The key to the strength of any structure is the foundation - this truth is undeniable. Therefore, in order to create a reliable foundation that can withstand the weight of the house structure, it is necessary to calculate the foundation - determine its geometric parameters and evaluate the feasibility of using the selected type of foundation, taking into account the specific type of soil. The services of professional designers do not always suit developers due to their high cost, and there is always a desire to check the results of the calculation. In this regard, it is proposed to master the basic rules and sequence of calculations.
The reliability and safety of the structure depends on the consistency of the selected foundation with the resistance of the soil to the load. This parameter for different soils varies from 1 - 3 kg / cm2 (for plastic clay) to 5 - 6 kg / cm2 (for gravel or crushed stone).
It is quite difficult to independently find the total load on the soil under the base. The final sum consists of several terms.
- House weight. It is found by summing up the mass of all the structural elements of the building: walls, ceilings, roofs and foundations. Starting data for calculations: height and thickness of walls, partitions, facing layers, finishes; roof type; type of overlap; dimensions of stairs; the composition and dimensions of the foundation (its width is preliminarily taken equal to the thickness of the walls, and then specified). According to the initial information in the directories, they find specific gravity of each material (kg/m2, kg/m3) and multiplied by the corresponding area or volume.
- Payload. This is the approximate weight of furniture, heating equipment, communications, household appliances, all residents of the house. To simplify the calculations, they take the average value of the specific load of 180 kg / m2 and multiply by the area of \u200b\u200bthe house.
- seasonal load. It represents the pressure of the snow cover. The specific gravity of snow depends on the climatic zone and varies from 190 kg/m2 (for the northern zone) to 50 kg/m2 in the south of Russia. The specific indicator is multiplied by the total area of \u200b\u200bthe roof (twice the product of the length of the slope and the length of the eaves). For more accurate calculations, the angle of inclination of the roof is taken into account: the larger it is, the less snow accumulates on the roof.
Having calculated the total load, it is divided by the area of \u200b\u200bthe foundation. The resulting value must be less than the bearing capacity of the soil on the site, otherwise the house will “float”. If this condition is not met, change the dimensional parameters of the base.
Calculation of the area of \u200b\u200bthe foundation for a house
At this stage, it is determined what size the sole of the building should be so that it can withstand the calculated load and at the same time not push through the ground. If it is supposed to put the house on a monolithic foundation in the form of a slab, then it does not require calculation. Its area is equal to the dimensions of the house - this contributes to the uniform distribution of the load, the plate provides sufficient resistance to the ground.
The minimum area of tape, columnar and pile foundations must be calculated according to the formula:
S > γ n * F/ γ c *R,
where γ n is the safety margin factor, 1.2 is assumed;
F is the total load on the sole, calculated earlier;
γ c is a coefficient that depends on the combination of the type of soil and the future structure and is in the range of 1.0 - 1.4 (for example, if a stone house is placed on plastic clay, γ c \u003d 1.0; when building any structure on fine sand, γ c=1.3);
R is the design resistance of the soil when laying the foundation to a depth of 1.5 to 2 m.
To calculate soil resistance, you need to know the value of resistivity - it depends not only on the composition of the soil, but also on its porosity and moisture content. The calculation of any foundation is based on a preliminary soil analysis of the site. According to its results, a reference value of R o is taken. It is corrected according to the formula:
R=0.005R o * (100+h/3), in which h is the depth of the foundation.
Substituting all the necessary quantities, find the area. Its value is used to further select the width of the tape, the diameter of the pile or the support column. The dimensions of the foundation are also needed in order to determine the volumes of materials for its manufacture.
Calculation of the amount of concrete for the foundation and reinforcement to strengthen it
Method for determining the volume concrete mix has some nuances depending on the type of foundation.
- Tape. Its volume is the product of the total length (including under the walls) and the depth and width. For a house with dimensions of 6 x 10 m, with a total length of piers of 12 m, the total length of the foundation is determined: (6 + 10) * 2 + 12 = 44 m. With a foundation depth of 1.6 m and a tape width of 0.4 m, its volume (and the amount of concrete) will be 44 * 1.6 * 0.4 = 28.2 m3.
