Sand concrete is a dry non-shrink mixture intended for pouring screeds, foundations, elements of benches, flowerpots, porches, etc. Currently, this material is very popular with both private and large developers. Especially often in the construction and repair of buildings and structures, sand concrete M300 is used. The consumption of this material, in comparison with cement, of course, will be large. However, when using sand concrete, there is no need to perform operations such as sifting sand to separate it into fractions and manually preparing a dry mixture.
Grades and composition of the material
Sand mixture can be used in the construction of buildings and structures only if the pressure on the finished surface does not exceed 300 kg / cm 2 . There are several grades of this material - from M200 to M500. Sand concrete consists of:
- Building sand. Its fractions can be different - from 0.5 to 7 mm.
- Portland cement brands M400 and M500.
- All kinds of additives and plasticizers.
The brand of sand concrete depends on the brand used for the manufacture of cement, as well as on the size of the filler fractions. The finer the sand, the denser and stronger the resulting construction.
Sand concrete M300
In private housing construction, this brand of material, as already mentioned, is used most often. It is possible to apply M300 sand concrete both for internal, and for external works. Paving slabs, foundations, partitions, walls, etc. are made from it. But especially often this material is used for pouring screeds in garages, basements and houses. These are the main areas where M300 sand concrete is used. The consumption of this material is quite high, but its quality is excellent.
Material advantages
The main advantages of sand concrete of this brand, in addition to low cost, include:
- high density and strength of finished structures;
- lack of shrinkage;
- ease of use;
- quick hardening;
- water resistant.
The disadvantages of sand concrete
This material has practically no disadvantages. Judging by the reviews, consumers consider the drawbacks to be not very convenient packaging (carrying bags of 40 and 50 kg is pretty hard) and the unreliability of the bags themselves. Also on sale are often fakes for sand concrete. Therefore, when buying, you should be more careful.
Features of use
As with the use of any other material, certain rules should be observed when erecting structures from M300 sand concrete. If using this material it is supposed to arrange a screed or repair any concrete structure, preliminary preparatory work should be done. The surface on which it will be applied must be cleaned of dirt and dust, coatings, grease, etc. In addition, all loose areas must be removed.
M300 sand concrete consumption per screed
So, as already mentioned, this material is used mainly for pouring high-quality screeds. It can be used for flooring in premises both for household purposes and in residential.
Of course, before you start pouring screeds, you should find out how much material you need to purchase. This dry mix is sold in bags of 40 and 50 kg. The consumption of sand concrete m300 per 1 m2 of surface with a layer thickness of 1 cm is 20 kg. Thus, a screed of 2 cm will require 40 kg of the mixture or one bag. Knowing the area of the room, it is easy to calculate the required number of them. So, about 100 bags will go to a house of 100 m2.
Next, let's see how much this amount of material can cost. For this, of course, you need to know what its price is. Peskobeton in bags of 40 kg costs about 150 rubles. Thus, a 2 cm floor screed in a house with an area of 100 m 2 will cost about 15,000 rubles. On a four-centimeter, respectively, 30,000 p.
A bag of ordinary M400 cement of 50 kg, provided that the mixture is made in proportion to 1x3 sand, is enough for 1 m 2 of a ten-centimeter screed. That is, about 5 m 2 two-centimeter. It costs a bag of cement about 200 rubles. Thus, 20 bags will go to a house of 100 m2. Therefore, filling the screed in 2 cm will cost 4,000 rubles without taking into account the cost of sand (quarry - 130-170 p. Per ton), 4 cm - 8000 p. In the end, filling the screed with a conventional cement-sand mixture is thus much cheaper.
However, the quality of home-prepared concrete is significantly inferior to sand concrete. It is all about the composition of the latter. In the preparation of sand concrete, sand of different fractions is used. The ratio of particles of different sizes is calculated so that in the end we get the most durable, non-shrink, not prone to cracking surface. At home, a mixture of this quality cannot be prepared, of course.
M300 sand concrete: consumption during foundation construction
Since about 20 kg of sand concrete leaves for 1 m 2 of the finished surface with a centimeter thickness, therefore, for 1 m 3 you will have to purchase 200 kg or 4 bags of 50 kg each. The volume of the foundation for the house is 100 m 2 (40 m - length) with its height of 110 m (70 underground and 40 - base) and a thickness of 40 cm will be 17.6 m 3 . Therefore, for its construction you will need to buy 17.6 x 4 = 70.4 or 71 bags of 50 kg.
Sand concrete in such a container is about 170 p. So, you have to pay for it 71 x 170 = 12070 p. M300 sand concrete (50 kg), the consumption of which is not so great, as you see, for the construction of the foundation - the material is very suitable. In the end, 12070 p. - the amount is not that big.
So, the consumption of M300 sand concrete per 1 m2 (with a thickness of 1 cm) is 20 kg. Cement, as we found out, takes less. On the foundation (with a proportion of 1x3) of a house of 100 m 2 it will need about 27 bags, and therefore, the base of the building will cost 27 x 200 = 5400 r without taking into account sand. With sand - roughly 6000-7000 rubles. When using crushed stone or buta - about 5500-6500 rubles. However, the quality of such a foundation for sand concrete will be significantly inferior.
How to make a solution
So, we have figured out how much will be needed to fill the foundation or screed of a material such as M300 sand concrete. Its consumption is quite large, but in general, the use of this material in private housing construction seems appropriate. Of course, when using this material should be properly kneaded. This operation is best performed in the following sequence:
- Warm water is poured into a container of the required volume (from +15 to +25 gr.). Consumption, depending on the purpose of the mortar, should be 0.18-0.23 liters per kilogram of sand concrete.
- Further, the dry mixture itself is poured into the water itself.
- The resulting mass is thoroughly mixed until all, even the smallest, lumps disappear. The finished mixture should be absolutely homogeneous.
Use the solution should be within 2 hours. It is allowed to work with M300 sand concrete at a temperature from +5 to +35 gr. Water cannot be added to an already prepared solution. During pouring, it is recommended to periodically pierce the mixture with a stake, rod or shovel to remove air bubbles. Drying time of the finished mixture is 24 hours. You can walk on the screed in a week. The formwork is removed from the foundation on the second day. Sand concrete gains its final strength after 28 days, that is, like ordinary concrete. Reinforcement with a screed thickness of more than 2 cm is mandatory. Of course, the frame will need to be installed when pouring the foundation. Crushed stone is not added to the mixture when used. Its role is played by large particles of sand (3-7 mm). Waterproofing is carried out in the usual manner.
From the foregoing, a simple conclusion can be drawn. Sand concrete foundations and screeds are more expensive than cement-sand foundations. Therefore, it is advisable to use this material when resistance to cracking of the finished structure is necessary or its final price plays a not very important role. Sand concrete, for example, is an excellent option when erecting walls from not very strong aerated concrete and foam concrete blocks.