Without sand, any modern construction will be incomplete. It is used to knead the mortar, to create baked clay bars, building mixtures, to create a thick lime mortar, as well as glass. This material is obtained in several ways: by washing and sieving. It is characterized by its physical and chemical parameters. For example, few people know that the bulk density of the building material under consideration is even based on its unconsolidated weight in kg during the period of transportation in bags. It can be different (the material was transported in bulk in the back of a dump truck or in bags).

Distinctive features of dry construction sand

The sand mixture can be conditionally divided into several types:

• the one that was mined in;

• the one that was mined from the river bottom.

A distinctive indicator of excellent quality is the degree of density of construction sand kg m3. An important role for density is played by the material's ability to accumulate moisture and its porosity. The density of the sand will differ from that of the building sand.

If a person is interested in a one-time home construction of a house, it may not be calculated separately, you need to pay attention to the average indicator, which is accepted as the norm. At the same time, during professional construction, the strength of the constructed structure depends on this number.

The total amount of sand is determined by density. The density of building sand is 1.3-1.8 t / m3. This indicator varies so much due to the addition of clay impurities (the more there are, the higher the number will be).

The resulting value will help you know the quality of the granular composition, for example:

• material that was mined from the river bottom will stand out with moderate density indicators of 1.3 t / m3; its mineral composition is based on geographic location. In any case, this material is considered to be of very high quality, as a rule, there are no impurities in it;
• for the material that was mined in open pits, this figure reaches 1.4 t / m3; in him there are some clay impurities;
• This is the reason that the material is rarely used for the preparation of high quality mortar; but it is used to make the solution more affordable.

How to calculate the amount of sand in kg using the density of GOST 8736 sand

This method is quite simple, but only preliminary calculations can be obtained with it, so always check the results mathematically.

The radiometric method is also no less popular. It is based on the use of radioactive radiation.

This parameter is assessed based on how the material can absorb and scatter radiation.

Average additional sand indicators that is extracted from quarries:

• first class radioactivity;
• density in an unconsolidated state - 1.4 t / m3;
• mass of particles per unit of their volume - 2.6 g / cm3;
• crushed rock content - 1.9%;

Average extra features that is extracted from the river bottom:

• the ability of atoms of some isotopes to spontaneously decay, emitting radiation A (47 BK / kg);
• density in an unconsolidated state - 1.4 ± 0.1 t / m3;
• amount of chemical elements, passed into the composition of the alloy in the process of its production as a technological additive - 0.1%.

The number of voids should be determined by the density of the material in the unconsolidated state. On their own, this value can be measured in this way: a little sample material is poured into a measuring liter container and weighed.

If the material has accumulated moisture very strongly, then the sample can be placed in a ten-liter container, then the values ​​are converted to the required value.

If there are clay impurities in stock, this negatively affects the quality of the material.

From sand, which contains a high percentage of clay, it is forbidden to make high-quality building mixtures, various for construction.

All this is due to low frost resistance and strength.

How to determine density - true and bulk

It must be understood that the true density of building sand differs from the bulk. The first value consists of the indicators of the material in dry form, based on the density - the specific sand that is used during construction work.

These are extremely necessary indicators, for example, to dose building material before mixing concrete.

At the heart of the density, as mentioned earlier, is the moisture content of the building material. So, if the sand has accumulated ten percent of moisture, lumps appear in it, which cause voids to appear.

Despite the visual increase in the material (its volumes seem large), the density becomes lower, that is, in order to knead, you need to take more material. With higher humidity, the water will begin to displace air bubbles between the grains, as a result, the sand will become denser.

When the density of a material in a non-compacted state is calculated, this allows us to understand and represent its future volumes in cubic meters, which will depend on the mass.

By making accurate calculations, you can find out exactly how much material needs to be ordered for a particular construction. And this indicator does not depend on how the value of the goods is determined: per cubic meter or per tonnage.

For more information on determining density, see the video:

Non-compacted density of material - technological and commercial value

Mass in construction practice is the ratio of mass to volume that a material occupies in a compacted or non-compacted state. This number is especially significant from the economic and technological point of view.

