What cement to choose

Any construction with work related to the pouring of a concrete foundation, which, first of all, requires cement. This material, however, is necessary during all the work, including finishing, despite the appearance of new technologies and materials in the construction sector. Since no turnkey buildings are complete without cement, it is important to be able to choose the right cement, understand the label and look for reliable suppliers. To do this, you need to find out what cement is, and where it is used.

Content:

1. The concept of cement marking
2. Popular types of cement
3. The right choice of cement
   • Cement quality
   • Price and manufacturer

The concept of cement marking

An important characteristic of cement strength is its brand, which is the basis for the choice of this building material. A laboratory test was taken as the basis for the classification, within which the cement product was subjected to increasing load. For all varieties of material, except for rapidly hardening, clay -ground and slag port -cement, the brand will correspond to the strength limit when bending samples, which have dimensions of 40 by 40 by 160 millimeters, and compressing their halves from a plastic mass of 1: 3 at the age of 28 days.

Quick -hardening Portland cement and slag portland cement is checked after 3 and 28 days. Marking for clay -ground cement is installed according to the test results after 3 days. As a result, the following scale was accepted, which gave the marking of various varieties of cement: m 100 700. The letter M (or may be the designation of the PC) next to the number indicates the maximum strength qualities of the material.

For example, the M300 cement, according to this marking, can withstand loads of 300 kilograms per cubic centimeter, brand cement 500 in 500 kilograms, etc. The higher the brand, the greater the efficiency of the use of cement in concrete. The most popular are cements with the labeling inclusive 350 - 500. The most durable is the cement of the M400 and M500 grades, which is customary to use for the construction of the foundation. For the work of finishing work, M200 and M300 brands are used.

What cement brands are except the above? In addition to the ability to withstand certain loads, the cement is also marked in another parameter - the percentage of the total volume of cement of different additives, which is contained in the building material. The additives can be a slag from the waste of a metallurgical plant or gypsum. This parameter is indicated by the letter D.

For example, in cement with the designation D20 there are 20% of additives. A similar characteristic is important, because the level of content of additives is able to influence its strength and plasticity. The construction market is currently most popular with 4 types of cement: M400 D0, M400 D20, M500 D0 and M500 D20. The price of a cement with additives is slightly lower, because the clinker is much more expensive than any additive.

What are the cement brands yet? In addition, there are additional designations b, pl, SS, GF, N. This is evidence of a specific purpose of this building material. The letter B means fast -hardening, that is, cement, which is capable of rapidly hardening in the initial period.

The SS designation is inherent in sulfate cement, GF - hydrophobic cement, PS is plasticized cement, which contains a plasticizer that increases the plasticity of the structure and the possibility of changing its shape. Marking N is applied to cement, which is performed on the basis of the clinker, which has a normalized composition, and is used for the production of road coatings and airfields.

Popular types of cement

Depending on the composition and ratio of additives, today the such varieties of cement are distinguished: Portland cement, white, slag, pozzolan, fast -hardening, expanding, clay -ground, waterproof expanding, tampon, sulfate, straining, magnesia, hydrophobic. To better understand which cement is better, we offer to get acquainted with the description of the main varieties of cement.

Portland cement is widely used in modern construction. The material is made of small portland -cement clinker, additives and gypsum thinly. The clinker for this cement is obtained through the procedure for firing raw materials before sintering, after which the content of calcium silicates increases to optimally. Two-water gypsum (15-35%) is often introduced into the clinker to regulate the capture speed of Portland cement. Today, unlimited and mineral and slag portland cement are also made.

A slag or slag -bore cement combines all varieties of binder substances, produced by the method of thin grinding of domain slag in granules, which contains activating additives of anhydrite, lime and construction gypsum. Today we can name such types of slag cement as sulfate-lump (15-20% anhydritis or gypsum, 5% Portland cement and 2% lime) and slag-knowing (10-30% lime, 5% gypsum).

Quick -hardening cement is able to increase the strength at the first time of hardening, which is useful in the manufacture of various prefabricated products from reinforced concrete. High mechanical strength can be achieved at the expense of a special mineral composition, an accurate dosage of additives and the subtleties of cement grinding. Today, the production of such types of this material has been established: a fast -hardening Portland cement, which reaches the compression strength after 3 days, a slag portland cement of fast hardening and Portland cement of a particularly fast hardening.

