Difference between gray and yellow sand. What sand to use: types and characteristics of construction sand. What kind of sand is needed for the foundation?

Sand is a loose, loose mixture consisting of small grains that are formed as a result of the natural destruction of rocks. widely used in construction and industry. It has various technical characteristics, primarily due to its origin.

Some features of sand

Raw sand is extracted mainly from quarries. This material has a high content of clay particles and other impurities, so it is only suitable for sprinkling under the foundation of construction sites.

Sand, processed big amount water is called “alluvial”. It contains a minimum amount of impurities. This sand has completely different technical characteristics. It is used for masonry, plastering, and foundation construction. It is also used to produce paving slabs and concrete products.

Types of sand and their main characteristics

Depending on the location and method of extraction, there are three types of sand:

Most often, quarry sand is yellow and gray-yellow in color. Clay and other substances are removed from it in two ways - washing and sifting. Sifted sand is somewhat inferior in quality to washed sand, since it contains more foreign impurities. For this reason, seeded sand is not used for the production of concrete products, which may crack as a result of exposure to low temperatures.

River sand, taken from different rivers, usually has its own shade and can be yellow, brownish, gray or light gray. White river sand is less common. Nature itself, through natural washing with water, ensured that its composition contained clay and other particles in minimal quantities. This sand has a very wide range of applications and is a universal material. It is used in the production of artificial stone, concrete and sand concrete, and paving slabs.

Quartz sand owes its origin to the crushing and destruction of natural quartz. It is a milky white material, but can be easily dyed to any other color. Quartz sand has a homogeneous composition and is a harder substance, unlike other types of sand. It is also distinguished by its sorption ability and chemical inertness. In addition to construction, this material is used in glass production and in the operation of water purification facilities.

Depending on what kind of sand is considered, it can be said that each of them can be distinguished even visually. Mined in different places, for example, sea and river sand will differ very noticeably in color. Sea sand is larger than river sand, and it also has completely different colors. Sea sand will appear more grey, while river sand may be a white-yellow hue. Quarry sand contains large particles and impurities and can also be of different colors, which helps to distinguish it visually from other types of natural building materials. When characterizing quarry sand, you can easily notice that it will definitely contain impurities from clay, quartz crystals and dust, which also indicates that its color can be very different. Despite the content of some unnecessary elements in it, a solution prepared specifically from quartz sand will give colossal strength and durability to the future structure. There is also artificial sand, and its name itself makes it clear that the color of such material can be completely different: from light white to the darkest.

There is an established opinion that choosing sand is quite easy: I ordered construction sand - here you have both a raw material component for concrete and backfill for a path. But this opinion is wrong. Since there are several varieties of sand, which have their own distinctive characteristics, and are used to perform certain jobs.

Classification

So, according to the place of origin, sand is usually classified into the following types:

river sand

River sand is mined from the bottom of rivers. It is characterized by natural purity and good water-permeability qualities. The size of sand grains in river sand ranges from 0.3 to 0.5 mm.

This type is used for the preparation of concrete solutions, cement screeds, treatment filters, and drainage structures. It is worth noting that when preparing a concrete mixture, this type of sand quickly settles, so the solution must be constantly stirred. The cost of river sand ranges from 600 to 800 rubles per 1 m 3.

Quarry sand

Quite logically, quarry sand is mined using the open-pit method and includes impurities in its composition: dust particles, stones. Sand grains of quarry sand are much smaller than those of river sand, their sizes range from 0.6 to 3.2 mm.

In its original unprocessed form, the building material can be used to construct trenches or as a foundation foundation. Typically, leading manufacturers wash and screen quarry sand. In this case, it can be used when performing plastering and finishing work, to create an asphalt concrete mixture, and to form a screed.

Sea sand

This non-metallic mineral is extracted from the seabed using hydraulic projectiles. There are practically no foreign impurities in it, and salt is involved in purification.

