, the volume is determined by the formula: V=M/ρ.
When preparing solutions, mixtures and during the construction of structures based on concrete, sand should be used in a given proportion in relation to the other components. In order to correctly determine the proportion of sand in these mixtures or structures, it will be necessary to know exactly what its density is.
If you make calculations with an error, the amount of sand in the total volume will be insufficient or excessive. If you make up for the lack of sand, then, most likely, you will have to do this at the expense of more expensive components, which will entail an unjustified increase in the cost of the entire mixture. Whereas if the amount of sand turned out to be greater in the volume of the mixture, this will cause a decrease in the quality of the products or solution. Due to this, frost resistance, abrasion resistance and water resistance will suffer; as a result, the master will receive products or designs whose characteristics will differ from those provided for by the standard.
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Types of indicator ρ
Sand is characterized by several types of density, among them: true, bulk and average.
In Fig. 1 presents a table in which you can see bulk density sand in different states. If we consider this material, then it is represented by hard rock of non-metallic origin. This explains that it has an indicator approximately equal to 2500 kg/m 3. This indicator is the true density. If it is necessary to make calculations for use in practice, another indicator should be used - bulk. It characterizes building materials in their uncompacted form and is calculated taking into account the volume of grains and the hollow space that remains between them. This leads to the fact that the level of bulk density in all cases is less than the true one. But when compacting material that is in a granular state, it is possible to increase its ρ level. So, if the material is in the body of a car, then it has a natural, uncompacted state and is characterized by a bulk level. If this value is known, then it is possible to determine the volume and mass of the material. This is important, because the price of transporting building materials can be calculated not only by weight, but also per 1 m 3 of volume.
The density of sand, which is in bulk, is 1300-1500 kg/m3. The level of humidity in the external air can influence the volume of the material, this leads to variations in the level of bulk density. If the humidity increases, this entails a decrease in the level of ρ of the material. This is explained by the sticking together of grains. The reduction in this level can last until the humidity reaches 10%. After this, the moisture particles cause an increase in the volume of liquid in the building material, and the level of ρ begins to increase. This feature changes in the indicator under consideration should be taken into account if the dosage is made by volume.
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Calculation of bulk level ρ
In order to calculate the density of the grains in bulk, the material must be sifted in advance using a sieve with a mesh size within 5 mm. After this, it must be placed in a 1 liter measuring vessel. In this case, it must be freely poured from a height of 10 cm, forming a cone over the vessel, which must be cut off using a ruler. You need to know how much the vessel weighs when empty and when filled. It is permissible to calculate the bulk level using the formula: ρн=(m2-m1)/V. In it, m1 and m2 are the masses of the vessel in the empty and filled states, while V is its volume. The table may not be needed, since all calculations can be done independently.
The level of the average ρ is influenced by voids and humidity. There is a dependence: with fewer pores, this indicator is higher. It can be assumed that ρ characterizes the fractional composition.
Its average level varies for certain types sand. Dry quartz-based material in its natural state has a density in the range of 1500-1550 kg/m3, while when compacted this level is 1600-1700 kg/m3. This indicates that the indicator medium density determined by the structure of the fractional composition.
If you need to make concrete that will have the qualities of high strength and frost resistance, then you should use a material that has an increased average density.
During construction, you can use the data from the tables, but you should be aware that in a loose state quartz material has ρ within 1500 kg/m 3, but the level can reach 1700 kg/m 3.
In order to determine bulk density, you can use not only the measurement method described above. By the way, you can also use an ordinary construction bucket as a vessel. These calculations will allow you to obtain the result closest to the true one. If you use a bucket, you can use a scoop to pour the material.
Without sand, the construction industry will simply stop. It is required for mixing mortar, installing drainage, making bricks, concrete, plaster, and glass. It is mined in three ways: washing, sifting, and the open method. It has physical parameters. For example, the bulk density of construction sand affects the amount of sand that is not compacted during delivery in bags or in bulk in the back of a dump truck.
Distinctive characteristic
Sand is divided into 2 types:
- career,
- river.
An important indicator good quality is the degree of density. It determines how much sand is contained in 1 m³. This, in turn, depends on humidity and porosity. For one-time home construction, this indicator is not calculated separately, but the average number accepted according to the norm is taken. However, in professional field The strength and durability of the constructed objects depends on this parameter. In addition, it can be used to determine the total amount of bulk building material.
The density of natural construction sand is 1.3-1.8 t/m³. This difference is due to the admixture of clay (the more of it, the higher the indicator), as well as its quarry origin. This figure helps determine the quality of the grain composition, for example:
How to calculate quantity using density?
Mass is calculated by the formula: m=Vxp (m - mass, V - volume, p - density). Let’s say we need to find out its quantity in 10 m³, then the data is substituted in this way:
m = 10 x 1.3 = 13 t.
Used here average density p equal to 1.3 t/m³.
Always keep in mind that insufficient density means increased voidness. Then preparing the solution will require increasing the amount of binders. Why is this disadvantageous for construction? Increasing the volume of binders increases costs and costs concrete mortar. As a result, the construction of objects becomes unprofitable in terms of payback. This is important for construction companies. In private housing construction, the rise in price will not affect costs, because its scale is much smaller.
An increase in humidity will lead to a decrease in density. This is explained by the clumping of fractions. In this case, the decrease continues until the humidity reaches 10%. Further growth increases the volume of liquid, it fills the free space, and the density begins to increase. Constantly changing the parameter changes the quality concrete mixture. It is important here that the standards are observed during deliveries.
How to measure it manually? Sand is poured into a 10-liter bucket from a height of 10 cm. The bucket should be filled completely to form a slide. It is cut strictly horizontally to obtain a guaranteed flat surface of the filled bucket. This amount of sand is weighed, then the density is calculated. To do this, divide the mass by volume: the resulting kilograms are converted into tons, divided by 0.01 m3. An even more accurate calculation is obtained if measurements are taken twice. Then they are summed and divided by 2.
Other calculation methods
This characteristic is taken into account when drawing up a project for carrying out earthworks. The loose type of soil allows you to use the pit method. To do this, the soil is dug out in the form of a small pit (pit), and the displaced sand is placed in a special container for weighing. A tin cone is placed above the pit to determine the density of construction sand, which is filled with dry sand. Next, the volume of the pit is determined, from which the volume of suspended sand is subtracted. This method is quite simple, it gives only tentative calculations, so the radiometric method is sometimes used. It is based on the application radioactive radiation. This parameter is assessed by the ability of sand to absorb and scatter this radiation.
Average additional values of quarry sand:
- radioactivity - class 1;
- bulk density 1.4 t/m³;
- grain density 2.6 g/cm³;
- clay content 1.9%.
Average additional characteristics river sand:
- class A radioactivity (47 BC/kg);
- bulk density is 1.4±0.1 t/m³;
- amount of impurities 0.1%.
Voids are determined by bulk density. This value can be measured independently in the following way: a sample is poured into a 1-liter measuring vessel and weighed. If the humidity is too high, the sample is placed in a 10-liter vessel, then the values are converted to the required values. The content of clay impurities reduces the bulk density and deteriorates the quality of the material. Sand with a high clay content cannot be used to make plasters, high-quality concrete, or various mortars, because their frost resistance and strength decrease.