How to make high-quality and strong concrete yourself? High-strength concrete, grades, composition and application The hardest concrete.

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

Mortars and concretes are man-made stone materials that are produced by mixing a binder (usually lime and Portland cement) and certain aggregates. When mixed with water, the binder forms a stone-like body, which is explained by the processes of setting and rapid hardening. The strength of the stone-like body is ensured 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 the solution

1. Filler

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 construction 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 has a special texture, it is possible to add sand with a grain size of up to 4 millimeters. In our market, customers are offered two types of sand: river and ravine. River sand is considered medium-grained, it is quite expensive, but its purity facilitates its use as a component for concrete mixtures. Gully sand can be fine-grained (from 0.5 to 1.5 millimeters), with a large number of clay particles and other impurities. It is not suitable for good and strong concrete, but for mortars it can be used without fear.

For lean (light) cement concrete with strength class B7.5, only sand can be used as a filler. In concrete of greater strength, in addition to sand, you can also use crushed stone or gravel with a diameter of up to 31.5 millimeters. It is considered correct to use a crushed stone mixture of different fractions in order to ready-mixed concrete contained a minimal amount of voids between the pebbles.

Attention! The aggregate of concrete and mortars should not contain pollutants such as soil, glass, pieces of wood, peat, plants, dusty or silty soil. If contaminants are present, they should be removed by sifting gravel or sand through a sieve.

2. Cement

Cement is a general name for binding powdery substances based on marly, calcareous and clayey rocks and various additives. The most commonly used type of cement is Portland cement, which takes its name from the British peninsula of Portland. This cement contains a large number 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 a 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 grade 500 Portland cement. As we have already found out, this characterizes type II cement. As for the DO designation, it characterizes type I cement, that is, a material without additives.

To prepare plaster and masonry mortar, you need to take cement of classes M400 (32.5) and M500 (42.5). Portland cement is ideal for preparing concrete mixtures that will be used at low temperatures (daily average below 10 degrees Celsius). If the temperature is high, for example, in the heat, then 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 making masonry and plaster solutions, used for fences and floors.

Attention! Cement can only be purchased in bags with appropriate markings. Immediately before purchasing, you need to check whether the cement is damp or caked. If all the signs are present, it is recommended to refuse the purchase. Only a trusted, reputable manufacturer who has been selling the solution for several years can guarantee compliance with the brand of cement stated on the packaging or bag. By the way, the main difference good manufacturer What makes it underground is not the cost of ready-mixed concrete, but the availability of a high-quality delivery service.

3. Lime

Lime is required for the production of cement-lime mortars. In addition, it is used to increase the workability of the solution. Today, to prepare solutions, it is no longer necessary to slak lime. Instead, you can buy slaked (hydrated) fluffed lime at a low price, which is sold packaged in bags in ready-made form. Alternatively, instead of a dry mixture, lime can be sold in buckets in the form of lime paste. 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, be extremely careful, since lime has strong corrosive properties. It is recommended to carry out work wearing protective gloves, remembering to ensure that the material does not get into your eyes or 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 contain 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 with a more liquid consistency. This solution is much easier to apply.
Thinning additives or superplasticizers can reduce the amount of water poured for mixing.

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

Certain additives allow you to accelerate the hardening of a concrete mixture or solution.

Also, there are additives that make it possible to carry out work in the temperature range from 10 degrees below zero to 35 degrees hot.

There are special additives on the market 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.

Typically, supplements are sold in plastic containers in liquid form. The packaging must contain information about dosage, quantity and basic properties. Additives in mass ratio should not exceed 2 percent of the total mass of cement.

5. Water

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

Composition and proportions

Before you start considering the question of how to prepare concrete or reinforced concrete, I would like to draw your attention to the fact that the composition and proportions will directly depend on its main purpose. That is, for the foundation it is correct to use strong, high-density concrete, while for pouring the fence you can choose lighter grades. Once you have decided on the ingredients, choose the right brand. In most cases, for imported concrete and mortars created by yourself, it is better to choose grades M300 or M400. As for proportions, the components “cement/sand/crushed stone” should be used in proportions of 1/3/5. This means that per 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 fillers. For example, if you have 100 kilograms of dry mixture, 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 apply great effort for stirring the solution with a shovel. For wet sand there should be less water. If work is carried out in the cold, the 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 devices/mixers and containers made by yourself. You can read what material and what components they consist of (pumps, molds, vibrating screeds, etc.) in another article.

