When buying cement, many of us know very little about this building material. As a result brickwork, the foundation and mortar screeds are of poor quality and crack under the influence of load, frost and groundwater.
Ignorance of application specifics various types cement, its grades and characteristics lead to excessive consumption of this material.
Untimely use and improper storage lead to damage and loss of investment.
In order to confidently navigate when choosing cement for repairs, landscaping or new construction, let’s take a closer look at its classification, as well as strength and price indicators.
Cement is a powdered building material consisting of a binder base - clinker, filler and modifying additives. Upon contact with water, it turns into a plastic mass called cement paste. When hardened, it turns into a durable stone.
Unlike other binders (gypsum, lime), all types of cement harden and gain the necessary strength not only in air, but also in water.
The main characteristic of any cement is its brand. This is a digital designation of its strength in the solid state, expressed in kg/cm2. The grade is determined in accordance with GOST standards by testing samples for bending and compression after 28 days of exposure. Rapid-hardening types of cement are tested for strength 3 days after preparing the solution.
Brands of this group of binding materials are designated in numbers from 100 to 900(in increments of 100 or 50 kg/cm2). Today, cement grades below 300 are not produced. The most popular on the market are M400 and M500. High-quality cements (from M600 and above) are used in military, mine, airfield and hydraulic engineering construction.
When buying a bag of cement in a store, you will see on it not only the brand designation, but also other abbreviations, the meaning of which we will now explain. In the retail network, Portland cement is most often sold, marked with the letters - PTs.
To regulate the setting speed, increase frost resistance and water permeability, special additives are introduced into the cement composition. They are designated by the letter D, after which the percentage of additives is indicated (0, 5, 10 or 20%). For example, Portland cement grade 400 with 20% chemical additives is labeled as follows: PC 400 D20.
Slag Portland cement
In addition to Portland cement, Portland slag cement is used in construction. In addition to clinker, granulated blast furnace slag is added in an amount of 30 - 65% of total weight.
It is marked with the letters ШПЦ and differs from Portland cement in several important parameters:
- resistant to soft river and aggressive sulfate groundwater;
- low resistance to low temperatures;
- gains strength slowly over the first 4 weeks;
- Withstands high temperatures (from +600 to +800 C) without reducing strength.
Listed specifications cement using slag allows us to draw two important conclusions: it should not be used to make concrete that will be used at low temperatures or subject to periodic freezing and thawing.
In the cold season, it is better to use it for preparing mortars and concrete laid in heated rooms, and to use it for open work in the summer.
The light shade of Portland slag cement allows it to be used for preparing decorative mortars, saving on the purchase of expensive alkali-resistant dyes.
An important advantage of cement based on blast furnace slag is the low rate of loss of activity. Therefore, it can be stored longer than ordinary Portland cement.
The beginning of setting (hardening) for this cement occurs 3.5 hours after preparing the solution, and ends after 6 hours (air temperature +18 - +22C). By this time, the solution loses its plasticity, and any mechanical impact on it leads to irreversible destruction of the cement stone. With ordinary Portland cement, the setting process ends after about 2 hours.
Special types of cements
Since cement is used in all industries construction production, there are many varieties of this binder.
The most famous of them are:
- Rapid hardening Portland cement, abbreviated as BTC. It gains 60% of brand strength within 3 days and is used for high-speed construction;
- Sulfate-resistant cement (SSPC) used for massive foundations that experience the destructive effect of sulfate groundwater (dams, piers, breakwaters);
- Cement using surfactants. If an additive is introduced into the composition that improves the plasticity and workability of the mortar, then the cement marking contains the letters PL. To reduce water permeability, a hydrofibizing substance is added, and the letters GF are added to the marking;
- Portland cement cement. Used to isolate boreholes from groundwater penetration.
- Waterproof Expanding Cement. Denoted by the letters VRTs. It has a very high density and is used to seal cracks in reinforced concrete structures, waterproofing water pipes and mine structures;
- White (BC) and colored cements. They are used for the preparation of decorative concretes and mortars used for laying facade and facing bricks.
The cost of this material depends on its brand and type. In addition, the final price of cement is influenced by the reputation of the manufacturer (brand).