To make a concrete mixture or mortar in order to create a sand cushion, it is necessary to use a material with known characteristics.

From an economic point of view, it is advisable to calculate several basic criteria - weight in volumetric unit and density in certain conditions.

Determining the density of sand is important in terms of the ratio of its mass to the actual volume occupied. From an economic point of view, density affects money, what the customer is willing to spend - he must purchase suitable material for use, of sufficient volume.

To do this, it is advisable to establish the number of particles in a volumetric unit without seals and take into account moisture indicators, which significantly affect the weight.

Determination of the density of a material in an uncompacted state in accordance with GOST should be carried out according to a standard procedure.

The required amount of material is taken, the given ability to accumulate moisture is taken into account, sent to a measuring container and weighed repeatedly.

The value of measuring the density of river sand in an unconsolidated state

Why is it so important to determine this indicator before the future construction of real estate? It is he who is able to display the real amount of materials in a single volume - a cubic meter. Thanks to him, you can use the material in terms of the ratio of expended resources and functionality.

The building material considered in the article is subject to the norms of a separate GOST 8735-88, and this testifies:

• material with such indicators has fully passed the compliance with construction technologies;
• material properties during work and after the construction of the house is quite predictable;
• a method to determine the mass of a material in a unit of its volume, tested and approved as a reference, allowing you to get the long-awaited and truthful result;
• During the material verification phase, only approved methods and technical recommendations were used.

You must remember that when purchasing sand, its bulk density will be equal to 1600 kg / m3, which fully meets the construction standards. In addition, this material can be stored for a long time, it does not accumulate moisture, and lumps and voids do not form in it over time.

Excessive indicators of the mass of sand per unit of its volume at high humidity indicates a decrease in its characteristics, it can be used only in limited areas. An increase in humidity causes a decrease in the percentage of quality.

This indicator is critically important for many non-ore elements. To clarify this indicator in a specific batch of material, the manufacturer uses correction values. These numbers make it possible to determine the values ​​from the technological and economic point of view.

During the acquisition of a large batch coefficient allows you to level deviations, which are caused by the scatter of indicators. For example, at the stage of purchasing ten tons of material, the amendment will allow determining the amount of material up to 2 tons per batch.

Conclusion

Often there are situations when the need for sand is limited, in addition, there is no need to purchase and arrange delivery of large masses to the object all the time.

The most optimal solution would be to purchase one batch of the required size, which has passed several basic tests for the ability to accumulate moisture and bulk density.

remember, that the density of sand depends a lot on the ability of the material to accumulate moisture and its porosity. Indicators for each specific type of sand will differ, so here it is important to take into account the specifics of the material, the method of its extraction, etc.

Construction Materials

Why do you need to know the density of building sand (kg / m3)?

From the author: hello dear reader. From this article you will learn how the true density of building sand kg / m 3 is determined. Why is this needed? - first of all - so as not to be deceived when purchasing this building material. Indeed, it is rather difficult to determine exactly how many tons of sand for construction work were brought to you. You won't weigh the car, will you? And now, quite often, suppliers of building materials use this, simply - not enough sand.

But knowledge of this criterion is important not only because of the possible deception. The fact is that during construction, in principle, it is important to know whether it will be required, say, to fill the foundation or floor. After all, if suddenly there is not enough, it can turn into a real disaster, especially if it is necessary to hand over the object as soon as possible.

And we will start, perhaps, with general definitions in order to correctly introduce you to the course of the matter. The bottom line is that the bulk density of building sand is measured depending on how compacted the material is. With cement, the situation is about the same: the older it is, the higher its density, since over time any loose substance "clumps together". The analogy can even be drawn with ordinary flour that is used for baking.

It follows from this that one and the same volume of bulk material can have different densities (and, therefore, different amounts). In its original state (without compaction) - the material can be characterized by the term "true bulk density".

Therefore, - the bulk density is the density of the material in the state in which it was not compacted. That is, when determining this value, it is necessary to take into account not only the volume of grains of sand (or parts of other building material), but also the distance at which they are removed from each other. From this, we conclude that the bulk density is several times less than the usual density of the material.

After the material is compacted (and this depends primarily on the conditions in which it is stored and on the time), its density ceases to be bulk. She gets taller.

