The start of the construction season is just around the corner, but building a house is a very expensive process and people are looking for ways to save money. Cement is one of the main building materials, and its quality significantly affects the final result of the work performed, be it pouring the foundation, screeding or masonry. Unfortunately, when choosing bagged Portland cement, consumers rarely think about the possible risks of purchasing a low-quality product. However, it is low-quality cement that can cause a burst foundation, cracked screed or efflorescence on the wall.

The advice in our article will help you minimize the risk of purchasing low-quality products.

• How consumers are deceived when buying Portland cement
• Tips for choosing bagged Portland cement
• How to properly store cement and what is its shelf life?

How people cheat when buying cement

Competition in the building materials market is quite high, so there are “entrepreneurs” who offer Portland cement packaged in bags at a price below the market price. The number of such products especially increases during the active construction season.

How can you tell if such a product is of high quality? And how can a consumer distinguish counterfeit?

When constructing multi-story buildings, cement-based building materials or ready-mixed concrete are brought to the site directly from the factory. In private housing construction, the situation is different: the consumer purchases products independently, and therefore runs the risk of being deceived. At the same time, the price range for the product from the manufacturer and from the artisanal packer can vary significantly. They lower the price in different ways: from a banal body kit to changing the composition of the cement.

Therefore, private homeowners are interested in the question of how not to be deceived?

Dima4 User FORUMHOUSE

I'm building the foundation. Wondering what cement to buy? There are so many manufacturers - domestic and imported - that it’s simply dizzying.

Markovkin FORUMHOUSE Member

I want to know why cement in bags of the same brand, from different factories, costs differently? I looked at several manufacturers. One has good packaging. The cement does not spill during transportation and, most importantly, costs 40 rubles. cheaper than a brand from a company located in my region.

Etznova Member of FORUMHOUSE

I wanted to buy cement. To find my bearings, I researched prices online in advance. I went to the market. I began to choose. The seller told me the price for a bag of 100 rubles. higher than indicated on the websites of other companies. Who to believe? I called my friend to get advice on what to do. He said that it is generally better not to buy cement from the market, because... a lot of fakes. Now I’m sitting and thinking, where to buy high-quality Portland cement, and not a surrogate?

The following information must be indicated on the bag:

1. type and class of cement;
2. number of the current certificate of conformity;
3. GOST;
4. contacts and address of the manufacturer's plant.

2. Check the documentation

Each batch of factory cement is accompanied by appropriate documentation confirming its quality and origin. The list includes the following documents:

• quality certificate for cement with the date of shipment;
• conclusion about its physicochemical properties.

At the slightest suspicion, ask the seller for these documents!

3. Do an examination

If you have purchased a suspicious batch of cement, contact a special laboratory to conduct an independent examination. This is much more profitable than discovering shortcomings during the construction process, or then wondering what to do with a cracked foundation or a delaminated screed where heated floor pipes have already been laid.

4. Check your weight

The weight of a bag of cement cannot differ from that declared by the plant by more than 1 kg. Hand-packed bags tend to be lighter.

If the batch of packaged cement is large, carry out selective weighing before purchasing.

5. Find out how the cement was stored

The seller of packaged cement must comply with the rules for its storage. Factory cement is usually packaged in special multilayer paper bags. Buy bags of cement without mechanical damage, because... Portland cement deteriorates when exposed to moisture from the air. Check that paper bags of cement are stored on pallets and not piled on the floor of the warehouse and are packaged plastic film. Only dry and well-ventilated areas are suitable for storing cement.

Shelf life of cement and rules for its storage

Cement is a perishable building material. If you bought Portland cement in bags and did not immediately use it in construction, remember that:

• According to GOST, the manufacturer guarantees the quality of cement for 60 days from the date of shipment from the plant. However, when proper storage, most cements can be stored for more than six months without significant loss of quality characteristics.
• It is advisable to use the opened bag of cement as soon as possible.