The price of one bag of Portland cement grade 500 (weight 50 kg) that does not contain additives (PTs M500-D0) ranges from 200 to 250 rubles.
Cement with additives is slightly cheaper. A 50-kilogram bag (M500, 20% additives) will cost you from 190 to 220 rubles.
A standard bag of M400 cement from different manufacturers costs from 160 to 190 rubles.
Prices for domestically produced white cement M500 start at 390 rubles. Turkish white cement M600 D0 (50 kg) is significantly more expensive. Its cost ranges from 540-570 rubles.
Consumption rates
When answering the question of how much cement is needed per cube of concrete, you need to take into account its brand and the required structural strength. The release date is also of great importance, since this type of binder loses activity over time and is very sensitive to storage conditions.
Practice shows that it is more profitable to buy cement of a higher grade, since to prepare concrete or mortar of the same strength, it can be taken 15-20% less than low-grade cement.
For example, the cement consumption per 1 m3 of mortar of the “three hundredth” grade is: M500 - 500 kg, and M400 - 600 kg. To prepare one cubic meter of M200 concrete, you need to buy 400 kg of M500 cement or half a ton of M400 Portland cement.
To simplify the calculation of the composition of concrete or mortar, you can use the following formula: for structures that do not bear a large load (paths, floor screed, plaster), a ratio of M500 cement to sand of 1:5 is sufficient.
For foundations, floors and other critical structures, the proportion should be 1:2. For tub mortars, a ratio of 1:4 is usually used.
Deciding for yourself which cement is better to choose, remember that the date of its release is no less important than the brand. Even if all storage conditions are met, it loses about 10% of its activity every 30 days. This means that if 3 months have passed since the date of manufacture, then instead of the M500 you will buy the M350.
If the cement has been in the warehouse for six months, then its grade will not exceed 200 kg/cm2. It is unrealistic to make a high-quality solution, much less durable concrete, using such material. Therefore, before purchasing, ask the seller for a document that clearly indicates the date of manufacture.
“Cement is different from cement.” This obvious statement acquired a negative connotation after a recent raid by an independent commission from the Consumer Society of St. Petersburg and the Leningrad Region on construction hypermarkets in St. Petersburg. As a result of the inspection, it turned out that no more than 10 percent of packaged cement complies with Russian GOST standards. It is logical that at the height of the season, construction hypermarkets offer a fairly large selection of cement. The average consumer often has the question of which cement to choose.
It is not so easy to find high-quality cement, because of the 20 varieties of cement that were tested for quality, the vast majority are packaged in the same type of gray bags, without any “identification marks.” No reliable information necessary for the consumer was found on the product. In this article we will try to determine what high-quality cement should be and provide tips that will help distinguish high-quality cement from a fake.
What information should a buyer have to choose a good cement? The instructions provided by the Consumer Society of St. Petersburg and the Leningrad Region will help answer this question.
Which cement to choose: Step-by-step instructions
2. It is necessary to decide between producing countries.
The choice in favor of domestic manufacturers may be the only correct one, since they are located on the same territory as you, which allows you to make possible claims directly.
On the contrary, it is practically impossible to make claims to a foreign manufacturer. Meanwhile, there are plenty of reasons for lawsuits. Imported products arriving at Russian market, sometimes, so to speak, not always fresh. The reason is that paperwork and delivery of the goods themselves take a lot of time, and for cement this fact can be disastrous. Stale cement quickly loses its properties, thereby increasing its consumption several times.
3. Now we carefully examine the packaging. Cement, which is packaged in bags by the manufacturer, must indicate its weight. Standard factory packaging is designed for 25 and 50 kg. High-quality cement will be packaged in four-layer (or three-layer) paper bags in accordance with GOST 2226, glued (or stitched) with a valve of the NM, BM, BMP brands with a closed neck - this is a mandatory requirement for any factory packaging.
4. Read and evaluate the information on the packaging. It must indicate all the characteristics of the cement and information about its manufacturer.
Ask for certificates and quality passports. They must be available from the seller. Otherwise, you may become a victim of scammers who use all sorts of tricks for their own benefit. In particular, many of them mix different brands of cement. But this is not so bad - along with the cement in the bag, you can find substances of unknown origin, or you may be missing several kilograms of the total weight of the cement. Remember! The packaging must be marked and contain the contact information of the manufacturer or organization that packaged the cement.
