For many years in construction practice, people have not found a more durable, practical, durable material than concrete. It consists of a mixture of cement, sand, water, gravel.

Also, modern builders add special hardening additives to the solution, which make the material almost eternal, indestructible, and as strong as possible. However, in the manufacture of a concrete mixture, it is necessary to strictly observe the proportions of all components. Otherwise, the foundation, the reinforced concrete wall of a multi-storey building, the basement floor, which is underground, will not be strong. The material will crack, will be out of service ahead of time, and emergency situations will be created. So what are the mistakes in concrete production that negatively affect the quality of finished products?

The most important mistakes

Immediately it should be noted that concrete mixtures can be made in different ways. Everything will depend on what building structures need to be made from the resulting mixture. The most important mistake is the incorrect use of cement dosage. Exceeding, as well as underestimating this component, totally affects the finished structure. You also need to clearly see which brand of cement to use before putting it in the future solution.

Note! For the construction of reinforced concrete structures that will be used under water, the strongest, most expensive brand of cement is used. For simple structures used in the open air, it is permissible to add a low grade of inexpensive cement to the solution.

Another very important mistake is the lack of high-quality mixing of the mortar in the manufacture of large batches of cement.

• Good mixing is one of the most important components in the manufacture of concrete on an industrial scale;
• In no case should dirty fillers, unsifted sand, interspersed with pieces of clay, be used. All this leads to a poorly made mortar, which will be very poor in finished products;
• Also cannot be used dirty water. The liquid must be cleaned before kneading occurs. Water is purified from mud, pieces of clay, all kinds of biological pollutants;
• Under no circumstances should cement powder be used after a long period of storage.

And very carefully you need to ensure that there is no overdose of various kinds of hardening additives that are added to the reinforced concrete mortar.

• Date: 20-11-2014
• Views: 1709
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• Rating: 24

Concrete is a unique and multifunctional material. It is successfully used at almost all stages of construction, it is used to make Decoration Materials And paving slabs. The strength and durability of any structure depends on its quality. How to make strong concrete that can last for decades?

The technological process of preparing durable concrete seems straightforward, but at the same time, the number of complaints about cracking, for example, the foundation, is growing.

What you need to know and consider in order for concrete for any purpose to live up to expectations?

Basic concepts

Classically, concrete means a mixture of the following components:

1. Cement - connecting link, which turns the components into a monolith.
2. Sand is the basis of strength and filler of small voids.
3. Aggregate - it can be gravel, crushed stone and some other materials. It is the stone component that provides the unique strength of the material.
4. Special additives - all kinds of plasticizers, etc. With the help of these chemical compositions concrete is given the desired consistency and its quality is improved.
5. Water.

The main indicator of concrete quality is compressive strength. This characteristic reflects the ability of the solution to withstand mechanical stress, which is inevitable. This indicator is measured in MPa (megapascals) and reflects the level of load that concrete can withstand without deformation and change in properties. The strength of concrete depends on the quality and type of cement used for preparation, the fraction of sand and aggregate, compliance technological process. Concrete is marked depending on its strength from B 3.5 to B 80, where the number is an indicator of the pressure that this composition can withstand in 95% of cases.

The simplest concrete, often used for laying the foundation substrate, is a simple mixture of cement and coarse sand. Depending on the use of auxiliary components, the strength of the composition increases, and hence the durability and reliability of the structure.

But before choosing a recipe that will make concrete durable, it is important to understand all the components. The effectiveness of the work will depend on their quality.

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Cement - the basis of the foundations

Cement is the main and most important ingredient in a compound called concrete. It provides binding of additional components.

Portland cement is an ideal option for making durable concrete. Due to the high content of calcium silicates, it ensures perfect adhesion (adhesion) of materials. An additional advantage of this material is the permissibility of work at lower temperatures, but this advantage should not be abused. Mixing and pouring at temperatures below +16°C will adversely affect quality. If it became necessary to work in a cold climate, it is imperative to use special plasticizers. To work in warm summer period slag Portland cement is suitable.

When purchasing cement, the main reference point is the brand. It is indicated on the bag, and the cost will depend on it. Usually it looks like this: M 500-D 10 (numbers may vary). The first indicator is the same strength, the optimal grade is M 500, you can also use M 400, but this will affect the quality, the concrete will be less durable. The second indicator is the content of impurities, the value D 10 indicates that the cement contains 10% of foreign elements. In order for concrete to be light enough and strong enough, you should choose a material with an indicator up to D 20.

In addition to a thorough approach to choosing a brand of cement, a visual assessment is also necessary. quality material must be dry, uniform and free-flowing. Even slight dampness will adversely affect the strength of the structure.

It is necessary to assess the need for concrete immediately before the start of work, the maximum period is 2 weeks. In this case, it is better to purchase the missing bag than to leave a surplus; during storage, they will absorb moisture from the environment and become poor-quality ballast. When buying, you need to carefully check the integrity of the packaging and the presence of appropriate markings.

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Not without sand

It is possible to do without this component of concrete in extremely rare cases. In the rest, it is sand that will provide sufficient density and high-quality filling of voids. What should be the sand in order to?

1. Pure. This is one of the most important characteristics. Foreign impurities, especially of plant origin, will decompose in the thickness of concrete, reducing its strength. If the sand was purchased clogged, it must be sieved. Let it take time, but it will significantly increase the strength of the future structure.
2. Homogeneous. Sand with a fraction of 1.5 to 5 mm is suitable for construction. But at the same time, you need to try so that the run-up is no more than 1.5-2 mm. The more homogeneous the sand, the stronger the structure.

It is preferable to use river sand, as it is often already clean. The ravine often contains loamy impurities and silty inclusions. In some cases, it is possible to perform a thorough washing and subsequent settling of the sand, but this is laborious, especially at home.

In some regions, remote from large rivers, you can find the so-called stone or rocky sand. It is a rock crushed to the required fraction. When using such a material, it must be borne in mind that it is much heavier than ordinary sand, which means that its use will not allow you to get lightweight concrete, which is especially important when installing interfloor ceilings.

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What should be a quality filler

Almost any stone can act as a concrete filler right size. But here, too, there are several requirements that will help improve the quality of concrete.

1. The placeholder must be clean. As in the case of sand, it is necessary to make sure in advance that there are no impurities. If necessary, resort to sifting.
2. Regardless of the type of filler, all elements must have a rough surface, which ensures high adhesion. For this reason, it is worth refusing to use pebbles.
3. The optimal fraction is from 8 to 35 mm, the rule of uniformity is preserved. But in the case of self-filling, it is better to use gravel of different fractions, for example, fine and medium. In this case, it will provide better compaction even without the use of professional rammers.
4. In order to obtain a light but very durable casting material after solidification, it is recommended to use expanded clay.

Aggregates are usually quite heavy, so they must be stored in close proximity to the place where the concrete is mixed. In addition, it must be taken into account that gravel can also become contaminated during storage, which means that it is better to organize the embankment on a solid base or on a tarpaulin. When storing the material on the ground, the lower layer becomes a marriage or requires washing and drying.

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But what about water and other components?

In order for concrete to be durable and last for many years, you need to use tap water, which is at least conditionally drinkable. It is strictly not recommended to use water from natural reservoirs, it contains acidic and alkaline impurities that will not allow you to make durable and lightweight concrete.

In addition, various components are often added to the solution, changing the properties in the direction of improvement.

1. plasticizers. This special formulations to change the properties of concrete. With their help, you can reduce the need for water, adjust the fluidity and plasticity.
2. Lime. It is usually added to simplify work with concrete, which is especially important for fine manipulations. This is not a required component and use is at the discretion of the wizard.
3. corrective components. With their help, you can make concrete resistant to low temperatures and other aggressive conditions. Moreover, if the work is carried out outside the permissible temperature range, the use of such means becomes mandatory.
4. reinforcing additives. As a rule, a PVC sheet is used, it is soft and not too strong, but when laid between the layers of the screed, it successfully protects the concrete from tearing and cracking. With it, you can make a fairly strong, but at the same time light layer.

So, all kinds of additives make it possible to improve concrete and make it more resistant to external factors.

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The correct ratio of components

So, the qualitative components of the future durable concrete have been selected and purchased, but that's not all. Their ratio is no less important, in addition, the proportions vary depending on the type of work.

For pouring, crushed stone of a large fraction is needed and enough liquid concrete good fluidity. This will fill in all the voids. But before pouring, it is recommended to mount a low-grade cement substrate, the material for it should resemble moist soil in consistency.

The most common ratio is 1:3:6, respectively, cement, sand, aggregate and up to 1 part water, depending on the need and type of construction. But this ratio is not universal, since the density of materials can change under the influence of many factors. It would be most reasonable to calculate the indicators, armed with technical reference books. If weight is chosen as the main measurement, it is necessary to dry the sand and aggregate so that the liquid does not disturb the calculation.

This rule holds true for any definition of the ratio of components. It is necessary to use the same dishes and, if necessary, make adjustments. Otherwise, the error will definitely make itself felt, but at the time when it will be impossible to fix it.

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Mixing components

Equally important is the process of mixing the components. Heterogeneous concrete is not only a difficulty in pouring, but also a change in the ratio of the components due to their sticking to the tool.

The ideal option is to use a concrete mixer, this device is designed to make perfect concrete. The unit can be purchased or rented, today many construction companies offer this service. It is necessary to install a concrete mixer at a minimum distance so that during transportation the concrete does not have time to harden - this is contrary to the technological process.

You can make high-quality concrete in the old fashioned way, kneading in an old trough. But in this case, you will have to make a lot of effort to make the mixture homogeneous.

There are two methods for preparing the solution:

1. Dry. When using it, all dry components are pre-mixed, and only after that water and plasticizers are added. The danger of this method is that it is extremely difficult to qualitatively and quickly enough provide liquid access to the lower layers, and this can disrupt the proportion. With long mixing, the cement will begin to set, which will affect the strength of the concrete.
2. Wet. All dry ingredients are gradually added to the measured water. This method is not without drawbacks, but it is still preferable, especially when preparing a small volume of solution.

Concrete brand

Concrete class

Water resistance of concrete

Frost resistance of concrete

Mobility of concrete

The choice of concrete for the foundation

Concrete has been holding the leading position among building materials for many years in a row. He owes such popularity to his unique operational qualities, incl. high strength, frost resistance and moisture resistance. Moreover, varying the ratio of the constituent components of concrete makes it possible to obtain a material with slightly different properties, which allows it to be used in almost any conditions. The question of choosing the right concrete remains the most important and difficult, because the further properties of the structure depend on it.

It is no less difficult to choose a suitable concrete manufacturer. Growing demand for this construction material led to the emergence of a huge number of proposals, which are quite difficult to navigate. In order for a potential buyer of concrete to be able to quickly find the best offer for himself, the M350 concrete tender system was developed. It is presented on the page http://m350.ru/price/m350/ and allows the user to quickly get acquainted with all the offers for the sale of concrete M350 and other grades in the Moscow region and choose the most suitable one for themselves, based on the price, location of the plant or mode of operation manufacturer. The system allows save time and money.

To be able to choose the right concrete mix for specific purposes, you need to know what indicators to look for. Among the most important are the brand and class of concrete, the characteristics of moisture and frost resistance, as well as the mobility of concrete.

Concrete brand

The most important characteristic of concrete is its ability to withstand compressive loads. This parameter is denoted by the letter M, and the index behind it indicates what load each square centimeter of concrete can withstand. The exact value is determined in the laboratory by testing concrete that has hardened for 28 days, and the rounded value is recorded in the marking. For example, concrete that can withstand 98 kgf / m2 is designated as M100, and concrete that can withstand 196 kgf / cm2 - M200. Simply put, the digital index indicates the number of kilograms that can put pressure on 1 cm2 of concrete without destroying it.

Today, concrete is produced from M50 to M1000, But Concrete grades M100-M500 are consistently in the greatest demand. Different levels of concrete strength are explained differences in composition: Influence the proportions of the components used and their quality. The composition of concrete includes sand, cement, crushed stone or gravel. Sand together with crushed stone (the so-called skeleton) are responsible for bearing capacity future construction, and cement, connecting with water, is responsible for the strength of molecular bonds. The higher the proportion of cement in the composition of concrete, the higher the strength of the concrete itself.

The quality of the components also plays a role. Sand can be both river and quarry- it is important that it be large and with a minimum amount of clay impurities. Optimal size crushed stone - 20-25 mm, it must be from strong rocks. The brand of cement also affects the strength of concrete. As a rule, cement M400 and M500 are used, the latter will need less to prepare concrete of a given strength.

The least durable concrete grades are used in the construction of the lightest and least critical structures. The foundations of private and multi-storey buildings, industrial buildings are created using more durable compounds (M200 and above). With an increase in strength, the price of the composition also increases, so it is useless to use overly strong compositions, as well as save.

Concrete class

The class of concrete also indicates the strength of the material, this modern derivative of the brand of concrete. If the average value of the strength of the material is used when determining the grade, then the strength class assumes the definition of strength with guaranteed security. This is a more accurate value, which is expressed with a coefficient of variation of 13%. Despite the fact that the class more accurately determines the characteristics of concrete, today most specialists use the concept of grade.

The classes define letterBand a number from 3.5 to 60: the higher it is, the more durable the composition is in front of you. There is a direct relationship between classes and brands: for example, brand M100 corresponds to class B7.5, brand M200 - B15, etc.

The ratio between the class and grades of concrete in terms of strength

Water resistance of concrete

The water resistance of concrete is understood as its ability to keep water out. Previously, this characteristic was denoted by the Russian letter B, now useW, and the numerical designation next to it may begin from 2 to reach 20, equaling the pressure of the water column in kgf / cm2, at which a cylindrical concrete sample of standard height does not let water through.

If a concrete foundation is being built under conditions advanced level ground water, then it makes sense to choose a composition with a high water resistance value, in which special hydrophobic additives are added. By the way, the use of such material will reduce the cost of complete waterproofing of the foundation.

The highest rates of water resistance and water resistance have hydrotechnical concrete. For its production, hydrophobic or plasticized Portland cement, sand and gravel of higher quality are used than for ordinary concrete. High levels of water tightness are also achieved through installation with maximum sealing.

Frost resistance of concrete

The frost resistance of concrete is indicated by the letter Fwith a numerical value from 25 to 1000: the higher it is, the more cycles of freezing and thawing concrete can withstand without losing its strength properties. The choice will depend on the conditions in which the finished structure will be operated, on the characteristics of the climate, the number of periods of freezing and thawing during the cold season.

For the construction of hydraulic structures, airfield pavements and bridge supports, it is better to choose the most frost-resistant compositions. In private construction, concrete of the F100 or F200 class is suitable for the construction of the foundation. You can also focus on density: the higher its value, the more frost-resistant the composition will be.

Mobility of concrete

The mobility of concrete (P) speaks of the degree of its fluidity, which directly affects the convenience of working with the composition. The numerical coefficient is expressed in the range 1 to 5: the higher it is, the more liquid the composition will be. In private construction, concrete is used in the arrangement of the foundation P2 and P3. More fluid compositions are used only in cases where it is necessary to pour a densely reinforced base, or when concrete is supplied using concrete pumps.

Of course, it is more convenient to work with a more fluid composition, but water cannot be added to ready-made concrete to increase the mobility of the composition. In this case, the mortar brand immediately decreases, reducing the final strength.

Areas of use of different grades of concrete

Concrete has become ubiquitous, used to create foundations and many other structures. Depending on the purpose of use, concrete of one brand or another is selected. Here are the main areas of use of the most common grades of concrete:

The choice of concrete for the foundation

Since concrete is used in the organization absolute majority foundations, the question of its choice for these purposes requires more detailed consideration. To select the required brand, you need to know the weight that will be assigned to the structure, its operating conditions, take into account the type of soil, groundwater level, etc. All this should be mentioned in the project documentation, and for those who are building on their own, we will provide information on the scope of use of different grades of concrete.

The lower the load from the building being erected, the less durable concrete will be needed. If it will be built frame house, then you can do with concrete M200, for a wooden house, it is better to make a foundation from M250 concrete. For two-story wooden houses, houses from gas silicate and expanded clay concrete blocks it is better to choose M300 concrete. If reinforced concrete wall panels will be used or the construction plans are brick house, then concrete M350, M400 and above is used for the foundation.

Influences the choice of brand of concrete and soil type. The more heaving the soil, the greater the differences in load are on the foundation. So, for clay soils it is better not to use concrete below M350, and for sandy and rocky soils, M200 is also suitable. If the groundwater level at the site of construction of the house is high, then it is better to choose concrete with increased water resistance: even if M250 is suitable for loads, it is better to use M350, for which W is almost twice as high.

Whatever brand of concrete is used, the characteristics of the finished structure are also largely affected by the correct dilution of the mixture with water, as well as the process of filling the form with concrete and the uniformity of concrete distribution.

01. We get high-strength concrete in ANYONE region

02. We are nothing NOT sell

03. You NOT have to buy equipment

04. Concrete only from your LOCAL components

05. Someone will do better? We will pay you!

Why are we the best
on high-strength concrete?

candidate of technical sciences
Vladimir Volodin

gets concrete
brand M2500 (B180)

Volodin Vladimir Mikhailovich(Technical Director)

01. He brought the brand of concrete to the incredible M2500
(obtaining the strongest mass-produced concrete in Europe)

02. Participated in the exposure of concrete in the skyscrapers of "Moscow City"

03. Developed high-strength concrete for the Vostochny Cosmodrome

04. Wrote a dissertation on high-strength concrete

05. PhD ()

06. Winner of international competitions in concrete science ()

08. Inventor (patent holder)

Abramov Dmitry Alexandrovich(director)

01. Implemented the technology at more than ten large plants in the CIS

02. Found a site with a raw material base for the production of the cheapest high-strength concrete (in Europe)

03. Inventor

Where is high-strength concrete used in Russia?

Completely in Russia
can't make
high-strength concrete
(in tangible volumes)

According to the latest research...


Less than 0.3% profit concrete plants spend on R&D

"High-strength concrete" in Russia is:

High-rise buildings (above 40 floors)- strength about M1150 (B90)

Glass fiber reinforced concrete- M900 (at the same time super-expensive, super-cement-intensive)

Floor hardeners- maximum strength M800 (B60)

Architectural products (facades, etc.)- less than M800 (B60)

paving slabs- less than M700 (B55)

Junctions (for roads of the 1st category)- occasionally M600 (B45-B50)

Special reinforced concrete products- M600 (B45-B50)

Why is high-strength concrete sold 2-3 times more expensive than its cost?

The lack of standards for the selection of high-strength concrete recipes gives rise to a lot of intermediaries and sellers of additives.

No one guarantees the production of high-strength concrete (except us).

Factories spend 0.3% of their expenses on research (concrete science).

Prices for concrete for skyscrapers "Moscow City"

Price list of CJSC "Ingeokomprom" supplier of concrete for skyscrapers "Moscow City" for concrete mixes dated June 01, 2014
Source of information: http://eprom.su/prajjs-list/ (screenshot from 07/03/2015)

Due to what we get the most durable concrete in the Russian Federation?

We "peeped" from the Germans

We have worked for many years

over high-strength concrete

As a result, they surpassed Western counterparts

In which cities did we get high-strength concrete?

Moscow - from М1450 (to М2500)

Ulyanovsk - М1200

Alma-Ata (Kazakhstan)- M1200

Samara Region- M1300

Vladivostok - M1200

Yakutia - M1000

Republic of Bashkortostan- M1200

Chelyabinsk - M1300-M1400

Krasnoyarsk - M1300-M1400

Yekaterinburg - M1200

Penza - М1400

Vladimir - savings from 85 to 850 rubles. per cube

Naberezhnye Chelny- M1300

Kaluga - M1200

St. Petersburg - М1400

and others

Minimum 100.000 rub. per day
we save for our customers

How much do our services for setting up the production of high-strength concrete cost?

The price depends on the degree of our involvement.

The minimum price for the introduction of high-strength concrete:
The amount of your savings
per 500 m 3 of high-strength concrete

Unclear? Call us and we will explain

THREE WEEKS is the average period from the beginning of work with us to the release of the first batch of high-strength concrete at your production.

If we start working with you, You will receive unlimited annual technical support for concrete engineering (telephone, mail, additional alterations of compositions, if necessary, business trips).

What if it doesn't work? If something does not work out, we will return all the money.

Need more information?

Come for a visit!
We are in a HUGE concrete plant
Address: Russia, Tolyatti, Nikonova 52
International. Airport: KUF (Kurumoch) (40 min drive to us)
Railway station: "Zhigulevskoye More" (6 minutes drive to us)

How to make strong concrete (concrete mortar) with your own hands.

Mortars and concretes are artificial stone materials that are obtained by mixing a binder (usually lime and Portland cement) and certain aggregates. The binder, when mixed with water, forms a stone-like body, which is explained by the processes of setting and rapid hardening. The strength of the stone-like body is provided by the filler (gravel, crushed stone, sand). Next, I will tell you about all the stages of the question of how to make concrete with your own hands.

Components for making mortar

1. Placeholder

For mortar, most often, fine sand or other fine aggregate is taken. For concrete mortar you can take not only fine sand, but also coarse gravel or crushed stone. To make a building plaster or masonry mortar, it is best to use fine sand, the grains of which do not exceed 2 millimeters in diameter. If the plaster will have a special texture, it is possible to add sand with a grain of up to 4 millimeters. In our market, buyers are offered two types of sand: river and ravine. River sand is considered medium-grained, it is quite expensive, but its purity favors its use as a component for concrete mix. Ravine sand can be fine-grained (from 0.5 to 1.5 millimeters), with a large amount of clay particles and other impurities. It is not suitable for good and durable concrete, but it can be used without fear for mortars.

For lean (lightweight) cement concrete with strength class B7.5, only sand can be used as aggregate. In concretes of greater strength, in addition to sand, crushed stone or gravel with a diameter of up to 31.5 millimeters can also be used. It is considered correct to use a crushed stone mixture of different fractions, so that the finished concrete contains a minimum number of voids between the pebbles.

Attention! The aggregate of concretes and mortars should be free from contaminants such as soil, glass, pieces of wood, peat, plants, dusty or silty soil. If contaminants are present, they must be removed by sifting gravel or sand through a sieve.

2. Cement

Cement - common name for astringent powdery substances based on marl, lime and clay rocks and all kinds of additives. The most commonly used type of cement is Portland cement, named after the British peninsula of Portland. This cement contains a large amount of calcium silicates. Under construction country house Two types of Portland cement can be used.

Type I - does not contain additives, or their content does not exceed 5 percent. The European classification for such cement indicates the name CEM I.

In Russian practice, the presence of cement additives is indicated by the letter D and the number in the marking code that follows the brand. For example, if you see the marking PC 500-D20, then it means the presence of 20 percent of additives in Portland cement of the 500th grade. As we have already found out, this characterizes type II cement. As for the designation DO, it characterizes type I cement, that is, a material without additives.

To prepare a plaster and masonry mortar, you need to take cement classes M400 (32.5) and M500 (42.5). Portland cement is ideal for preparing concrete mixes to be used in low temperatures(the daily average is below 10 degrees Celsius). If the temperature is high, for example in hot weather, it is better to use portland slag cement or type III cement (the European classification indicates the name CEM III). It is well suited for the manufacture of masonry and plaster mortars used for fences and floors.

