Quarry sand density kg m3 depending on its type. Bulk density of bulk materials Sand river density kg m3 GOST

The name of the sand, type or variety.	Other name.	Bulk density or specific gravity in grams per cm3.	Bulk density or specific gravity in kilograms per m3.	-	-	-
Dry.	Dry sand.	1.2 - 1.7	1200 - 1700	-	-	-
River.		1.5 - 1.52	1500 - 1520	-	-	-
River compacted.	Sand from the river, washed without clay fraction.	1.59	1590	-	-	-
River grain size 1.6 - 1.8.	Sand from the river, sand mined in the river, sand from the bottom of the river.	1.5	1500	-	-	-
River alluvial.	Sand from the river, sand washed up in the river, sand from the bottom of the river obtained by the alluvial method.	1.65	1650	-	-	-
River washed coarse-grained.	Coarse-grained sand from the washed river.	1.65	1400 - 1600	-	-	-
Building.	sand for construction, sand for construction and finishing works, sand used and used in construction.	1.68	1680	-	-	-
Construction dry loose.	Sand for construction, sand for construction and finishing works, sand used and used in construction.	1.44	1440	-	-	-
Construction dry compacted.	Compacted sand for construction, compacted sand for construction and finishing works, compacted sand used and used in construction.	1.68	1680	-	-	-
Career.	Quarry sand, quarry sand.	1.5	1500	-	-	-
Quarry fine-grained.	Fine-grained sand from a quarry, fine sand mined in a quarry.	1.7 - 1.8	1700 - 1800	-	-	-
Quartz regular.	Sand from quartz.	1.4 - 1.9	1400 - 1900	-	-	-
Quartz dry.	Sand from quartz.	1.5 - 1.55	1500 - 1550	-	-	-
Quartz sealed.	Sand from quartz.	1.6 - 1.7	1600 - 1700	-	-	-
Nautical.	Sand from the sea, sand from the seabed.	1.62	1620	-	-	-
Gravely.	Sand mixed with gravel.	1.7 - 1.9	1700 - 1900	-	-	-
Dusty.	Sand mixed with dust.	1.6 - 1.75	1600 - 1750	-	-	-
Dusty compacted.	Compacted sand with an admixture of dust.	1.92 - 1.93	1920 - 1930	-	-	-
Dusty water-saturated.	Sand mixed with dust.	2.03	2030	-	-	-
Natural.		1.3 - 1.5	1300 - 1500	-	-	-
Natural coarse.	Sand in natural origin, usually quartz.	1.52 - 1.61	1520 - 1610	-	-	-
Natural medium grain.	Sand in natural origin, usually quartz.	1.54 - 1.64	1540 - 1640	-	-	-
For construction work - normal humidity according to GOST.	Construction sand.	1.55 - 1.7	1550 - 1700	-	-	-
Expanded clay grade 500 - 1000.	Sand from expanded clay.	0.5 - 1.0	500 - 1000	-	-	-
Expanded clay size of firm grains (particles) - fraction 0.3.	Sand from expanded clay.	0.42 - 0.6	420 - 600	-	-	-
Expanded clay size of firm grains (particles) - fraction 0.5.	Sand from expanded clay.	0.4 - 0.55	400 - 550	-	-	-
Mountain.	Quarry sand.	1.5 - 1.58	1500 - 1580	-	-	-
Fireclay.	Chamotte sand.	1.4	1400	-	-	-
Forming normal humidity in accordance with GOST.	Sand for molding parts, foundry sand, sand for molds and casting.	1.71	1710	-	-	-
Perlite.	Expanded perlite sand.	0.075 - 0.4	75 - 400	-	-	-
Perlite dry.	Expanded dry perlite sand.	0.075 - 0.12	75 - 120	-	-	-
Ravine.	Sand lying in ravines, sand from a ravine.	1.4	1400	-	-	-
Alluvial.	Alluvial sand, alluvial sand.	1.65	1650	-	-	-
Medium size.	Medium sand.	1.63 - 1.69	1630 - 1690	-	-	-
Large.	Coarse sand.	1.52 - 1.61	1520 - 1610	-	-	-