Potzzolane cement is a substance in which more than 20% of mineral additives are present. Potzzolans were used as an additive to the lime in ancient Rome in the manufacture of a puzzola-lime substance. Currently, a puzzlan Portland cement is obtained after grinding 60-80% of the clinker, 20-40% of the mineral additive and gypsum. It is highly resistant to corrosion, which manifests itself better in soft and sulfate water. However, the speed of hardening and frost resistance is low.

Expanding cement is a group of cement substances with the ability to increase their volume in the process of hardening. The expansion is performed due to the formation of a high -axial hydraculomatoal of calcium during the interaction of the powder with water. This substance is able to bind a large amount of water, exceeding the initial volume of solid mass by 15-25 times. How to choose a cement of this variety - gypsoglin -ground, waterproof and straining, as well as Portland cement, solve only to you. All expanding cements can well harden and optimally expand in a humid environment.

The waterproof expanding cement is known as a hydraulic binding substance, produced by joint grinding and further mixing of clay -ground cement, gypsum and calcium hydrogenum to a homogeneous composition. This material is inherent in a very rapid setting, which begins after 4 minutes and ends after 10 minutes. The linear expansion of products made from this cement, which are in water during the day, remains at 0.3%.

Clay -enemized cement is distinguished by fast -harding abilities. It acts as a product of the thin -dispersed clinker grinder, which is obtained from a burned raw material mass, which includes limestone and bauxite. The process of firing and melting the clinker is performed in vagra or electric domain furnaces. Classify clay -earth cement in content in the product AL2O3. There is a standard clay -zoom cement with a clay content of 55% and high -clinomic cement, in which there are 70% of clayema.

Sulfato -resistant Portland cement has a high resistance to aquatic environment with an increased concentration of sulfates in comparison with standard material, a slight release of heat, low hardening and significant resistance to frost. This cement is produced by means of thin clinker grinding, which has a special mineralogical composition. Such cement is operated mainly in an aggressive sulfate environment.

Strengthening cement is a separate variety of expanding cement, which is produced using the grinding of such components: Portland -cement clinker (65%), clay -zoom slag (15%), lime and gypsum stone (5%). The straining cement is inherent in high speed of hardening and setting. A fully hardened solution of such straining cement has a rather high water resistance. This feature is used to pre -create voltage in different reinforced concrete structures, tension in the reinforcement in several directions.

Temponal cement is a special type of cement used in oil and gas production. This cement is carried out by means of thin -dispersed clinker grinding with the addition of gypsum. Today, two varieties of tamponal cement are made: for oil and gas wells of hot and cold type. In solutions based on this cement there is 40 - 50% of water.

Hydrophobic cement, which is not difficult to understand from the name, is characterized by increased water resistance. This material is the result of a finely dispersed grinding procedure of gypsum, clinker and special additives responsible for the characteristic properties of the powder. The additives include cubic residues of fatty acids, oleic acid, oxidized Petrolatum and Asidol Myylonaft. They are introduced into a proportion of 0.1-0.3% of the total mass of cement. But even such a small number of additives leads to the formation of a monomolecular hydrophobic film on the surface of particles of cement, which reduces the hygroscopicity of cement. Needless to say, which cement is better for the foundation?

Magnesial cement serves for the production of floors. It is made on the basis of finely dispersed powder, part of which is a magnesium oxide product of the medium -compulsory firing of the natural carbonate breed of magnesite or dolomite. With the noisy of magnesian cement using a solution of magnesium chloride, a binding substance called a sorel cement can be obtained. Magnesial cement has increased elasticity, greater resistance to lubricants, organic solvents, alkalis and salt, high resistance to fire and low thermal conductivity.

The white sequence is made of a low -stroke clinker. Its gray color is determined by the presence of iron compounds in the raw material material. To eliminate greenishness and increase the clinker, they are whitened. The composition is white and white Portland cement with cement additives. In white Portland cement, the content of mineral additives is excluded, they should be in Portland cement with additives of not more than 20%, inert not more than 10% of the total mass of Portland cement. The unique characteristics of white cement allow it to be used in the manufacture of sculptural elements and in finishing work, for example, when decorating the facades of the building.