5. We evaluate the brand of cement. The grade of cement is one of its main characteristics and is used to indicate strength. The higher the grade of cement, the stronger concrete structures, obtained on its basis. This is an axiom.
When buying cement, you need to pay attention not only to the marking itself, but also to ensure that it is affixed in accordance with GOST. So, if the cement is certified according to the current GOST 31108-2003, the marking for high-quality cement, in this case, will be CEM I 42.5. For additional cement - CEM II/A-Sh 32.5. According to State Standard 10178-85, such cement is marked PTs500 D0 and PTs400 D20. For cement with a fast-hardening variety, the letter “B” is displayed, and the letter “N” is indicated for a normal-hardening variety.
6. We are asking the price. Of course, the desire immediately arises to choose a cheaper product. However, low cost is usually synonymous with low quality. This fact is especially important if you buy cement specifically for high-strength and durable structures.
What makes the price low? Firstly, the price of cement can be reduced by adding various admixtures. This is ash, granite dust and other materials that look like cement, but only in appearance. In fact, these are nothing more than ordinary thinners. The use of such cement can lead to serious defects that will appear in a particular building over time. Secondly, some suppliers reduce prices by saving on transport and storage. As a result, such savings inevitably lead to a decrease in the quality of cement. Let's look at what makes up the price of cement:
a) Brand of cement. The higher it is, the more expensive it costs.
b) Scope of application. Special cement is always more expensive than general construction cement.
c) Form of sale. Bulk cement is cheaper than bagged cement.
7. Please pay attention to the date of packaging. It must be remembered that the longer a bag of cement is in a warehouse or store, the worse the quality of the product.
60 days is the shelf life of cement established by GOST. It should be noted here that there is no requirement in GOST for mandatory indication of the date on the container. Naturally, no one voluntarily indicates the date. The accompanying documents indicate the batch number of the goods and its characteristics.
Also, you need to be extremely careful when purchasing goods in bulk. You should be sure to check the expiration date of each package. It is important to find out from the seller all the conditions for storing the goods. Better yet, check these conditions by personally verifying that the cement was stored under normal conditions. To do this, simply probe the bag from different sides. If it is soft, without suspiciously protruding hard lumps, the goods can be processed.
Typically, low-quality cement is most often sold at the height of the construction season, and not only in large construction stores and hypermarkets. There are many who want to make money on our trust. Therefore, our advice to you: purchase cement only from trusted places. You can only be guaranteed that you have purchased a quality product if:
a) cement is sold in branded packaging.
b) the goods were packaged at a cement manufacturing plant.
And lastly, to make sure the quality of the product is 100 percent, take one bag “to try” in order to eliminate possible financial losses in the future.
The basis for any construction is the foundation. The quality and durability of the building directly depends on what materials are used for it. If you make the wrong choice, cracks will soon appear on the building, the walls will begin to move apart and sag. In this case, it is important to know which cement is best for the foundation so that the structure can withstand any load.
When choosing, you need to rely on several basic conditions. It is worth considering the type of soil in which the work is carried out. Be sure to take into account the height of the future building. In extreme climates, a special brand of cement for the foundation is also selected.
General physical criteria
You need to understand that foundation cement is a binding material. The manufacturer offers this product to consumers in powder or lump form. In the process of contact with water in a set proportion, the mass loses its plasticity and becomes hard. Fixation occurs on average after 7-8 hours. Next, the mass gets rid of excess moisture.
Materials such as clay, gypsum or lime have similar binding properties to cement, but to a different extent. In certain cases they are added to concrete mixtures.
Since 2003, the current GOST concerning cements has been in force. It implies a standard classification according to the name.
The most popular is Portland cement. It is necessary to select which brand of cement is needed for pouring the foundation not only by name, but also based on the markings. In the context of the construction of private houses or buildings, brands from “one hundredth” (100) to “seven hundredth” (700) are relevant.
The brand of cement (numerical designation) indicates how much weight in kilograms a square centimeter of hardened mortar can withstand.
The best brands of cement for foundations
On the packaging, the manufacturer indicates the brand in large font. Most often it is expressed by a letter and a three-digit number. To figure out which brand of cement is best for the foundation of a house, you need to understand the meaning.