Medium grained.	Medium grain sand.	1.63 - 1.69	1630 - 1690	-	-	-
Small.	Fine grained sand.	1.7 - 1.8	1700 - 1800	-	-	-
Washed.	Washed sand from which soil, clay and dust fractions are removed.	1.4 - 1.6	1400 - 1600	-	-	-
Compacted.	Sand artificially compacted and rammed.	1.68	1680	-	-	-
Medium density.	Sand of normal density, normal, medium density for construction work.	1.6	1600	-	-	-
Wet.	Sand with high water content.	1.92	1920	-	-	-
Wet compacted.	Sand with a high water content is compacted.	2.09 - 3.0	2090 - 3000	-	-	-
Wet.	Sand with high humidity, different from normal according to GOST.	2.08	2080	-	-	-
Water-saturated.	Sand deposited in an aquifer.	3 - 3.2	3000 - 3200	-	-	-
Enriched.	Sand after enrichment.	1.5 - 1.52	1500 - 1520	-	-	-
Slag.	Sand from slag.	0.7 - 1.2	700 - 1200	-	-	-
Porous sand from slag melts.	Slag sand.	0.7 - 1.2	700 - 1200	-	-	-
Swollen.	Perlite and vermiculite sands.	0.075 - 0.4	75 - 400	-	-	-
Vermiculite.	Swollen sands.	0.075 - 0.4	75 - 400	-	-	-
Inorganic porous.	Porous light sand of inorganic origin.	1.4	1400	-	-	-
Pumice.	Pumice sand.	0.5 - 0.6	500 - 600	-	-	-
Aggloporite.	Sand obtained after the burnout of minerals - burnout of the original rock.	0.6 - 1.1	600 - 1100	-	-	-
diatomite.	Sand is diatomaceous.	0.4	400	-	-	-
Tuff.	The sand is tuff.	1.2 - 1.6	1200 - 1600	-	-	-
Eolian.	Natural sand formed naturally as a result of eolian weathering of hard rocks.	2.63 - 2.78	2630 - 2780	-	-	-
The ground is sand.	Sand in natural occurrence, soil with a very high content of sand.	2.66	2660	-	-	-
Sand and gravel.	Construction Materials.	sand 1.5 - 1.7 and crushed stone 1.6 - 1.8	sand 1500 - 1700 and crushed stone 1600 - 1800	-	-	-
Sand and cement.	Construction Materials.	sand 1.5 - 1.7 and cement 1.0 - 1.1	sand 1500 - 1700 and cement 1000 - 1100	-	-	-
Sand and gravel.	A mixture of sand and gravel.	1.53	1530	-	-	-
The sandy-gravel mixture is compacted.	A mixture of sand and gravel.	1.9 - 2.0	1900 - 2000	-	-	-
The battle of the usual red clay brick.	Sand obtained by crushing red ceramic clay bricks.	1.2	1200	-	-	-
Mullite.	Mullite sand.	1.8	1800	-	-	-
Mullite-corundum.	Mullite-corundum sand.	2.2	2200	-	-	-
Corundum.	Corundum sand.	2.7	2700	-	-	-
Cordierite.	Cordierite sand.	1.3	1300	-	-	-
magnesite.	Magnesite sand.	2	2000	-	-	-
Periclasospinel.	The sand is periclase spinel.	2.8	2800	-	-	-
from blast furnace slag.	Slag sand from blast-furnace slag.	0.6 - 2.2	600 - 2200	-	-	-
From waste slag.	Slag sand from waste slag.	0.6 - 2.2	600 - 2200	-	-	-
from granular slag.	Slag sand from granular slag.	0.6 - 2.2	600 - 2200	-	-	-
From slag pumice.	The sand is slag pumice.	1.2	1200	-	-	-
from ferrotitanium slag.	The sand is slag pumice.	1.7	1700	-	-	-
Titanium aluminous.	Titanium aluminous sand.	1.7	1700	-	-	-
Basaltic.	Sand from basalt.	1.8	1800	-	-	-
Diabase.	Sand from diabase.	1.8	1800	-	-	-
Andesite.	Andesite sand.	1.7	1700	-	-	-
Diorite.	Diorite sand.	1.7	1700	-	-	-
From scrap heat-resistant concrete with fireclay filler.	Sand from heat-resistant concrete scrap with fireclay aggregate.	1.4	1400	-	-	-

Some explanations for the question.

