Which sand is better than river sand? Which sand is best for concrete? Positive aspects of river sand

Sand is one of the most important components concrete mixture required for the construction of the foundation. This bulk building material is classified as a type of sedimentary rock. Sand is also obtained artificially - by crushing crushed stone or stone.

Due to some differences building material, question - what kind of sand is needed to fill the foundation? - extremely relevant among developers. In this article we will try to give a comprehensive answer to it.

A little theory...

Even for a person who is not familiar with the various nuances of the construction business, it is clear that sand for the foundation needs clean sand. The presence of various types of organic matter (grass, branches, etc.) is unacceptable. However, it is not difficult to clean sand from organic matter: just sift it.

Things are worse with impurities: clay, lime, etc. Determine the presence of contamination in in this case quite problematic. Impurities such as clay in the sand used to fill the foundation should not exceed five percent of the total mass. If there is more clay, this will lead to a decrease in the reliability of the finished structure.

To check the cleanliness of the sand in field conditions, builders use a glass or plastic transparent container.

Fill a third of an ordinary bottle with sand and fill it with water to half the volume. Now you need to shake the bottle, achieving maximum moisture in the sand, and leave it alone for five minutes. If the water remains dirty after this procedure, such sand is not suitable for building a foundation.

Sand is also not suitable for top layer which produces a foreign substance more than five millimeters thick.

Types of construction sand

When choosing sand for the foundation, it is necessary to take into account not only the size of the fractions (grains), but also the characteristics of the material, which vary depending on the type.

The main types of sand are:

1. River.
2. Nautical.
3. Career.

river sand

This material is mined from the bottom of the river and is considered universal. Fraction sizes river sand range from 1.6 to 2.2 millimeters, which allows it to be used not only for pouring foundations, but also as a material for equipment drainage system, when finishing premises, etc. River sand has virtually no clay impurities.

Sea sand

Sand is extracted from the seabed, then cleaned of shell debris and other impurities. This material is considered an excellent component when constructing reinforced concrete structures, thanks to the extremely small size of the fractions: just one millimeter.

Just like river sand, sea sand is considered extremely clean, as it goes through certain stages of washing and cleaning before use.

Quarry sand

Quarry sand, of course, is not as good in quality as river or sea sand, but it has an important advantage: it is cheap. Quarry sand is extracted by destruction method rocks. One of the varieties of such material is mountain sand.

It is difficult to unequivocally answer the question which type of sand is optimal for the foundation. It all depends on the type of structure being constructed, on technical characteristics and so on. Many builders recommend using the most inexpensive sand - quarry sand, believing that the quality of the building will not suffer much from this.

From a functionality point of view, the best sand for the foundation it will be river containing minimal amount small fractions. Depending on the size of the fractions, sand is divided into:

• Very thin (sand grain size does not exceed 0.7 millimeters). Such sand is not suitable for foundation construction.
• Thin (from 0.7 to one millimeter). The material is not recommended for use for pouring foundations.
• Very fine (fraction size up to 1.5 millimeters). It is better not to use for preparing concrete.
• Small (from 1.5 to 2 millimeters). Not suitable for foundation construction.
• Medium sand (fraction size - from two to 2.5 millimeters). Ideal for making concrete for foundation construction.
• Coarse sand (up to three millimeters) - used for high-quality concrete.
• Increased coarseness (up to 3.5 millimeters) - recommended as a pillow under the foundation.

It is best to purchase sand locally: straight from the quarry. The best option is to select screened and washed quarry sand with a fineness modulus of 2 to 2.5 millimeters. Particles of such sand have sharp edges, which increases the binding properties of concrete.

Suppliers often underweight a load of material, so you should check the weighing, taking into account the weight of the empty and loaded dump truck. The accompanying documentation must indicate the density of sand; the ideal density for this material is 1.5 t/cubic meter.

Low density indicates excessive sand moisture; high - the presence of impurities.