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01. We obtain high-strength concrete in ANYONE region

02. We are nothing NOT sell

03. To you NOT will have to buy equipment

04. Concrete only from yours LOCAL components

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

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. Brought the grade of concrete to the incredible M2500
(having obtained the strongest mass-produced concrete in Europe)

02. Participated in exposing concrete in the Moscow City high-rises

03. Developed high-strength concrete for the Vostochny Cosmodrome

04. Wrote a dissertation on high-strength concrete

05. Candidate of Technical Sciences ()

06. Winner of international competitions in concrete science ()

08. Inventor (patent holder)

Abramov Dmitry Alexandrovich(director)

01. Introduced the technology at more than ten large factories 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?

In Russia absolutely
don't know how to 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)

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

Special products made of reinforced concrete- M600 (B45-B50)

Why is high-strength concrete sold at 2-3 times higher than cost?

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

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

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

Prices for concrete for Moscow City high-rises

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

How do we get the most durable concrete in the Russian Federation?

We "spied" on the Germans

We have worked for many years

over high strength concrete

As a result, they surpassed their Western counterparts

In which cities did we receive high-strength concrete?

Moscow - from M1450 (to M2500)

Ulyanovsk - M1200

Almaty (Kazakhstan)- M1200

Samara Region- M1300

Vladivostok - M1200

Yakutia - M1000

Republic of Bashkortostan- M1200

Chelyabinsk - M1300-M1400

Krasnoyarsk - M1300-M1400

Ekaterinburg - M1200

Penza - M1400

Vladimir - savings from 85 to 850 rubles. per cube

Naberezhnye Chelny- M1300

Kaluga - M1200

St. Petersburg - M1400

and others

Minimum 100,000 rub. per day
we save for our clients

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

The price depends on the degree of our involvement.

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

Unclear? Call us and we will explain

THREE WEEKS is average term from the start of working with us to the release of the first batch of high-strength concrete in your production.

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

What if it doesn't work out? If something doesn't 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: “Zhigulevskoe Sea” (6 min. drive to us)

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Siberian Marina Selivanova chose design as her profession - after two specialized higher educations she worked in interiors, advertising, event design, food design, etc. But one day the idea came to her about making jewelry, and not from traditional materials, and from... concrete. Marina Selivanova told the portal site about how much demand there is for accessories made from building materials and what are the nuances of their production.

29 years old, entrepreneur from Novosibirsk, founder of a brand of concrete jewelry. Graduated from Yenisei teacher training college(specialty “teacher of fine arts and drawing”) and Novosibirsk State University architecture, design and art (specialty “designer”). The accessories brand was launched in 2016. Single.

Combine the incongruous

When I figured out my higher education, then worked for six months in the field of interior design and graphic design. Now I still continue to receive such orders: I make business cards, banners. I also do food design and design events.

I didn’t have a goal to start making jewelry - just one day, as part of my design work (as well as the renovation of my apartment), I somehow took a new look at concrete. I liked its texture - uneven, interesting; In my apartment, I even left one wall concrete, without finishing. I decided that concrete could make something truly stylish and beautiful.

When it comes to concrete, many people immediately think of something massive and heavy. I wanted to make something light, small and unusual from this material. This is how I came to jewelry. In general, I really like this concept: comparing the incomparable, combining the incompatible. Concrete with gold is interesting. With minerals semiprecious stones and many masters work this way, but it’s great to find something of your own, your own style. A person carries himself in his work.

In my jewelry, I combine concrete with acrylic, copper, gold and silver leaf; I also use pigments in the concrete itself (in particular, black).

My brand Haf Maer has no translation. I had no intention of tying the name to anything. So I came up with this - simple and sonorous, a little reminiscent of Scandinavian motifs and Vikings. Besides, I didn’t come across such a name in hashtags on Instagram.

Sand in the art salon, cement in the construction store

Acquaintance with working tools occurred gradually. The first thing I purchased was sanding paper, needle files, files, then grinder(which I don’t use now because it’s big and it’s inconvenient for sanding small parts).

At first I worked without protective equipment, but later I realized: this is not worth saving on. I bought additional gloves, a respirator and special glasses. My dad gave me the drill. That is, I only needed 10 thousand rubles to start.

To begin with, I just started trying to work with a material that was new to me and poured concrete into some kind of cream lid. As planned, it was supposed to be a pendant. It turned out to be very large - 10 cm wide. I drilled a hole in it and that’s how I got my first pendant. Now, however, I don’t know where she is. But I would like to find and compare with current products: progress, I think, would be obvious.

