To fill the foundation, it is customary to buy the highest quality cement with a high grade of strength. This is due to frequent loads placed on the structure: the weight of the building, soil displacement, exposure to precipitation and capillary water, freezing of the base in winter. Portland cement from M400 and above has proven itself, but in some cases it is allowed to use a less expensive brand. Each specific grade is selected according to the construction and operating conditions; it is also important to maintain the correct proportions and carry out concreting taking into account the requirements of the pouring technology.
The strength of cement is indicated by the letter index “M”, followed by an additional abbreviation: d0 - without additives, d20 - with 20% impurities. Varieties that have a specialized purpose are labeled separately, but they are rarely used when pouring foundations. When determining which cement is best for the foundation, the future load, the presence of a basement and soil conditions are taken into account. It is recommended to choose:
1. M200 - when pouring the base for prefabricated panel structures.
2. M250, M300 - for the foundation of a log house.
3. M350–M400 - for brick buildings. This is the minimum acceptable grade, suitable for the construction of buildings with a basement, bathhouse foundations and for objects on clay soils.
4. Portland cement M400 d0 - when mixing concrete for pouring the foundation of a private house, regardless of the number of storeys in an area with moving soil or a high groundwater level.
5. PC M400 d20 - for the same structures, but with lower requirements for frost and water resistance. This brand of cement is recommended for preparing foundations and constructing small buildings.
A binder with a minimum strength of M100 is suitable only for pouring a concrete pad over a backfill of crushed stone and sand when constructing strip foundation types. In turn, Portland cement with a high grade (M500) is not economically profitable to use in private construction; it meets the requirements of industrial and residential construction. But if the other components in the concrete for pouring are inferior in quality (for example, crushed stone with low strength was purchased), then the use of an expensive type becomes not only justified, but also a necessary action. The recommended brand for columnar and pile foundations is Portland cement M400.
To correctly determine soil conditions and groundwater levels, they are measured; this is best done in the summer. For sedentary, dry and sandy soils, it is allowed to use cement for pouring the foundation with a strength of M250. For clay soils and loams the minimum is M350. The same strength is the initial strength when building houses with a basement. For masonry mortar when constructing foundations from blocks, it is recommended to choose M400 cement without additives; in general, this brand is considered optimal in terms of the price/result ratio and meets almost any requirements of private construction.
The influence of slags and impurities
Despite the fact that for the foundation of a house it is better to use Portland cement without mineral additives (they lead to a decrease in the strength of structures), in some cases mixed varieties are also needed. Their main advantage is their cost-effectiveness (with the exception of formulations with modifying and specialized additives, they, on the contrary, are more expensive); the PPC M400 d20 brand is considered an example of a good price/quality ratio.
The advantages of using slag and pozzolanic cements include sulfate resistance; they should be chosen when there is a high proportion of salts in the soil or other aggressive influences. But they reach the required strength more slowly, so foundations are laid on their basis in the spring. A significant disadvantage of cement mixed with slag is that it reduces the frost resistance of concrete; it cannot be used on moving soils.
Cooking proportions
To pour the foundation, you should make concrete with a grade of at least M200. The quality of work directly depends on the use of the correct components, their preparation and mixing in proven proportions. Ideally, this is: fresh Portland cement without lumps, dry and sifted river sand, gravel or crushed stone from hard rocks, clean (drinking) water. Coarse-grained filler is selected with a grain size of no more than 30 mm, preferably with a square flakiness; it must be cleared of debris and, if possible, washed. The mixing is carried out in a concrete mixer; this is required not only to reduce the labor intensity of the process, but also to obtain the desired structure.
The ratio of cement, sand and gravel depends on the type of base. So, for columnar foundations it is better to choose a proportion of 1:3:4 with a W/C of no more than 0.65; the same mixture is suitable as a masonry mortar when building it from blocks. In this case, a grade of cement not lower than M400 is used. For a strip foundation type, these proportions are 1:4:6, with the same W/C ratio equal to 0.65. Excess water is unacceptable; it leads to disruption of the hardening processes and the formation of cracks.