Why do you need to know what is the density of sand (natural) for construction work? First of all - to compare the volume and mass of building material. The price for bulk substances can be indicated not only for 1 ton (ton), but also in cubic meters. Yes, and during cooking - the proportions of the substance may be needed not in weight, but in volume.

Below is a small table, in which the second column shows the bulk density of building sand (kg / m³), ​​and the third - the number of cubes in 1 ton.

Important! With an increase in density, the bearing capacity also increases.

What does density depend on?

The density of a bulk substance (in this case, sand) primarily depends on its origin and state. The table below shows us the fundamental differences in the bulk density of various types.

How to determine the bulk density?

This indicator is usually determined in laboratory conditions. Basically, the material is simply weighed using measuring vessels (1 L and 10 L). A liter container is used to determine the density in a state in which the material has not been compacted, the sand is dried to its constant weight and passed through a sieve with a hole diameter of 5 mm.

A ten-liter capacity is used when it is necessary to determine the material indicator of interest to us, which is contained in the batch. Thus, we can convert units of passes to units of volume.

In this case, the material is not specially dried. It is taken in a state of moisture inherent in its natural state. It is also passed through a similar sieve (hole diameter 5 mm).

The procedure for determining the density looks like this: the already sieved material is poured into a measuring vessel from a height of ± 10 cm. To do this, use a scoop. When the vessel is full, the slide should be removed using a metal ruler. The height of the sand should be level with the edges of the measuring vessel. Further - this measuring vessel, along with the contents, should be weighed on an accurate balance. It goes without saying that we are only interested in the net weight of the contents, so the weight of the container must be subtracted.

To convert units of mass to units of volume, the procedure is essentially the same. As, however, and equipment. But only the material should be poured not from 10 cm, but from 100 cm.

Below is the formula by which the indicator of interest to us is determined.

In this γn is the density indicator, m1 is the mass of a measuring vessel without contents, m2 is the total mass, and V is the volume, respectively.

To visually familiarize yourself with the determination procedure, watch the video below, where research is carried out in a virtual laboratory, in ideal conditions.

Conclusion

That's all, dear reader. Thank you for reading the article. Today we learned how to determine the bulk density, and also found out why to do it. For convenience and clarity, we have provided a table and a formula. I hope that the presented materials were useful for you.

If you are interested in another construction issue, use the navigation on the site to find the information you need. I am sure there is what you need here. Good luck and see you again at Seberemont, dear reader.

Most construction work cannot do without the use of sand, as it is required for the production of glass, plaster, concrete mortar, brick, drainage, subbase and more. Extraction is carried out by screening, washing or open-cut mining. The material has such characteristics as specific gravity, fractional content and bulk density, which affects the amount before compaction when transported in bags or in bulk by a dump truck.

The main types of density

Sand is mined naturally or artificially. The particles come in different fractions from 0.05 to 5 mm. The quality directly depends on the content of impurities of silty clay or organic origin, as well as on the strength of the grains. However, the most important is the density in a dry state: the higher it is, the stronger and more durable the product or structure from the solution with its presence will be.

There are three parameters that can be measured empirically, while the values ​​can be unchanged or depend on moisture, compaction, etc.

1. True density is a constant value and characterizes the weight of sand in a compacted state in 1 m3. Since it is obtained as a result of the processing of hard rocks, the indicator is 2500 kg / m3, it will be obtained only in laboratory research. This value is rechecked annually, and the results are recorded in GOST 8736-93.
2. Bulk - indicates the specific gravity at natural moisture in a suspended state. In laboratory conditions, it is determined using a flask, which is filled up to 10 cm. It is measured before compaction and averages 1.5 g / cm3 (1500 kg / m3) and takes into account not only the net weight, but also the volume of voids between the grains.
3. Average density - this characteristic additionally includes the degree of moisture saturation. Shows the average weight that fits into the required volume. As a rule, it is higher than the bulk one, but does not exceed the true one. The sand is exposed to moisture up to 7% and the parameter is determined. If it is high enough, then this indicates its excellent frost resistance and strength in natural conditions. To get a more reliable number, the product is tested several times.

