Strength and durability of any structure directly depend on the quality of the foundation. And in any case, to achieve success, you can not ignore the preparatory phase. Correct calculations save not only time, nerves, but also resources. How to calculate the volume of concrete for pouring the foundation correctly and what nuances must be taken into account in order not to get into a mess, we will discuss this article.
Classification of the foundations and structural features of buildings
It is necessary to immediately say a few words about the types of foundation and buildings, since calculations directly depend on this. If we are talking about the foundation, then first of all, its functionality is considered. Similar designs can be load-bearing or combined. Bookmark level - deep or shallow. In addition, it is important to consider the region, the type of soil and the depth of groundwater. Before approaching the question of how to correctly calculate the cubic capacity of concrete, we consider the building structures, the materials from which it will subsequently be built, the layout and the number of storeys. There are 3 main types of foundation: strip, slab and columnar.
Under what conditions is the use of various types of foundation most effective?
The strip foundation is a continuous continuous tape under the supporting walls. This type is used so that the load is distributed evenly over the entire area of the base. Consequently, the skew of the building due to swelling of the soil is not expected. However, it should be understood that silted, peat or marshy soil is not suitable for such a base. In these cases, piles are used. Therefore, the determination of the soil and its features is an important task, and specialists can solve it. With normal soil, the strip foundation is equally well suited for the construction of both private cottages and monolithic buildings.
The next type of concrete base is slab. Over the entire area of the future structure, one continuous monolithic slab is poured. This foundation has proven itself in problematic soils. It will not only evenly distribute the load during freezing of the soil, but even with expansion, the base will rise, so that later it will return to its previous position under its own weight. Additional benefits include durability and reliability.
A column foundation is a series of supports that are usually located at the corners and places where the greatest load will be distributed. The main minus - to build a basement will not work. It is used for buildings and structures with low weight.
When deciding the question “how many cubes of concrete a foundation of various types may be needed”, it is also necessary to take into account the climatic features of the terrain in which the construction will be carried out.
Optimum foundation depth
Freezing of soil in various regions of Russia and the CIS countries has its own individual characteristics. For the most accurate calculations, it is best to use data on the depth of freezing of the soil and lay the foundation below. In Vorkuta, Surgut, where winters are harsher, the soil freezes by no less than 250 cm, and in Moscow this value will be only 140 cm. In Minsk, Kiev and Rostov, even less - an average of 90-100 cm. But here An important role is also played by the type of soil. For example, take rocky or semi-rocky soil. To lay the foundation for a 2-storey cottage in this case, you can, in principle, at any distance. The depth of groundwater during the period of freezing the earth will also not play a role. But if we are dealing with clay or loam, then it is not recommended to go deep below the calculated data on soil freezing for this region - if work is being done, say, in Minsk or Kiev, then digging trenches under the foundation should be at least 100 cm. And so on by analogy . When considering how to correctly calculate the required volume of concrete, it is worthwhile to dwell on such an important point as concrete grades.
The specifics of using various grades of concrete
The choice of a particular brand of concrete is influenced by strength characteristics. For preparatory work (for example, rough screed floors), grade 100 or 150 is used. For small outbuildings with a strip foundation and concreting of tracks, 200 and 250 marks are suitable. 300 and 350 - for the foundations of houses. 400 and 500 are used when there is a need for special strength. How to calculate the volume of concrete in relation to the strip, slab and columnar types of foundation? This will be discussed below.
Calculation of concrete volume for a strip type of foundation
How to calculate the volume of concrete with minimal errors? In fact, the task is not particularly difficult. For the calculation by the formula, data on the width of the base (n), the height of the foundation (k), the length on the outside of the foundation (a) and the length on the inside (b) are needed. Inserting the values in the formula, you can get the desired volume of concrete (S):
S = 2nk × (a + b).
Slab foundation calculation
How to calculate the volume for pouring the foundation of this type? Here again, simple calculations borrowed from the school course in geometry will help. In order to obtain volume, it is necessary to multiply the values of different sides between themselves - this gives the necessary value of the area, which, in turn, is multiplied by the height of the future foundation. And all: now the required volume of concrete is known.
You can, of course, use ordinary monolithic plates, but in practice this rarely happens because of the high cost of the latter. Although the slab foundation is just a find in conditions of unstable soils, and even with close occurrence of groundwater, it also proved to be excellent. And its longevity is beyond praise.
Column foundation and its calculations
The most economical option for buildings with low weight and at the same time unacceptable for all those who would like to have a basement. How to calculate the volume of concrete for a given foundation? It is not difficult. Again, geometry helps us. For an accurate calculation of the volume of concrete used, you need to know the number of columns in the base of the building and the concrete consumption per unit. The calculations are carried out according to a formula that takes into account the length of one support (g) and its cross section (k):
V = (3.14 × k2 / 4) x g.
Suppose you need to calculate the amount of concrete on a column foundation with the parameters of the pile g = 1.5, k = 0.28 and the number of columns 15 pieces. The solution will look like this:
(3.14 × 0.28 × 2/4) x 1.5 = 0.09 cubic meters of concrete (consumption per pile).
To calculate the total mass, multiply the result by the number of piles at the base:
0.09 x 15 = 1.35 cubic meters.
Foundation concrete calculator
To facilitate the calculations, you can use the program - the calculator of foundations, the benefit of them is full on various sites. Recommended parameters are already set there - not only the material of the wood from which the formwork can be made is taken into account, but also the thickness of the board. You can also enter such parameters there: thickness, depth and height of the foundation above the ground, its perimeter (the sum of the lengths of all walls).
In order to calculate the right amount of concrete using an online program, it is not necessary to know the volume formula. The calculator will independently perform the necessary operations. Even the amount of cement needed can be calculated without difficulty, but another online calculator will help with this.
You can arrange a self-test by reading the information from the cement consumption tables of different grades for the manufacture of concrete of the desired strength. To prepare the brand of concrete M400 using cement grade 500, it will take 440 kg per m 3 . It is clear that in any calculations there may be an error. Usually it is from 3 to 10 percent. There may be several factors. These are inaccuracies during earthworks, and unloading of concrete (there may be losses), and soil shrinkage. In any case, these, at first glance, little things can easily lead to negative consequences. There wasn’t enough concrete - and this is already a rush, because you can not break the solidity. To transport the missing material, taking into account transportation costs, will cost 2.5 times more expensive.
So it’s better to calculate everything in advance and get a little more material than you need. You already know how to calculate how much concrete is needed on the foundation. It is not difficult to make the necessary calculations with the calculator, it is convenient to work with it, but even if you have such an assistant, remember: calculations and preparatory work in such an important business as construction do not endure fuss and haste.
Conclusion
Consulting a qualified professional will help you save resources and time. However, do not fully trust the design documentation. Practice shows that volume calculations are incorrect in most cases. Theory often diverges from practice. Therefore, armed with stationery, notebook and tape measure, you can avoid many unpleasant surprises. Especially if you order 10 percent more than what happened in the calculations.
There is one more nuance when calculating the required amount of concrete. Always work with large and trusted organizations. Unfortunately, releasing their products, some not-so-tidy manufacturers produce fewer building materials. If you take care of convenient access roads and several unloading places in time, cooperation with factories will also significantly reduce losses. If you carefully and painstakingly work out all the nuances, then the question of how to calculate the volume of concrete will not pose any particular problems.