In any construction work it is necessary to adhere to a specific procedure to ensure that the result is of the highest quality. The exact order of loading the concrete mixer is one of the most important factors that affect the final quality of the mortar.
Concrete mixer - construction equipment designed to prepare a homogeneous concrete mix.
To begin with, it is necessary to distinguish between concrete and cement, since they are used for completely different needs. The structural component in them differs only in the presence of rubble (in cement there is none), but in practice there are differences.
Concrete is used for bulk work: pouring foundations, grillage, monolithic walls, columns and other elements more than 2 cm in thickness. Usually they are filled in only 1 time for the whole life of the building, therefore it is desirable to use materials of the highest mark
Concrete is needed when pouring foundations, columns and other elements more than 2 cm in thickness.
Cement is used for more delicate work, and it is often possible to meet layers of 3-5 mm, because Such indicators are used when working with most building materials. Also sometimes small-sized columns and panels are cast from cement, i.e. those items for which it is impossible to use rubble for one reason or another.
Brand - bearing capacity in the ratio of kg \ cm ², i.e. M300 means that 1 cm² can withstand up to 300 kg.
The composition includes up to 4 components: cement, sand, gravel and water, and many companies implement sand-gravel mix (CBC), which is immediately mixed in an optimal ratio. Sand and cement must be washed before use.
Dry cement mixture is the main binding material, and it is desirable to take the highest brand, because when diluted with third-party impurities brand decreases. Even with proper storage, the cement is caking, which is why it can be used only as a low-quality mixture.
Table of application of cement mortars.
Sand is the main impurity, and its granules come in different sizes, which significantly affects the final result. Large granules of sand can partially compensate for cement, but not more than 7-10%, so you can not rely on this factor.
Gravel is a large aggregate, directly affecting the strength indicators, as well as the volume of other additives consumed. It is necessary for filling massive solid products.
Water - only drinking water is used, without garbage, so as not to harm the solution. It is usually required in small quantities.Back to table of contents
Mixing options and order
There are two loading sequences in the concrete mixer, the first for the manual version and the second for the industrial one. With manual loading, a lot of solution cannot be made in one go, while the industrial version of ordering is a bit more expensive, but the result is also better.
Manual loading of a concrete mixer begins with mixing 1.5: 1.5 ratio of sand and gravel in a mixer bowl or filling 3 shares of the mixing and mixing unit. Then the mixer is started and 1 share of cement is poured in, and it is desirable to leave 1 minute for mixing. And only at this stage you can begin to fill the water, and its amount varies from 0.8 to 1.2, depending on the preparedness of the solution. Mixing time - 2-3 minutes, after which you can stop the mixer and extract the resulting mixture from it.
The proportions of the components of concrete.
If not concrete, but cement is prepared, then the ratio of sand, cement and water will be 2: 1: 0.8.
But the industrial version is much more difficult, because requires greater accuracy:
- Sand and gravel are mixed in a ratio of 1: 1.5, which results in maximum quality. If cement is to be prepared, then 1.4 fractions of sand are used.
- Mixing the cement mixture and cement, but the process still occurs in separate dry containers.
- 70% of water is poured into the automixer.
- The dry mix is poured as fast as possible, after which the rotation of the concrete mixer starts.
- After 1 min, the remaining amount of water is added, and you need to carefully observe, because the planned volume is far from being always needed.
If the sequence is disturbed, then a solution with lumps or insufficient quality can be obtained at the exit. It is worth remembering that with prolonged stirring the solution will gain momentum, but it lasts 23-30 minutes, after which the opposite effect takes place sharply, therefore it is better not to risk it.
Sometimes there are misunderstandings when the order of loading the concrete mixer is disrupted for some reason, and it turns out to be noticed after the start of the mixer, which is still not fatal. If the solution turns out to be too liquid, then 10% of coarse sand or 5% of cement should be added, depending on the circumstances, whereas 5-10% of water is poured for too thick.
It is worth remembering that even in those places where high quality results are not required (M100 is enough), it is better to overpay a little, but make the most durable construction.
It is because of the high grade and durable construction foundations withstand the pressure of heaving soils, seasonal frosts, flooding and other adversities.