For long-term storage, wrap the unopened bag of cement, provided it has not become saturated with moisture, in a sealed plastic bag. Store packages in indoors on pallets, not on the street. Replace the bags once every 2-3 months. Check the quality of cement when purchasing Can visually. Open the bag. Scoop it up with your hand. Make a fist. Good cement will flow through your fingers like water without forming lumps. The color of quality cement is gray or light gray. The mixture should be homogeneous, without foreign inclusions.

conclusions

The desire to save money and buy cement in bags cheaply is understandable. But in the race for low prices, it is easy to lose, especially when it comes to building materials. Bagged cement is no exception, because... There is a risk of running into a fake. Approach your choice wisely, analyze the information. Manufacturers' websites contain addresses and contacts of authorized distributors. Buy packaged cement directly from the factory or from its official representatives, which guarantees quality by providing the consumer with all the necessary documentation.

The article tells you how to make self-mixing concrete of excellent quality yourself.

In the video - How to choose high-quality sand concrete and determine its quality.

The term “cement” is usually understood as a binding building material of inorganic origin, which, when interacting with water, forms a solution that turns into a dense monolithic formation of increased strength. Used for the production of concrete and other compositions used at various stages construction production.

The basis for it is limestone with an admixture of clay and additives, which after crushing becomes a crumbly substance consisting of small homogeneous fractions, depending on the combination and percentage of components that have a different set of physical and technical characteristics that determine the further nature of its use.

One of the most important indicators characterizing the quality of cement is its compressive strength. This parameter is determined during laboratory tests, according to the results of which the material is divided into grades with numerical designations from 100 to 800 and indicating the degree of compression in BAR or MPa.

In addition to the standard ones, special types of cement are used in the construction industry, which have a special set of qualities and individual properties that distinguish them from their analogues.

To designate the strength grade of cement, the abbreviation PC or M is used. For example, marking in the form of M400 applied to the packaging means that it is capable of withstanding pressure up to 400 kg/cm3. In addition, it may contain information about the presence of additives in the total mass of the substance, denoted by the letter D and their percentage percentage.

Photos of various brands of cement in paper bags

Special letter designations are used to mark them:

• B, indicating the rate of hardening of the material;
• PL, indicating the presence of plasticizing additives;
• CC confirming the presence of sulfate-resistant characteristics;
• H, used to denote standardized cement produced from clinker.

Until recently, various grades of cement were actively used in construction, including the “weakest” version with a strength index of M100, but this variety is currently out of production.

A similar “fate” befell cement grades 150 and 200, which, due to their insufficiently high strength, ceased to be used in the construction industry, “giving way” to high-quality, progressive materials of higher grades.

On this moment The best, most in demand and popular are cements of grades 400 and 500, which best meet the needs and requirements of modern construction production. The brand of cement used to prepare the concrete mixture directly determines the brand of the resulting mortar.

In this case, this dependence will look like this:

Concrete grade	Cement brand
M150	M300
M200	M300 and M400
M250	M400
M300	M400 and M500
M350	M400 and M500
M400	M500 and M600
M450	M550 and M600
M500	M600
M600 and above	M700 and above

The scope of application of the M400-D0 brand is the production of prefabricated structures from concrete and reinforced concrete, the creation of which uses the method of thermal and moisture treatment. Cement grade M400 D20 is also widely used in various industries, including the production of foundations, floor slabs and the production of concrete and reinforced concrete products of varying complexity. Has good frost resistance and water resistance.

The M500 D20 grade, used in housing construction, as well as the creation of industrial and agricultural facilities, best complies with the above parameters and technical and physical standards. Cement of this brand is also used in masonry, plastering and finishing works.

A distinctive characteristic of M500 D0 cement is its high strength, combined with increased frost and water resistance, which makes this material indispensable when carrying out work of increased complexity, with high requirements for the quality of construction.

Higher brands, such as M600, M700 and higher, are quite rare on the open market. The main area of ​​their application is the military industry, where these compounds, which have the highest degree of strength, are used to create fortification and specialized structures.

Composition and fractions

In addition to the additives used, the quality and characteristics of cements are directly influenced by such factors as the fineness of their grinding, the granulometric composition of the product, as well as the shape of the particles included in the powder mixture.

Bulk cement compositions, as a rule, consist of grains having sizes from 5-10 to 30-40 microns. The quality of the grinding material is determined by the presence of residues on sieves with mesh sizes of 0.2, 0.08 or 0.06 mm, as well as by testing on specialized devices that determine the specific surface area of ​​the powder.