It took me a lot of time to understand what components were needed for my author’s composition of the material. The fact is that I developed the technology for my concrete myself; it is not similar to construction concrete. I needed the material to become denser and harder. The concrete used for construction would crumble in my jewelry—especially the miniature pieces. It also absorbs moisture.

After six months of experimentation, I managed to develop a suitable recipe for my concrete. I won’t reveal the entire composition, but there is sand and cement (these are, in general, the main components of concrete).

I take pigmented, black sand, buy it in art salons and hand-made stores. I buy regular cement, in a 15 kg bag, at a hardware store. This amount is enough for a year. It’s unlikely that the sellers think that I need this bag for dozens of earrings and pendants, and not for repairs.

As a result, my jewelry, of course, can last a long time, thanks to the special composition of concrete. Unless you try really hard, it's hard to break them.

In the fight against allergies

In addition to concrete, production also requires forms for it - to make different elements of decoration and connect them. I either buy the forms or make them myself if I don’t find suitable ones on sale. They are filled with a composition that hardens within 24 hours. Thus, a simple decoration consisting only of concrete takes 24 hours to make. Complex decoration requires two days.

After hardening, the product must be processed engravers, grinding machines, drills and drill bits.This is a very dusty job, I do it on a separate table - so that concrete particles from grinding do not fall on those decorations that are currently in the process of drying.

We still need fittings. She's not with me today precious metals, this is a jewelry alloy. But now I'm switching to surgical steel, which does not cause allergies. In the process of working as part of the Haf Maer project, I was faced with the fact that many of us cannot wear costume jewelry due to allergies. In general, there are accessories in Russia big problems– you can’t really let your imagination run wild if you want some interesting additions to the concrete (and I would like this in many models).

Usually accessories for jewelry self made They order from China, but the quality there leaves much to be desired. Good suppliers in Korea and the USA. My new supplier for surgical steel is from Russia. It also cannot offer a wide selection of shapes of clasps, chains, etc. – but in this case, for me, of course, hypoallergenicity is a priority.

Looking for clients

I started in my apartment, but in last month I work in the workshop. We are filming it together with a friend who sews bags. Between us we have 30 square meters, and since there are no other employees besides ourselves, this is enough for now. We also have one individual entrepreneur for two. Today, working with Haf Maer takes up 50% of my time.

For sales, the first thing I did, of course, was create Instagram page. At first I just gave away my jewelry. Including, when I worked as a designer at some events, I made presents for guests from it. Then I gave a few pieces by barter to small bloggers: that is, I give them jewelry, and as a return courtesy, they write about my brand in their profiles. So big money I haven’t invested in my promotion yet. I also participated in markets in Novosibirsk, where I presented my products and gradually met new clients.

And then, towards the end of 2018, girls themselves began to contact me. Now in the city I am already better known as a jewelry designer than as a designer of anything else. My target audience is women 20-40 years old; they are united only by some kind of affiliation or commitment to creativity and style. By the way, such a range in age surprised me: I was more likely counting on young people.

The most interesting and at the same time difficult order for me were earrings for my mother for her anniversary. She doesn’t have pierced ears, so I made special clips (so now we have this option in our line). As a result, the earrings suit her very well, and I... Once again I was convinced how jewelry can transform a woman.

I’m also especially interested when, for example, a girl wants asymmetrical earrings. And together we look for shapes that will go well together and put together a set.

Often people don’t even pay attention to the fact that my jewelry contains concrete. For them it is paramount general form decorations. It's funny that in last time A girl who works in a hardware store ordered a ring from me - and I was very intrigued by its composition.

A year ago I was selling a couple of pieces of jewelry a month. Today I sell 15-20 a month. And on the market I can sell 15-20 pieces in one day. The cost of my jewelry is 1-2 thousand rubles. I am sure that sales will grow and this business will bring me significant income.

Today my jewelry is sold in Moscow (in a showroom with clothes and accessories), Yaroslavl (in a beauty salon) and Irkutsk (in the Bonstein Gallery). They found me themselves, which is interesting, and offered to collaborate. But mostly my sales are on the Internet and in two Novosibirsk points (a showroom and an art space).

Basically I work to order using models that I have already developed. Fully individual orders I usually don't take it. The difficulty is that then in each case you will have to make a separate mold (and people are usually not willing to wait an extra week). Plus it’s irrational - then you don’t know what to do with all these forms.

