Choosing a brand of concrete
Before thinking how to prepare concrete, it is important to choose the appropriate brand that shows the compressive strength measured in MPa. The higher this indicator, the higher the quality. When choosing a brand, you need to consult a specialist, since each of them is designed for a particular type of work. For example, if you need concrete for a building that requires high accuracy and reliability, the M350 is suitable.
It is used for the erection of foundations, slabs, walls, beams and other things. By the way, before that, the brands M250, M300 were used for the same purposes, but now they are not as popular as the previous one( due to lower performance characteristics).In the event that your construction is not so responsible and you need to make a foundation for the utility room, a blind area, the track, the concrete M200 is suitable. Well, and for primary, preparatory work often choose M-100 and M-150( for the manufacture of monolithic slabs).
You can even not look at such brands as M400, M500.They are used only for large-scale projects( erection of dams, bridges, hydraulic structures).In addition to the brand, it is also important to pay attention to other indicators: frost resistance, water resistance. The first parameter indicates the number of defrost-freeze cycles and is indicated by the letter "F".The second indicator shows how much water can withstand the concrete coating. Its designation is expressed by the letter "W".
Choosing a filler
After you have decided on the brand of concrete, it's worth picking the placeholder correctly. It is he who creates a rigid framework that, when dry, will keep the shape of the product. For example, when constructing a residential house or a garage, only natural placeholders should be used. These include sand, gravel, rubble, stone. The main requirement for solid components( gravel, stone, crushed stone) is the absence of any synthetic particles and dust in them.
Sand should not contain parts of clay, because it has a plastic structure that adversely affects the concrete solution. It is better, if it is an inline sand. There is also a separation of all materials in size( grain size).For example, it is desirable to use the same sand coarse, rather than fine-grained. Sometimes make a mixture of both, as the first( with large grains) has a high cost. Well, the last, in some cases, you can still use an artificial filler( this may be slag).
Note! If you are building a dwelling, buy all the same natural fillers. Artificial can be used in the construction of sheds, utility rooms.
Manufacture of concrete by own hands
All materials are ready, the main question arises - how to make concrete with your own hands? As it turned out, it is not so difficult to cook it. This requires the following components: cement, crushed stone, sand, water. All this is mixed in the following proportion: 1: 2: 3( cement-sand-rubble). First mix sand and cement, as these two ingredients have a loose structure.
Then add water. It needs so much to get a homogeneous mass. That is, pour it into the composition to homogeneity. Only after that it is possible to lay rubble and add water again. The quantity of it can not be measured practically, as it directly depends on the brand of concrete used, and also on the quality of the fillers.
Therefore, the main recommendation: add it slowly with a small stream until the mass gets a uniform state. In the process of mixing, a concrete mixer can be used. However, it should be bought only if you are expecting large-scale construction. If you intend to build an ordinary garage, you can do without it( carry out the process manually).