These devices also serve to determine the air permeability of the material.

Modern industry produces cements that are as finely ground as possible, with increased strength and a high hardening rate. For example, Portland cements normal looking crushed to 5-8% of the remaining particles on a 0.08 sieve. Grinding of fast-hardening cements occurs to a residue of 2-4% or less.

The specific surface area is 2500-3000 cm2/g of product in the first case and 3500-4500 cm2/g of material in the second.

After reaching a specific surface area of ​​7000-8000 cm2/g, the strength characteristics of cement begin to decrease. For this reason, excessive grinding of cement into dust is considered unsustainable.

According to research and practical experiences in the field of testing various grades of cement, it was proven that the main influence on the activity of the material in the short term is exerted by fractions whose size is up to 20 microns. Larger grains (within 30-50 microns) affect the activity of cements at later stages of their hardening.

Thus, chopping raw material to a finer state, it is possible to obtain cements of varying degrees of strength and grades. For example, materials marked M600, M700 and M800 are obtained from clinker crushed to contain general composition powder 45, 50, 65 and 80% fractions with sizes from 0 to 20 mm.

The video talks about the marking of cement according to the old and new GOST and their differences:

Classification by type

In addition to brands, classes, types and degrees of grinding, cements are usually distinguished into several main types, differing in the combination of individual components and composition.

These include:

• Portland cement; It is obtained from grinding Portland cement clinker - a product of firing to the state of sintering of a raw material mixture, including limestone, clay and other materials such as blast furnace slag, marl, etc., with the addition of gypsum and special additives. It can be pure, with an admixture of mineral additives, Portland slag cement, etc.
• pozzolanic; This category includes a group of cements containing about 20% mineral additives. Obtained by co-grinding Portland cement clinker, which makes up the total mass ready-made composition about 60-80%, an active mineral component, the share of which is 20-40%, and gypsum. It has increased corrosion resistance, a lower hardening rate and low frost resistance.
• slag; It is produced by joint grinding of blast furnace slag and activator additives in the form of gypsum, lime, anhydrite, etc. It can be lime-slag (with 10-30% lime content and 5% gypsum content) and sulfate-slag (where gypsum or anhydrite makes up 15-20% of the total mass). Cements of this type are found in underground and underwater structures.
• aluminous; It has a high hardening rate and good fire resistance, which makes it indispensable in the production of high-density mortars and concretes with increased water resistance.
• cement with fillers, romancement; A material produced by grinding fired raw materials without subjecting them to a sintering process. Suitable for masonry and plastering works, as well as the production of low grade concrete.
• phosphate cement; It is divided into two main subtypes: hardening at normal temperatures and when heated to a temperature of 373 - 573 K. It has great mechanical strength.
• straining; Has a short setting period and good strength. Has high pressure during the hardening process. It is used for the manufacture of pressure pipes used to create tank structures.
• waterproofing; It is divided into subspecies with penetrating and coating ability. After hardening, it acquires waterproof qualities and strength.
• magnesian; It is a finely dispersed powder type composition, the basis of which is magnesium oxide. It is used for the construction of seamless monolithic floors.
• plugging; Used during cementing of gas and oil wells.
• zinc phosphate; It is produced by firing a charge containing oxides of zinc, magnesium and silica. It has high compressive strength of 80-120 MPa.
• silicophosphate; The production process involves firing the charge until it is completely melted, after which the composition is subjected to rapid cooling in a water bath. Has high strength and durability.
• high strength; It has a very high setting speed, good ductility and strength.
• lightweight etc.

Promising types of cements and their advantages

In addition to large-scale construction production, concrete is widely used in the private sphere, for the construction and reconstruction of housing and agricultural buildings. For this reason, when purchasing this material, consumers are faced with the question: which of the existing cements is the best in terms of quality and set of individual characteristics?

Cement is one of the main building materials. It is preferred by many builders due to its high strength and bonding characteristics, in addition, it allows you to connect almost any materials. Choosing good cement is not always easy and you need to understand that there are different types of it, which are characterized by strength grades. This is what distinguishes the mixture of household and industrial purposes. New manufacturers appear every year, various additives are added to dry mixes, and the article will help determine which cement is better in 2019 for screeds, masonry, blind areas and reinforced concrete structures.