This type of sand is considered the most popular. It is used everywhere, from the creation of concrete structures to the formation of finely dispersed dry mixtures. But, despite the unique characteristics of this building material, there is a shortage of it, since it cannot be mass produced.

Sometimes construction sand is considered a separate type. But, as a rule, it means both river and quarry sand. River sand can be of two colors - yellow and gray, and quarry sand - brown and yellow.

But it turns out that in nature there is also black sand, which shines like metal. It can be found in different places globe. This type of sand is formed as a result of geological processes.

This mineral consists of dark-colored heavy minerals and is formed by washing out the light components. The main minerals are magnetite, ilmenite, hematite.

Such sands are characterized by high radioactivity - 50-300 microroentgens per hour, but sometimes this parameter can reach a thousand microroentgens per hour. Due to its high radioactivity, this mineral is not used in construction and economic activities.

Artificial sand

It is worth noting that the above types of sand are natural, as they were formed by the natural destruction of rocks. But there is also on the market artificial sand, created by crushing marble, limestone, granite.

The most popular among artificial types of sand is quartz. It is made by grinding and dispersing the white quartz mineral to obtain a homogeneous fraction. From natural species sand, it is distinguished by the fact that it does not contain impurities and has a homogeneous composition. These advantages allow you to accurately calculate the parameters of a structure made on quartz sand.

Looking at a pile of sand brought to a site, two builders will behave differently.

The newcomer will cast an indifferent glance at her and take up the shovel.

An experienced builder will first take a handful of sand, look at it carefully and rub it in his palms. After that, he will give a verdict: it’s suitable for concrete, but not suitable for plaster and masonry.

What is the secret of construction sand that requires such careful evaluation? We will examine this issue in more detail.

Physical and mechanical characteristics

Volume weight

It shows the mass of 1 m3 of sand in its natural state (wet, with all impurities). On average, the volumetric weight of this material ranges from 1500 to 1800 kg.

The composition of construction sand is assessed according to the following parameters:

Granulometric;
Mineral;
Chemical.

Granulometric shows the percentage of grains of different sizes. To determine it, sand is sifted through calibrated sieves (from 0.16 mm to 10 mm).

A sieve with aperture sizes of 5 and 10 mm reveals gravel granules. GOST allows the presence of grains measuring 1 cm. However, their quantity should be no more than 0.5% of the total mass of sand.

Granules larger than 5 mm are normalized as follows:

Maximum content - up to 10% in natural;
up to 15% in crushed;
up to 5% in enriched sand.

Mineral composition

Chemical composition

It plays an important role in determining the suitability of bulk material in various fields of construction. Red, yellow, and orange shades indicate the presence of oxidized metals. Green and blue colors are characteristic of river sand, which contains aluminum salts.

Types of construction sand

The classic definition states that sand is a mixture of mineral particles (quartz, mica, limestone) formed as a result of natural or artificial destruction of rocks.

GOST 8736-93 lays out the most important properties of sand “on the shelves”. According to this standard, sand is divided into two classes:

Class I - very coarse, then comes sand of increased coarseness, coarse, medium and fine;
Class II - very large, extra large, large, medium, small, very small, thin and very thin.

The main difference between these classes is that lower quality sand (second class) includes three additional fractions. Fine dust particles are an undesirable component of mortars. They impair the bond between the large sand granules that the cement binds.

In real production there is no such fine gradation.

Here the extracted sand is conventionally divided into three fractions:

0.5-1 mm – small;
1.5-2 mm – average;
2.5-3.5 mm – large.

Sands with a particle size modulus of 2-2.5 mm are used for the production of concrete and reinforced concrete structures. Bulk material measuring 1.5-2 mm is used to make bricks. The finest sand is used for preparing dry construction mixtures.

Having taken note of the GOST classification, let’s move on to the practical aspects of the origin and use of construction sand.

Based on the type of production, they are distinguished:

Career;
River;
Nautical;
Quartz (artificial) sand.