The cement grade M400, for example, means that a square centimeter of surface can withstand a load of 400 kg
Using the value “M100” as an example, let’s look at these symbols. “100” in this case corresponds to the maximum permissible load in kg per 1 square cm of area. A higher value will lead to destruction of the material. In this case, concrete is prepared from cement and sand in a ratio of 1:3.
When solving the problem of which cement is best for the foundation of a house, pay attention to the number of floors. For low buildings, brands ranging from M200 to M400 are relevant. Materials with more powerful values can also be used. They will also provide a powerful base.
When using denser grades for low-rise buildings, the proportion will be smaller - 0.5-0.8:3 in relation to river sand. The result will be similar.
What kind of cement is needed for the foundation can be decided by the owner himself. Either take a larger mass of low grades, or purchase a smaller mass with higher strength values. In the second case, the physical consumption of material will be obviously lower.
The most popular brand of cement for foundations is M400, but the M500 material is almost as good as it. The use of higher values or the use of pozzolanic grades is in demand when constructing buildings under special conditions, for example, when water resistance is required. These parameters include significant moisture from groundwater located close to the surface.
VIDEO: How to choose cement
When are slag centes used in foundations?
For certain areas of the country, when choosing which cement is best for the foundation of a house, you should give preference to Portland slag cement or pozzolanic type. They contain as additional materials some slag, gypsum, etc. They provide excellent protection against fresh and mineral waters.
Slag cements differ from ordinary cement in the following characteristics:
- has a lower cost;
- has a lower degree of deformation;
- releases less heat during hardening;
- resistant to sulfate water.
The disadvantage is lower frost resistance compared to classical types of cementitious building materials. It takes quite a long time for complete hardening to occur with an increase in strength, up to several months. In this case, preference is given to their fast-hardening varieties.
To understand what kind of cement is needed for the foundation, you need to carefully study its parameters indicated by the manufacturer on the packaging. CEM I of all varieties has no additional components.
Based on the rate of hardening, the material is divided into two groups:
- normally hardening (N);
- quickly hardening (B).
The possible load is described in GOST 31108 2003. Compressive strength is differentiated by classes: 22.5; 32.5; 42.5:52.5. An example of marking according to this standard is the designation: TsEM I 42.5B GOST 31108-2003. This will be a fast-hardening class of Portland cement.
You can also find an older gradation (GOST 10178-85). According to it, the manufacturer designates its products as follows: PC400-D20-B. “Four hundredth” grade with mineral impurities of about 20%, and the class quickly hardens.
VIDEO: How to make concrete - proportions of ingredients in buckets
Making the right choice
If pure cement is needed, then you should choose by name, for example, M 500 D 0. “Zero” after “D” means the absence of additives in percentage terms. It is important to take into account the date of manufacture, since most often bulk material is produced in paper bags and certain conditions must be observed during its storage.
If you have doubts about the quality of the cement, you can touch it with your hands through the bag. It should not be a monolithic piece, but must always be free-flowing.
When a material has a certain degree of fossilization, it is not recommended for use in critical applications. Any lumps and clogged areas can be easily identified through the paper. Such material cannot be used in the foundation.
During the pouring process, the ambient temperature must be taken into account. The lower it is, the longer hardening will take.
High-quality cement has positive characteristics:
- sulfate resistance;
- frost resistance;
- water resistance;
- strength;
- anti-corrosion.
A five percent addition of gypsum helps manufacturers increase the transportability of the finished mixture. The prepared solution can be transported in a concrete mixer to the place of use without worrying that it will have time to harden ahead of time.
It is worth considering the amount of water poured into the mixture. When preparing it yourself, cement and water are taken in approximately equal proportions. The amount of crushed stone or wedge does not affect the proportion of sand and cement.
In civil one-story construction, the M400D0 grade is often used for concrete with crushed stone. It hardens quickly and tolerates temperature changes well. If you intend to insert from reinforcement, then you can use M400D20. It has increased moisture resistance. In a two-story building, you can choose the more durable material M500D0 or M500D20.
The quality of the finished product and the hardening time are affected by the degree of grinding.
