What concrete is made of: components and their role

Today, artificial building material is one of the leaders in its field. High-strength concrete of different brands has outstanding characteristics. From it erected buildings, characterized by reliability, durability and durability.

Concrete interacts well with the reinforcing material. This tandem is highly valued when building reinforced concrete structures. If you are interested in the question of what concrete is made of, then it is worth paying attention to 4 main components, among which:

• sand;
• cement;
• Crushed stone;
• water.

These ingredients are added in certain proportions and play a role.

Main Components

Concrete mixture, also called commodity concrete, is a rolling stock of components that are kneaded in a given proportion. If the crushed stone is not added to the composition, then it is possible to obtain a traditional cement mortar, or sand concrete. However, in the latter, sand is used in a larger fraction.

For the preparation of a concrete mixture, four pieces of crushed stone, part of cement, two parts of sand and 0.5 parts of water are usually used. Quite often beginners are interested in the question of what concrete is made of. This material can be considered on a concrete example. To obtain it, you should connect 180 liters of water, 1250 kg of crushed stone, 330 kg of cement and 600 kg of sand. These figures are approximate, but in fact the specific values will depend on a number of factors, among them it should be noted:

• Brand of cement;
• Brand of concrete;
• Use of plasticizers and other additives;
• Characteristics of sand and gravel.

For example, if you take cement mortar grade M400, then applying the above ratio will produce concrete M250. But the work can be applied cement grade M500, then the brand of concrete in the final case will look like the M350. Dozens of characteristics and parameters are taken into account when manufacturing concrete under the conditions of a plant.

The role of the main components in concrete

If before you, too, the question arose of what concrete is made of, then you should become more familiar with the role of the main ingredients. Thus, water and cement act as main components. They are entrusted with the main function, expressed in a combination of ingredients in a single structure.

If you correctly observe the proportions of these components, you will be able to perform the main task when shutting down the concrete. In construction, this relationship is called water-cement. This is not only about the volume of liquid and cement, but also the humidity of sand, as well as rubble and their water absorption.

When combined with water, cement begins to interact with it, which is called cement hydration. This component begins to grasp and harden, forming a cement stone. Many faced this stone when they opened a bag of cement, stored in a barn for several years.

Cement and water are already ready material. But with solidification, the cement stone is deformed. Shrinkage can be 2 mm per meter. This, though a little, but because of the unevenness of the shrinkage processes, internal stress can arise, which contributes to the formation of small cracks. Although they are almost invisible, the durability and strength of the cement are reduced. In order to reduce deformation, traditional fillers are added to the composition, among them sand and crushed stone.

Role of aggregates

Now you know what concrete is made of, but it is also important to know the role of fillers. Crushed stone is the largest, while sand is fine. These ingredients are designed to create a structural framework that takes on shrinkage stresses during operation.

The ready-made concrete as a result gives not so impressive shrinkage. Strength becomes higher, under load the deformation of concrete is reduced. Creep is reduced when the material changes its dimensions under long loads. To reduce the cost of concrete, fillers are still needed. For the reason that cement is more expensive than sand and gravel, the last ingredients are simply necessary in the material.

Transfer of weight fractions into three-dimensional

At the very beginning of the article, you got acquainted with the proportions of the main ingredients of concrete. It is not superfluous to translate into volume fractions and weighted ones by making a calculation. This information will be useful to you, if you are thinking about how to make concrete, the proportions need to be studied. If the cement is taken in an amount of 0.25 m ³ , then the water must be taken in the volume of 0.18 m ³ . The first ingredient is taken in a weight of 330 kg. The average bulk density of cement is 1300 kg per cubic meter.

As for water, it is taken in the volume of 180 liters. Weight 0.9 m ^{3 of} crushed stone at a bulk density of 1350 kg per cubic meter is 1250 kg. But 0.43 m ^{3 of} sand is 600 kg of material, while the bulk density of this aggregate is 1400 kg per cubic meter.