As you have already noticed, it is quite difficult to find a clear answer to a specific question on the Internet: what is the density of sand or its specific gravity. A search engine, such as Yandex or Google, provides a lot of information. But all of it is rather "indirect" in nature, rather than accurate and understandable. The search engine selects different references, snippets of phrases, lines from large and obscure tables of the specific gravity of building materials, in which values \u200b\u200bare very chaotically given in different systems of units. "In passing" on the sites "falls out" a large amount of "additional" information. Mainly: according to the types and varieties of sand, its use, application, origin, mineralogical composition, color, solid particle size, color, impurities, mining methods, cost, price of sand and so on. Which adds uncertainty, inconvenience to normal people who want to quickly find an accurate and understandable answer: how much is the density of sand in grams per cm3. We decided to “correct the situation” by bringing together data on different types of sand into one common table. Having excluded in advance the “superfluous”, in our opinion, “passing” information of a general nature. And indicating in the table only exact data, what is the density of sand.

What is the density of sand or its specific gravity (volumetric gravity, specific gravity - synonyms)? The density of sand is the weight that fits in a unit of volume, which is most often considered cm3. Quite objectively, the issue is complicated by such a situation that the sand itself has many types that differ in mineralogical composition, the size of the fraction of solid particles in the sand, and the amount of impurities contained. Impurities in the sand can be clay, dust, crushed stone, stone chips and larger stones. Naturally, the presence of impurities will immediately affect the sand density determined by laboratory methods. But most of all, the density of sand will be affected by its humidity. Wet sand is heavier, weighs more and immediately significantly increases the specific gravity per unit volume of this material. What is related to its value when buying and selling. For example, if you want to buy sand by weight, then its sale should be tied to the so-called normal moisture content, determined by GOST. Otherwise, by buying wet or damp sand, you run the risk of losing a lot on its total amount. In any case, for the consumer, it is much better to buy sand measured in units of volume, such as cubic meters (m3), than in units of weight (kg, tons). The moisture content of sand affects its density, but has very little effect on volume. Although there are some "subtleties" here. More dense wet and wet sand, occupies a slightly smaller volume than dry sand. Sometimes this needs to be taken into account. The specific gravity of the sand contained in the selected volume, that is, the density, will largely be affected by the “laying method” of it. Here, it is understood that sand of the same type can be: in a state of natural occurrence, be under the influence of the weighing effect of water, be artificially compacted or simply poured. In each case, we have completely different values, how much is the density of this type of sand. Naturally, it is difficult to reflect all this diversity in one table. Some data must be sought in the specialized literature.

Among all the numerous options for the density of dry sand, only one is usually of practical interest to site visitors - this is bulk density. It is for her that we give the values \u200b\u200bof the specific gravity of dry sand in the table. It is useful to know that there is another density - this is the true density of dry sand. How to define it? It is determined by laboratory methods or calculated by a formula. Although, it is more convenient to use the reference data in a special table. The true density of dry sand gives us a different specific gravity - a theoretical one, which is always much higher than those values of the specific gravity of dry sand that are used in practice and are considered technological characteristics of the material. With some reservations, the true specific gravity of dry sand can be considered the density of solid particles (grains) included in its composition. By the way, when determining the bulk density, and hence the technological specific gravity of dry sand, the size of the grains also plays a certain role. This characteristic of the material is called grain size. In this case, in this table we are considering medium-grained dry sand. Coarse-grained and fine-grained are used less often and their specific gravity values may differ slightly. Not only the grain size, but the mineralogical composition of this bulk building material can be different. This table shows the bulk density of a material consisting predominantly of quartz grains. Quantity and weight are measured in kilograms (kg) and tons (t). However, let's not forget about other types of material. On our site you can find more specific information that is rarely found on the Internet.

Note.

The table shows the density of sand of the following types: river ordinary, river natural, river compacted, river with a grain size of 1.6 - 1.8, river alluvial, river washed coarse-grained, construction ordinary, construction loose, construction compacted, quarry ordinary, quarry fine-grained, quartz natural, dry quartz, compacted quartz, marine, gravelly, dusty, compacted dusty, water-saturated dusty, natural, natural coarse-grained, natural medium-grained, for construction work of normal humidity according to GOST, expanded clay grade 500 - 1000, expanded clay with a hard grain size of 0.3, expanded clay with a size hard grains 0.5, mountain, fireclay, molding with normal humidity according to GOST, perlite, dry perlite, ravine, alluvial, medium size, large, medium-grained, fine, washed, compacted, medium density, wet, wet compacted, moist, water-saturated, enriched , slag, porous from slag melts, vermic ulite, expanded, inorganic porous, pumice, aggloporite, diatomite, tuff, aeolian, soil sand, sandy gravel mixture, sandy gravel mixture compacted, from the breakage of ordinary red clay ceramic bricks, mullite, mullite-corundum, corundum, cordierite, magnesite, periclase spinel, from blast-furnace slag, waste slag, granulated slag, slag pumice, ferrotitanium slag, titanium-alumina, basalt, diabase, andesite, diorite, from heat-resistant concrete scrap with fireclay filler and some other types.

Sand is used in almost all areas of production, but especially a lot of it is required for construction work. Without sand, it is impossible to prepare concrete, build a foundation or pour a blind area. The preparation of concrete and other building mixtures is based on the use of various materials in a certain proportion. Therefore, it is very important to be able to correctly determine the specific gravity of construction sand.

The specific gravity of sand and methods for its determination

Specific gravity or specific gravity is the weight of sand contained in a certain volume. Usually, this value is indicated by the weight of sand, measured in kilograms, contained in a volume equal to one cubic meter. However, in the technical literature there is another designation for the specific gravity of sand - tons / cubic meter and grams / cubic centimeter. The specific gravity of building sand in kg / m3 is calculated by the formula:

m=V*p, where the weight of the sand is m; its volume is V and its density is p.

Knowing the weight of the sand and the degree of its density, which is reported by the supplier, it is possible to determine the specific gravity. It is not necessary to do calculations, as you can use the reference data or perform the calculation on the online calculator.

Factors Influencing the Specific Gravity of Sand

The weight in 1 m3 depends on its density. And the density value is influenced by many factors, of which the following are considered the main ones:

the amount of impurities contained in the sand;
composition of minerals;
the size of individual grains of sand (fractions);
compaction percentage;
humidity level;
storage method.

In the regulatory literature (for example, in GOST 8736 of 1993), the average value of the specific gravity of construction sand is 1500 kg / m3. For the same type of sand with other moisture and density indicators, the following standard data are used:

dry sand - 1440 kg/m3;
sand dry and compacted (compacted) - 1680 kg/m3;
wet sand - 1920 kg/m3;
wet and compacted sand (compacted) - 2545 kg/m3.

Volumetric weight of construction sand in kg/m3

In some cases, when it is not possible to weigh sand, its volumetric weight is determined - how many kilograms of sand are in a predetermined volume. The value of the volumetric weight is variable, since the following parameters influence its value:

humidity;
specific gravity;
density.

Therefore, the volumetric weight of sand in 1 m3 is most often determined from tables in reference books or using an online calculator. An incorrectly determined weight of m3 of sand can lead to a deterioration in the quality of concrete and cement-sand mortar, to a decrease in their strength, and even to premature destruction of manufactured structures.

Buy sand in our company

According to its technical characteristics, all of them meet the requirements of GOST 8736 of 2014 and, when sold, are accompanied by a certificate of conformity, which must indicate the specific gravity of the sand. Call and or self-delivery of high-quality construction sand.

