What kind of sand should be used for the foundation. What kind of sand is needed for the foundation: river or quarry? The choice of sand for construction

Builders, especially for those who do it unprofessionally, often have questions about what raw materials to choose for construction. It is especially difficult for them to decide when there are several varieties of the same material. This statement is true for sand. It is indispensable in the production of concrete and cement mixtures, but which sand is better, river or quarry?

What is the difference between river sand and quarry sand

The features of each of these types of sand are due to their origin. River sand is mined from the bottom of the rivers, in which it lies for thousands of years and is constantly polished by streams of water. As a result river sand has a rounded shape, it is smooth and turned.

The absence of sharp edges ensures that the sand will be distributed more evenly in the concrete mixture, and this has a positive effect on the quality of the mixture. The cleaner the river sand, the higher its quality, so you should pay attention to how the sand is contaminated with silt, clay and other organic formations.

Quarry sand is formed due to the destruction of various rocks that settle for millennia and overgrow with the soil layer. Such sand is mined in quarries, pulling it out with the help of excavators and other special equipment. The peculiarities of quarry sand include the fact that it has a high content of various impurities, due to the fact that it is under a layer of soil. As a result, during mining, sand is mixed with clay, shells, dust, and stones.

The use of quarry sand for concrete is highly undesirable, since it shrinks, most of it settles at the bottom, due to which the concrete is fragile and crumbles. It is possible to improve the quality of quarry sand if it is washed and cleaned. Such sand is preferable to use than ordinary quarry sand, but due to the fact that its extraction requires a lot of effort, it costs more.

Which sand is better, river or quarry?

It is impossible to answer this question unambiguously, both river and quarry sand have their positive and negative sides. If the issue of cost is primarily important, the price of river sand is much higher than quarry sand, so river sand is still the most popular type of sand for construction. In addition, it is suitable for the manufacture of various mixtures.

Bulk sand price

The price of sand in bags with delivery

River sand has the highest characteristics, due to which the concrete made from it lasts a long time and is not subject to rapid deformation and destruction. Its only downside is high price, because of which many prefer to continue to use quarry sand.

Nevertheless, despite their differences, both quarry and river sand are actively used in various areas of construction. River sand is part of the mixtures from which concrete is formed for foundations, walls, ceilings in large structures that are designed for a serious load. Quarry sand is used in the construction of small structures: private houses, outbuildings, structures for which a light load is planned.

When choosing sand for construction, it is important not to make a mistake, because the service life and reliability of the structure depend on it. You should not save on building materials, especially since high-quality raw materials are not always expensive. You can buy quarry or river sand from us at the most affordable price with delivery or pickup.

Quarry or river sand - which one would be more reasonable to use when pouring the foundation, brickwork, plastering and others construction work? This question gives rise to a lot of controversy, even among experienced craftsmen, not to mention the "dummies" in the construction business. But it is more correct in this case to separate the sand not by the type of extraction, but by qualitative characteristics, such as the amount of impurities, fineness, etc.

It is known that quarry sand often has too large quantity foreign impurities, the most harmful of which is clay. It envelops sand particles, preventing the components from setting in solution, and negatively affects the strength and frost resistance of the final product. But for the sake of fairness, it is worth noting that quarry sand can also contain a different percentage of impurities, and besides, sand washing helps to solve the problem.

The second thing that quarry sand differs from river sand is the shape of the grains themselves. If in the process of crushing the rock, angular grains are formed that improve the quality of the solution, then the grains of sand treated with water are smoother and more rounded, their adhesion will be noticeably less. From this point of view, quarry sand wins. An additional advantage is its low cost.

So what is better anyway?

You should choose a river or quarry based on its “purity”.

How to check the quality of sand, we have already written. If the washed quarry sand has a meager amount of impurities, you can take it (after conducting a small test and checking real content clay and, accordingly, the honesty of the seller). But in the case of river sand, you can not be afraid of the presence of clay inclusions in it. And do not expect that after a year or two your foundation will begin to crack because of them.