As for the price of sand, the cost of a cube depends on factors such as order volume and transportation costs. The further the supplier has to transport the sand, the more expensive its cost will be. In the Moscow region, the cost of a cubic meter of sand without delivery ranges from two hundred to two hundred and fifty rubles. If you order sand with delivery, you will have to pay about three thousand rubles for five cubic meters of material.

How much sand do you need for a house?

Construction experts say that the best recipe foundation mortar is 1 to 5, that is, one part cement to five parts sand. The proportions of materials in this case are not affected by either the size of the fractions or the type of sand.

Basically, the answer to the question is how much sand is needed for the foundation of a house? - should be decided based on the individual characteristics of the future structure, but the above recipe should be considered universal.

Many builders add crushed stone to the mixture, in which case the final composition of concrete will be as follows: 1: 3: 5 (part cement, three parts crushed stone, five parts sand). As you can see, when building a foundation, in any case, more sand is required than other components. But often for many types of foundations for houses it is necessary to construct a special sand cushion.

The foundation, as you know, is the basis of any building, be it a private house, country house or country cottage. Construction must be approached as scrupulously as possible, carefully selecting the necessary components. This is especially true for materials such as sand.

Concrete consists of sand, cement, crushed stone and water. Each of these components has its own role, both in manufacturing concrete structure, and during its subsequent operation.

Sand for concrete is a fine aggregate that fills the voids formed between crushed stone. It allows you to evenly distribute internal stresses during concrete hardening and reduce final cost mortar by reducing the amount of cement mixed.

The main thing is to take into account all the requirements for preparing the solution, select those components that are best suited, and maintain the appropriate proportions.

Particle size

Bulk material is divided into two classes depending on the particle size: class I and class II. The composition of the higher quality I class does not contain very small, thin and very fine groups, which are undesirable components for mortars. If they are present, the connection between larger factions worsens. Therefore, when preparing the solution, it is better to use class I sand.

Classification by factions

According to GOST 8736-93, according to the particle size modulus, the division can be:

• very large;
• increased size;
• large;
• average;
• small;
• very small;
• thin;
• very thin.

In reality, division is usually conditional. May be:

• small;
• average;
• large.

To prepare a high-quality, durable solution, it is better to use a large fraction. Preferably with a particle size of 2-2.5 mm. With a smaller size, the cost of the prepared solution will increase significantly, and the quality will decrease.

Place of extraction

The location of extraction has a significant impact on the composition and properties of the material. It is customary to distinguish river, quarry, sea and quartz. Sand is mined open method.

Career

In the quarry there are admixtures of clay and stones, so it can be used exclusively as a backfill for foundations or concrete screeds. When preparing concrete, quarry sand can only be used after washing with water, carried out at the mining site. When performing this operation, clay and dust particles are removed.

River

River sand initially no longer contains clay. It may contain a minimum of stones. Actively used during execution construction work, allowing you to obtain a higher quality solution. It is distinguished by its ability to naturally precipitate, so when preparing the solution it must be constantly stirred.

It is worth considering that the cost of river transport is slightly higher than quarry material. When choosing, you should analyze what is better: reducing the cost of manufacturing a concrete structure or ensuring sufficient strength.

Marine and quartz

The marine one is close in its characteristics to the river one. It is distinguished by its purity and uniformity of granulometric composition. May require additional cleaning due to possible shell content.

Quartz is the result of mechanical crushing of rocks containing quartz. Homogeneous, pure and chemically inert. Obtained artificially.

Processing method

Depending on the processing method, it may be:

• alluvial, obtained by washing;
• sieved, obtained by sifting the feedstock to remove large particles and debris.

Characteristics

The requirements for sand used in the preparation of concrete are reflected in the relevant regulatory documents. Some characteristics can be tested exclusively in laboratory conditions, others can be checked directly on construction site.

Volume weight

An indicator reflecting the mass of 1 m³ in its natural state. A cube of wet sand with all the impurities weighs on average about 1500 - 1800 kg. A lower value is preferred.

Compound

The composition can be:

• granulometric, which reflects the ratio (in percentage) of grains of different sizes;
• mineral: quartz, dolomite, feldspathic and limestone;
• chemical, depending on the elements present in the composition, the possible area of ​​use is determined.