Without sand, any modern construction will be inferior. It is used to knead the mortar, to create bars from baked clay, building mixture, to create a thick lime mortar, as well as glass. This material is extracted in several ways: by washing and sieving. It is characterized by its physical and chemical parameters. For example, few people know that the basis of the bulk density of the building material in question is even its uncompacted mass in kg during 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 got from the river bottom.

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

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

Density determines the total amount of sand. 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 of them, the higher the number).

The value obtained will help to find out the quality of the granular composition, for example:

the material that was extracted 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, it does not contain any impurities;
for material that was mined in quarries, this figure reaches 1.4 t/m3; in him there are some clay impurities;
This is the reason why 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 GOST 8736 sand density

This method is quite simple, but thanks to it you can only get preliminary calculations, so always check the results in a mathematical way.

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

According to how the material can absorb and scatter radiation, this parameter is evaluated.

Medium extra sand performance that is extracted from quarries:

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

Medium Additional features, which is mined from the river bottom:

the ability of atoms of some isotopes to spontaneously decay, emitting radiation A (47 BK/kg);
density in unconsolidated state – 1.4±0.1 t/m3;
number 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 uncompacted state. On your 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 \u200b\u200bare converted to the required value.

If clay impurities are present, this negatively affects the quality of the material.

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

All this is due to low frost resistance and strength.

How to determine the density - true and bulk

It must be understood that the true density of building sand is different from bulk sand. The first value consists of the indicators of the material in dry form, the density is based on 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 already mentioned earlier, is the moisture content of the building material. So, if the sand has accumulated ten percent moisture, lumps appear in it, which cause voids.

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 more 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 an uncompacted state is calculated, it allows one 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 you need to order for a particular construction. And this indicator does not depend on how the cost of goods is determined: per cubic meter or per tonnage.

For more information about determining density, see the video:

Density of the material in an uncompacted state - meaning from the technological and commercial side

Mass in building practice is the ratio of mass to volume that a material occupies in a compacted or uncompacted state. This number is especially significant from the economic and technological side.

In order to make a concrete mix or mortar in order to create a sand cushion, it is necessary to use a material with known indicators.

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

Determining the density of sand is important in terms of the ratio of its mass to the volume actually occupied. From an economic point of view, density affects the money that the customer is willing to spend - he must purchase a usable material of sufficient volume.

To do this, it is advisable to set 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 the material in an uncompacted state according to GOST should be carried out according to the standard procedure.

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

The value of measuring the density of river sand in an uncompacted 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 resources spent and functionality.

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

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

You must remember that when purchasing sand, its bulk density will be equal to 1600 kg / m 3, which fully meets construction standards. In addition, this material can be stored for a long time, it does not accumulate moisture, lumps and voids do not form in it over time.

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

This indicator is critical for many non-ore elements. To clarify this indicator in a particular batch of material, the manufacturer uses correction values. Such numbers make it possible to determine the values from the technological and economic side.

During the acquisition of a large batch coefficient allows you to equalize deviations, which is caused by the scatter of indicators. For example, at the stage of purchasing ten tons of material, the amendment will determine 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 an object all the time.

The most optimal solution would be to purchase one lot 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. The indicators for each specific type of sand will be different, so it is important to take into account the specifics of the material, the method of its extraction, etc.

The average density of sand is an important indicator that directly affects the performance properties of the substance and the future parameters of the concrete building mixture, the strength and stability of buildings, as well as the possible consumption of raw materials. It shows how much sand is contained in one unit of volume, which is taken as a cubic meter (1 m3).

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

This parameter is closely related to such material indicators as voidness and moisture, the degree of compaction and porosity. The features and correctness of the measurement of parameters can also introduce a certain error into the final result. Between these factors there is the following relationship: the greater the void between the particles and the moisture content of the substance, the smaller the bulk characteristic and the less pure sand fits in a cubic meter. This rule is identical for humidity, but with the opposite sign - due to the 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 1.5) than that of purified sand (for construction, the ratio is 1.4).