If quarry and river sand are equally in demand in the production of concrete, then for mixing some mortars sand mined in quarries should not be used. For example, in the manufacture of dry plaster mixture mainly pure river sand is used.

Due to its ability to pass water well (in other words, due to the high filtration coefficient), river sand is also much better than quarry sand for drainage work.

So, when choosing a material, one should proceed not only from financial considerations, but also pay Special attention the quality of the purchased sand. Then the result of your work will withstand any test, including the most rigorous and objective - the test of time.

Choose sand for concreteamong the many proposals, it is quite difficult if you do not get an idea of ​​\u200b\u200bwhat the properties of this material are. In construction and decoration, several types of sand fillers are used, each of which has typical characteristics. The quality of sand and the possibility of its use in the preparation of concrete mortar is influenced by several factors that are closely related to its origin.

Properties and characteristics of sand

Sand properties , mandatory for accounting in the construction business and the formation of concrete monoliths, depend on its chemical composition, places of occurrence and partially - from the method of extraction. Existing standards strictly link the requirements for the strength and ductility of concrete with the characteristics of sand:

• fraction grain size;
• bulk density per cubic meter;
• the shape of the grains, which affects the settling in solution;
• the presence of contaminants and foreign matter.

It is these parameters that determine not only the quality of the mortar and concrete monolith, but total costs, since they are affected by density - the amount of sand in one cubic meter. Profitablebuy sandfor the preparation of concrete means to choose it correctly according to its main characteristics.

What is the difference between quarry sand and river sand

For construction, two main types of material are used by origin - quarry sand (ravine) and reclaimed from the riverbed. In coastal regions, material can be mined from the bottom of the sea, but its transportation is quite difficult, so in central regions Russia is much more accessible river sand . The sandy massif mined in the river and the quarry has noticeably different properties.

Features of river sand

Sand of river origin is characterized by a pronouncedly rounded shape of grains, which have been rolled over by streams of water for thousands of years, turned, and become smooth. AT concrete mortar this means a more uniform distribution of the mass of sand grains, which means high plasticity and predictable density.

Construction practice, experience and standards require the use of medium and coarse sand in the concrete solution - with a grain size of 2.8 mm. Great importance attached to the absence of impurities of clay, silt and other deposits of organic and mineral origin. It is this feature of river sand that is highly valued in the production of concrete products, pouring foundations and forming monolithic structures.

Builders with extensive experience attach importance to the place of extraction of the material. Xcharacteristics of river sandfor pollution with silt and clay are indicated in the documentation, and this figure should not exceed 0.3%. The origin and method of extraction create all the conditions for obtaining a mass of high purity, plasticity and the correctness of the shape of the grains.

Features of quarry (mountain) sand

Characteristics of quarry sand(mountain and ravine) allow you to use it as a filler and the main material for brick production, production of mixes for couplers, backfilling of roads and platforms. The characteristic uneven shape of the grains and clay impurities make it possible to obtain compositions for the manufacture of bricks and masonry mixtures - they have a pronounced force of internal adhesion.

Quarry sand is too fine and non-plastic for use in concrete mortar - its uneven grains do not give the effect of uniform distribution, settle faster, which leads to a decrease in the quality of concrete. The amount of clay deposits is somewhat less in alluvial quarry sand, but this is not the main indicator in concrete production and monolithic construction.

Choosing sand for concrete

The difference between quarry and river sandso noticeable that in construction practice it is customary to use material of precisely river origin. At the same time, it is worth carefully studying the analysis data - the minimum amount of contamination and the homogeneity of the fraction significantly increase the predictability of the properties of the concrete solution and the final concrete monolith.

Based on the opinion of professionals, the question of whetherwhich sand is betterfor the preparation of concrete, then the championship will remain with the river - medium and large fractions, with minimal sedimentary impurities. River material with throughput(filtration coefficient) 12 m per day, which is three times higher than the rate of quarry sand.

Uniformity, smoothness and purity of the mass extracted from the bottom of the river or a dried-up channel allows you to pack and sellsand in bags40 kg each, as a material with predictable properties and a guaranteed level of quality.Properties of quarry and river sandare so different that in the field of professional construction and concrete work it is practically different materials with their own specific areas of application. It is possible to save on the use of alluvial sand from a quarry in concrete mortar - provided that the monolith does not carry a large load, and its strength does not become critically low for the integrity of the entire structure.

River sand is quite popular construction material. It has been formed for thousands of years, and its reserves are inexhaustible, because water still leaches rocks and minerals from the earth bit by bit, accumulating insoluble sediment. In riverbeds, it continues to act on small grains, grinding off their sharp edges and removing organic matter. As a result, layers of pure silicate sand without impurities and with a uniform fractional composition are formed at the bottom.

If the sand is river, it initially does not need complex cleaning: re-sieving on sieves to remove debris or washing. The maximum that remains to be done is to dry it and divide it into fractions. The output is a mass of gray or yellow shade with a more or less uniform composition. It contains 50-95% SiO 2, and the more it is, the lighter the material will be. But depending on the deposit, in addition to quartz, other minerals may also be included here:

• 3-10% calcite;
• ≤5% feldspar and the same amount of mica;
• ≤1% natural gypsum.

Characteristics that fully comply with the requirements of GOST 8736-93 should be as follows:

• Dry density - 1500 kg / m3, for large fractions - 1650-1700.
• Bulk weight at natural humidity(4%) - 1450 kg/m3.
• The content of polluting and weakening particles (silt, dust, clay) is 0.7%.
• Filtration rates - 5-7 m / day.

High-quality sand does not contain foreign inclusions such as pebbles or soil residues and has good flowability in a dry state. But most of all it is valued for its chemical stability. Due to its simple mineralogical composition, it does not provoke any unpredictable reactions in solution, since it is completely inert. The quality of any products and works with its use will be quite high.

What does the cost depend on?

Since bulk building materials mined from the bottom of the rivers are considered the best, the cost will always be higher than quarry. This takes into account not only high performance finished filler. Manufacturers can even save on product fortification by eliminating complex processes from the technological chain.

The extraction itself turns out to be an expensive pleasure. We need a floating dredger and a receiving barge-hydraulic dump with the ability to dump flowing water. Some simple cleaning operations can also be performed on it, after which the prepared mass is sent to temporary warehouses. If the bottom of the river is silty, the mixture must pass on the bank additional processing- this is how washed river sand is obtained. The technology is simple, but due to the high cost of equipment, the cost increases markedly.

The grain size in such a mass is usually medium (1.8-2.2 mm), but mining in the old mouths of dry rivers can also produce coarse-grained material suitable for use in some types of finishing and decorative works. Enlarged fractions are suitable for the preparation of good masonry mortars. But since their share in the total production and on the market is noticeably lower, the cost of a cube of sand with a particle size of 3 mm will always be high.

Also, the price per ton or cubic meter may vary depending on the following factors:

• Geographical proximity of the mining site.
• The situation on the market in a particular region (number of suppliers, demand).
• Transportation method.

The cost per 1 m3 with delivery to a large extent depends on the volume of the lot. If you need to save money, you will have to understand not only the pricing policy of manufacturers and suppliers, but also the peculiarities of logistics, as well as the possibilities of freight transport. For example, MAZ includes about 6 cubic meters of sand, KamAZ - 12. But ordering one big car in any case, it will cost less than two smaller ones, although the amount of delivered material does not change from this.

Depending on volumes upcoming work can be bought in bulk and in bags. The first option in terms of cubes is always cheaper, but here you should pay special attention to quality. Visually distinguishing it from washed quarry will come out in the form of grains: the particles should be rounded and not scratch the hand. Next, you need to take the sand in a handful and squeeze it tightly in your fist. If you get a sticky lump, most likely the clay content is exceeded here.

Application

River sand in construction is in demand in the most difficult works. It is used to make plaster and masonry mortars, dry PC mixtures are added to the compositions for self-leveling floors. Fine mineral aggregate is used as a raw material for the production of various blocks and reinforced concrete products. He attaches finished products and castings high strength and frost resistance. Its use allows to reduce the consumption of the binder due to the partial filling of voids between large fractions.

The smooth surface and the rounded shape of the grains should be taken into account - they adhere worse to each other and to the components concrete mixtures. And if river sand is included in them, after mixing the viscous mass will need to be mixed regularly. This will prevent the fine aggregate from settling to the bottom of the tank.

Coarse and medium-grained sand is excellent for concrete. In order to save money, you can add a quarry to it, but the effect is unlikely to be impressive (although everything here depends on the volume of construction). The preparation of masonry compositions also allows such experiments - the clay contained in the cheap aggregate makes the mortar more plastic and makes it easier to work with it. Fine sand is more in demand among manufacturers of dry mixes for sale - they buy up to 25% of the total volume of bulk materials on the market.

Application in other areas

The demand for sand is also determined by its filtration characteristics: it is used for draining filling, lining the bottom of aeration wells. bulk material will improve the condition of the soils on the building site if they have a high groundwater level or are too weak to support the weight of the building. And although replacing soil layers with such a backfill is considered a difficult and time-consuming task, it subsequently allows you to choose more economical types of foundations.

Sand freely passes excess moisture through itself, without turning into a "quicksand". This valuable property is widely used in road construction, where under durable coating you need an equally reliable pillow that will hold the canvas and will not allow it to deform under any circumstances. About 40% of all production goes to these needs.

Fine aggregate in bags and in bulk is used in everyday life: it is better not to find it for sandboxes or filling paths on a material site. For greater decorativeness, it is even allowed to color the bulk mass with safe food dyes in order to obtain multi-colored river sand at the output.

Natural natural sand - loose rock, which contains grains of feldspars, mica, quartz and other natural minerals. In fact, any sand is suitable for construction. Both river and sea or quarry are used, but the use of quarry is in demand due to its low price and good natural properties.

Description of building material

Quarry sand - almost universal material, which is used in many areas of the economy and industry. Construction, road works and landscaping are key applications for quarry sand.

This sand is mined in a quarry way, as its name implies. Various careers provide different types sand with different structure, grain size and composition. The final properties that quarry sand will have are also influenced by the methods of its extraction: washing, screening and open pit mining.

By fineness and grain size, fine-grained, medium- and coarse-grained sand is distinguished. Fine-grained - sand, whose grains have a diameter not exceeding 2 mm. Medium-grained - from 2 to 2.8 mm, and coarse-grained has grains of sand up to 5 mm.

The fact that various impurities are present in quarry sand (sometimes percentage reaches 7%), is a disadvantage on the one hand and an advantage in some cases.

When the sand is mined open way rather than by washing, the presence of clay makes it more convenient when mixing solutions. It settles less and makes the building composition more elastic and mobile.

Varieties of quarry sand

According to the type of processing used after mining, sand is divided into:

• Alluvial (washed) — this species quarry sand is extracted from flooded deposits and deposits in quarries by using hydromechanical equipment. Thanks to the use of this technology, the sand is ultimately clean, that is, without impurities and unnecessary components. During mining, clay and dusty particles are washed out of the sand by hydromechanical devices. The use of alluvial sand is considered the most appropriate for the production of concrete and bricks, as well as in the construction of buildings, roads and reinforced concrete products.
• seeded sand is obtained as a result of simple technical and mechanical screening from large particles and stones. Such sand is perfect for forming a plaster mass, preparing a mortar for masonry or casting a foundation.
• sandy soil- this is an unrefined mixture of quarry sand with various components. The price of such sand is minimal, and the scope of use, as a rule, is limited to backfilling trenches or leveling the relief of the land.