Career

The name clearly indicates the origin of the sand. It contains clay and stones, so quarry material is used to a limited extent: for site planning, backfilling under concrete screeds or foundations.

To improve its properties, quarry sand is washed with water right at the mining site, freeing it from dust particles and clay. This is how alluvial (washed) sand is obtained. It is suitable for plastering and masonry mortars. In addition, sifting through sieves can be used to remove clay.

Important practical conclusion: If you are offered to buy quarry (gully) sand, do not forget to check whether it has been cleaned (washed, sifted) or not.

Areas of application of washed (sifted) quarry sand:

cement screed, masonry and plaster mortars;
Finishing work;
brick production;
foundation installation;
preparation of concrete.

river sand

This building material is extracted by a dredger from the river bottom. There are no clay particles and very few stones in river sand. This allows you to use it for concrete work without restrictions.

It is very valuable that medium-sized river sand (1.8-2.2 mm) practically does not shrink. This makes it ideal for masonry and plastering.

Quarry sand is more difficult to use in this capacity. In the solution it settles to the bottom and has to be stirred periodically.

Areas of application of river sand:

concrete production;
brick production;
masonry work and cement screed;
preparation of asphalt concrete;
drainage device;
filler for paints and grouts.

Sea sand has similar properties to river sand. It is also highly valued in construction for its high purity and uniformity of particle size distribution.

Quartz sand

This material is obtained by mechanical crushing of quartz-containing rocks. It is homogeneous in structure, chemically inert and pure.

The main area of application of this type of sand is industry. building materials. It goes into dry building mixtures, sand-lime bricks, blocks and concrete, and is used to prepare grinding compounds. Landscape design, expensive interior and facade plasters also cannot do without quartz sand.

It is impossible to unequivocally answer the question which sand is better., since each material is intended for certain types of work.

Still, the main conclusions are already obvious:

for brick and large-block masonry, it is better to take river sand. If you mix it with a small amount of unwashed quarry sand, the solution will become more plastic (due to clay particles);
for concrete, coarse or medium river sand is better suited (you can add a little fine washed quarry sand to it);
For plaster, washed quarry sand with or without a small addition of river sand is better suited.

Approximate prices

Obviously, the cost of sand is higher, the more manipulations had to be done with it during extraction and cleaning.

The cheapest is quarry unwashed and unsown. Its price per cube ranges from 300 to 400 rubles. Quarry sand purified by water or sifting for construction work will cost from 550 to 700 rubles per 1 m3 with delivery.

River sand is significantly more expensive than quarry sand. Its price starts at 750 rubles and ends at 950 rubles/m3.

Fractionated quartz sand is the most expensive. When purchasing from 10 tons (1 KAMAZ), its price with delivery is from 4,500 rubles per cubic meter.

Sand is an indispensable material in construction. But before you use it, you need to know about it technical specifications and features. Different types sand have different characteristics. Therefore, when purchasing, you should check its chemical and fractional composition, the presence of impurities, pay attention to the brand and other important factors.

What is river sand, description and composition

All natural sand is divided into several types, differing in many factors. River sand is most in demand in construction.

Washed

Smooth, uniform grains of sand of yellow or gray color are obtained from the bottom of rivers. They contain oxides of silicon and iron. Its chemical formula is SiO2. River sand usually does not contain particles of clay and other impurities, as it washes naturally. Most grains of sand are of medium size.

Coarse grain

Coarse-grained river sand, which is much less common, is most valued, for this reason it costs much more. It is usually mined in the beds of dry rivers. This type of sand is used for finishing, masonry, and design work. It is included in coating compositions highways, it is used in brick production.

Coarse-grained sand has a neutral, unobtrusive color; it is excellent for arranging the design of personal plots.

Large

Coarse sand differs from coarse river sand. It is extracted from rocks by splitting stones using specialized crushing and grinding equipment. Its particle size module can be up to 5 mm.

Factions

River sand is divided into the following types:

dusty;
coarse-grained;
medium grain;
clayey

Sand is sorted by grain size, sifting it through special sieves.