Attention! Cement can only be bought in bags with the appropriate label. Immediately before buying, it is necessary to check whether the cement is damp or caked. If there are all signs, it is recommended to refuse the purchase. Only a trusted reputable manufacturer who has been selling mortar for more than a year can guarantee that the brand of cement that is declared on the package or on the bag can be guaranteed. By the way, the main difference good manufacturer from underground is not the cost of ready-mixed concrete, but the availability of a quality delivery service.

3. Lime

Lime is required for the manufacture of cement-lime mortars. In addition, it is used to improve the workability of the solution. To date, for the preparation of solutions, lime is no longer required to be extinguished. Instead, you can buy slaked (hydrated) fluffy lime at a low price, which is sold ready-made packed in bags. Alternatively, lime may be sold in pails as lime paste instead of a dry mix. It is added to cement-lime plaster and masonry mortars to increase their workability.

Attention! If you decide to use lime as part of the question of how to make concrete at home, use extreme caution, as lime has strong corrosive properties. Work is recommended to be carried out in protective gloves, not forgetting to ensure that the material does not get into the eyes or on the skin. The same applies to the use of dyes, as well as subsequent work on grinding and polishing the product.

4. Additives

The composition of a concrete mixture or mortar may include certain additives that can either improve or simply change their certain properties.

Plasticizers or plasticizing additives can increase the fluidity of the mixture, as a result of which builders receive a solution in a more liquid consistency. This solution is much easier to apply.
Thinning additives or superplasticizers can reduce the amount of water poured for stirring.

In addition, their use can improve the workability of the mixture, increase the strength, frost resistance and water resistance of mortar or concrete.

Separate additives allow you to accelerate the hardening of the concrete mixture or mortar.

Also, there are additives with the help of which it becomes possible to carry out work in the temperature range from 10 degrees of frost to 35 degrees of heat.

Special additives are commercially available that slow down the hardening of the concrete mixture, which is useful when concreting in hot conditions.

Air-entraining or aerating additives increase frost resistance and reduce the moisture capacity of the solution in the hardened state.

As a rule, additives are sold in plastic packages in liquid form. The packages must contain information about the dosage, quantity and main properties. Additives in a mass ratio should not exceed 2 percent of total weight cement.

5. Water

The quality of water used for mortars and concretes is regulated by GOST standards. In particular, water must comply with drinking standards, must not contain third-party impurities, including sugars, oils, alkalis and acids. It is forbidden to use poorly cleaned marsh and wastewater. It is better to be guided by the principle that any drinkable water can be used to stir the solution. If you prepare a concrete solution using water from a lake or from a river, you will have to check the suitability of such water in a special construction laboratory.

Composition and proportions

Before starting to consider the question of how to prepare concrete or reinforced concrete, I draw your attention to the fact that the composition and proportions will directly depend on its main purpose. That is, it is correct to use strong concrete for the foundation. high density, while for filling the fence, you can stop at lighter grades. Once you have decided on the components, choose the right brand. In most cases, for imported concrete and do-it-yourself solutions, it is better to choose the M300 or M400 grades. As for the proportions, the cement / sand / gravel components should be used in proportions of 1/3/5. This means that for a cube of concrete, one part of cement requires the addition of three parts of sand and five parts of crushed stone or gravel. If we talk about water, then its amount should be half the weight of other aggregates. For example, if you get 100 kilograms of dry mix, then you need to take 50 liters of water.

If you get too thick (dense) mixture, you can add a little more water. The consistency should be such that you do not need to make great efforts to stir the solution with a shovel. For wet sand, there should be less water. If work is carried out in the cold, water and concrete must be heated, which will protect the composition from premature setting and loss of strength. For work, it is better to use a purchased concrete mixer or do-it-yourself devices / mixers and containers. What material and what components they consist of (pumps, molds, vibration screeds, etc.), you can read in another article.

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