Example of particle size distribution:

Example of chemical composition:

Example of mineral composition:

Humidity

Usually, this characteristic equal to 5%. If the mixture is dried, the indicator will decrease to 1%. When moistened by precipitation, the value can increase to 10%. The amount of water added to the solution at such humidity should be reduced.

Humidity requirements are important, since the amount of water added to the solution depends on it. Humidity is determined by calcining a kilogram of the mixture. The indicator will be equal to the difference in weight of wet and dried.

At a construction site, the humidity level can be checked as follows. If you squeeze sand into a ball, it should crumble. If this does not happen, the humidity is more than 5%. Although this indicator is still better controlled in laboratory conditions.

Porosity coefficient and bulk density

The porosity coefficient reflects the ability of sand and, accordingly, concrete in the future to pass moisture. Can only be determined in laboratory conditions.

The average bulk density is considered to be 1.3 – 1.9 t/cub.m. 1.5 t/cub.m is considered optimal. A lower value may indicate the presence of undesirable impurities, a higher value may indicate excessive moisture. The necessary information must be specified in the accompanying documents.

Which one should you prefer?

To understand what kind of sand is needed for concrete specific brand, you should definitely take into account the upcoming type of work.

Masonry

It is better to produce brick and large-block masonry using river masonry. If it is necessary to increase the plasticity of the prepared solution, it can be added to the river solution. a large number of unwashed quarry, which will also help reduce costs.

Concrete

To prepare concrete, it is preferable to use medium or coarse river sand, to which a little washed quarry sand can be added. It is worth noting that grains of quarry sand, unlike river and sea sand, have an irregular shape and a rough surface. Under influence aquatic environment the surface of the particles is ground, which significantly impairs adhesion to the other components of the solution.

However, by washing the quarry it is not always possible to completely remove the clay. Therefore, when preparing a concrete mixture, it is preferable to use river sand. It's already washed. The particles are approximately the same size. It does not contain clay, which significantly reduces the strength characteristics of the prepared solution.

Criterias of choice

Thus, when choosing sand, you need to focus on:

• cost - river and sea will cost more than quarry.

We prepare concrete, maintaining proportions

To get high-quality concrete, you need to maintain the correct ratio of sand and cement. The optimal ratio of components (c – cement (M400, M500); sch – crushed stone: p – sand) of the solution is as follows:

The grade of concrete is important. If it is below M300, it is better to take sand with a particle size of less than 2.5 mm. This type of concrete is traditionally used to pour the foundation for a garage, one-story buildings, outbuildings. For grades above M350 used in construction multi-storey buildings, floor slabs, reinforced belts, it is worth taking river one with a grain size of 3 mm or more.

In the most general case, when preparing a solution, you can use the following data:

And water, mixed in certain proportions, creates such a super-strong building material as concrete. Each ingredient plays its important role. Thus, sands are an integral component of the concrete mixture, which fills the space between the crushed stones. The quality of the fine aggregate plays a role key role, since from the correct distribution internal tension depends on the wear resistance and strength of the final product.

General requirements for selection

Sand for concrete, which is used for making concrete mortar, must comply with GOST standards. The material is suitable if it contains less than ten percent of particles with a fraction of up to 0.14 mm and no more than three percent of impurities represented by dust, silt and clay. It is the presence of the latter in the mixture that can negatively affect the frost resistance and strength of concrete, since it covers the grains of sand, preventing them from properly combining with the other components. Also, according to the standards, the content of large-sized particles larger than 10 mm is not allowed, and the proportion of particles measuring 5-10 mm should be within five percent of the total mass of the bulk component. Organic inclusions in the material, represented by humus or plant elements, must be absent.

Particle size

To figure out what kind of sand is needed for concrete, we first determine the most important parameter when choosing a bulk building material - the particle size module (fraction). There are:

• very large (more than 3.5 mm in size);
• increased fraction (within 3-3.5 mm);
• large (2.5-3 mm);
• medium size (2-2.5 mm);
• small (1.5-2 mm);
• very small (1-1.5 mm);
• thin (0.7-1 mm);
• very thin (up to 0.7 mm).

To determine the fineness modulus, manufacturers sift sand alternately through sieves with fractions of 10 mm, 5 mm, 2.5 mm, 1.25 mm, 0.63 mm, 0.315 mm and 0.14 mm.

A simplified classification can be presented as follows:

• small;
• average;
• large.

Making concrete involves using coarse sands with a sufficient amount of smaller grains, otherwise the concrete mixture will contain many voids. The resulting voids will be filled with cement, which means an increase in the cost of the final product. It has been noticed that grains of sand of the same fraction do not come into good contact with each other, forming more free space. Therefore, a mixture of different particle sizes is used en masse to obtain the greatest density between the elements.

Based on particle size, bulk materials are classified into two classes. The first class is characterized by the absence of microparticles less than 1.5 millimeters in diameter. Such sand material are considered better, since the presence of very fine aggregate has a negative effect on the density of sedimentation of larger fractions. The second class, accordingly, includes small components. That is why for cooking quality concrete use bulk first class.

Kinds

Sand is a fine-grained sedimentary rock found in finished form or obtained by crushing rocks. In addition to the grain size, important indicator is the place of extraction, which determines its properties. Highlight:

• river;
• nautical;
• career;
• quartz.

River sand is preferred because it contains no clay and a very small amount of stone. It is somewhat more expensive than other types of bulk, but the best in quality. Its grains of sand are homogeneous and have a smooth oval shape, their sedimentation density is much higher than that of quarry sand, the shape of which is not symmetrical and has irregularities on the surface. It is extracted using dredging devices that suck up water along with sand and transfer the mixture to storage. In this case, the water flows back into the reservoir.

The properties of sea sand are similar to river sand. Its peculiarity is the content of small grains of shells and sea ​​stone. Therefore, it needs additional cleaning. Sea salt makes grains of uniform size and correct form. It is the most expensive bulk material, because its extraction takes place on the seabed using expensive technologies.

The composition of quarry bulk is often burdened with clay impurities and stones, so after mining it needs to be washed to remove foreign particles. It is the cheapest. Rock mining in sand quarries is the most widespread.

Quartz sand material is mined by artificially crushing quartz rocks using special grinding units. It is obtained without various types of impurities and is characterized by chemical neutrality. Based on the processing options, there are the following methods for cleaning the material:

• alluvial (a method of purification by water washing);
• sifted (according to this method, sieves are used for sifting).

Sand washing occurs right at the mining site. To do this, the material is immersed in water and mixed several times. Thus, various types of impurities and dust are removed from the grains of sand. Unnecessary particles float to the top and are separated from the total mass. This procedure is carried out several times. True, the cost of bulk materials increases significantly. Sifting is a less expensive procedure, but it does not eliminate dust microparticles.

Material characteristics

Various kinds sand can have different physical and chemical characteristics depending on the composition, which can be:

• chemical;
• mineral;
• granulometric (display of particle composition as a percentage depending on the fraction).

An important indicator is the actual weight of one meter of cubic sand. It ranges from 1.5-1.8 tons. Less weight is considered better since the mass of impurities is minimal.

Humidity plays an important role. Normally it should be 5%. The amount of water added to the concrete solution depends on this indicator. During home construction, you can check the moisture content of the material “by eye”: if, after squeezing it in your fist, the sand does not crumble, it means that the normal humidity level is exceeded, and the mixture will need less water.

The foundation, translated from Latin, means “foundation”; the fate of the entire structure depends on its strength and reliability. That is why it is so important to choose for this part of the development quality materials. To the fortress concrete base Not only the brand of binder affects, but also the aggregates - sand and crushed stone.

Let's consider the main properties, advantages and disadvantages of the most common construction sands - river and quarry sands, compare them and try to answer the question of which one is more suitable for building a foundation.

Construction sand

Natural sand- This is a loose granular rock of sedimentary origin, has a crystalline structure with a grain size of up to 5 mm and consists of destroyed mineral residues, most often quartz with a small amount of other inclusions.

Requirements for it as a building material, according to GOST 8736-93, include such parameters as grain size, bulk and true density, permissible limit for the content of dust and clay particles, harmful impurities, radionuclides.

river sand

River sand is mined from river beds. It has a uniform consistency, good fluidity, and an average granule size in the range of 1.5–2.5 mm. Thanks to long-term natural washing, it is clean, the grains have the correct rounded shape.

It is believed that this is the highest quality filler for concrete mortar, the strength of which is especially important during construction load-bearing structures. The advantages of the material, as a rule, include the following features.

• It does not contain clay and silt particles, which are unacceptable in cement-sand mortars and deteriorate their quality.
• The oval-shaped crystals are not compacted during the preparation of the concrete mixture, the cement laitance evenly envelops them, and ready-mixed concrete practically does not shrink.

river sand

It also has disadvantages.

• Mixing with this type of filler requires more cement and more thorough mixing.
• This is the most expensive of construction sands.

Quarry sand

The most common and affordable concrete filler. There are quarries with its development everywhere; manufacturers abundantly saturate the market with inexpensive and in-demand products.

Unlike its river analogue, quarry sand has a wider range of fractions, its granules irregular shape, angular. Contains a fairly large percentage of impurities, including dust, organics, clay, and rock fragments.

There are several ways to enrich it.

The washed (alluvial) product is obtained using the technology of special directed hydraulic influence on the rock mass with its subsequent settling. As a result, removal of foreign substances, primarily clay deposits, occurs.

The second method of enrichment is sifting through a system of sieves that retain large fragments of stones, lumps of clay, etc.

Development sand quarry

Despite the fact that quarry sand is inferior in quality to river sand, it is in demand in construction industry and has a number of advantages.

• Much more common.
• Less cement is used to prepare concrete - this is due to the property of irregularly shaped crystals to compact more strongly.
• It has an attractive price.
• The enriched product meets the highest standards.

Among the disadvantages experienced builders note the following.

• Quarry sand contains a higher percentage of organic clay and silt particles - up to 7% versus 0.05% in its river counterpart.
• Due to its structural composition, it settles and becomes compacted at the moment the concrete sets and hardens. Finished design shrinks up to 1 mm per 1 cm.

Criterias of choice

Most builders agree on one thing when choosing sand for the foundation - the fraction minimum percentage foreign matter and density are much more important than the origin or location of extraction.

A quality sand aggregate must meet following criteria.

1. The most acceptable grain size modulus is from 1.5 to 3 mm.
2. The maximum content of organic and clay impurities is 3-5%.
3. It should not contain harmful components that can enter into a chemical reaction with cement alkalis - silicon dioxide, sulfur, chlorine, etc.
4. Contain no more than 370 Bq/kg of active radionuclides, which corresponds to class I radioactivity.

An important point that allows you to control the quality of the delivered products is their bulk weight. The average for clean dry sand is 1500 kg/m3. Less weight indicates availability foreign impurities, larger - about high humidity.

IN natural form River sand better meets these criteria. Seeded or alluvial quarry is in no way inferior to it. But if the requirements for future development are low, and the foundation will not be subject to heavy loads, then inexpensive filler from a nearby quarry is quite suitable.

Amount of sand for the house

Many people wonder how to correctly calculate the volumes of concrete mixture components required to build the foundation of a house.

To pour the foundation you need concrete of at least M300. It takes approximately 650 kg of sand to prepare 1 m3. Calculate the volumetric indicators of your foundation (multiply the height by the width and depth) and calculate the tonnage of sand, then convert it to volume at the rate of 1.5 t/m3.

Sand should always be purchased with a small margin (15–20%) to the calculated figure - this material tends to compact, some of it will be scattered throughout the area during transportation, some will be useful for backfilling.

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What kind of sand is needed for the foundation?

Before starting construction work, many first calculate everything and prepare the material. This is correct and commendable. But at this stage, various questions arise, one of them is what kind of sand is needed for the foundation. The choice of sand needs to be given Special attention, since it is one of the main and important components used in mixing concrete. And your future foundation, foundation, depends on the quality of the concrete mixture. Considering that the market provides big choice different sand both natural and artificially obtained, it is important to choose the most suitable one for performing these works. In this article we will tell you how to make your choice.

