Determination of the true density of sand for building materials. Density of quarry sand Density of sand kg m3 table

Almost no construction can be completed without the use of sand. This is, in essence, universal material, extracted from various deposits and, accordingly, having different characteristics(density, humidity, etc.) and names: dune, river, sea, quarry.

Below we will talk about the last type of sand from the list.

What is quarry sand?

This is one of the most common types sand, used in various fields - construction, road work, landscaping and other areas.

It is extracted from the bowels of the earth by developing quarries, the location of which determines the structure, composition and fraction of the material.

In this case, the building material does not shrink, and the finished product is flexible and elastic.

Kinds

According to the processing method to which the product is subjected after extraction, sand is also divided into several types.

Alluvial – extracted from flooded deposits using hydromechanical equipment for this purpose. This processing method allows you to remove foreign impurities and components from sand and ultimately obtain a pure, high-quality product.

It is used for the production of mortar and bricks, as well as in the construction of roads and in the manufacture of reinforced concrete products.

Screened – the material is sifted through special equipment, equipped with a system of sieves and cells. During the cleaning process, clay particles, dust and small pebbles are separated from the sand. As a result, the material is freed from foreign impurities and large fractions.

Can be used for preparing mortars and mixtures.

Ground sand is an unrefined product containing foreign components (up to 40%). The material is low cost and is more suitable for roughing procedures - leveling land plots and filling trenches.

Density

There are several types of material in question.

But the most useful include two types:

• true;
• bulk.

The true density of a material is the density of the grains of sand themselves.

When determining the true density, the amount of air between the grains is not taken into account, which can be 35-40% of the total volume, as well as the density of dust particles and clay components.

It follows that the true density is always greater (1.5-1.9 times) than the bulk density. According to technical requirements specified in GOST 8736-2014, this parameter should be 2-2.8 g/cm3.

Determination of density

Possible methods, their essence, necessary equipment and instruments for measuring procedures are designated in GOST 8735-88. The same standard specifies the stages of test actions and methods for processing the obtained data.

The bulk density of the material is determined by weighing it in special cylindrical metal containers.

For this purpose, vessels with a volume of 1 dm3 and 10 dm3 are used. A small container is used for weighing dry and sifted sand, a larger container is used for unsifted material with natural moisture.

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Empty and filled vessels are weighed, after which the bulk density is calculated using a formula. To perform calculation procedures in everyday life, use a ten-liter bucket, into which sand is poured “with the top” from a small height (about 10 cm).

After this, the “slide” is removed, comparing the material with the edge of the bucket, the sand remaining in it is weighed and the net weight in kilograms, without container, is determined. The resulting figure is divided by 0.01 m3, thanks to which it is possible to calculate the bulk density of sand or the weight of 1 m3 of product in tons.

The true density of sand grains is determined in the laboratory using one of two methods:

• pincometrically - using a pincometer (special glass container);
• accelerated method, which uses the Le Chalier device - glass vessel with a funnel-shaped top and a scale on the neck.

For more information on determining pitch density, watch the video:

Characteristics

In addition to density, there are other characteristics, by which the properties of sand can be assessed:

• presence of foreign impurities. There should be as few of them in the material as possible. Thus, the permissible content of organic components is 3%, and sulfur and sulfides – up to 1%;
• humidity. The mass of sand depends on it. The wetter the material, the greater the weight, and vice versa. According to standards, this parameter should not exceed 7%;
• level of radioactivity (depending on deposits). Material with a high degree of radioactivity cannot be used in residential construction;
• coefficient . This refers to the ability of the material to pass water. For quarry sand this figure is 0.5-0.7 meters per day.
• coefficient ;

Conclusion

To summarize, we can say that quarry sand is a product that can be used in the most various fields: agricultural industry, road development and building construction, for preparing solutions and decorating summer cottages.

At the same time, the material has a reasonable price, which is also the reason why it is worth giving preference to it.

Sand is free-flowing natural material resulting from natural destruction rocks under influence external factors. May contain small amounts of various impurities. It is used in almost all types of construction. To properly mix the solution, you need to know the density of the sand, since the proportions of the other components depend on it. It also affects the volume of purchases, for example, for arranging a cushion for the foundation.

What is density and what does it depend on?

Density shows how many grains of sand in kilograms fit into 1 m3. It is measured in kg/m3, sometimes in t/m3 or g/cm3 (this indicator affects). But this value is not always constant, as it can change depending on the following conditions:

1. Grain size. It can be fine-, medium- and coarse-grained. The larger the grain of sand, the lower the density, and, conversely, small ones fit more tightly. Coarse- and medium-fraction sands are used for manufacturing building materials And masonry mortars, and fine-grained ones are used for the production of dry construction mixtures.

2. Porosity. Shows the number of voids. The high porosity option has lower density. If it is loose, then the value is 47%, if compacted - 37%. The degree of porosity decreases when sand grains are saturated with moisture, as they are enveloped in water and the voids between them disappear. It also decreases after transportation, since during movement everything is compacted due to vibration. Different fractions have different degrees of porosity. For construction sand made from large and medium grains it is 0.55, for fine sand it is 0.75. The denser it is laid, the greater the load from the foundation it can withstand and distribute it more evenly.

3. Humidity coefficient. You should definitely check the degree before purchasing. The more water it contains, the lower the density. The weight of 1 m3 of wet sand differs significantly from the same amount of dry sand.

4. Impurities. Depending on their volume, the density of sand kg/m3 also changes. It may contain clay, dust, salt, gypsum and much more. Density pure material is about 1300 kg/m3, with clay impurities - 1800 kg/m3. To remove contaminants, it is washed, but because of this, the cost increases significantly.

Types and prices

There are several types of densities:

• true;
• bulk (medium).

The first type is also called specific gravity and is also measured in kg/m3. True density shows how much is in one cubic meter of bulk building material, without taking into account the voids between the grains. They calculate it in laboratories empirically. Its value for non-metallic sand rock is 2500 kg/m3.

Bulk density shows the quantity in one cubic meter, taking into account voids and gaps. Its value is always less than the true value. To measure it, you will need a 10 liter bucket. Sand in its usual uncompacted state is poured from a height of 10 cm from the edge of the container until a slide appears above it. As soon as the bucket is filled, the excess is leveled with a metal ruler, without compacting the sand, after which the container is placed on the scale. The result obtained must be divided by the number 0.01, which means the volume of the bucket, converted into cubic meters. For example, sand weighs 16.5 kg, it is equal to: 16.5/0.01 = 1650 kg/m3. In this case, it is convenient to use the formula P=M/V, where P is density, M is mass, V is volume. And, conversely, knowing the compaction indicator, it is calculated how much the bulk building material weighs, for this it is multiplied by the volume of the container - M = P * V.

The true density of construction sand is a constant value. The average value is used for calculations. Prices vary depending on its type, purity and fraction size. Uncleaned is noticeably cheaper than washed. Therefore, if a small batch is required, you can purchase unwashed sand and clean it of impurities yourself, especially if it is needed for the construction of a non-load-bearing structure. If you need it for making a foundation, you should purchase only clean and quality material. Clay and other impurities reduce the degree of adhesion of sand grains to cement, which is why the strength grade of concrete decreases.

Table with prices at which you can buy construction sand:

When choosing sand, you should take into account: the lower its density, the more binding powder is required to fill the voids between the sand grains and connect all the components, as a result, the cost of the mortar increases.

The degree of radioactivity of most bulk building materials is first, but it is better to check the quality certificates, especially if it will be used to build a house, in which case it should only be class one.

Average sand density - important indicator, on which they directly depend operational properties substances and future parameters of concrete construction mixture, strength and stability of buildings, as well as possible consumption of raw materials. It shows how much sand is contained in one unit of volume, which is taken as cubic meter(1 m3).

The amount of substance that fits in 1m3 strongly depends on the type of sand - for example, fine construction sand is more compact than medium-sized sand, since in the first case the gaps between individual particles of building material are much smaller, and a larger mass fits into one cubic meter.

This parameter is closely related to such material indicators as voids and humidity, degree of compaction and porosity. Features and correctness of parameter measurement can also introduce a certain error into the final result. The following relationship exists between these factors: the greater the void between particles and the moisture content of the substance, the lower the bulk characteristic and the less clean sand fits into a cubic meter. This rule identical for humidity, but with the opposite sign - due to the adhesion of fractions, the wet building material is compacted.

Density also depends on the structure of grains, with decreasing size the this characteristic, and also on the content of clay and other impurities. For the reasons stated above, the density river sand usually higher (average ratio 1.5) than purified (for construction, the ratio is 1.4).

What varieties are there?

Density in kg/m3 is an ambiguous characteristic that has two main varieties, differing in definition, some features and methods of measurement:

• True. It is the ratio of body weight (in in this case dry sand) to its volume and is measured in kg/m3. In this case, free voids between individual particles are not taken into account, that is, we are talking about the density of the material in a compressed state. True density (like any other substance) is a constant value.
• Bulk density. An indicator that takes into account not only the volume of the substance itself, as in the previous case, but also all the existing gaps between the particles. Bulk is always less than true and average density, measured in kg/m3.

There is also an average value, which has already been mentioned above.

Options various types material

As mentioned earlier, density varies greatly depending on the properties of the raw material. The following table is intended to help trace this fact:

Thus, one cubic meter of dry sand will have a mass of 1200 to 1700 kilograms, and a cubic meter of wet sand will have a mass of 1920.

The table does not reflect all types - a more extended list with the coefficients necessary to calculate the density of raw materials can be found in reference sources.

In order to measure density, the following methods are used on site:

• Application of conversion factors that differ for each type of material. This method not entirely accurate, since the measurement error can reach 5%. At large quantities raw material losses amount to more than one cubic meter!
• Weighing bulk raw materials (for example, river) together with a vessel completely filled with it, and then calculating by dividing the mass of sand by the volume of the vessel.

Determining bulk density plays an important role in construction, since the number of cubic meters of raw materials required for work largely depends on its value. This is especially important in cases where every cubic meter counts.

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. He 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 total 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 this way:

m = 10 x 1.3 = 13 t.

Here, an average density p of 1.3 t/m³ was used.

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? An increase in the volume of binders increases the costs and cost of the concrete solution. 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 free space, 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 ensure guaranteed flat surface 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. Loose type soil allows you to use the method of pitting. 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 use of 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 of 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.

Sand extracted from the quarry is a very popular material today. As is already clear, it is mined using open-pit mining. For this they will use special equipment, 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 manufacturing concrete solutions, 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 deposit of material is not located at a great depth under the soil layer.

Where and how to use career construction sand, you can find out from 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.

What is the cost of 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're talking about 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 water film, 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, then such a 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 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.

By grain composition 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, 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 matter, negatively affect quality characteristics.