- Columnar. Suppose, for the manufacture of the base, concrete supports with a diameter of 0.2 m and a length of 1.5 m are used. The sectional area of the column is 3.14 * 0.2 2 / 4 = 0.03 m2. Dividing the total quadrature of the foundation by this number, determine the number of supporting pillars. It is multiplied by the volume of one column (0.03 * 1.5 = 0.045 m3) and the cubic capacity of concrete for the foundation is obtained.
- Slab. Thickness monolithic slab varies from 15 to 40 cm - it is selected depending on the weight of the building. With a parameter of 40 cm and a house area of 60 m2, the required amount of concrete mix will be 0.4 * 60 = 24 m3.
When choosing reinforcement, they are guided by the weight of the building and the type of soil. If it is sufficiently dense and low-porous, then the foundation will experience moderate deformations and does not require a particularly rigid frame. In addition, the parameters of the bars depend on the type of base.
- Plate. For a light frame or panel house, standing on hard clay or rocky ground, fittings with a diameter of 10 mm are suitable. If you plan to put on the stove brick house, and the soil is weak, then the bars get thicker - from 14 to 16 mm. The frame is usually made in increments of 20 cm, performing two reinforcement belts. A bunch of belts is made at each intersection point of the longitudinal and transverse reinforcement. If the plate thickness is 40 cm, the length of the connecting rods will be 30 cm (both belts are 5 cm away from the base planes).
- Ribbon. It is less prone to bending, therefore reinforcement 10-12 cm thick is sufficient. It is also laid in two layers, each of which is buried in concrete by 5 cm. With a foundation width of 0.4 m, two longitudinal rods in each tier will suffice. If the base is wider, 3 - 4 lines of reinforcement will be required. Transverse elements and vertical connections can be placed every half a meter. They are, as in slab foundation, should be 5 cm from the tape surfaces.
- Pillars. They are reinforced with rods 10 - 12 mm thick. Vertical rods (2 - 6 pieces) are evenly distributed over the volume of the column - their length corresponds to the length of the support. Cross ties made of smooth reinforcement with a diameter of 6 mm are placed at intervals of 0.4 - 0.5 m in height.
Knowing the consumption rates of reinforcement and its location, it is easy to determine how much it is needed to create the foundation of a particular house
Calculation example
The basis is the construction of a box of a 6 x 10 house on a monolithic strip foundation from concrete (density 2300 kg/m3). Bookmark depth - 1.5 m (below the level of soil freezing). Other inputs:
- foam block walls - thickness 20 cm, height 2.7 m, density 900 kg / cm3;
- preliminary tape width 0.2 m, laying depth 1.5 m;
- pitched slate roof with a slope of 45 degrees, specific gravity 40 kg/m2; total area of slopes 86 m2;
- attic floor with wooden beams and insulation, specific gravity 150 kg/m2;
- soil - wet clay (calculated resistance R - 6kg / cm2);
- coefficients γ c =1.0; γ n = 1.2;
The calculation of the foundation is carried out in the following order.
- The weight of the house is considered element by element. Roof: 86 * 40 = 3440 kg. Walls: (6 + 10) * 2 * 0.2 * 2.7 * 900 = 15552 kg. Overlap: 150 * 6 * 10 = 9000 kg. Foundation: 0.2 * (6 + 10) * 2 * 2300 = 14720 kg. The total weight will be 3440 + 15552 + 9000 + 14720 = 42712 kg.
- The total load on the foundation F = 42712 + 10800 + 8600 = 62112 kg.
- Minimum footprint. S \u003d 1.2 * 62112 / 1.0 * 6 \u003d 14906 cm2 \u003d 1.49 m2. With a tape length of 32 m, its minimum allowable width is considered as follows: 1.49 / 32 \u003d 0.05 m. The actual size of 0.2 m is quite consistent with the working conditions (combination of soil and house weight).
- volume of concrete. (6 + 10) * 2 * 0.2 * 1.5 = 9.6 m3.
