What does the weight of reinforced concrete

Reinforced concrete is a universal building material, which is quite widely used in construction. It is with the help of inlet or precast concrete structures that most modern buildings are erected.

The design process is associated with the calculation and taking into account the huge number of different indicators. One of the most important parameters in the design process is the weight of the cube of reinforced concrete. This value is necessary for the calculation of the load on the foundation of the structure, to determine the complexity of construction work and the time of operation of construction equipment and vehicles.

Types of reinforced concrete

The weight of 1 m3 of reinforced concrete may be different depending on which of the following types of solution was applied:

• Especially heavy - limonite, magnesium and barite has a weight of more than 2.5 thousand kg in 1 m3;

• Heavy - crushed stone or gravel. Weight 1 m3 of reinforced concrete of this type is 1.8-2.5 thousand kg;
• Light, with such fillers as expanded clay, perlite, arbolit, etc. Also to this class of building solutions include foam concrete and aerated concrete. The weight of 1 cube of such a mixture is 500-1800 kg;
• Especially light - 500 kg per cubic building weight.

Note! These weights indicate only the weight of the solution itself without including in the mass value of the reinforcing cage.

Such a spread of mass indices is caused by the fact that in various mixtures there are various densities of fillers, the weight of which has a fundamental effect on this value.

For example, consider some density coefficients of reinforced concrete, using aggregates of different types:

1. Expanded clay, depending on the type of sand, may have a different mass of one cube:

• 0.8-1 thousand kg using perlite sand;
• 0.8 - 1.2 thousand kg using quartz sand;
• 0.5-1.8 thousand kg with the use of expanded clay dust as a filler;

1. Tuff will weigh 1.2 to 1.6 thousand kg per cubic meter;
2. One cubic meter of a penosilicate weighs from 0.3 to 1 thousand kg;
3. The weight of the cube of shungizite is from 0.1 to 1.4 thousand kg;
4. Pump masses of 0.8 to 1.6 kg per cubometer.

The effect of reinforcement on mass

The weight m3 of reinforced concrete is a value equal to the sum of the mass fractions of the concrete solution and the metal reinforcement cage. The mass of steel will also have a serious impact on the proportion of reinforced concrete.

In order for the monolithic construction to have excellent strength characteristics, various types of reinforcing bars are used.

Note! Class AII I reinforcement is the most commonly used in practice. The density of such steel is 7,850 kg per 1 cubic meter, which is several times higher than the proportion of any type of concrete solution.

Depending on the calculations used in the design, and the required level of strength of the structure being constructed, a different number of rods is used for reinforcement with different cross-sectional diameters.

The steel content in the concrete raster is an indicator that should vary from 70 to 320 kg.

Note! When calculating the structural strength, one should take into account the volume of the solution that will displace the steel used for the construction of the framework. Thus, it will be necessary to subtract this displaced volume from the total volume and add steel. The resulting figure will be the calculated bulk density of the building material.

Differences between calculated and real density

In practice, the density of the structure is slightly lower than calculated in the project documentation. The reason for such circumstances is the presence of a small number of voids in the monolith.

Filling of concrete structures at a construction site or pouring prefabricated structures in a production environment are processes directly related to the formation of voids of various sizes in the thickness of the solution.

The emergence of air in the monolith process is inevitable, but its amount can be reduced by applying the solution compaction method after pouring the building mass into a form or formwork. But even after compaction, some air will still remain in the interior of the solution.

Note! The volume of air in the solution should not exceed 1% of the total mass. Such a volume does not significantly affect the performance of the structure.

Instructions for the manufacture of concrete products with their own hands provides for the need to reduce the number of cavities in the concrete mass. Thus, it is possible to significantly increase the strength and durability of the finished product.

Calculation of mass of reinforced concrete structure

To calculate the specific weight of a structure made of reinforced concrete, the weights of the metal and the concrete solution are simply summed. The result of this summation is divided by the volume of the resulting structure. The use of such a simplified calculation allows us to exclude complex mathematical calculations in which inexperienced builders can make serious mistakes.

Example

Consider the weight calculation on the example of heavy concrete. In this solution, fillers are used, in the role of which is crushed stone and gravel. They have a sufficiently large mass, so this concrete weighs from 1.8 to 2.5 tons per cubic meter.

The composition of this raster in mass fractions will be as follows:

• Water - not more than 0.2 tons;
• Sand - not more than 0.75 tons;
• Crushed stone - not more than 1.3 tons;
• Cement - no more than 0.45 tons.

If we sum up the mass of all these fillers, then the weight will be 2 tons 700 kg. This value is correct, because in the process of drying the water will evaporate, and the mass will just learn equal to 2.5 tons.

The heaviest types of solutions have a mass in excess of 2.5 tons due to the fact that they contain magnetites, scrapes, barites and hematites. Such solutions are used to create armored caps in places of radioactive contamination.

Finally

The weight of a reinforced concrete structure is a parameter that has a serious impact on such characteristics as strength, density, reliability and operational performance of a future structure. If it is wrong to calculate this indicator when designing a building, the cost of correcting this error can be very high.

The video in this article allows you to learn even more about how important it is to correctly calculate the mass of reinforced concrete structure.