Cement additives: Features of application

In order to increase the quality characteristics of the cement mortar, special substances are added to it. There are several types of cement additives that give it certain properties. We will consider further about the features and varieties of additives for cement.

Cement additives: varieties and features of cement

Cement did not appear so long ago, but managed to gain popularity very quickly. To obtain it, clay and lime were interconnected and burned them in a special way. Cement is the main component of most of the construction compositions. In addition, polymer -cement compositions are made on its basis.

Cement also contains substances based on aluminum and silicates, for the formation of which raw materials subject to high temperature are used. At the same time, after solidification, the cement becomes rather solid and durable.

There are several options for cement, in relation to their composition. Each of them has a certain characteristic of hardness, on which the brand and product quality depends. There are several cement options, the most common brands from two hundred to six hundred. At the same time, the choice of a particular type of cement is directly determined by the sphere of its application. We offer to get acquainted with the main types of cement:

1. The use of Portland cement is quite common. This material is also called silicate. It has the form of a hydraulic binder, which hardens both in an ordinary environment, in contact with air, and dissolving in water. In appearance, this material is gray-green powder, which needs to add water to knead it. When grasping the cement composition, its gradual hardening occurs. Portland cement is the main component for almost every type of cement compositions.

2. The use of a plasticized cement version is characterized by a large number of advantages. This material allows you to reduce the level of cost of preparing the solution, the cement mixture becomes not subject to frost, moisture, evaporation and other negative environmental factors.

3. There is another type of cement called slag. For its manufacture, a clinker and blasting slag are crushed. Certain substances are added to the resulting mixture, in the form of gypsum or lime. This solution is used in the process of mixing construction compositions.

4. The material in the form of clay -earth high -acting cement is unique. The time of its setting is no more than forty -five minutes, and in order for the composition to gain strength, ten hours are enough. The main advantage of this composition is the ability to quickly grasp, despite the high humidity of the environment. If you add this version of cement to concrete, it has additional resistance before moisture, corrosion, a sharp change in the temperature regime.

5. If you interconnect Sillynftoride sodium and quartz sand, you will get a cement of an oxyupported type. Simple water is not used to dissolve this composition. For these purposes, applied liquid glass based on sodium. Among the positive characteristics of this cement, we note a high level of its resistance to mineral and organic acids. However, during the operation of this solution in caustic or moist conditions, the duration of its use is significantly reduced.

6. For the manufacture of colored cement, a regular Portland cement is used, to which various kinds of pigments are added. This type of cement is widespread in the decoration of facades. Also, it is the basis for the manufacture of concrete -based roads.

Portland cement, mixing with water, forms a plastic substance, which after drying acquires a stone shape. The widespread use of this substance is explained by the following advantages:

the ability to harden without extraneous intervention;
the formation of a stone product, which is characterized by high strength and hardness;
minimum level of chemical danger;
environmental Safety;
Fire safety;
affordable cost;
The wide area of \u200b\u200bapplication is versatility.

The independent use of Portland cement is a rarity, since most often it is a component of various kinds of composites, such as dry mixes, building concrete and solutions. To determine the Portland cement of the mixture, you should compare it with three criteria:

the quality of the initial powder mixtures;
cement dough and its characteristic;
The resulting cement stone.

Additives for cement and concrete - principle of action

Portland cement contains substances in the form of a clinker. To obtain this product, raw materials with calcium aluminals and silicates are firing. In order to make Portland cement, clay, Mergel and lime is used. Carrying out with water, cement is crystaging. After that, a substance is formed in the form of concrete stone, which has special qualities.

In the ratio with GOST, such types of additives in cement are distinguished:

1. In relation to the main action, they are:

material components;
regulators;
elements that simplify the process of cement grinding.

2. Foreign elements, in turn, are:

active minerals;
Filling components.

3. Mineral supplements in the cement of an active action are:

hydraulic action;
Potzzalanic action.

4. Regulatory additives are:

determining the time of setting the solution;
hardeners;
increasing strength characteristics;
plasticized substances.

Using a certain kind of additives for cement and concrete, it is possible to perform the following functions:

reduce moisture release from concrete solution, that is, increase its plasticity;
make a cement mortar more resistant to moisture;
increase or reduce cement shrinkage;
adjust the release of heat;
improve the decorative qualities of cement mortar;
adjust the cement dough in density;
Make the composition of the cement mortar more plastic.