Features of choice

Construction stores offer a very large assortment of cement, so choosing it often becomes complicated, especially if the work will be carried out by beginners. Determining the best cement for various purposes is possible by understanding its features and properties. When choosing, you need to look at the following characteristics:

• Compound. The basic material is considered to be crushed substances, including limestone, clay, min. additives. Based on the recipe and dosage of substances, there appear different types mixtures, the most popular is Portland cement. This product is suitable for construction and concrete products.
• Strength. An equally important parameter for any type of mixture. This is the product marking. Mixtures M400, 500 and 600 are available on the market, which is the most durable and can withstand heavy loads. The first 2 types are suitable for household needs.
• Purity. Often, manufacturers make marks on the pack in the form of the letter D and a numerical value. This indicates the presence of additives, for example, D20 includes about 20% fillers and other excipients. D0 – pure cement without additives.
• Hardening speed. Based on the main type of work, the solution in liquid form should harden differently. If CEM I is indicated on the package, the mixture will quickly set and harden. For the M400 brand, CEM V is considered the norm.
• Packing. Many manufacturers use special bags or paper bags with many layers. If construction is being carried out, it is better to buy 50 kg packaging; for small-scale work, it is more profitable to buy 5-30 kg bags.
• Best before date. Often, mixtures will have a shelf life of 3-6 months, but when purchasing, you need to understand the storage period, transportation time and other indicators. You can check the quality by hitting the corner of the bag; if it has already petrified, then you should refuse the purchase.

The article describes different variants dry mixtures for household and industrial purposes. The rating is based on the opinions of consumers and experts to make it easier for a potential buyer to decide which brand of cement is better. For this purpose we present brief characteristics with pros and cons.

TOP cement M400

This cement is perfect for floors, screeds, and masonry walls inside a house or apartment. The brand is characterized by an optimal strength value, so it is suitable for medium loads. In addition, the choice is good for waterproofing basements and damp areas.

Holtzim M400

Manufactured by a Russian company that is known abroad and has many years of experience work. The products are characterized by white color, which will be up to 74%. The composition uses a special clinker, which contains a minimal amount of iron, which makes the cement unique in its category. Diatomite and gypsum are also added to the composition to increase the degree of light reflection. Positive reviews of the product from ordinary consumers and experts were received due to the quality of the mixture and the strength of the finished solution. The only drawback can be considered the difficulty of purchasing at construction sites. retail outlets.

pros:

• Excellent quality.
• White color.
• Affordable price.
• Versatility and ability to be used for construction or repair.

Among the disadvantages is the difficulty of purchasing in stores.

Portland M400 Hercules

This product is considered the best for floor screeding, as it is characterized by high strength and can withstand any household loads. In addition, the liquid solution dries quickly and makes it possible to walk on the screed within a day after pouring. This helps speed up repairs and other work without harming the floor itself. They are sold in small 5 kg bags with handles that are easy to carry. Other features include a long service life and the elimination of cracks.

Pros:

• Environmentally friendly, as can be seen from the packaging and the “ECO” icon.
• Can be used in a dry building or basements, cellars and buildings with high humidity.
• Contains up to 5% gypsum.
• Includes active mineral additives to enhance strength.
• Does not take over the influence of corrosion from the steel that is nearby.
• Impact resistance.
• Long service life.
• It is not affected by frost and can withstand up to -40 degrees without changing its characteristics and properties.
• Grey colour.

Minuses:

• Small packaging, only 5 kg.
• For a small pack you get a high price of 50 rubles or more.
• The shelf life is up to 2 months, so after purchase it is necessary to carry out repairs immediately.
• Cannot be used for outdoor use.

Eurocement M400 D20 CEM II A-SH 32.5

High-quality type of cement from Russian manufacturer, which is liked by specialists and ordinary people. The mixture meets all international requirements and is used by many countries. This option is suitable for domestic and industrial applications. The mortar is used to make floor slabs, reinforced concrete products, screeds, foundations and walls. It is packaged in bags and has a shelf life of six months.

pros:

• Affordable price.
• Resistance to frost, temperature changes and moisture.
• Excellent quality of the dry mixture and the finished solution.
• Wide range of applications.