Do right choice possible by taking into account all factors, which include the total mass of the building, the presence of a basement or ground floor, able to withstand groundwater. The hydraulic component of the area can be identified in the spring-summer period, starting with the melting of snow. In winter, their level drops significantly.
For sandy soil, you can save money by choosing less expensive brands, for example, M200 or M250. They are able to withstand buildings in dry climates. For loamy and clayey soils, it is worth choosing a higher grade.
The influence of foundation type on the choice of cement grade
Full strength characteristics Portland cement collects after preparation for a month. In domestic conditions, it is used to fill foundations located deeper than the groundwater level. The disadvantages of the M 400 brand include the presence of shrinkage.
Adding plasticizers to the finished mass of cements can increase their pliability and plasticity. Such additives increase the ability of the mass to penetrate into all voids. Concrete with optimal physical parameters can be obtained with less labor in a concrete mixer. It can also be ordered from companies specializing in the production of such mixtures.
VIDEO: Mistakes of an inexperienced self-builder when self-construction foundation
Cement (mortar) is an indispensable material in construction with excellent astringent characteristics. Today, not a single building of a house can be completed without the construction of a foundation.
If you correctly calculate the proportions of the solution, you end up with a monolith for your home that can withstand heavy loads. Read below about how to choose the right cement for the foundation of a house, how to calculate the quantity in order to prepare a high-quality solution.
- Mortar M400 and PC400 (D20) are optimally used for small-scale construction. This option - great combination cost and quality.
- PC400 (D0) is no different in characteristics from the previous one, but in this case the absence of additives will allow the solution to be used for the foundation of a house on wet and frosty soil.
- Brands M500 and PC500 (D20) are perfect for building foundations for multi-storey buildings, supermarkets, warehouses and other industrial buildings. The type of soil in this case does not play a special role.
- PC500 (D0) - correct calculation is important, since this solution is used for industrial purposes, in areas with wet soil and in regions with an unstable climate.
It's not enough to know what cement is better for the foundation and how much is needed, it is also important to correctly calculate and select fillers.
For the solution to be stable, the sand must be clean. The use of impurities, and even with incorrect calculations, can negatively affect the quality of the foundation as a whole.
Helpful advice. To check the quality of sand, you must do the following: pour some of the material into a container with water for a day. After the time has passed, check the condition of the water. If it becomes cloudy, then such sand is not suitable for the production of a foundation.
As for gravel, it is necessary to take into account that it the choice depends solely on the type of construction.
If you plan to build a one- or two-story building, then the diameter of the gravel should be about 0.8 cm. In the case of a reinforced foundation, it is necessary to use finer gravel - approximately 0.3 cm.
1.2 Brand and class of concrete - what's the difference? (video)
2 How to check the quality of cement?
Foundation cementation- This is a very important stage in construction. Here it is important not only to know how much gravel or sand to use, but also to use only high-quality cement. How to do this if there is no manufacturing date on the packaging? In this case, a prerequisite is a quality check, that is, you need to check how soft the consumable is.
Tap the bag: if the building material has been in the warehouse for a long time, you will immediately feel how hard and petrified it is. It is advisable to start checking the quality from the corners, since these are the areas that are problematic and harden more often.
Look at the contents of the package. Any specialist will tell you that cement should be gray in any shade, from the lightest to the darkest. If the building material is fresh, then it will be more fluid in its structure, that is, taking a handful of cement in the palm of your hand, it will quickly “flow” down your hand between your fingers.
When you try to squeeze the cement in your palm, you get a lump that will also quickly crumble when exposed to it.
But if you notice that lumps have formed in the bag, which disintegrate without problems when compressed, then such cement is not the first freshness, it is better to look for a fresher option.
But if the lumps disintegrate only with increased impact on them, and at the same time they form hard grains of sand, then this material is not of high quality. Use these recommendations wisely.
2.1 We evaluate the quality of the composition
We have figured out how to make the calculation and how much sand and gravel is needed to mix the solution, now let’s move on to the question - how to evaluate the quality of the composition? To do this, we will need to conduct an experiment. To do this, follow these steps:
- Prepare a small container in advance, buy mineral water containing sodium bicarbonate. It can be “Essentuki” with any number or “Borjomi”.