At some point I began to wonder if someone somewhere was creating similar jewelry. I found those who make decorative items from concrete (pots, stands, etc.) - including those who also make jewelry. But they work with regular gray concrete, and the style is completely different. I wouldn’t want to scale my project this way in the future. Rather, I will come up with some other unusual material.

My competitors are other masters who work with the most different materials. For example, in Krasnoyarsk a girl pours jewelry out of epoxy resin, they are also made of wood, etc. I began to notice that sometimes they even take jewelry models from me and repeat them. I haven’t thought about a patent yet, but it’s probably worth doing one.

In the future, I would like to open something like a showroom-workshop. I would also like to switch to jewelry metal (silver).

I’m unlikely to ever have million-dollar sales, since concrete is a specific material. However, the potential is there. So I plan to invest in advertising. There is an intention to expand the number of its representatives in other cities.

I like to create new things and the fact that you can put an “equal” sign between my business and me: concept, idea, brand philosophy H af Ma er is me. And there are people who understand and appreciate this. This is why I continue.

Concrete grade

Concrete class

Waterproofness of concrete

Frost resistance of concrete

Mobility of concrete

Choosing concrete for the foundation

Concrete has held the leading position among building materials for many years in a row. It owes such popularity to its unique performance 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 makes it possible to use it in almost any conditions. The question of choosing suitable concrete remains the most important and difficult, because the further properties of the structure depend on this.

It is equally difficult to choose a suitable concrete manufacturer. Growing demand for this construction material led to the emergence huge amount proposals that are quite difficult to navigate. To potential buyer concrete was able to quickly find the optimal offer for himself, the concrete tender system “M350” was developed. It is presented on the page http://m350.ru/price/m350/ and allows the user to quickly familiarize themselves with all offers for the sale of M350 concrete and other brands in the Moscow region and choose the most suitable one for themselves, based on price, plant location or operating mode manufacturer. The system allows save time and money.

To be able to choose the right concrete mixture for specific purposes, you need to know what indicators to pay attention to. 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 grade

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 laboratory conditions, 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 is M200. Simply put, the digital index indicates the number of kilograms that can press on 1 cm2 of concrete without destroying it.

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

The quality of the components also plays a role. Sand can be either river or quarry sand– it is important that it be large and with minimum quantity clay impurities. Optimal size crushed stone - 20-25 mm, it must be made of strong rocks. The grade of cement also affects the strength of concrete. As a rule, M400 and M500 cement is used; less of the latter will be needed to prepare concrete of a given strength.

The least durable grades of concrete are used in the construction of the lightest and least critical structures. Foundations of private and multi-storey buildings, industrial buildings created using more durable compounds (M200 and higher). As strength increases, the price of the composition also increases, so there is no point in using overly strong compositions, nor is there any need to save money.

Concrete class

The class of concrete also indicates the strength of the material, this modern derivative of concrete brand. If, when determining the grade, the average value of the strength of the material is used, then the strength class involves determining the strength with guaranteed security. It's more exact value, which is expressed taking into account the coefficient of variation of 13%. Despite the fact that the class more accurately defines the characteristics of concrete, today most experts use the concept of grade.

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

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

Waterproofness of concrete

The waterproofness of concrete refers to its ability not to allow water to pass through. Previously, this characteristic was denoted by the Russian letter B, now useW, and the numerical designation next to it may begin from 2 to 20, equal to the pressure of the water column in kgf/cm2, at which a cylindrical concrete sample standard height does not allow water to pass through.

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

Has the highest levels of waterproofness and water resistance hydraulic concrete. For its production, hydrophobic or plasticized Portland cement, sand and crushed stone are used. High Quality than for ordinary concrete. High levels of water resistance are also achieved through installation with maximum compaction.

Frost resistance of concrete

The frost resistance of concrete is indicated by the letter FWith numerical value from 25 to 1000: the higher it is, the greater the number of freezing and thawing cycles 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 climate, the number of periods of freezing and thawing during the cold period of the year.

For the construction of hydraulic structures, airfield pavements and bridge supports, it is better to choose the most frost-resistant compounds. In private construction, concrete class F100 or F200 is suitable for constructing 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) indicates degree of its fluidity, which directly affects the ease of working with the composition. The numerical coefficient is expressed in the range from 1 to 5: the higher it is, the more liquid the composition will be. In private construction, concrete is used for foundation construction. 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.

It is, of course, 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 grade of the solution is immediately reduced, reducing the final strength.

