Before kneading concrete, the proportions of which will be indicated below, it is necessary to choose the right components. Generally speaking, concrete is a mixture based on all kinds of aggregates and cement. Thus, 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. We can distinguish the main characteristic of concrete, which consists in compressive strength. Based on the strength of the solution after solidification, it is divided into grades.
Concrete composition
If you are thinking about how to mix concrete, the proportions of which will be indicated in the article, you first need to 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. At the same time, a small amount of water is added to the composition so that the solution regains its density according to the type of wet soil. If there is a need to prepare stronger concrete, it is necessary to use crushed stone as a filler, the fractionality of which varies from 3 mm to 35 mm.
Aspect Ratio
Before mixing concrete, the proportions must be studied. For different purposes, it will be necessary to prepare concrete of different compositions. For example, if it is supposed to form balusters, then, choosing a placeholder, it is necessary to prefer one that has a medium or small fraction. The same applies to pouring garden utensils, decorative elements, as well as steps. The most common proportions for the preparation of concrete are 1: 3: 6, with regard to cement, sand and aggregate. Among other things, it is necessary to use half or one part of water, which will be determined by the desired fluidity of the solution.
If you are thinking about how to mix concrete, the proportions of the 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 humidity than usual, it must first be dried, since it will have a more impressive weight than that which will be required to prepare the correct solution. The same applies to gravel.
Proportions for the preparation of a particular brand of concrete
In order to prepare M100 brand concrete from M400 cement, it will be necessary to use cement, sand and gravel in the following proportion - 1: 4.6: 7. But for the manufacture of concrete grade M 150 it will be necessary to prepare all the same materials, but in a slightly different ratio, while cement must be used in the amount of one part, while sand will be used in the amount of 3.5, but crushed stone should be used in proportion 5.7. To prepare concrete M200, it will be necessary to prepare the listed materials in a ratio of 1: 2.8: 4.8. In order to prepare a solution of brand M 250, you need to prepare materials in a ratio of 1: 2.1: 3.9. To prepare a solution of M 300, the master will have to take materials in a ratio of 1: 1.9: 3.7. Concrete grade M 400 will turn out if you use the feedstock in a ratio of 1: 1.2: 2.7. Concrete brand M 450 comes out if you apply a ratio of 1: 1.1: 2.5.
Component Requirements
Before mixing concrete, the proportions must be carefully studied. But it is important not only to observe the correct ratio, but also to take into account the requirements that apply to each component of the solution. For example, if you use cement grade M 400, and not M 500, the structure after hardening will not be so strong. In any case, manipulation with concrete can not be performed at temperatures below 16 0 C. If such a need arose, then plasticizers will need to be used.
Before mixing concrete, study the proportions well. It is important to pay attention to the state of the individual components. Cement, for example, should be not only loose, but also dry. Do not buy cement, which has clumps or has high humidity. You should not purchase goods that are not marked. It is preferable to purchase cement immediately before starting work, as during storage it is able to gain moisture and lose its qualities. The recommended time for the purchase of cement is 2 weeks before the start of work.
Sand requirements
If you are thinking about 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. It is preferable to use sand for concrete, 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 and plant debris in the sand. The presence of all these components can affect the quality of concrete. Once you know in what proportions to mix concrete, you can start work. But you should 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.
Placeholders
If you are concerned about how to mix concrete, the proportions table will help determine. It is important to consider the quality of the placeholders. They give strength to the concrete mixture after solidification. So, do not use regular 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 fragmented by nature. Among other things, claydite is used to prepare concrete, which is strong enough, but at the same time it has a small weight. When choosing gravel, you need to be guided by a fraction ranging from 8 to 35 mm. Larger fractional elements are used in production, which is very rare. In this case, it is also important to take into account that the aggregates should contain the least amount of extraneous clay inclusions. If necessary, you need to free the raw materials from extraneous debris. It is important to choose a filler that has the greatest roughness. This will guarantee high grip quality.
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 consider not only the ratio, but also the need for additional components. Among them, lime can be distinguished. About it will be discussed below. It is necessary to use good quality water when mixing the solution. It should be clean, it should not have inclusions in the form of acids and alkalis. It is unacceptable to use untreated or river, lake water. Drinking water 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 mixing 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 can interfere with the bond of cement with aggregate, which is contained in the composition, which can significantly affect the strength. Thus, to use lime or not, you need to decide the master. Do not think that its use will be extremely difficult, it does not need to be extinguished on its own. Instead, you can use ready-made slaked lime, sold in stores of building materials.
Finally
Before mixing concrete, the proportions (they do not differ in the concrete mixer) must be carefully studied. This will allow to obtain high-quality concrete, which after solidification will be characterized by high strength.