Humidity is a pretty good reason why the specific gravity changes dramatically. If this value does not exceed 10%, then the material may become lighter due to the clumping of grains of sand. With an increase in humidity, water is formed in the voids, which displaces air, as a result of which the specific gravity increases.

Often, bulk products are not able to dry out completely, therefore, under natural conditions of storage and operation, the density will differ from bulk in a larger direction. The humidity level can be independently determined empirically. For this, the weight of a certain amount of river sand is measured before and after drying in a hot container or on a sheet of metal, then the difference between the obtained indicators is calculated.

Density values ​​for different species

Without sand, the construction industry will simply stop. It is required for mixing mortar, device drainage, making bricks, concrete, plaster, glass. It is mined in three ways: washing, sieving, open method. He has physical parameters. For example, the bulk density of building sand affects its unconsolidated amount during delivery in bags or in bulk in a dump truck.

Distinctive characteristic

Sand is divided into 2 types:

• career,
• river.

An important indicator of good quality is the degree of density. How much sand is contained in 1 m³ depends on it. This, in turn, depends on moisture and porosity. For a one-time home construction, this indicator is not calculated separately, but the average is taken, taken according to the norm. However, in the professional sphere, the strength and durability of the erected objects depends on this parameter. In addition, it can be used to determine the total amount of bulk building material.

The density of natural building sand is 1.3-1.8 t / m³. This difference is due to the admixture of clay (the more there is, the higher the indicator), as well as its extraction of sand from a construction quarry origin. This figure helps to determine the quality of the grain composition, for example:

How to calculate the quantity using density?

Mass is calculated by the formula: m = Vxp (m - mass, V - volume, p - density). Suppose you need to find out its amount in 10 m³, then the data is substituted in 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 the preparation of the solution will require an increase in the amount of binders. Why is this disadvantageous for construction? The increase in the volume of binders increases the costs and cost of the concrete solution. As a result, the construction of facilities becomes unprofitable in terms of payback. This is important for construction firms. In private housing construction, the rise in price will not have an impact on costs, because its scale is much smaller.

An increase in moisture will lead to a decrease in density. This is due to the adhesion of fractions. In this case, the decrease continues until the humidity reaches 10%. Further growth increases the volume of the liquid, it fills the free space, and the density begins to increase. A constant change in the parameter changes the quality of the concrete mix. It is important here that the norms are respected for deliveries.

How to measure it in an improvised way? Sand is poured into a 10-liter bucket from a height of 10 cm. The bucket should be completely filled 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 up, divided by 2.

Other methods of calculation

This characteristic is taken into account when drawing up a project for earthworks. The loose type of soil allows you to apply the method of boreholes. To do this, dig out the soil in the form of a small pit (pit), 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 covered 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, therefore the radiometric method is sometimes used. It is based on the use of radioactive radiation. This parameter is estimated by the ability of sand to absorb and scatter this radiation.

Average additional 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 BK / kg);
• bulk density is 1.4 ± 0.1 t / m³;
• the amount of impurities is 0.1%.

The voidness is determined by the bulk density. This value can be measured independently in the following way: a sample is poured into a 1-liter volumetric vessel and weighed. If the humidity is too high, then the sample is placed in a 10 l 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. It is impossible to make plasters, high-quality concrete, various mortars from sand with a high clay content, because their frost resistance and strength are reduced.

The average density of sand is an important indicator on which the operational properties of the substance and the future parameters of the concrete construction mixture, the strength and stability of buildings, as well as the possible consumption of raw materials directly depend. It shows what mass of sand is contained in one unit of measurement of volume, for which a cubic meter (1 m3) is taken.

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 large mass can fit in one cubic meter.

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

Also, the density depends on the structure of the grains, with a decrease in the size of which this characteristic grows, and also on the content of clay and other impurities. For the above reasons, the density of river sand is usually higher (average coefficient of 1.5) than that of cleaned sand (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 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 constant.
• 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 gaps between the particles. Bulk is always less than the true and average density, measured in kg / m3.

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

Parameters of various types of material

As mentioned earlier, the density varies greatly depending on the properties of the raw materials. 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 - 1920.

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

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

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

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