- The number of fittings. The length of the foundation is 32 m, the width is 0.2 m. If you place ribbed rods with a diameter of 14 mm in 2 lines and 2 tiers, you will need 32 * 4 = 128 m. The length of the transverse rod: 0.2 - (0.05 + 0.05 ) \u003d 0.1 m. Their number with an installation interval of 0.5 m will be: 32 * 2 / 0.5 \u003d 128 pieces, and the footage is 128 * 0.1 \u003d 12.8 m. Vertical connections also need 128 pieces. The length of each of them is 1.5 - (0.05 + 0.05) = 1.4, and the total length is 1.4 * 128 = 180 m.
In total, 128 m of ribbed reinforcement are needed for the foundation, and 12.8 + 180 = 192.8 m for smooth reinforcement.
The calculation of the final cost of the foundation is determined based on the volume of concrete mix and reinforcement materials. The price of a cube of concrete and a linear meter of reinforcement is specified by the sellers. Another option is to purchase cement and sand to fill at the construction site. In addition, you should take into account the cost of geodetic work, excavation. If earth-moving equipment is involved, then it is necessary to provide for the remuneration of the excavator operator. The calculation also includes the cost of lumber and the manufacture of formwork. The total cost of the foundation is usually 15 - 30% of the total cost of building a house.
In order not to make mistakes when determining the parameters of the foundation of the house and the amount of building materials for it, a special program is used - a calculator for calculating the foundation for a house. It will allow you to check the preliminary calculations and significantly speed up the design process.
Online calculation service
Calculator Concrete-Online v.1.0
Calculation of the composition of concrete for one batch in a concrete mixer, as well as any other container. Under the calculator you will find explanations and the algorithm of work, according to which the calculation is carried out.
*Explanations to the calculator
- The calculator can calculate the volume for both an integer and a fractional number.
Example: concrete volume 3m 3, concrete volume 50l (0.05m 3). - If your crushed stone has a mixed fraction of 5-20mm, then you need to select the maximum fraction, that is, 20mm.
- Superplasticizer C-3 (Dofen, SP-1, SP-3) is used in the calculator in dry form. If you use a superplasticizer in liquid form, then you must independently recalculate the dry matter of the additive.
- When calculating 1 batch in a tank with vertical loading (bucket, trough, box, etc.), the concrete mix output coefficient is used according to the bulk density of the components.
- When calculating 1 batch in a concrete mixer, the average concrete mix output coefficient is used, calculated from a sample collected from real mixing data in concrete mixers of different nominal volumes.
- If the number of batches is greater than 1, then the number of components for the last batch is calculated independently according to the calculated proportions. (The calculation of the components for the last batch can also be implemented in the calculator if necessary. Please unsubscribe in the comments if you really need it).
Algorithm for calculating the proportions of concrete components
To calculate the components for the manufacture of heavy concrete, the book by V.P. Sizova: Guidelines for the selection of compositions of heavy concrete.
1. Calculate W / C (water-cement ratio) according to the formulas:
2. We determine the water consumption for crushed stone (gravel) of different fractions:
The water demand of sand in the calculator is not taken into account and is taken by default 7% (sand of medium size).
3. Determine the consumption of cement:
When using the superplasticizer C-3 or an analogue (Dofen, SP-1, SP-3), the consumption of cement and water is reduced to obtain a given mobility (rigidity) of the concrete mixture.
4. Determine the coefficient of separation of particles. The spreading data was taken from Appendix No. 4 of the book by M. Feiner "New patterns in concrete science and their practical application " .
For mixtures with stiffness Zh3-Zh4, the average value of the coefficient of grain separation equal to 1.1 was taken.
The following data were used for the calculation:
- bulk density of cement - 1300 kg/m3
- bulk density of sand - 1500 kg/m3
- crushed stone bulk density - 1480 kg/m3
- true density of cement - 3100 kg/m3
- true density of sand - 2630 kg/m3
- true crushed stone density - 2600 kg/m3
The use of superplasticizer C-3 in the selection of concrete composition
The purpose of the superplasticizer in this calculator is to obtain a given mobility (rigidity) of the concrete mixture without reducing the strength of concrete.