There are no downsides to the product from this manufacturer.

Cement CEM II 32.5 (M400 D20) gray De Luxe

Perfect option for blind areas and outdoor work, since the mixture is made for outdoor use. When hardened, the formation of cracks is excluded; they do not appear even after several years, which eliminates the need for constant sealing. The finished solution has good strength, which helps to securely fix any materials and elements. After drying, the made blind area will withstand up to 330 kg per 1 sq. cm. It is packaged in 50 kg bags, so it is profitable to buy for large construction projects.

Pros:

• Affordable price, only about 260 rubles for 50 kg of cement.
• Resistance to moisture and low temperatures.
• Long period of operation of the frozen solution.
• Includes additives that increase strength and hardening time.
• Optimal temperature Range for work, which is +5-30 degrees.
• A month after pouring, maximum hardness and the ability to withstand peak loads are achieved.
• Setting occurs within 75 minutes, so it can be used to remove defects that appear during pouring.
• Meets GOST requirements.

Minuses:

• Only 50 kg packages are available for sale.
• Shelf life up to six months.
• Cannot be used at temperatures below +5 degrees.

TOP cement M500

When choosing which cement is best for the foundation, you should definitely pay attention to this brand. It is characterized by high strength and is suitable for floors that bear heavy loads, for masonry load-bearing walls and pouring the foundation for the building.

Eurocement 500 Super

This product has many positive reviews, and cement is often used in the construction of houses. It is recommended to use for pouring foundations, building walls, screeds. Specialists often buy it because of its quality, the mixture meets GOST standards, the solution sets quickly, which helps reduce the time of the main process. In addition, the consumer receives protection from moisture and frost.

pros:

• High quality composition.
• Strength.
• Durability of the poured solution.
• Fast drying.
• Wide scope of use.

There are no downsides to this brand.

Holcim Tared 50kg CEM II/A-K(SH-I) Class 42.5N

This option is considered one of the best for pouring a foundation for a house, since the solution can withstand heavy loads. This allows the mixture to be used for buildings of 2-3 or more floors. Hardening is optimal, the dry mixture includes minerals, eliminating the appearance of cracks or peeling. The product is sold in 50 kg bags, which is convenient during construction.

Pros:

• Great for load-bearing structures thanks to its strength.
• Can be used indoors and outdoors.
• The maximum bending strength is 78 kg/cm2.
• Includes mineral and plastic substances.
• Withstands loads within 433 kg/cm2.
• Does not have a blue tint, the color is gray.
• Affordable price within 300 rubles per bag.
• Excellent adhesion.
• Optimal hardening time, which helps remove defects in the form of smudges or sagging.

Minuses:

• If you work in the cold, setting may occur with the formation of small voids.
• It is inconvenient to grasp the carrying bag.

EuroCement 500 Extra D20 CEM II

The product is characterized by optimal drying speed and durability. After preparing the solution, it is convenient to pour it into voids and level the surface. The mixture is not afraid of frost, so it can be used even in winter. The quality is at a high level, but at temperatures below +10 degrees, hardening will be slow.

pros:

• Excellent quality.
• Easy to use.
• Long storage period.
• No cracks appear during shrinkage.

Minuses:

• High price.
• If the temperature is low, the hardening process will be slow.

Stone flower M500 D20

This the best option for laying bricks, foundations and others important works. Cement is characterized by a high degree of strength, which is 500 kg/cm2. The composition contains polymers to accelerate hardening and eliminate cracks when drying. To increase adhesion, the manufacturer adds glue and other elements, which also make the solution insensitive to weather. Sold in packages of 40 and 50 kg.

Pros:

• Optimal hardening time, which is suitable for mixing the solution, laying it with further leveling.
• The solution is easily prepared using technology or manually.
• Affordable price.
• Availability of mineral supplements.
• Suitable for outdoor or interior work.
• High strength.
• Ecological cleanliness.
• Meets GOST.
• Resistance to frost and moisture.
• The ready-made and hardened solution serves for a long time and retains its properties.
• High degree of adhesion to materials.

Minuses:

• Shelf life up to six months.
• The corners of the bags are smooth, so it is inconvenient to carry and take the goods.

