How to knead concrete: proportions (table)

Before mixing concrete, the proportions of which will be indicated below, you must select the right components. Generally speaking, concrete is a mixture based on all sorts of aggregates and cement. Thus, the concrete contains gravel, pebbles, gravel, sand and cement. Among other things, special additives such as plasticizers can be used. Their task is to give concrete certain properties. It is possible to distinguish the main characteristic of concrete, which is the compressive strength. Based on the strength of the solution after solidification, it is divided into grades.

Composition of concrete

If you are thinking about how to mix concrete, the proportions of which will be indicated in the article, you should first know that the simplest kind of concrete consists of cement and coarse sand. Such a solution, as a rule, is used as a substrate under the base of the building. In this case, a small amount of water is added to the composition, so that the solution gains density as wet soil. If there is a need to prepare a more solid concrete, it is necessary to apply as aggregate crushed stone, the fractionality of which varies from 3 mm to 35 mm.

Selection of proportions

Before mixing concrete, the proportions must be studied. For different purposes it will be necessary to prepare concrete of different composition. For example, if it is supposed to form balusters, then, choosing a filler, it is necessary to prefer one that has an average or shallow fraction. The same applies to pouring garden utensils, decor elements, and steps. The most common proportions for the preparation of concrete are considered 1: 3: 6, as for cement, sand and aggregate. Among other things, it is necessary to use half or one part of the water, which will be determined by the required fluidity of the solution.

If you are thinking about how to mix concrete, the proportions of materials should be taken into account, but it is important to pay attention to the composition of the ingredients. Thus, if the sand has a higher moisture content than usual, it must first be dried, since it will have a more impressive weight than that required for the preparation of the correct solution. The same applies to gravel.

Proportions for the preparation of a certain brand of concrete

In order to prepare concrete grade M100 from cement M400, it will be necessary to use cement, sand and crushed stone in the following proportion - 1: 4,6: 7. But for the manufacture of M 150 concrete it will be necessary to prepare all the same materials, but in a slightly different ratio, with cement used in the amount of one part, while sand will be used in a volume of 3.5, but rubble should be applied in proportion 5.7. For the preparation of M200 concrete it will be necessary to prepare the listed materials in a proportion of 1: 2.8: 4.8. In order to prepare a solution of grade M 250, it is necessary to prepare materials in the proportion 1: 2,1: 3,9. To prepare a solution of M 300 the master will have to take materials in the proportion of 1: 1.9: 3.7. Concrete brand M 400 will be obtained if the raw materials are used in a proportion of 1: 1.2: 2.7. Concrete brand M 450 comes out, if you apply a ratio of 1: 1.1: 2.5.

Requirements for components

Before mixing concrete, the proportions must be carefully studied. But it is important not only to keep the correct ratio, but also to take into account the requirements that are imposed on each component of the solution. For example, if you use cement M 400, not M 500, the design after hardening will not be so strong. In any case, manipulation with concrete can not be carried out at a temperature below 16 ^° C. If this need arose, plasticizers will need to be applied.

Before mixing concrete, the proportions are well studied. It is important to pay attention to the state of the individual components. Cement, for example, should not only be loose, but also dry. Do not buy cement, which has a lump or has a high moisture content. Do not buy a product that is not labeled. It is preferable to purchase cement immediately before the start of work, because during storage it is able to collect moisture and lose its qualities. The recommended time for the purchase of cement is 2 weeks before the start of work.

Requirements for sand

If you are thinking about the question of how to mix concrete correctly, the proportions for its preparation can be seen above. It is necessary to take into account the quality of the sand that will be used in the work. Use for concrete is preferable to sand, the fractionality of which varies from 1.5 to 5 mm. It is recommended to use sand of uniform size, there should be no impurities in its composition. Make sure that there is no debris in the sand and plant debris. The presence of all these components can affect the quality of concrete. After you have learned in what proportions to mix concrete, you can start work. But do not use materials that have not been tested for quality. So, for reliability, sand is preferable to pass through a sieve. It is recommended to use river sand for high-quality concrete, despite the fact that it is more expensive compared to what is called ravine.

Fillers

If you are worried about the question of how to mix concrete, the proportions of the table will help determine. It is also important to take into account the quality of the aggregates. They give the strength of the concrete mixture after hardening. So, do not use ordinary or sea pebbles, which has a smooth surface and does not guarantee adhesion to the solution. It is recommended to use material that has been shattered by nature. In addition, it is used for the preparation of concrete expanded clay, which is strong enough, but at the same time it has a negligible weight. When choosing gravel, you need to be guided by a fraction ranging from 8 to 35 mm. Larger faction elements are used in production, which is very rare. In this case, it is also important to take into account the fact that the aggregates should have the least amount of extraneous clay inclusions. If there is a need, you need to free the raw materials from foreign debris. It is important to choose such a filler, which has the greatest roughness. This will ensure a high quality grip.

Additional components

If you are thinking about how to mix concrete in a concrete mixer, the proportions presented above can be used by you. It is important to take into account not only the relationship, but also the need for additional components. Among them, lime can be isolated. It will be discussed below. It is necessary to use good quality water when mixing mortar. It should be clean, it should not contain inclusions in the form of acids and alkalis. It is inadmissible to use untreated or river, lake water. Water, suitable for drinking, can be used in the preparation of concrete.

Additives

If there is a need to make concrete more convenient for laying, lime can be used in the process of kneading the composition. After laying the solution prepared with its use, it will be easier to level the surface. But it is worth remembering that lime is capable of hindering a bunch of cement with a filler that is contained in the composition, which can significantly affect the strength. Thus, to use lime or not, it is necessary to solve the master. Do not think that its application will be extremely difficult, it does not need to be extinguished on its own. Instead, you can use the ready slaked lime, sold in stores of building materials.

Finally

Before mixing concrete, the proportions (in a concrete mixer they do not differ) must be carefully studied. This will make it possible to obtain high-quality concrete, which after hardening will be characterized by high strength.