What varieties are found?

Density in kg / m3 is an ambiguous characteristic that has two main varieties that differ 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. This does not take into account free voids between individual particles, 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 the true and average density, measured in kg / m3.

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

You can find out how to choose sand for a sandblaster here.

Parameters of various types of material

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

Thus, one cubic meter of dry sand will have a mass of 1200 to 1700 kilograms, and a cube 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 the density, the following methods are used on site:

Apply 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, the 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 made by dividing the mass of sand by the volume of the vessel.

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

The first plan is the issue of acquiring materials. To calculate how much sand to buy for mixing the required volume of masonry, you need to know the density of the bulk component. This indicator significantly affects the strength parameters of structures and buildings. The conversion of mass into volume (and vice versa) is also carried out because the price of the material is indicated in different ways: per weight or volume unit.

What is density and what does it depend on

This is a physical characteristic of a substance, showing the mass of its unit volume and expressed in g / cm3, kg / m3, t / m3. Sand, like all bulk materials, has the following feature: depending on the conditions, the same amount of sand can occupy a different volume. The density index of building sand is influenced by the following factors.

1. Grain size (fineness modulus). Sand is a mixture of particles ranging in size from 0.14 to 5 mm, formed naturally during the destruction of rocks. The smaller the grain size and the more uniform the composition, the denser the sand. Coarse and medium-grained material is used for the manufacture of concrete, fine-grained - for cement mortars, fine-grained (pulverized) - for building fine mixtures.

2. Porosity and level of compaction. They characterize the number of voids in the bulk material. In a loose state, building sand has a porosity of about 47%, in a dense state - no more than 37%. Looseness is reduced due to saturation with moisture, vibration, dynamic effects. Porosity is estimated using a special coefficient e: for fine-grained sands of dense composition, it is about 0.75, coarse and medium-grained - 0.55. The compacted sand mass takes on fairly high loads and distributes the stress that occurs in the foundations well.

3. Humidity. Usually, reference books give density at a normal humidity level, regulated by GOST. When buying, it should be borne in mind that the weight of a cubic unit of raw material differs significantly from the theoretical indicator. With an increase in humidity from 3 to 10%, the grains of sand are enveloped in water - due to this, the volume increases, and the density, respectively, decreases. With further moisture saturation (up to 20%), water displaces air and fills the voids between the grains - while the weight of a cubic meter increases.

4. The presence of impurities. Sometimes particles of clay, dust, salt, mica, gypsum, humus, crushed stone, stone chips are contained. They affect the quality characteristics of the building material: if for pure sand it averages 1,300 kg / m3, then for clay - 1,800 kg / m3. Sand can be cleaned by washing with water, but this increases its cost.

Types of density

Building sand can be characterized using different indicators of its volumetric weight: theoretical and actual.

1. True (former name - specific gravity). This is the mass of a cubic meter in an absolutely compacted state, without taking into account between particles. The true indicator is determined in a complex laboratory way, its value corresponds to the weight of a cubic meter of solid non-metallic sandy rock - approximately 2500 kg / m3.

2. Medium (bulk). When determining it, it is taken into account that the calculated volume includes not only grains, but pores and voids that fill the gaps between them. The average is usually below the true value.

To independently determine the average density, use a bucket with a capacity of 10 liters. Sand is poured into it from a height of 10 meters until a hill forms - it is carefully cut horizontally at the level of the upper edge of the bucket. The material that fits in the container is weighed, and then its density is calculated in kg / m3: divide the mass in kg by 0.01 (the volume of the bucket in cubic meters).

The true value is a constant value and has an auxiliary value. In order to competently conduct construction, make practical calculations and evaluate the quality of the purchased material, it is more important to know the average. For example, if a cubic meter weighs less than 1300 kg, this indicates a large number of voids and requires them to be filled with a binder. At the same time, the cost of materials increases, making construction more expensive.

The approximate indicators of bulk (average) density indicated in the table will help you purchase sand with the necessary parameters, quickly switch from weight to volume, and calculate the weight fractions of the mortar.