If you are faced with the question of how to make concrete in what proportion, you should familiarize yourself with the data presented above. But according to estimates, in the end you will be able to get 1.76 m ³ . You may be interested in the question of how all this is placed in 1 cube of concrete. To answer, you need to take a liter jar and fill it with rubble. Between the stones there will be a lot of space, which is called intergranular emptiness.

This voidness should be covered with two glasses of sand, a glass of cement and the same amount of water. All this is shaken and mixed, as a result of such manipulations you will receive a dense substance. All pores of the material will be filled, the constituents will rub against each other. If the concrete is not touched, it will begin to harden. With mixing and vibrating, the material will again become plastic, it will retain thixotropy.

It is important to mention a few more words about the large aggregate - gravel. Its brand should be 2 times as much as strength. This is true if you compare with the design mark of concrete. This requirement is due to the fact that the design grade of concrete is lower, compared to the real strength, which the material collects in six months. But the strength of the rubble remains the same. Therefore, their leveling is necessary.

In addition to the proportions of concrete from cement M400

If you are still thinking about the question of how to make concrete, the proportions of this material should be considered more carefully. Using cement M400, you can get concrete of different brands, if you add the main ingredients: cement, sand and gravel in certain proportions.

To obtain concrete grade M100 components in the above sequence should be added in the following ratio: 1: 4.6: 7.0. But if there is a desire to get concrete grade M200, then cement, sand and crushed stone are added in such proportions: 1: 2.8: 4.8. The highest grade of concrete - M450, for its preparation, the ingredients are added in the following ratios: 1: 1.1: 2.5.

Preparation of concrete for the foundation

If you started building a house, you should know how to make concrete for the foundation. You need to take 10 kg of cement, 40 kg of rubble or gravel and 30 kg of sand. To obtain concrete grade M300 water should be added half as much as the weight of the remaining components. If the solution is too dense, then it can be slightly diluted. It is better to stick to the consistency, which will allow to mix the liquid material with a shovel with the application of forces. That is, the solution should not drain off the shovels easily and quickly.

Asking about the proportions in which to make concrete for the foundation, you must answer yourself to it even with the fact that the sand may turn out to be moist. If it contains moisture, then before mixing the components, a small aggregate should be dried or taken away several liters of water. Sand should be checked for cleanliness. The purer it turns out, the better it will grasp the solution.

Additional recommendations

Gravel and crushed stone are better used in the fraction within 2 cm. Cement should not be purchased long before the beginning of construction, as it will absorb moisture during storage and will certainly deteriorate. It is recommended to do this about a week before the mixing of the concrete mix.

If we make concrete with our own hands, the proportions must be observed. In this case, it is better to fill the foundation in the warm season. When the temperature is lowered, it is necessary to heat the water and the solution so that it does not catch before. Otherwise, the material will not be so strong, besides, it will not be tightly connected with the armature or not at all condensed.

Using a concrete mixer for the preparation of concrete

If you decide to use a concrete mixer when preparing a mortar mixture, it is important to make sure that the ingredients do not contain foreign impurities. Crushed stone should be granite or gravel, only then the batch will turn out better.

Then, the dry components are mixed together in a separate container. For this, cement and sand are combined. For this, a trough or bath is usually used. If you, too, are among those who are wondering how to make concrete in a concrete mixer, then at the next stage, the resulting mass must be poured into a container where the kneading will be carried out. However, before that, crushed stone and water are added.

Methods of work

It is necessary to knead only after the last component, crushed stone, has been added. For good mixing, it is desirable to take the water clean, it should not contain salt. After completion of the work, the concrete mixer is cleaned, there should not be any mixture left in it. For this, water is poured inside and a little gravel is added. Mix concrete in the concrete mixer until a homogeneous mass can be obtained.

Conclusion

Now you know how to properly make concrete in a concrete mixer, and also in what proportions to add the basic ingredients. Use can be concrete mixers of different designs. Some of them are gravitational. In this case, the drum blades are responsible for the mixing. The angle of the drum can be changed.

The second type of concrete mixers are devices of forced action. Whichever equipment you use, the main thing is to mix the components in the right proportions.