The method of preparing concrete for pouring the foundation, taking into account the grade recommended by the standards, has proven itself to be effective. A proven proportion is selected: 1 part cement, 3 sand and 5 gravel. The W/C ratio in this case depends on the required concrete parameters:
| Expected grade of concrete | Cement strength grade | ||
| 300 | 400 | 500 | |
| 200 | 0,55 | 0,63 | 0,71 |
| 250 | 0,5 | 0,56 | 0,64 |
| 300 | 0,4 | 0,5 | 0,6 |
| 400 | Not preparing | 0,4 | 0,46 |
The humidity of the sand plays a huge role; using undried sand or preparing the solution in damp weather leads to a violation of the proportions. In general, the concrete should be workable, but not liquid; it is recommended to leave some of the water and add it in small portions to the concrete mixer in the last minutes of rotation.
What else do you need to consider?
The quality of cement is inversely proportional to its shelf life, and taking into account the fact that high-quality cement is purchased for pouring foundations (that is, quickly losing its properties), it is necessary to use the freshest powder of a light gray or greenish color that spills through your fingers. The attached certificate is checked, if the volume of work allows, then the material is purchased in plastic big bags, the packaging is opened immediately before preparing the solution.
Strengthening the strength of concrete is very simple: just add fiber or plasticizers, but this method increases costs. Strip foundations must be reinforced; for them it is recommended to purchase gravel or hard crushed stone with a maximum fraction size of up to 20 mm. Regardless of the type of structure, waterproofing work is provided.
Cost of materials.
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.
You can make the right choice by taking into account all factors, which include the total mass of the structure, the presence of a basement or ground floor that can 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 brand
Portland cement gains full strength characteristics 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 constructing a foundation on his own
Before starting construction of his own house, the developer decides which cement is best to choose and use for the foundation. Almost every person knows that cement and concrete have their own brands. What do the numbers in the labeling of these building materials mean?
Cement marking
Cement is supplied by the manufacturer in paper bags with markings. The grade of cement characterizes the strength properties of the material. The numbers following the letter M indicate the load in kilograms on the surface of the face of a cement cube with a side of 1 cm.
For example, cement grade 200 can withstand a load of 200 kg per 1 cm2. To prepare a concrete mixture for pouring the foundation of a private house, foundation cement of grades M 400 and M 500 is used.
Savings when using lower grade cement for the foundation of a house can lead to irreparable damage to the foundation.
Concrete marking
The grade of concrete depends on the strength characteristics of the cement. To fill the foundation of a private house, concrete grade M 300 is mainly used. Such concrete can withstand a load of 400 to 500 kg per 1 sq. m. cm. This is enough to build the foundation of a two-story private house.
There are a wide variety of types of cement with various additives. These can be substances that improve certain qualities of the material. As a rule, additives are used when performing special work. To prepare the concrete foundation pour, Portland cement is used without any additives.
Composition of concrete mixture for foundation
A developer who decides to lay the foundation of a house himself can order concrete of the required grade at the nearest mortar station. If this is not possible, the concrete mixture of the required grade is prepared independently at the construction site.
There are many sources of information on how to prepare a particular brand of mortar. To obtain concrete of the desired grade, when preparing the mixture, certain proportions of the amount of constituent materials are observed. These are cement, sand, crushed stone and water.
To fill the foundation of a house, concrete grade M 300 is chosen. Concrete of this grade is prepared using material marked M 400 and M 500. When using M 400, cement, sand, crushed stone and water are poured into one batch in the following proportions: 1: 1, 9: 2, 8:0.6. The proportion by weight of the constituent materials with M 500 will be: 1:2, 4:4, 3:0.6.
From this it can be seen that M 500 will need less than M 400. You need to know that the highest brand is always more expensive. The developer must choose for himself which brand is best to use for the foundation of his house.
Technology for preparing concrete for pouring the foundation
The process of preparing the concrete mixture must be inextricably linked with pouring the formwork for the base of the house. You should prepare for pouring the foundation so that the process is continuous.
