On what concrete grade is needed for the construction of the foundation of the house, you need to know to get a solid bearing foundation, on which the duration of the operation of the structure will depend.
As a material for pouring the foundation for the construction of residential and administrative facilities, a concrete mixture is used.
It is used to form castings of different configurations, which later serve as supports for the structure.
These supports can be:
- strip foundation - with a certain level of penetration;
- different kinds of columnar foundation;
- combined carrier base;
- flat monolithic base.
In this case, the constituent parts of concrete are the decisive factor that allows to obtain the expected stability.
Contents:
- Types and features of concrete mixtures
- How to calculate the load on the foundation
- What kind of concrete is needed for the construction of a two-story house?
- What kind of concrete should be used to build a bathhouse foundation?
- What kind of concrete is needed for building a garage foundation?
- What kind of concrete is needed to build the foundation of the fence?
Types and features of concrete mixtures
As a rule, during the preparation of the mortar mixture, in addition to cement, sand and water, crushed stone of a certain fraction is added.
It is also possible to add various additives to the solution, whereby concrete is endowed with the following characteristics: moisture resistance and indifference to sudden temperature changes.
A variety of binder - water used as a diluent, and filler( gravel, gravel, etc.), determine the brand of concrete.
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Thus, for each specific case, you can calculate the individual ratio of materials.
So concrete, used as a permeable blind area around the foundation, may not be suitable for the construction of the base itself.
The main characteristic of the concrete composition, which is based on the designation of the material grade, is its strength or ability to effectively transfer pressure to compression.
To find out which concrete is needed to build the foundation of a house, a fence or any other structure, you need to calculate the expected load.
How to calculate the load on the foundation
Its calculation includes the planned weight of the house, takes into account wind and snow loads, as well as the size of the area of the concrete foundation to which pressure will be applied.
It is possible to calculate the future weight of the house correctly by a special formula taking into account the severity of internal communication structures and the impact of natural conditions.
The basic expression by which the required value is calculated is the formula in the form:
H = Nf + Nd,
where:
- H - determined value( total load on concrete);
- Nf - load of the foundation on the ground;
- Nd is the total load from the house.
The values of Hf and Hg can be calculated using other formulations, or by using a special table.
Load of the foundation on the ground( Нф = Vф х Q), where:
- Vф - the amount of the foundation for the house( get multiplied by the area of the object to the height);
- Q - the density of the structure of building materials( the value can easily be found in special reference books).
Calculate the pressure of the house on the foundation( Nd) can be based on the above indicators( weight of communication structures, wind load, etc.).
Possible load values of materials used for building a house were previously calculated by specialists. The results of their work are in the special.reference books.
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For example:
- For carcass structures with wall thickness taking into account the insulating layer no more than 150 mm - loading up to 50 kg per m 2 is possible;
- Brick walls of the house( red brick) with a thickness of about 150 mm - loading pressure 270 kg per m 2;
- Log house about 100 kg per m 2;
- Monolithic concrete walls, thickness up to 150 mm - 350 kg per square meter.m;
- Reinforced concrete floors for the house - up to 500 kg per square meter;
- Overlapping of wood and thermal insulation at a density of 200 to 500 kg per m 2 - from 100 to 300 kg per m 2;
- Roof load: from steel sheet - up to 30 kg / m 2, slate and roofing material - up to 50 kg per m 2, tile - about 80 kg / m 2.
Calculating the area of the erected object, find what you are looking for.
For temporary snow load, take the indicator: for southern regions - 50 kg per m 2, for northern regions - 190 kg per m 2.
Wind load is calculated by the following formula:
HB = PX( 40 +15 x H)
where:
- Нв - wind load;
- H - height of the object;
- P - the area of the house.
As a result of summarizing the obtained values, it is possible to quickly calculate the amount of load in tons that the house will create.
What kind of concrete is needed to build a two-story house?
It is recommended to build a tape-type foundation for a two-storey house. Its erection involves mounting the reinforcement and its subsequent pouring with concrete.
For greater strength of the base under the two-story structure, the concrete is mixed with crushed stone.
Armature is associated with part of the foundation, located above the ground level, and the part located in the ground can not be bandaged.
The depth of the bearing foundation of a two-story house is one of the important factors that are taken into account when erecting it. The average level of the foundation foundation is at least 500 mm.
So, with a soft type of soil, the depth of the bed should be about 1 meter. The optimal option for a soil with a dense structure is a depth of 500 mm.
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In this case, concrete grades used for pouring a foundation for a two-story structure can have a score of 250 or higher.
The following is indicated which brand of concrete should be used for the following objects:
- for a house based on foam blocks, use concrete of grade 350;
- for a house from a solid monolithic base, you need to use concrete solutions of grade 400 and more;
- for pouring the foundation under the timber house suitable concrete mixes grade 300;
- frame house - for its foundation you can apply concrete grade 200.
What kind of concrete should be used to build the foundation of the bath?
Usually for pouring the foundation of a bath, concrete mixes of M250 grade are used. But still the last word is due to the peculiarities of the soil structure.
This fact applies not only to pouring the foundation for the bath, but also all types of buildings.
The more complex the structure of the soil, the more requirements are put forward to the brand of concrete. So, for an argillaceous rock of a ground optimum mark 350, for sandy ground - mark 200.
At a deep level of freezing and a high level of ground waters prefer mark 350.
Besides, the answer to a question, what brand concrete is better for building a foundation of a bath onclay or sandy ground, also lies in the features of the future design.
But since the bath is a relatively light structure, usually the walls of the bath are erected from wooden material, so the best choice is a columnar or ribbon foundation of a shallow depth type.
At the same time, the base brand indicator may drop from M200 to M150.The brick structure in this case will require the use of concrete grade 200 and above.
What kind of concrete is needed to build a garage foundation?
Choosing a concrete brand for the construction of a garage foundation, most often stop on the composition with an indicator of 200 and above.
The main thing in the preparation of a mixture is to use only quality ingredients.
Determining the optimal version of the brand of concrete for filling the garage foundation, take into account the features of the structure. So for the prefabricated panel structure, the concrete composition M200 can be used.
For a garage constructed using gas silicate or expanded clay products - concrete 300 grade is suitable. The reinforced concrete structures and brick garage walls can be erected on a concrete basis with a strength index of 350.
The calculation of the basement for the garage is carried out according to the above formulas.
But how many cubes of material can be used can be considered on the example of a tape base:
- Suppose a 6x9 base is built, a height of 1.6 m, 0.28 m is a width;
- We use the formula: V = 2ab ×( c + d);
- We get the size of the footprint of the basement and find out how many cubes are needed for pouring:
9 × 0.28 × 2 +( 6-0.28 × 2) × 0.28 × 3 = 5.04 + 4.56 = 9,6( m 2); - Result - the volume of concrete is: 9.6 × 1.6 = 15.36 m 3. Hence, that's how many cubes of concrete will be needed for the construction of a bearing base.
What kind of concrete is needed to build the foundation of the fence?
The bearing base of the fence is not as demanding as for the construction of a foundation for other objects.
This means that the design is calculated without taking into account the index of groundwater occurrence and the depth of soil freezing.
Since fence designs are often referred to as lightweight structures, a concrete grade with a strength factor of 150 is used to build the foundation of the fence.
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If a fence construction is planned on a rocky ground, a concrete grade of 100 is used.
Higher grades, 200and above, can be used for soils with complex structure or in a territory with complex terrain.
In another case, the use of heavier compounds is not appropriate and will lead to a rise in price of the structure.
With regard to the type of foundation used for the fence, it can be a tape or columnar structure.
