Calculation of the composition and proportions of heavy concrete

Information on the purpose of the calculator

Online calculator for calculation and selection of heavy concrete compositions on cement binder with the use of large and small aggregates. Taking into account plasticizing additives, compaction method and mobility of the concrete mixture. The calculation is approximate, and may differ from the real one, depending on the materials used, their humidity and other characteristics. For a more precise definition of proportions it is necessary to make a trial batch.

Brief description of heavy concrete

Reinforced concrete products for construction are made not only on specialized enterprises, but also very often cast directly on the object being built. Without no construction site is complete without concrete. To create a reliable design with the specified technical characteristics use heavy concrete, which in accordance with building regulations has with a volume weight of over 1,800 kg/m3.

Distinctive features of heavy concrete

The production of building materials is carried out in two categories: light and heavy concrete products. They differ significantly in physical and technological characteristics and accordingly, according to the scope of application:

• Light concrete
- produced on the basis of "light" fillers, which significantly reduce the bulk weight and increase thermal insulation properties. In addition, the lighter the concrete, the more porosity it has, which means low hydraulic resistance, therefore, lightweight concrete products are used for internal non-responsible structures without a strong dynamic destructive effect.
• Heavy concrete
- characterized by high strength and low porosity, which guarantees excellent resistance to any mechanical and chemical influences. Building materials made of heavy concrete are applicable for especially responsible structures with open (natural) operation, including for the construction of foundations, walls, and pouring floors.

Characteristics of heavy concrete

Calculation and selection of the composition and proportions of heavy concrete is carried out taking into account required characteristics (properties):

• Strength
- the main indicator of the ability of reinforced concrete products to withstand a destructive load. Exactly this one the indicator indicates the scope of concrete application in high-rise buildings, foundations or hydraulic structures. The indicator is classified from B3.5 to B60, which corresponds to the marking of the tensile strength from 5 to 100 Mpa.
• Thermal expansion and fire resistance of heavy concrete
- an indicator of the possibility of using construction products in areas of temperature exposure. So, the filling of the floor made of heavy concrete has an expansion coefficient of no more than 0.5 mm per linear meter. Concrete it is able to withstand temperatures up to 500 degrees (destruction occurs above), and at a temperature of about 200 degrees, its strength is lost by no more than 30%.
• Porosity, water resistance and frost resistance
- related indicators, the sum of which determines the operational durability of reinforced concrete products. The porosity of heavy concrete should not exceed 15%. Frost resistance is marked by ability withstand cyclic freezing from F50 to F1000. Heavy concrete is used in construction channels and bridges, therefore their water resistance is within the limits of marking W2 - W20 (figure - indicator water exposure in kgf/cm2).

Structural features of heavy concrete

The composition and proportions of the components used for heavy concrete directly affect its technological and physical characteristics, therefore, the calculation should be carried out accurately enough, which is more convenient to carry out on an online calculator. For casting high-quality concrete products with suitable technical characteristics, it is necessary take into account a number of features of the manufacture of heavy concrete:

• Placeholders are necessarily used of two types: large and small.
Large aggregates (crushed stone or gravel) ensure the strength of concrete, and small ones - due to compacted distribution increases the density and reduces the porosity of concrete. Placeholder for large formats with angular shapes, it provides less shrinkage of the casting and operational high dynamic endurance. The fraction of fine aggregate also affects the characteristics of the concrete product: the smaller, the density and water resistance increases. It is worth considering that the strength of the large-format filler depends on the strength of the concrete casting itself also depends.

It is a mistake to think that adding water can increase the plasticity of concrete without harm its quality, because its uniformity and strength decreases and shrinkage increases. To increase plasticizers are used to improve the plasticity of concrete, which improve the ability to move fillers, which guarantees high-quality filling of the mold and an easy exit from the casting of air with a uniform structure all concrete. Professional construction necessarily uses plasticizers.

The following is a complete list of calculations performed with a brief description of each item.

General information on the results of calculations

• Amount of cement
- The total estimated amount of required cement for the entire volume.
• Amount of water
- The total estimated amount of required water for the entire volume.
• The number of small and large fillers
- The total number of small and large aggregates for the entire volume in kilograms.
• Concrete mix density
- The density of the concrete mixture in the raw state.
• Water/Cement
- Water-cement ratio of the concrete mixture.
• Proportions
- The relative ratio of the components of the concrete mixture.
• Cost
- The cost of each material and the total for the entire volume.