Purely theoretically

Main criterion- purity

Any person who is not versed in the construction business and its nuances can guess that it is necessary to choose clean sand for the foundation. The sand may initially contain various organic elements, such as grass, branches, etc. Such sand is not suitable for work, but it can be easily cleaned. Perhaps you have seen more than once how workers sift sand, clearing it of unwanted elements.

But if we talk about impurities such as clay, lime and other similar ones, then simple sifting is not enough. It is more difficult to clean such sand, so you need to immediately pay attention to this when purchasing. The presence of clay in sand should not exceed 5% of the total mass, especially when it comes to foundation mortar. Otherwise, the future structure will not be reliable, it will shrink, and this will lead to cracks. It is important to check how clean the sand is before purchasing. You can use a simple method to check.

You will need a clear bottle, either glass or plastic. You need to fill it 1/3 with sand and fill it with water up to half. Next, shake the bottle vigorously so that the sand is mixed with water and completely wet. After that, put it down and wait 5-10 minutes. If the water has become dirty, this sand will not be suitable for the foundation. If a foreign substance has formed on the surface in a layer of more than 5 mm, such sand cannot be taken. Let's look at what types of sand there are, how they differ and what type of sand is best to purchase for the foundation.

Varieties of sand

river sand

Sand is divided into several types, depending on the place of its extraction:

1. River.
2. Nautical.
3. Career.

The very name of river sand suggests that it is mined from the river bottom. This universal material, as it contains fractions of different sizes - from 1.6 mm to 2.2 mm. Due to this, it is used not only for pouring the foundation, but also for various construction purposes. The main advantage of river sand is its natural purity and uniformity. There is very little clay, vegetation particles and other impurities in it. This sand is ideal for foundations. Only its price is quite high.

Nautical

Sea sand is mined from the bottom of the sea, after which it is cleaned of shell rock and other impurities. The difference between this sand is its grain size, which is approximately 1 mm. This size of granules allows it to be used for the construction of reinforced concrete structures. It can be called quite pure, since before sale it is cleaned, screened and washed. But you have to pay for quality, which is why sea sand is the most expensive.

Career

Quarry sand is extracted by open pit mining. If you compare it with river and sea sand, this is the worst option. And it’s not surprising, since it contains a lot of impurities - clay, vegetation and crushed stone. Because of this, the price of such sand is the lowest and it is suitable for rough work on initial stage construction.

To unambiguously determine which sand would be better suited for concrete, it is important to consider other features. Some craftsmen advise buying quarry sand, which is cheaper, citing the fact that this will not affect the quality of the house’s foundation. Others say that quality is higher than price, so you need to choose expensive sand, which will ensure the reliability of the foundation, on which you cannot skimp. Be that as it may, you need to consider other features and criteria that will help you make your choice.

Characteristics

It is better to use coarse sand

As mentioned above, the sand must be clean. If there is vegetation or branches in it, it’s not a big deal, they can be weeded out. But clay, silt, gravel and other particles can reduce the quality of the concrete solution. The presence of clay should not exceed 5%. The presence of gravel as a percentage of the total mass should not be more than 5%, and the particle size should not be more than 10–12 mm. If the gravel size ranges from 5 mm to 10 mm, then more is allowed percentage– up to 10% of the total mass.

Quite a lot important point when choosing a material - its granulometric composition, that is, the size of the granules. Based on the size of sand granules, it is divided into:

• very fine sand, the granule size of which is no more than 0.7 mm. Such sand will not be suitable for making concrete;
• fine sand, the granule size of which is from 0.7 mm to 1 mm. This type is also not used for making concrete;
• very fine sand, the granule size of which ranges from 1 mm to 1.5 mm. There is no need to choose it for concrete either;
• fine sand, the granule size of which is from 1.5 mm to 2 mm. Not suitable for preparing high-quality concrete mixture;
• medium-sized sand, the granule size of which is from 2 mm to 2.5 mm. It is sand of this coarseness that is ideal for preparing a concrete mixture for the foundation;
• coarse sand, the granule size of which is from 2.5 mm to 3 mm. It is used for the production of high-quality quality concrete;
• sand of increased coarseness, the granule size of which ranges from 3 mm to 3.5 mm. Sand of this fraction is best used to cushion the foundation for the base of a building.