This is how alluvial (washed) quarry sand looks like in the photo

Sand mining in quarries: process features

Of course, the open method is considered the most popular, in which construction and mining companies can get by with ordinary equipment: excavators, bulldozers, and so on. This method quite cheap, so the sand is not suitable for all work. Quarry sand mined in this way is usually found in upper layers soil, so miners mainly use the technique of opening upper layers and occasionally explosives.

For quarries flooded with water, a dredging unit is used, which is a powerful pump for unloading sand from the bottom. The floating pontoon on which the equipment is installed (the so-called dredger) is attached with anchors and cables, or is located on board a specially equipped vessel. The suction sand is called "pulp" because it passes through the pulp channel, which screens out clean sand without impurities and returns water to the quarry. This method of extraction is called hydromechanized.

In other cases, other equipment may be used that has a specific purpose, and is also not typical for regular use. For example, a sieve is used to screen stones and clay from open pit sand. Instead, the usual metal grid, which allows you to sift the sand with your own hands. Before developing a new quarry, it is necessary to prepare all calculations and coordinate work with government services.

Dredger S-42 sand extraction hydromechanically:

Specifications and properties

The main property of quarry sand is its purity and the absence of impurities. Moreover, alluvial career material has the following characteristics:

1. Fractions range from 1.5 to 5 mm.
2. Low percentage of dust, clay and other impurities - no more than 0.03%.
3. The density of alluvial quarry sand is 1.60 g/cm3.

Depending on what fraction the sand grain has, the alluvial material is divided into the following categories: fine, large fraction and medium-sized fraction. Shades of quarry sand are also different and can be either amber yellow or Brown color depending on deposits and quarry.

Applications

Due to the exceptional quality of quarry sand and its compliance with GOST 8736-93, it is widely used in the construction industry, national economy as well as decoration. The use of sand in the production of bricks and concrete, as well as in housing and road construction, is especially relevant and cost-effective.

Alluvial quarry sand of coarse fraction has gained great popularity in the production of high-strength concrete and various reinforced concrete structures. paving slabs, masonry and street curbs also use quarry sand in their production. And due to the absence of impurities, the resulting materials will have exceptional strength and durability.

Surface and coating mortars use sand with a fine grain fraction, which allows to achieve an aesthetically attractive appearance of the final mixture. Decoration, use on summer cottages and on playgrounds, makes the extraction of fine sand quite cost-effective.

Some more information about the use of quarry sand:

Advantages and disadvantages of quarry sand

Enterprises that are engaged in the extraction and sale of sand, gravel and granite, sand, as a rule, is a priority material. What is its popularity? For the most part, due to the fact that, compared to other types of sand (for example, quartz), quarry sand is not at all expensive.

This is because:

• Enterprises do not spend resources on sand cleaning. Since quarry sand is not affected and processed, enterprises save money on cleaning and screening quarry sand.
• The mining process is very simple. Absolutely, the easiest, cheapest and most common way is open, which is used by the vast majority of mining companies.
• Low shipping cost. There are a lot of quarries with sand deposits, so you can always find required amount sand nearby.

Although the performance of quarry sand does not reach alluvial or seeded, but a pleasant price and others quality characteristics make this sand more popular and in demand than its counterparts.

What is the difference between river sand and quarry sand

To be honest, according to GOST, river and quarry sand is not separated. The whole difference between these two breeds is the price, which is several times higher for a river breed than for a quarry one. If we compare the compositions of two types of sand, then the river sand is clean, without impurities and third-party elements, and the quarry contains clay (which is sometimes very useful). Therefore, it is impossible to unequivocally say which is better: quarry sand or river sand.

So, quarry sand is universal and also popular. building building material which is used in many industries. It has an exceptionally low price due to uncomplicated process extraction and lack of processing.