It is necessary to think about the placement of an electricity source, a concrete mixer, and a water supply. Sand and crushed stone should be in convenient proximity. It is necessary to organize ways to deliver the finished solution to the formwork. Be sure to check the serviceability of the carts. The working condition of the vibrators is also checked. The number of workers employed in this work is also important. All this must be done to ensure uninterrupted and rhythmic work on pouring the foundation.
If the house is small in size, then the foundation itself will be small, and in this case, all the work of pouring the formwork with concrete can be completed with the efforts of three or four workers.
You can use any suitable container (an old trough) to mix the solution. Water, in the absence of a nearby water supply, is poured into barrels or a large container. Sand and crushed stone are poured into piles close to the container. The cement is stored under a temporary shelter.
Watch the video on how to properly mix the solution.
When purchasing, transporting and storing bags of cement, it is necessary to check the integrity of the container. Cement is hygroscopic and instantly absorbs moisture through tears in the paper bag. As a result, this building material may become completely unusable.
Conclusion
The right solution is the key to the quality of the foundation of the house Based on extensive practical experience in constructing the foundations of private houses, a standard ratio of parts of cement, sand and crushed stone in the proportion of 1:3:5 is used to prepare the concrete mixture.
When purchasing cement, be sure to check the packaging. The bag should not feel like stone when palpated. When opening the container, the powdery substance should easily slip through your fingers. If there are lumps, they should crumble easily. Otherwise, the fossils indicate that the contents of the bag have become completely unusable.
The cement in the opened bag is to be used immediately. Subject to the above norms and rules, the developer can be confident in the high-quality and reliable foundation of his own home.
The content of the articleCement is a substance with astringent properties. It is irreplaceable in construction, including for the construction of foundations. If it is mixed with fillers such as sand, gravel, crushed stone and water, observing precise proportions, you will get a strong monolith that can withstand enormous loads.
But cement in its properties is divided by brand, differs in characteristics and price. Therefore, it is very important to understand which foundation cement is best for your home.
Choosing cement for the foundation - brand of building material
Cement, as a binding material, is produced in several types. The most popular among builders is Portland cement. It is produced with special additives, 
due to which the properties of the material are improved. Additives perform various functions: they promote rapid setting of cement, or, conversely, slow down the hardening process, increase resistance to the influence of chemicals and other aggressive substances on concrete.
When choosing cement, you need to pay attention to the brand of building material, on which the strength of the concrete being poured depends. With a high grade of cement, a more durable structure is obtained, and also, a higher value of the material indicates the rate of hardening of the solution. The grade of cement is indicated by the number following the “M” index: M 200, M400, etc.
In addition to markings, additional indices are written on bags of building materials, which also indicate the properties of cement:
- - D0 - denotes cement without additives.
- — D20 – the building material contains 20% additives.
If other letter abbreviations are attached to these indices, then the cement acquires additional characteristics:
- N – normalized. Standardized clinker is added to the building material.
- B – fast-hardening. Cement that can harden quickly.
- PC – Portland cement.
- BC – white cement. It is intended for finishing work.
- PL – plasticized, frost-resistant.
- GF – hydrophobic. Frost-resistant, plastic cement that does not immediately absorb water.
- SS – sulfate resistant. Used in conditions where there are aggressive environments.
- VRC – waterproof. Special cement that sets quickly and expands when hardening.
What brand of cement is needed for the foundation?
If the soil on the site is dry, you should buy regular Portland cement. The composition of concrete for the foundation will depend on the brand of this material. If you prepare concrete grade M350, then Portland cement can be used grade M500 D0.
The proportions for the solution are as follows: For one part of cement, take two parts of sand and four parts of crushed stone and add water equal to half of one part of the material.
To build a foundation, in addition to selecting cement, you need to professionally select fillers. The sand must be clean. Any impurities can affect the quality of concrete. Sand can be checked for cleanliness by pouring it into a tank of water and leaving it for a day to settle. If during this time the water becomes cloudy, then we can assume that the material is not suitable for preparing the solution.