Very coarse sand, larger than 3.5 mm in size, can also be used to cushion the foundation.

The sand must be dry

Another important point when choosing sand for the foundation is humidity. The water content in sand plays an important role, since its quantity must be taken into account when mixing a solution with the addition of water. The recommended moisture content of sand for the foundation should be no more than 5%. Dried rock may have 1% moisture content. If the sand is exposed to precipitation, then its humidity can reach up to 10%.

If you purchased sand, you need to take care to protect it from precipitation. To do this, you need to cover it with something or unload it under a canopy. Then he won't absorb excess water.

But how to determine the moisture content of sand? Use a saucepan or iron bucket. Take the container and place it on the weights. Having found out the weight of the container, take 1 kg of sand and fill the container with it. Now you need to dry the sand. To do this, place it on the stove over low heat and “cook”, stirring, for 30 minutes. After time has passed, everything needs to be weighed again. Subtract the weight of the bowl or bucket from the weighing result and multiply the result by 100. As a result, you should get a number in percentage, which indicates humidity. For clarity: a bucket or bowl weighs 0.2 kg. After you have dried 1 kg of sand, total weight it turned out to be 0.9 kg. It turns out:

0.9 - 0.2 x 100 = 70

The humidity of your sand is 7%. There is another method for determining humidity. Easy enough to use special device, which will show the exact figure.

Let's sum it up

It is better to buy sand at the place of extraction

So, having all the data, you need to analyze it and make a choice. You learned that the ideal sand for foundations is:

• clean sand, in which clay and gravel do not exceed 5% of the total mass;
• medium-sized sand, the granule size of which ranges from 2 mm to 2.5 mm;
• sand, the humidity of which does not exceed 5%.

When buying such building material for the foundation, you should definitely pay attention to these indicators. Most the best option in terms of price and quality is washed and screened quarry sand, the granule size of which is 2–2.5 mm. It is better to buy it directly at the place of production. If you have money and want your foundation to be strong and last for a very long time, choose river sand of the same fraction. Then your concrete for the foundation will have the necessary qualities.

When buying sand, you should control the process of weighing a loaded and empty dump truck, as there are unscrupulous suppliers who underweigh the sand, profiting from you.

We hope that this article helped you figure out which sand to choose for the foundation.

Read also:

Video

Tips for choosing sand below:

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How to choose the right sand for the foundation

When laying the foundation, it is important to choose building materials correctly and competently. It is necessary to choose sand especially carefully, since the strength of the foundation mortar, and therefore the strength of the entire foundation, depends on it. The question of which sand is best to choose for the foundation will be answered in this article.

Sand selection

Foundation sand is a bulk material obtained from sedimentary rocks or artificial creation. The quality of sand does not depend on its production method; it is important to consider only its purity.

If foreign objects larger than half a centimeter can be found in it, it is not suitable for laying a foundation. TO foreign objects may include branches, leaves, organic debris.

Of course, you can try to clean the sand yourself by taking a sieve and sifting it, but just imagine how much time and effort this process will take you. By sifting the sand, you will only remove large impurities, but what about the content of elements that are undesirable in the sand for building the foundation of a house, such as lime or clay.

It’s better to immediately choose high-quality sand and get to work. Remember that high-quality sand suitable for making a solution should not contain more than 5% impurities. In addition, a large number of additives will deteriorate the strength of the sand, which will affect the foundation and the house or building itself. The gravel content in sand should not exceed 10%, since gravel is an integral element of the solution for pouring the foundation.

Of course, you can only find ideal sand by conducting a special examination of its compliance with all standards in the laboratory, finding out the percentage composition of impurities in the total mass and other indicators. But such an examination is a costly and lengthy process, so the quality of sand can be determined using improvised methods.