- Open the bottle for a few hours, you need to wait until all the gases are completely released from it.
- Add a handful building material into a container and stir it with water. This should be done in such a way that the result is a cake, like a dough mixture, with an approximate diameter of about 15 cm. It is advisable to make the edges thinner, and the middle should be thick.
- This is where the most crucial moment begins. Wait about 10 minutes and watch the cake. If the cement is of high quality, then it will harden within this time. At the same time, the central part will heat up, you will feel it. Color may vary slightly it may acquire a blue-green color (but this indicator alone cannot be used as a guide).
If the cake does not begin to harden within the next half hour, this indicates that the material has already lost its astringent characteristics and there is an excessive amount of foreign impurities in it. The use of such material is allowed, but keep in mind that it may cause certain problems, such as cracking, lack of heating properties, uneven hardening.
The requirements for the binder when preparing concrete for pouring or assembling a foundation are high: the cement must have the correct strength grade, be suitable for reinforced concrete structures, be fresh and of high quality. Much depends on the type and weight of the building; for the foundations of residential buildings, PC M400 is considered the minimum; for temporary and lighter ones, a reduction in requirements is allowed. Checking the certificate and expiration date is mandatory in any case; preference is given to cement produced no later than 3 months; the material is not purchased in advance. Important technology standards include precise adherence to proportions, preparation and correct sequence of loading components into the mixer, and compaction of concrete after pouring.
Preference is given to Portland cement; concretes with it have the necessary strength and resistance to external influences. The choice of brand for foundations directly depends on the type and purpose of the building composition being mixed. To fill the drainage base, it is allowed to use cement with a low strength grade (the final concrete is from M75 to M150), in all other cases the rule applies: the grade of binder must be twice as high as the expected grade of the concrete mixture. Taking into account the minimum allowable for foundation structures M200, the solution is mixed with Portland cement with a strength of M400 (about this brand of cement).
The maximum proportion of foreign impurities in the binder is 20%; their introduction reduces the cost, slightly reducing frost and water resistance. As a result, suitable types of cement for pouring a foundation include:
- PC M400 D0 – can withstand loads of up to 400 kg/cm2 after curing, providing good durability, water resistance and frost resistance. Concrete based on it perfectly tolerates low temperatures, contact with ground and atmospheric moisture and exposure to aggressive environments. Cement M400 D0 is suitable for any type of foundation, including reinforced and prefabricated (it is used for mixing masonry mortar).
- PC M400 D20 - combining fairly good resistance to moisture and freezing and a reasonable price. The best option for the construction of foundations for light residential buildings in the absence of serious soil requirements.
- PC M500 D0 is recommended to be chosen when constructing critical objects; this brand consists only of cement clinker, the share of foreign additives (in this case, gypsum) does not exceed 1%. This has a positive effect on frost and moisture resistance; the variety is considered elite. Its use when mixing concrete for the foundation will pay off economically during construction in problem areas (in particular, flooded ones).
- PC M500 D20 is a similar brand of cement to the previous one, slightly inferior in terms of resistance to moisture and freezing (but not in strength), but in its characteristics it still surpasses M400.
Slag or pozzolanic based cements withstand the effects of sulfates dissolved in ground moisture well, but for laying monolithic or prefabricated foundations it is better to choose a different type. The main reason is the slow development of strength and low frost resistance. As a result, their use is permissible only on the recommendation of professionals and with the adoption of additional measures to protect foundation structures from frost heaving of soils. If there is the slightest doubt, it is better to choose Portland cement without impurities or specialized brands:
- B is a fast-hardening binder, which is recommended for limited work periods.
- PL is a plasticized variety with increased frost resistance. Its introduction allows you to save up to 8-10% of cement, but it is important to remember that it cannot be used with any other types except PC.
- SS – special sulfate-resistant PCs.
- NC – tensile cement. Concrete based on it has a compacted structure after hardening, preventing moisture from entering. NC is recommended to be chosen when laying the foundation of a house with a basement or erecting a monolith on flooded soils. They are also well suited for repairing and restoring existing structures.