Differences and features of river sand

River sand differs from other types of sand primarily in its natural purity; it does not contain clay particles, small pebbles and other impurities. Its second difference is fractional homogeneity. Dry mixtures for construction work are made from river sand.

It is used as a filler for floor screeds; it is the main component for the production of asphalt concrete. With its help, drainage is installed and used at treatment plants as a filter. Sand perfectly purifies water from mechanical impurities. In household plots, the soil is mixed with river sand to make it lighter and crumbly.

More details in the video:

Difference from sea

River sand is almost no different from sea sand. Sea sand has high quality characteristics and does not contain natural impurities, since during extraction it undergoes a two-stage enrichment. Therefore, concrete mixtures and solutions are prepared from it.

Difference from career

Which sand is better - quarry or river - depends on the characteristics of the further scope of their application. Quarry sand, as the name implies, is mined in quarries or crushed gravel and other rocks using special devices. It usually contains large quantities admixtures of stones and clay.

Quarry sand is easy to extract and is of high quality, but due to the organic impurities it contains, the sand often behaves unpredictably, reacting with chemical additives in the solution. Quarry sand is also not suitable for filtration; washed quarry sand is more often used for concrete.

Extraction of sand from water with a brief description of the process

Sand is extracted from deep rivers using a dredge, which is attached to a barge. Such dredgers are equipped with special hydromechanical equipment, with powerful pumps, tanks and sieves for dividing sand by composition.

Rippers lowered to the river bottom mechanically suck in sand. The sand is transported through a slurry pipeline to the surface and deposited on a barge platform called a hydraulic dump. It has a device for draining water. The sand is then dry-cleaned and loaded onto another barge.

Extraction of river sand from dry river beds is similar to quarrying. All sand received must have a certificate of conformity.

In the video: an amphibious excavator dredger washing up sand at 400 m:

Technical characteristics and properties

When purchasing river sand, you must require a passport and a certificate for it. The characteristics of river sand must comply with GOST - 8736-93.

Basic properties of river sand

River sand particles have different sizes. According to them, this material is classified into the following groups:

fine sand with grains up to 2 mm in size;
medium sand - from 2 to 2.5 mm;
coarse sand - over 2.5 mm.

For construction sand, there are two types of specific gravity - bulk and true. Volumetric weight (density) is the amount of material placed in a unit volume. Due to its high flowability, determining the mass of sand per cubic meter is very difficult.

True specific gravity is calculated in laboratories; in practice, its values are usually not used. In practice, they use bulk specific density, this is the amount of sand that goes into a container measuring 1 cubic meter.

Application of river sand

The areas in which river sand is successfully used are not limited.

It is used:

For the production of concrete products, sand increases their strength and frost resistance;
For the production of dry mixtures;
To form foundation cushions
In the production of mortars for plastering and masonry work
When screeding and laying;
For room decoration
For landscaping
In landscape work
For arranging children's playgrounds.
Sand for making concrete

River sand is indispensable in construction; it is used to produce concrete, from which various products are made. You can’t do without it in finishing work. River sand meets all construction requirements, but builders who prepare mortars do not like it because it settles very quickly, so it has to be constantly mixed.

Photo of river sand

For sandbox

The best option for a children's sandbox is river sand. It does not contain sulfites, sulfur, and other harmful particles that can harm the baby. It is better to take medium-fraction sand for the sandbox.

For aquariums

To constantly clean the water in the aquarium, you need to pour river sand into it. It is better to take coarser sand of a dark color, since light sand causes discomfort to the fish living in the aquarium.

Is it possible to paint river sand?

River colorful sand can often be seen in decorative works. To do this, it is specially painted: with gouache, tempera powder or food coloring. Pour the finished paints into jars and pour sifted sand into them. After some time, it is taken out and dried. In addition to all of the above, sand can easily be given any color using ordinary multi-colored crayons.

How to paint river sand using crayons can be seen in the video: