Before determining the concrete for the blind area, you need to clearly define the functions of the blind area and the conditions of its operation.
Functions of blind area
Based on SNIP, two functions of the blind area can be distinguished. The first performs a protective function, i.e.protects the foundation of buildings or its elements from the ground. During the year, the soaking, thawing and freezing of the soil is regularly carried out, which can affect the foundation of the building not in the best way.
The second function of the blind area is the creation of a convenient passage along the buildings. In urban conditions, the blind area is a function of sidewalks, and in this case, the evenness of the blinds is paramount, which will ensure a comfortable movement along them.
The first function, of course, is much more important. After creating a blind area near the building, it is necessary to do it as qualitatively as possible, so that the period of its operation was close to the lifetime of the building itself.
Fill concrete for blind area
Requirements for blind area
The main requirements for the blind are the protection of its structural elements, its simplicity in manufacturing, and, of course, the low price. It is also necessary that it is strong at the same time, but at the same time it is easily and quickly disassembled in case of repair. Therefore, concrete for the blind area should be resistant to temperature changes, moisture and regular physical influences.
For better frost resistance, the surface of the blind area is torn by heat-compensating seams. This seam can be made using a wooden strip, which is treated with bituminous mastic. The distance between such seams should not exceed 1.5-2.5 meters, technologically they serve as a beacon.
The highest quality concrete can be purchased at a concrete plant. Only in this case you can be sure that concrete consists not only of a mixture of cement, water and sand, but also much needed additives( plasticizing and protecting from negative temperatures).
If the construction budget and its volumes do not provide for the purchase of factory concrete, then it can be easily done by yourself. The composition of concrete used for the blind area is as follows: cement, sand, and also rubble. The ratio of volumes is always the same: 1 share of cement, 2 parts of sand and 3 parts of rubble. When self-made concrete should carefully monitor the amount of water in the solution. Concrete should not be liquid, its consistency is best checked with a cone.
Reinforcement of the blind area
Also, the order of solution preparation is important. It should be as follows:
1) Add water to the mixer and add cement, gradually stirring, until the production of cement milk;
2) Crushed stone, which is "bathed" in cement mortar;
3) Sand is added at the very end.
There are also some tricks that will help to make you a quality concrete mix. For example, if the air temperature drops, add a little ash and patch before adding cement to the water. If the use of reinforcement or reinforcing mesh is not provided in the area, then table salt can be added.
After the concrete mixture is ready, I put it back into place, carefully rammed, leveled, after which the surface is ironed. For such an alignment it is convenient to use vibrators, but you can completely manage manual tamping.