Waterproof and polymer additives in cement

Polymer additives act as surface-active substances. With their help, it is possible to improve the quality of the concrete composition. With the help of certain compositions, it is possible to urinate the plasticity of concrete, reduce its moisture absorption, adjust the release of moisture. Thus, the strength characteristics of concrete are significantly improved. In some cases, using additives, materials are formed inside which air is located.

There is the possibility of transition of polymer additives to a state of tractism. With their help, it is possible to web concrete pores, increase the adhesion of a concrete solution with aggregates and reinforcement.

Addresses for cement help to make it moisture, frost -resistant, durable to stretching, gas -resistant. Another variety of additives is composed of substances of organic silicon. They release gases inside the concrete solution. Therefore, with their help, air is involved in the solution. It becomes more porous and resistant to frost and moisture.

Some varieties of additives have a hydrophobic effect. The principle of their action is based on the collmatation of capillary plexuses inside concrete. Thus, moisture migration is carried out. Using moisture -proof additives, it is possible to improve the structure and increase the density of the concrete composition.

Features of antimorological additives in cement

A negative temperature regime does not affect the performance of a concrete solution. This is due to the fact that at low temperature, the water located inside the solution begins to freeze. During warming, it melts and expands, worsening the quality of concrete. The effectiveness of resisting moisture enlarged in volume is called the frost resistance of concrete.

The resistance of the concrete solution to the frost determines the content of moisture in it. To ensure this characteristic, special additives should be used, most often it is substances with surface-active substances.

Plasticizers positively affect the creation of the optimal concrete structure. The structure of the solution is characterized by a higher density level, which makes the cement dough sedimentative. Some of the additives are designed to make the solution more vocal -saturated, thus, the water, after expansion, fills the pores and does not affect the quality of concrete in any way.

Keep in mind that in order to achieve a positive effect from the introduction of additives, only high -quality materials from trusted manufacturers should be selected. In addition, before applying additives, you should familiarize yourself with the instructions from the manufacturer and strictly observe all the proportions recommended for a particular type of additive.

When adding a small amount of additive, concrete will still be subject to frost. If the amount of plasticizer is too much, then the design will lose strength.

Modifying additives for cement: characteristics

These compositions are introduced into cement mixtures to improve their elasticity, resistance in front of cracks, deformation. In addition, with their help it is possible to increase the adhesion of concrete to the reinforcement and any non -entertaining base.

By introducing this kind of additives, it is possible to increase their clutch with tiles. Most often, these additives have a liquid form. They make cement materials more elastic, reduce the level of their shrinkage, are used both inside and out of the room, while they are distinguished by complete environmental safety.

Cement without additives, although it has its own operational characteristics, however, is rarely used due to its exposure to various kinds of external stimuli.

Another option for additive for cement is a substance with an anti -corrosion effect. With the help of these substances, it is possible to knit free calcium hydroxide in the concrete composition. In addition, some of the additives improve concrete density, making it not only not subject to corrosion, but also moisture -proof.

The additive of gypsum to cement increases its solidification time. In addition, with its help it is possible to improve the quality of the finished solution, namely its strength characteristics, frost -resistant qualities and resistance to sulfides.

For the manufacture of cements with active mineral additives, a crushed clinker is used. Additives are granular slag or active substances that are of sedimentary origin. The concrete to which these substances added is characterized by a high level of moisture resistance, excellent heat release and frost resistance.

Varieties of additives for cement

1. For a dry mixture or concrete with special characteristics, a plasticizer is used. With its help, cement and water expenses are reduced during the preparation of concrete solution. Plasticizers make the solution more plastic and mobile. Thus, with it, it is possible to fill out all the pores.

2. The additives of a water holding nature are presented in the form of starch or cellulose. With their help, it is possible to achieve a homogeneous consistency of concrete. In addition, they help to get rid of concrete delapping and such an effect as cement milk. However, the negative side of the use of these additives is a decrease in the strength of the base and a decrease in its mobility.

3. The use of redeemed powders is an excellent binder in the process of using cement for staining the surface. In addition, these substances are the basis for cement glue, since they give the composition high adhesion.

4. The second or third aggregate is a polymer type fiber. It makes the foundation persistent in front of the cracks, in addition, the resulting composition is characterized by high mobility and self -leveling.

To increase water resistance, substances are used in the form of hydrophisators. With the help of accelerators or hardeners, it is possible to regulate this process. The combination of several additives helps to give the cement the characteristics necessary for this type of conditions.

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