The composition and proportions of concrete for the foundation
After completing all the necessary work prior to the foundation pouring, builders often have the task of determining the amount of sand, rubble and cement for the preparation of concrete mix. The surplus will have to be poured out, and in case of shortage  time is wasted (which is always not enough) to purchase, deliver and mix additional materials.It is clear that I would like to avoid this and make it so that the consumption of concrete on the foundation was optimal. In addition, the ratio of components in the prepared mixture has a great influence on the strength of the future building or structure. The proportions of concrete for the foundation are different. How do they differ, which are better suited for country building  this will be discussed in this article.
The proportions of concrete for the foundation
The composition of the mixture for pouring the foundation includes: cement (binds the ingredients), water (solvent), sand with gravel (as a filler). Cement in concrete fills the voids between pebbles and grains of sand and binds them together during solidification.Thus, the fewer voids there are, the less cement is required, and therefore gravel of different fractions is usually added to the mixture. Small gravel fills the space between large fractions, and the remaining gaps are filled with sand. Depending on what brand of cement is available, the proportions of concrete for the foundation (ratio of cement, sand and gravel) are usually used in construction: 135 or 124.The higher the grade of cement used, the greater the strength the mortar will receive and the less it will be required for the concrete mix. The amount of water for dissolving the components of the solution also depends on this. For convenience, we show the possible proportions of concrete for the foundation in the following table:
Type of concrete 
Cement type 
How much will a concrete mix of 10 liters of cement 
The volume composition of sand and crushed stone (P / Sch) per 10 liters of cement 
Mass composition, kg 
M100 
M400 
78 
41 / 61 
1ts4.6p7.0ch 
M500 
90 
53 / 71 
1ts5.8p8.1 

M150 
M400 
64 
32 / 50 
1ts3.5p5.7 
M500 
73 
40 / 58 
1ts4.5p6.6shch 

M200 
M400 
54 
25 / 42 
1ts2.8p4.8 
M500 
62 
32 / 49 
1ts3.5p5.6 

M250 
M400 
43 
19 / 43 
1ts2.1p3.9 
M500 
50 
24 / 39 
1ts2.6p4.5sh 

M300 
M400 
41 
17 / 32 
1ts1.9p3.7 
M500 
47 
22 / 37 
1ts2.4p4.3sh 

M400 
M400 
31 
11 / 24 
1ts1.2p2.7 
M500 
36 
14 / 28 
1ts1.6p3.2sh 

M450 
M400 
29 
10 / 22 
1ts1.1p2.5sh 
M500 
32 
12 / 25 
1ts1.4p2.9 
Concrete M100 is used only at the initial stage of construction for reinforcement and all sorts of preparatory work, as well as in the arrangement of roads.For the foundation of a singlestory building, the M200 brand is most often used, and in the urban highrise buildings  the M300 and M350. Knead the concrete in an iron container, concrete mixer, wooden box or in a special flooring of iron, wood and other improvised means. First, mix the dry ingredients according to the selected proportion, and after getting a homogeneous mass, water is added. The result should be a thick, soft mass that is poured into a preprepared formwork. If the total estimated volume of the mixture is quite large, the foundation is cast in several passes. At the same time, experts recommend to meet in one day  so the foundation will be as strong as possible.
Volume calculation
“How much concrete is needed on the foundation?”  the question is also very important. Usually during the construction of a country house, its foundation is arranged according to the tape principle with the use of wooden formwork. For the calculation, you need the tape height, width and its total length. Consider a simple example. Suppose we have a rectangular basement size of 10 x 3.6 m, the height of the casting 0.21 m, and the width of the belt  0.19 m. At the beginning is the perimeter: 2 * 3.6 + 2 * 10 = 27.2 m.Then it is multiplied by the width and height of the casting. The result is 1,0853 m3. We hope that now with the choice of proportion and calculation of the required volume of the concrete mix, there will be no difficulty.