Tip 1: Which concrete to choose for the foundation
Tip 1: Which concrete to choose for the foundation
Today, the foundation construction, made ofblocks of the FSB, is almost a thing of the past. In place of such structures comes monolithic foundation, for which concrete is used, it allows to build not only a tape but also a pile-and-girder base of the building.
Instructions
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In the event that the construction of the house is going onspecially designed project, this frees up from the problem of selecting the necessary brand of concrete for laying the foundation. If not, then the owner of the future house should have an idea of the correct choice of the concrete brand for the construction of its foundation.
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Concrete is chosen taking into account the load that will bebear the foundation during construction. It should also take into account the approximate weight of the finished building, the type of soil on which it will be built, the depth of groundwater and the availability of additional structures in the form of a basement and so on.
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If it is planned to build a prefabricated panelat home, this means that the foundation will not be very heavy loads, and therefore the concrete can be selected brand m200. If the future house is built of timber or wood, expanded clay blocks, foam blocks and others, in this case, concrete of the brand M300, or, in extreme cases, m250, should be used. For those who want to build the most solid house and use brick or metal structures for construction, one should choose a brand of concrete m350 or higher grades.
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When constructing a foundation, do not forget abouttype of soil on which the erection of the house is planned. If the soil is sandy or rocky, then in these cases it is better to use concrete m200 or m2. However, such a primer is rare. In most cases, during construction, soil is observed on a clay basis, which is characterized by a major drawback - a great deal of ripeness. To lay the foundation on such a soil, the soil must be dig deep enough that the clay on which the building will be built does not freeze. Therefore, for this option, concrete m250 is suitable. However, for a better guarantee it is better to use the brand m350.
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In addition, the choice of a brand is influenced bydirectly and type of foundation. If in the future the house is planned to install a cellar, then in this case it is necessary to take into account the level of groundwater. In this case, several options can be used. It is possible to take concrete of a lower grade, and from the outside, it is treated with waterproofing. Or you can install a foundation of medium-grade concrete, then treat it with specially designed impregnations. Of course, high grade concrete will provide a more reliable result. However, it is difficult to work with such materials, as they quickly solidify in the working process, and the price is higher.
Tip 2: What concrete is needed to fill the foundation
The strength of the foundation depends on the brandconcrete, from which it is made. In order to choose a solution of proper quality, it is necessary to pay attention to its characteristics. In regions with a harsh climate, only frost-resistant concrete should be used.
Instructions
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For the device of the house foundation it is recommended to pour concrete of certain grades: from M100, the strength of which is 7.5 MPa, to M700 with a strength factor of 50 MPa.
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The foundation is built on different types of soil. This factor should be considered when choosing a brand of concrete. For example, for weakly grooved, low-moisture soils, when casting a strip foundation, it is recommended to use concrete M100 and M150 grades. Its characteristics allow a load of up to 130 kg / cm2. Therefore, on such a foundation, relatively light structures can be erected: frame, cellular concrete, panel, of sandwich panels.
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Concrete brands M200 and M250 can be used forfoundations, the bearing capacity of which does not exceed 260 kg / cm2. Such a solution is used for pouring piles and pillars under fairly heavy low-rise buildings: from timber, bricks, rounded logs. Concrete of these grades can be used to build a base on strongly hectic soils: wet clays and loams, with high GW (groundwater level), in marshy soils.
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For foundations made from a monolithic slab or tape,built on complex soil types (abrasive, mobile, marshy) with a bearing capacity of the base not less than 393 kg / cm2, it is recommended to buy concrete of grades M300 and M400.
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When choosing a brand of concrete, you need to pay attentionto the fact that there are numbers and letters in it. Each of them has its own meaning. For example, "M" is actually a brand; "B" denotes a class of concrete; "F" - indicator of frost resistance; "W" characterizes moisture resistance; "P" is the mobility index of the solution.
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With the help of special additives you can influence themoisture resistance, ductility (flowability), frost resistance, strength and thermal conductivity of concrete. For example, with the Penetron-Admix additive, the foundation's resistance to moisture can be significantly increased. A similar property is possessed by special additives in concrete made on the basis of sulfates. These compounds can be bought in any store of building materials.
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The plasticity of the solution can be improved by addinga little inexpensive detergent. This property of concrete is especially important when pouring the top layer of the base, since its qualitative alignment is required.
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When self-made concrete is extremelyit is important to buy high-quality cement. It should be noted that 3 months after its manufacture, even in proper storage conditions, cement as a binder loses up to 10% of its properties. Therefore, you should always be interested in the release date of this material.
Tip 3: How to make a concrete mix for a foundation
To build a strong foundation, it is importantcarefully treat the composition of the concrete mix. Quality concrete after solidification turns into a strong material like a stone, which is widely used in construction precisely because of its strength.
The composition of concrete for the foundation includescertain parts of the following materials: water, sand, cement and gravel. In this case, sand and gravel are aggregates, and cement is a binder that combines all the components into a single block.
In a mixture of cement, the following purpose: fill the voids between gravel and sand. To economize the use of cement, it is better to use in the preparation of mixing gravels of different fractions. With this approach, small gravel particles can fill the voids between the large ones, and between fine grains they fill with sand.
After the foundation is poured, it will take some time until the material hardens completely. The concrete mix acquires a sufficient strength approximately one month after pouring.
Making concrete for the foundation
To make a composition for foundation pouring,It will take sand with particles from 1.1 to 3.6 mm. Sand of smaller size should not be used, in addition, it should be clean, without impurities of silt and clay. Quality can be checked as follows: in a transparent bottle, pour water, pour a little sand and shake. If the water is then transparent, the material is of good quality. A dark shade of water is acquired because of the clay - it is not worth using such sand. The use of substandard components will affect the strength of the foundation not in the best way, and this, in turn, will have a bad effect on the structure.
Gravel choose with a size of 1-8 cm. It is highly desirable to add portland cement to the mixture of concrete, a material of high quality, which is used for the most part in monolithic foundations. Cement brands can vary - 200, 300, 400 and so on. Mark denotes the quality of cement and its integrity during compression.