Cements below M400 are allowed to be used in the construction of bathhouses and light panel or wooden one-story buildings on dry and stable soils. To eliminate mistakes, they start from the grade of concrete; when selecting it, they must take into account such criteria as the expected weight load (weight of load-bearing structures, including the foundation itself, roofing system, snow cover and objects in the house) and soil parameters (level of freezing, rising water, structural composition and soil homogeneity), timing of filling and hardening conditions.
Cooking proportions
The minimum acceptable grade of concrete for pouring a foundation is considered to be M200 (more is better); when concreting the foundations of residential buildings within 1-2 floors, M250 is most often chosen. The recommended proportions of components when preparing the M250 solution are 1:3:5 (cement, sand, gravel or granite crushed stone, respectively). The W/C ratio does not exceed 0.65, it depends on the expected grade of concrete: the higher it is, the lower the volume of introduced water, minimum 0.4.
| Concrete grade | Ratio (C:P:SH) | Volumetric composition per 10 liters of cement for sand and crushed stone, l | Concrete yield per 10 liters of cement, l |
| PC M400 | |||
| M100 | 1:4,1:6,1 | 41:61 | 78 |
| M150 | 1:3,2:5 | 32:50 | 54 |
| M200 | 1:2,5:4,2 | 25:42 | 64 |
| M250 | 1:1,9:3,4 | 19:34 | 43 |
| M300 | 1:1,7:3,2 | 17:32 | 41 |
| M400 | 1:1,1:2,4 | 11:24 | 31 |
| M450 | 1:1:2,2 | 10:22 | 29 |
| When using PC M500 | |||
| M100 | 1:5,3:7,1 | 53:71 | 90 |
| M150 | 1:4:5,8 | 40:58 | 73 |
| M200 | 1:3,2:4,9 | 32:49 | 62 |
| M250 | 1:2,4:3,9 | 24:39 | 50 |
| M300 | 1:2,2:3,7 | 22:37 | 47 |
| M400 | 1:1,4:2,8 | 14:28 | 36 |
| M450 | 1:1,2:2,5 | 12:25 | 32 |
The indicated proportions are relevant when using the correct components: clean and dry quartz sand with a fraction size of at least 2 mm, washed and dried crushed stone with a strength grade of at least M1200. The activity of the binder plays an important role, reviews in this regard are clear: for the foundation of a house it is better to take cement no earlier than 1-2 weeks before the start of work, checking the release date and certificate is mandatory. Fresh powder has no lumps and is easily passed through your fingers.
If you doubt the integrity of the supplier, it is worth checking the quality of the material in advance: the correct cement sets well within 45 minutes.
In addition to using components of the required quality, the sequence of their loading into the concrete mixer is observed. Recommended scheme: 80% of the total share of water → crushed stone → sifted cement and sand → the rest of the water in small portions. Most plasticizers or hardeners are added at the end with strict adherence to proportions. These include liquid soap (added along with the main portion of water), factory-made specialized additives, fiber, inhibitors, substances that affect the setting time of concrete. Their use requires caution; exceeding their proportion worsens the structure of the artificial stone.
Material cost
Products are sold in bags, big bags and in bulk; wholesale purchases are the cheapest. The prices in this case are:
| Cement marking | Manufacturer | Price for 1 ton, rubles | |
| With delivery within Moscow by cement truck | pickup | ||
| PC M500 D0 | JSC Lipetskcement CJSC Belarusian Cement Plant |
4500 | 4250 |
| PC M500 D20 | JSC Maltsovsky Portland Cement | 4350 | 4100 |
| PC M500 D0B (fast-hardening) | |||
| PC M500 D0N (standardized clinker) | 4650 | 4450 | |
| PC M400 D0 | JSC Maltsovsky Portland Cement JSC Mikhailovcement JSC Lipetskcement |
4300 | 4150 |
| PC M400 D20 | 4200 | 3950 | |
When building a foundation on your own and delivering it using your own transport, it is more convenient to use bags (the proportions are easier to adjust to the measured weight). High-quality cement is offered by many domestic factories and manufacturers of dry building mixtures: Novgorod Central Plant, Borshchevsky Central Plant (Lafarge), Mikhailovcement, Maltsovsky Portland Cement, OJSC Voskresenskcement, Mordovcement, Sebryakovcement, Rusean. The cost when purchasing it in packaged form is.