Pour sand into a transparent bottle, a third of the way, and then fill it halfway clean water and shake. After this, let the mixture sit for 5 minutes and look at the clarity of the water. If it becomes cloudy and dirty, then the sand contains many impurities. Floating foreign substances, too bad sign, and such sand is unsuitable for construction. If the water is clear and without impurities, then sand is ideal for laying the foundation.

IN modern construction sand is used very actively and almost everywhere. Moreover, there are about 10 different varieties of this material, but in the practice of Russian builders, two types are most common: quarry and river. Naturally, each type has those properties that determine its advantages and disadvantages as a building or finishing material. Therefore, non-professionals who conceived on our own When building a structure, you are often faced with a choice:

Quarry sand - advantages and disadvantages

Quarry sand is sand mined in quarries from huge layers located at a certain depth underground. The qualities of such sand are largely determined by its origin. The fact is that such underground sand is formed as a result of the weathering of rocks. This process goes on for centuries; decay products are deposited underground, eventually turning into compacted masses of sand.

The formation of sand deposits is caused by the weathering of rocks such as mica, quartz, feldspar and partially limestone. The composition and characteristics of sand depend on which rocks predominate in a particular area.

What must be taken into account when deciding which sand is better, quarry or river sand, is the possible presence of impurities in the total mass natural material. Clay contamination is common in quarry sands and only the concentration of foreign matter varies depending on the deposit.

Other important characteristic– heterogeneity of fractions. The mass of quarry sand contains both very small and very large particles; it often contains fragments that, in terms of size, can be classified as fine gravel. However, in the case of using sand for construction purposes, call this property You can't use a minus. The fact is that the heterogeneity of sand fractions and the presence of various impurities in it determines the higher astringent characteristics of sand.

So, let's summarize. Quarry sand is characterized by increased surface roughness of the particles, as well as the angularity of their shape. This makes it ideal for use as an extra grip element. binder additives as part of building mixtures. There are also construction areas in which it is recommended to use quarry sand. It makes an excellent pillow for a recessed strip foundation. From this point of view, no other variety can be compared with quarry sand.

River sand - pros and cons

Now let’s look at the main characteristics and properties of river sand so that, through comparison, we can try to answer the question of which sand is better: quarry or river sand. River sand, as its name suggests, is mined from river beds. This circumstance is due extremely low content of various impurities in it, especially clayey rocks and loams. They are simply washed away by the current, which provides natural cleaning of the sand.

Also, the constant exposure to water to which river sand is exposed leads to the fact that it the particles are approximately the same size and almost perfect rounded shape . Thereby, this material actively used in landscape design to create the desired decorative effect.

One of the advantages of the material is the fact that to arrange children's sandboxes or volleyball courts, it is imperative to use river sand.

If we talk about construction, then the main properties of river sand, in addition to shape and size, should be recognized as low ability to absorb and retain moisture, as well as environmental cleanliness and safety.

Taking all this into account, river sand is used mainly to obtain decorative finishing materials. For example, if it is planned to arrange on the floor in the house cement screed, then river sand is better suited for these purposes. It will not accumulate moisture, and will also contribute to a more even and smooth surface coverings.

For the same reasons, river sand is the preferred material for making paving slabs. In Krasnoyarsk it is also used in the construction of drainage and filter systems.

In fact, the only, but very significant disadvantage of river sand as a building material is high price . The process of its extraction involves the use of complex, expensive equipment; special barges and powerful hydraulic pumps are required to lift rock layers from the bottom of the riverbed and subsequently wash it. As a result, the cost of the final product is very high.

It is precisely because of the significant cost that when deciding which sand is better, quarry or river sand, builders often give preference to the former. The issue of price becomes especially relevant when carrying out rough construction work, for example, arranging a foundation, creating open areas for cars, etc. And here for finishing work, especially internal, it is recommended not to save money and choose river sand, the use of which provides better results.

Our company is engaged in retail and wholesale supplies of river and quarry sand in Krasnoyarsk. For getting additional information and order delivery, call the phone number indicated on the “” page.

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