Concrete M350 is an excellent structural material, which makes it possible to produce very responsible structures for various purposes and various prefabricated elements. After hardening, this composition is characterized by high resistance to external influences, has good characteristics, especially compressive strength. In modern construction, concrete of class B25 is the leader both in popularity and in sales.
Material application
Concrete M350 class B25 is used in almost all types of construction. It is used to make floor slabs, monolithic foundations, walls, beams, columns, reinforced concrete structures and other structural elements of residential, industrial and administrative buildings that carry heavy loads. Also from this mortar make road airfield slabs, operating at maximum loads.
Consider in detail the characteristics that this building material has.
Specifications
Consider the strength index of the set in compression. It is measured in MPa, determined by class B25 (1 m3 of material without breaking integrity is able to withstand a pressure of 25 MPa). The increased strength of B25 is achieved due to the presence of more cement in the mixture. In addition to strength, this brand of cement has other, no less important indicators: frost resistance, mobility and water resistance.
Mobility
This indicator varies in values from P2 to P4. But the level of strength can be increased to large values if the concrete is supplemented with special additives - plasticizers.
Water resistant
Concrete B25 has a water permeability index of W8. This parameter indicates that the material is capable of not passing moisture through itself even if it acts on it under significant pressure. Due to this, the M350 concrete grade can be used in areas with a high occurrence of groundwater.
Frost resistance
The frost resistance index F200 indicates that this material will not lose its properties and structural integrity after two hundred cycles of freezing and thawing. Such concrete can be used in harsh climatic conditions.
Volume weight
This indicator in concrete M350 is 1800-2500 kg / m³. However, most often the bulk density (density) of this material varies from 2200 to 2400 kg / m³.
Main components
M350 concrete is typically produced as a mixture of cement, water, sand and a solid filler such as gravel or crushed stone. To improve the properties of this material, additives and plasticizers are mixed into its composition, which expands the scope of application of this concrete grade
For the manufacture of a solution of class B25 use:
- cement;
- sand;
- crushed stone;
- water
- plasticizers;
- antifreeze additives.
It should be noted that the components used to prepare the solution may have differences in their characteristics and parameters, namely, particle size, strength, purity, and moisture content.
For example, as a filler can serve:
- fine-grained, large or medium sized sand;
- gravel (calcareous or granite);
- crushed stone and screenings.
It is also worth noting that concrete B25 has an increased percentage of cement content, which contributes to a fairly quick hardening.
Proportions
To prepare 1 m 3 of this material you will need:
- 400 kg of cement M400 or M500;
- 752 kg of sand, cleaned of impurities;
- 175 liters of water;
- 1 t solid filler (e.g. crushed stone).
In order to obtain high-quality and durable concrete M350, it is important not only to strictly observe the proportions of the composition per 1 m 3 , but also thoroughly mix all the components so that the resulting mass is homogeneous. Poorly mixed composition significantly reduces the strength of this material.
Solution preparation
- First, dry components (cement and sand) must be added to the concrete mixer and mixed thoroughly.
- Add water. At the same stage, a plasticizer or other additive is poured into the solution.
- Crushed stone or gravel soaked in water is added.
- The solution is thoroughly mixed.
Concrete M350: price
Manufacturers themselves set the price of the material by summing up all costs, the bulk of which falls on crushed stone and cement. For profit, a trade margin is made in excess of cost. That is why each manufacturer has an “own” final cost, which largely depends on the cost of raw materials.
Each developer chooses from whom to purchase M350 concrete. The average cost of this material with gravel filling without delivery will be from 3,000 p. for 1 cubic meter of mixture, with crushed granite - from 3 700 rubles.
If anti-frost additives are introduced , the price will start from 4 000 rubles. Also, the cost of concrete is affected by its water resistance - the higher this indicator, the more expensive. So, we can conclude that the cost of the material depends on the manufacturer and the cost of acquiring composite components.