TOP cement M600

This is a good cement for foundations and floors in garages, parking lots, and warehouses with heavy equipment. The mixture can withstand very heavy loads, ready solution used for reinforced concrete products.

CimSa M600

Product from a Turkish manufacturer, white. The composition is made for finishing work, which achieves evenness and smoothness of the surface. After repair processes, cracks do not appear during drying, the solution is not exposed to external factors. In concrete products, cement helps protect metal products from corrosion. The product is characterized by low moisture absorption, strength and frost resistance.

pros:

• White color.
• Not affected by weather conditions.
• The formation of cracks is excluded.
• Protects fittings from corrosion.

This is the best brand of cement, which has no identified disadvantages.

Adana Super White M-600

Another Turkish product High Quality. The company itself is young, but is actively developing, offering high-quality products that meet international standards and requirements. Cement has high strength, can withstand heavy loads, and also looks beautiful after pouring. The color of the solution is 90% white, which is convenient for concrete products, creating architectural details, monuments, etc.

pros:

• Excellent aesthetic and decorative properties.
• Great opportunities for use.
• Strength.
• Endurance.

The main disadvantage is the overpriced product.

White polymer cement M600 Rusean

This option is the best in its class for creating precast concrete products, this is achieved for 2 reasons: excellent strength and a pleasant white color. This allows it to withstand heavy loads and eliminates the need for additional painting of concrete products. Whiteness is achieved thanks to the polymer in the composition.

Pros:

• Very fine grinding, which helps to use the mixture for self-leveling floors.
• Setting occurs within 1.5 hours, which is enough to level the surface.
• High density material that simplifies packaging and transportation.
• Nice white color.
• Minimal shrinkage.
• Frost resistance.
• Doesn't flake.
• High plastic qualities.
• Can be used as a finishing material.
• Suitable for indoor and outdoor work.

Minuses:

• High cost per 30 kg bag.
• To maintain whiteness, you need to add quartz sand.

Having studied the features of each brand and best products in its segment, even a beginner can pick up best option for construction or repair work. The article is made for informational purposes and does not force you to purchase a specific product.

“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 Leningrad region for 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, make a claim to a foreign manufacturer, almost impossible. 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 certificates. 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 cement is certified according to current GOST 31108-2003, marking for high-quality cement, in this case, will be CEM I 42.5. For additional cement - CEM II/A-SH 32.5. By State Standard 10178-85 similar cement comes with the markings 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 type.

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 it happen low price? 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 quality goods.

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 with 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. Guarantee what you purchased quality product, can only be obtained 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.

Cement is used everywhere: from laying the foundation to brickwork and carrying out interior finishing work. Such a wide and even immense scope of use of cement has led to the emergence of materials with different composition and characteristics. You can’t just buy the first cement you come across and start work - first it’s important to make sure that the composition matches the task. Going to hardware store, It is important to know theoretical basis, so it’s time to figure out how to choose cement, find out what brands and types of cement exist, where certain compositions are used, and also what to take into account when choosing.

No. 1. Main types of cement

Cement is an inorganic binder. Cement powder, when interacting with water, forms a plastic mass that quickly sets and forms a stone-like body. It is often used for the manufacture of mortars. The composition of cement can vary greatly. Accordingly, the properties and scope of use will differ.

Today the following main types of cement are produced:

• Portland cement– the most popular type of cement in construction. It is made from Portland cement clinker, gypsum and special additives. Clinker is produced from limestone, clay and additives by firing. Ready-made Portland cement consists of 70-80% calcium silicates, the rest is gypsum (regulates the setting speed) and corrective additives. Portland cement is produced in grades M400-M600 and is used to create mortars, asbestos-cement and other materials. Not suitable for the construction of structures exposed to sea water;
• white portland cement are made on the basis of gypsum, diatomite and clay-sand rocks with a minimum content of coloring substances. The result is a composition with high strength and resistance to atmospheric influences and quick setting. Only two brands are produced: M400 and M500. The composition is often used for external finishing work, as it has aesthetic appearance and is not susceptible to cracking. Used for the manufacture of decorative elements (statues,), when organizing self-leveling floors, in road construction, V . Made from white Portland cement color compositions;
• sulfate resistant Portland cement produced on the basis of Portland cement clinker and gypsum. The composition is characterized by a reduced content of calcium aluminates, which ensures resistance to sulfates. Cement can be without additives or have additives in the form of granulated slag. Brand M400 and M500. It is used in the creation and construction of structures that will be operated under the influence of mineralized waters. This cement is used in the manufacture of piles, bridge supports, and in the construction of external elements of hydraulic structures;
  