When choosing gravel, you need to take into account that for construction you need to choose it depending on the type of buildings. For the foundation for the construction of a one-story and two-story building, gravel measuring 0.8 cm in diameter is taken. If the foundation is reinforced, then you can add finer gravel - 0.3 cm.
How to test cement?
If bags of cement do not have a manufacturing date on them, then you must check how soft it is. To do this, tap the bag. If it is stale, then you can immediately feel its fossilization. The cement hardens faster in the corners of the bag, so you need to start checking from the corners.
The contents of the bag should be gray. Cement can give any shades - dark gray or light, sometimes even gray-greenish. Fresh cement has a soft fluidity and if you take it in your palm, it easily “flows” between your fingers. If you squeeze the powder in your palm, you get a lump that easily crumbles.
If lumps are found in the bag and they easily fall apart when compressed, this building material is no longer very fresh. But if the lumps need to be ground with force and they crumble, forming hard grains of sand, then it is better not to buy such cement - it cannot be used.
How to evaluate the composition of cement?
For the experiment you will need sodium bicarbonate mineral water (preferably Borjomi, Essentuki). The bottle must be opened to allow the gases to escape. Next, we knead the dough from mineral water and cement, and from it you need to make a flat cake with a diameter of up to 15 cm with thin edges and a thick center. If it is high-quality cement, then the cake will set in 10 minutes. During this time, the thickened part of the batch will heat up noticeably. The color of the cement will change slightly and become blue-green. But it doesn't matter
When purchasing cement from a store, most people have no idea which cement is best to choose. First of all, you should ask yourself what role it will play - will it be laid as a foundation or. Incorrect selection of material can lead to the fact that, under the influence of external factors and heavy loads, the hardened cement mortar will begin to deteriorate and crack.
Types of cementIn order to use cement most rationally and economically, it is important to know the specifics of working with a particular brand and manufacturer. At the moment, there are a great many manufacturers of the material, so it is not easy for the average consumer to independently understand its numerous classifications.
General concept
Initially, the material is a powder containing clinker binders, filler and other additives. When combined with water, it becomes a plastic mixture called cement paste.
Initially the material is a gray powder By waiting for it to completely harden, you will see how a liquid solution can turn into durable stone.
Types of cement
Today, Portland cement is in great demand among builders. Another type of cement mass - slag Portland cement (SPC) - has the following properties:
- withstands contact with river and sulfate water, which is groundwater;
- poorly preserved at sub-zero temperatures;
- the characteristics of the required strength appear only after 4 weeks;
- perfectly withstands maximum temperatures, up to 600-800 degrees Celsius.
ShPC is not suitable for creating concrete that is regularly exposed to low temperatures. However, this type of building material is ideal for installation in rooms where heating is carried out.
ShPC does not require any special conditions for storage; the material is stored longer than Portland cement. Complete hardening occurs within 6 hours, taking into account the air temperature of +18...+22 degrees, while for Portland cement 2–3 hours are enough. All work with ShPC must be completed within the first 3 hours, after which it loses its elasticity and may begin to crack with further processing.
Popular manufacturers in the CIS countries
Cement produced in the CIS countries shows good characteristics.
Consumers leaving reviews on relevant forums regularly mention Ambrosievsky cement in a positive context, the obvious advantages of which are the rapid hardening of the solution and convenient packaging of 25 kg per bag, which greatly facilitates the work process.
Regarding the Balakleyevsky plant, you should pay attention to the various brands in the classification of cement mass, which has also proven itself to be good, which cannot be said about the Kiev manufacturer - a complete discrepancy between the type of products stated on the bag labels.
Conclusion
Now you know what you need to pay attention to when buying cement, how to determine the quality of the material and not fall for a scammer.
Practice has shown that it is impossible to single out one manufacturer or brand of mixture that is suitable simultaneously for finishing and major repair and construction work. Reputable hardware stores and manufacturers will be reliable assistants in your choice.