Areas of use different brands concrete

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

Choosing concrete for the foundation

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

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

Affects the choice of concrete grade and soil type. The more heaving the soil, the big differences the load is placed on the foundation. Yes, 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 in the place where the house is built 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 finished design The correct dilution of the mixture with water, as well as the process of filling the mold with concrete and the uniformity of concrete distribution also largely influence.

• Date: 20-11-2014
• Views: 1709
• Comments:
• 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 many decades?

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

What do you need to know and take into account so that concrete for any purpose lives up to expectations?

Basic Concepts

Classically, concrete means a mixture of the following components:

1. Cement is the connecting link that turns the components into a monolith.
2. Sand is the basis of strength and filler of small voids.
3. Aggregate - this 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 the 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 changes 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 a foundation base, 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 strong, it is important to understand all the components. The effectiveness of the work will depend on their quality.

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Cement is the basis

Cement is the main and most important ingredient of the composition called concrete. It provides linking of additional components.

The ideal option for preparing durable concrete is Portland cement. Due to the high content of calcium silicates, it provides ideal adhesion (cohesion) of materials. An additional advantage of this material is that it can work at lower temperatures, but this advantage should not be abused. Preparing the mixture and pouring it at temperatures below +16ْ°C will negatively affect the quality. If there is a need to carry out work in a cold climate, it is imperative to use special plasticizers. For working in warm weather summer period Portland slag 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 sufficiently light and strong, you should choose a material with an index of up to D 20.

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

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

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Can't do 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 the sand be like in order to?

1. Clean. This is one of the most important characteristics. Foreign impurities, especially plant origin, will decompose in the thickness of concrete, reducing its strength. If the sand was purchased clogged, it must be sifted. Even if it takes time, 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 to ensure 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 thoroughly wash and then allow the sand to settle, but this is labor-intensive, especially at home.

In some regions, far from large rivers, you can find so-called stone or rock sand. It is crushed to required fraction rock. When using such material, you need to take into account that it is much heavier than ordinary sand, which means that its use will not allow you to obtain lightweight concrete, which is especially important when installing interfloor ceilings.

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What should a quality filler be like?

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

1. The filler must be clean. As with sand, you need 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; it is this that ensures high adhesion. For this reason, you should avoid using pebbles.
3. The optimal fraction is from 8 to 35 mm, the rule of uniformity is maintained. But in case 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 tampers.
4. In order to obtain a lightweight but very durable casting material after hardening, it is recommended to use expanded clay.

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

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What about water and other components?

So that concrete is strong and lasts long years, 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 strong and lightweight concrete.

In addition, various components are often added to the solution, changing the properties towards improvement.

1. Plasticizers. These are special compositions that allow you to change the properties of concrete. With their help, you can reduce the need for water, adjust fluidity and plasticity.
2. Lime. It is usually added to simplify working with concrete, which is especially important for delicate manipulations. This is an optional component and use is at the discretion of the artist.
3. Corrective components. With their help you can make concrete resistant to low temperatures and other aggressive conditions. Moreover, if work is carried out outside the permissible temperature limits, the use of such means becomes mandatory.
4. Reinforcing additives. As a rule, PVC sheeting is used; it is soft and not very strong, but when placed between layers of screed, it successfully protects concrete from tearing and cracking. With its help you can make it quite durable, but at the same time time is easy layer.

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

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Correct ratio of components

So, the high-quality 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.

To fill, you need coarse crushed stone and enough liquid concrete good fluidity. This will fill all the voids. But before pouring, it is recommended to install a substrate of low grade cement; the consistency of the material should resemble moist soil.

The most common proportion is 1:3:6, respectively, cement, sand, aggregate and up to 1 part water, depending on the need and type of structure. But this relationship 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 determination of the ratio of components. It is necessary to use the same dishes and make adjustments if necessary. Otherwise, the error will definitely make itself known, but at a time when it will no longer be possible to correct it.

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Mixing ingredients

The process of mixing the components is no less important. Inhomogeneous concrete not only causes difficulties during pouring, but also changes the ratio of 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 people offer this service construction companies. The concrete mixer must be installed at a minimum distance so that the concrete does not have time to harden during transportation - this is contrary to the technological process.

You can make high-quality concrete the old fashioned way, by mixing it in an old trough. But in this case, you will have to put in 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 ensure high-quality and fast enough access of liquid to the lower layers, and this can upset the proportion. When mixed for a long time, 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 its drawbacks, but it is still preferable, especially when preparing a small volume of solution.