• pozzolanic Portland cement obtained from Portland cement clinker, gypsum and additives of sedimentary origin, part of which is 20-30%. The composition is resistant to fresh and sulfate-containing waters and waterproof. Among the disadvantages are low frost resistance and low hardening speed. Used in pouring and laying basements of industrial and civil buildings, in the construction of subways, mines, canals, sluices, water supply lines;
• slag cements– a group of cements that includes slag Portland cement (SPC) and lime slag cement (ISC). The first is produced on the basis of Portland cement clinker, gypsum and blast furnace slag, part of which is 21-60%. The composition is characterized by a slow increase in strength, increased resistance to aggressive environments, but is not resistant to temperature changes. Used in hydraulic engineering construction. ISC is obtained from a mixture of slag and lime (its part is about 30%), small additions of gypsum and Portland cement are allowed. The composition hardens slowly, is most stable in fresh and sulfate waters, can be used for the production of low-quality concrete, in mortars for and masonry;
  
• rapid hardening Portland cement, as the name suggests, is characterized by a rapid increase in strength in the first hours of hardening. These properties are explained by the precise selection and dosage of special additives. As a result, the composition reaches its ultimate strength within 3 days, which speeds up the production process of reinforced concrete structures;
• aluminous cement It is also characterized by a high rate of hardening and strength gain. It is produced on the basis of bauxite or alumina with the addition of limestone. Based on the alumina content, ordinary (up to 55% alumina), high-alumina (up to 65%) and high-purity high-alumina cements are distinguished. The compositions are highly resistant to fire, corrosion and rapidly increase in strength. This cement has found application in emergency work, high-speed construction and winter concreting;
• expanding cements– a group of cements that are characterized by an increase in volume during hardening. A similar effect is achieved through a reaction between the powder and water, resulting in the formation of calcium hydrosulfoaluminate, a substance that can bind large amounts of water. The group of expanding cements includes waterproof, tensile, gypsum-alumina compounds and expanding Portland cement. Let's look at them all separately;
  
• waterproof expanding cement made from gypsum, aluminous cement and calcium hydroaluminate. The composition begins to set after 4 minutes, and after 10 minutes the hardening process ends. Used in underground and underwater construction, to seal cracks and to create monolithic structures from individual prefabricated reinforced concrete elements;
• tensile expansive cement produced from Portland cement clinker, lime, aluminous slag and gypsum stone. The composition hardens relatively quickly and is waterproof. Used in concreting bowls, producing pressure pipes;
• gypsum alumina expanding cement made from aluminous blast furnace slag and gypsum. The composition sets within 4 hours, expansion ends after 3 days. Cement is characterized by high frost resistance, strength and deformation resistance. It is used to carry out waterproofing work;
• expanding portland cement is a mixture of Portland cement clinker, slag with a high alumina content, gypsum and mineral additives. Depending on the composition, the expansion ranges from 0.3 to 2.5%. The expansion period is long, so the volume is filled evenly. Used in arranging road surfaces and repair of hydraulic structures;
• well cement used only when plugging oil and gas wells in order to isolate them from groundwater. Made from clinker and gypsum;
• hydrophobic cement in its composition, in addition to gypsum and clinker, it contains oleic acid or other hydrophobic substances, which make it possible to create a waterproof film on the surface of dried cement. This cement is ideal for foundations;
• magnesia cement differs in the content of magnesium oxide, which increases the elasticity of the composition and its resistance to aggressive substances. Used in arranging;
  
• waterproof non-shrink cement obtained from aluminous cement, gypsum and slaked lime. The composition sets quickly and is not afraid of water;
• acid resistant quartz cement– a product of mixing quartz sand, sodium silicofluoride and liquid sodium glass. The composition is resistant to aggressive substances, but loses strength in water;
• cement with surfactants has increased mobility and is used when working on complex objects from an architectural point of view.