Waterproof unsuccessful cement is a rapidly sinking hydraulic substance, which is made by mixing clay -earth cement, lime of extinguished and semi -water gypsum. The start of grasping ends no later than 5 minutes from the moment of closing. Cement is used for the device of waterproofing shells of concrete and reinforced concrete structures, which are operated in high humidity conditions, as well as hydrophobic types of cement.

Color Portland cement is made from the clinker of white cement, bleached and colored clinics by mixing or simultaneous grinding with pigments of different tones, for example, with ocher, chromium oxide or iron sorik. All pigments are alkalis and light-resistant. Color Portland cement is yellow, pink, red, brown, green, blue and black. Color Portland cement contributes to the architectural and decorative design of various buildings.

Acid -pushed quartz cement is carried out by a joint grinding method or mixing of separately ground silly sodium and quartz sand. Such material is shut up with an aqueous solution of liquid sodium glass. A similar cement stone opposes the action of different organic and mineral acids, but it loses its strength in water, and is destroyed - in caustic alkali. Acid -pushed cement is usually used for the manufacture of acid -resistant concrete.

The right choice of cement

Now it's time to talk about how to choose cement, what cement is needed for the foundation, and which for filling. The quality of construction primarily depends on the correct selection of the cement brand, as mentioned above. If you do not guess the strength of the cement, then this is fraught with the appearance of defects and the destruction of the structure. In each case, take into account the required strength of the cement mixture and the necessary strength for each design. For private development and do-it-yourself cementing, it is best to buy M400 cement, which is cheaper than the M500 material by 10-15%.

Cement quality

Without a cement mortar, no construction work will be able to carry out. Therefore, its quality remains very important. The quality of cement is confirmed by the ISO-9000 international standard. If you see such a designation on the packaging, this means that you have a product that meets all international quality standards, and guarantees that during construction, unforeseen situations will not happen to it.

Before buying cement, it is mandatory to investigate its packaging. The best packaging is two -layer paper. In this case, a waterproof is used in its hem, which protects the material from the negative effects of water. The packaging should be sealed, without scratches and traces of autopsy.

On the packaging material, you should see all the operational properties of building material: weight, brand, manufacturer. If you plan to buy cement wholesale, you can get to expired or poor -quality goods, so inspect every packaging if possible.

Like other things, you can determine the quality of gray powder by the date of manufacture and the terms of its fitness. The longer it was stored, the more its qualitative indicators decrease more. If the cement is already 6 months, then its activity decreases by almost a third. Also ask sellers exactly where this cement was stored, since this material has a strong influence of the environment, in particular dampness.

Find out what good cement, and whether quality material is in front of you in appearance. Remember that high -quality cement should not have a swamp or dark color. Its natural color is gray, sometimes with darker shades. Take it, high -quality cement is able to pour through the fingers when compressed in the palm of your hand. He is not compacted in whom. Naturally, aniered cement cannot be used. Most often, high -quality cement varieties are ocked.

Price and manufacturer

Most often, the difference in the cost of cement is determined by the accuracy of packing. The best option is cement in bags. The production of this building material in bags is engaged in the border and in the CIS on specialized bases, in construction narrowly -fired supermarkets or directly at the cement plant. On the other hand, it is much more profitable to buy cement in bags in comparison with the scatter, and it is easier to store it.

Any manufacturer who deserves attention and respect subsides his product in bags, which indicate its own address and phone number, as well as the accuracy of weighing. Usually, an authoritative and well -known figure in the market is considered a good supplier, which values \u200b\u200bhis customers and his reputation. If there is no information about the manufacturer on the bag, then you need to be personally familiar with the facultiers in order to safely buy such a product.

And finally, remember that the price of cement, which depends on the brand of cement, is not always a guideline. The modern construction market is rich in fakes, for example, unscrupulous manufacturers have been practicing in recent years to reduce the concentration of cement dust to reduce prices for their products, which subsequently leads to poor quality of cement mortar, which is not able to retain moisture and can crumble immediately after the construction is completed . Therefore, it is worth focusing not on the price, but on the reputation and guarantees of the supplier.