No. 2. Cement grades by strength

The most important characteristic of any type of cement is its strength. This indicator is determined experimentally: a solution is prepared from cement and in a ratio of 1:3, a sample is created in the shape of a parallelepiped with sides 40*40*160 mm. The resulting sample is subjected to gradually increasing load. The experiment is slightly different only for some types of cement.

The data obtained during laboratory research is reflected in the stamps. If the sample can withstand a load of 300 kg/cm2, then it is brand M300, 500 kg/cm2 - M500, etc. The grades are designated by the letter M and the subsequent index from 200 to 600 in increments of 50 or 100. The higher the grade, the more durable the composition we have, and the more durable and high-quality concrete it will produce:

Today, next to the classification of cement by strength grade, a division has appeared into strength classes. If the brand is an average indicator, then the class is more accurate and provides a 95% guarantee of compliance with the specified data. Strength classes vary from 30 to 60:

• 52.5 – cement withstands pressure of 52.5 MPa, corresponds to cement grade M600;
• 42.5 corresponds to M500 cement;
• 32.5 corresponds to M400 cement;
• 22.5 corresponds to M300 cement.

No. 3. Labeling of additives in cement

In addition to the strength mark, on the packaging you can see markings of the percentage of various additives in the cement. This indicator is denoted by the letter D, followed by a numerical indicator in percentage. For example, D20 cement means that it contains 20% additives. The higher the number of additives, the lower the price of the composition.

No. 4. Marking by speed of strength gain

The time it takes for cement to reach its maximum strength is another important compositional indicator. In some cases, it is required that it hardens instantly, in others, on the contrary, an excessive rate of strength gain will only cause harm. According to this parameter, cement is divided into the following types:

No. 5. What else could be in the marking of cement?

In the characteristics of the composition, after the designation of the cement brand and the percentage of additives, there may be various abbreviations indicating the specific qualities of the cement:

No. 6. What to look for when choosing cement?

The demand for cement is enormous, which has given rise to the emergence of many unscrupulous manufacturers who often mix additives into cement that greatly reduce the quality of the finished composition. To avoid making mistakes when choosing cement and buy a really high-quality product, you need to know something about what good cement looks like and what properties it should have:

• cement is sold in bags and in loose form. It is better to take cement in bags, since this way it is protected from external influences, retains its qualities longer, and on the packaging of the bag you can always find out information about the composition, production date, characteristics of the cement and its manufacturer. The bags are usually made of two layers of paper, the inner one protects the cement from getting wet. By the way, the absence of any information on the packaging is also a sign that you may have low-quality material;
  
• if you buy cement in bulk and it is packaged in bags, then it is better to check carefully best before date on each, since in general they can sell you stale goods. The activity of cement drops several times after 6 months from the date of production;
• check freshness of cement It can also be done experimentally. It is enough to hit the bag - the sensation should not resemble hitting a stone. The cement in the corners of the bag hardens first, so it doesn’t hurt to check them either. Naturally, if there is no production date on the packaging at all, then it is better not to buy such a product;
• cement should be stored in dry and well-ventilated areas, otherwise it will quickly turn to stone;
  
• color of quality cement– gray, more precisely from light gray to dark gray and even greenish. Dark and marshy shades are not allowed. Good cement should crumble in your hand and not crumple into a lump when squeezed;
• The fineness of grinding affects the curing process. The finer the particle fraction, the faster the composition will harden and the higher its price. Too fine a fraction increases water consumption, so ideally it is better to take cement where fractions from 40 to 80 microns are found;
• does not interfere with carrying out assessment of cement composition and characteristics. This is not difficult to do, but you need to prepare sodium bicarbonate water in advance (Borjomi will do) or sodium bicarbonate chloride water. Gas must be released from the water. Next, we use it to knead cement dough and form it into a cake with a diameter of 15 cm. It should be thicker in the center (5 cm), narrower towards the edges (1 cm). High-quality cement should begin to set no later than after 10 minutes, and the thickened part will noticeably heat up. If setting does not occur even within 30 minutes, then you have a composition of low quality.

No. 7. The best cement manufacturers

Finally, we once again emphasize the need for information on the packaging about the brand of cement, its properties, production date and contact details of the manufacturer.