For the calculation, "Table 1. Change in the mobility of the concrete mixture" from the book by Yu.P. Chernysheva: "Plastic concrete".
Useful information on the use of superplasticizer C-3 (Dophen):
Calculation of components for one batch in a concrete mixer
2. Determine the consumption of concrete mix components for one batch
- Cement for one batch \u003d (Vb * β / 1000) * C
- Water for one batch \u003d (Vb * β / 1000) * V
- Sand for one batch \u003d (Vb * β / 1000) * P
- Crushed stone for one batch \u003d (Vb * β / 1000) * Sch
where C, V, P, U is the consumption of materials per 1 m3 of concrete.
This calculation can be used to calculate the components of the concrete mixture for any container of vertical loading (trough, mason's box) in which you will knead the mixture.
For a real calculation in a concrete mixer, the output coefficient of the mixture from the concrete mixer was taken equal to 0.44. To calculate the coefficient, a sample was compiled from the answers of people from different construction forums, who mixed with their concrete mixers with different working volumes. ©
If you get a mixture that is too stiff, you can go in two ways to make it more plastic:
- adding a plasticizer;
- addition of water and cement in the calculated W/C ratio.
GOSTs, books, programs and calculators for calculating the composition of concrete
Methodological aids:
The procedure for selecting and coordinating recipes for cement concrete mixtures
Methodological guide for the preparation of concrete mixtures
Programs and calculators:
Application KSUBS (Dvorkin)
Application Concrete
Concrete Calculator-1.xls
Concrete Calculator-2.xls
Concrete Calculator-3.xls
M. Fainer "Concrete compositions for general construction purposes". Appendix 7
Comments
03/24/2016 05:52:46 PM Mikhail
Something your cement is too light ... 243 liters weigh 267 kg. Density 1100 kg/m3
03/24/2016 17:55:00 Maxim Gvozdev
Michael, thanks. Based on the following data. Portland cement has a bulk density in the range of 1000 - 1700 kg/m3. In "fresh" cement, it is on average 1100 kg/m3. As a result of storage and transportation, cement is compacted and has a bulk density of about 1500-1700 kg/m3. But I agree with you. The average value is still considered to be 1300 kg / cm3. I will take it as a basis then. This topic was raised on the forums. I didn't get an exact answer.
03/24/2016 05:58:14 PM Kirill
Thank you. Useful thing. But in practice, I would do trial batches. You also need to look at what kind of cement. There are different Portland cement with different content of additives.
03/24/2016 17:58:41 PPP
Thanks for the service. I will test your calculator in practice. As a result, I will try to unsubscribe. usually in practice and in theory the discrepancies can be significant.
03/24/2016 17:59:02 Ivan
I checked in practice, the concrete is excellent.
24.03.2016 17:59:31 Victor
Very convenient and understandable!
24.03.2016 17:59:49 Victor
Tomorrow I will evaluate the effect of the calculator in practice.
03/24/2016 18:00:29 Maxim Gvozdev
Victor, if you have time, please write back about the result.
03/24/2016 18:07:06 Victor
Yesterday we installed rebar into the formwork and poured concrete. I line the formwork with plastic film before installing the reinforcement f10mm. Concrete was prepared in an SBR-180 (l) Vympel concrete mixer. Filling composition: cement M400; fine sand 1.1-1.8; coarse filler 20-40mm; tap water. The volume of 1 bookmark in the concrete mixer, in liters: C:P:Gr:Water=10:25:42:8. Mixing sequence: start the concrete mixer; fill gravel; pour water; wash the gravel for about 10-15 seconds; pour cement in a "smooth" flow; by adjusting the angle of the drum, allow time for the cement to dissolve in water, 10-15 seconds; "smoothly" fall asleep sand. Stir the mixture for about 1-2 minutes. Pour concrete into the formwork. And bayonet. In appearance, the concrete turned out to be attractive, but it is better to pour water in 2 stages: pour 7.5 liters immediately, and add 0.5 liters little by little, assessing the fluidity of the mixture by eye. Finished pouring at 20:00. This morning I checked the hardness of concrete, there is a trace of a nail. He put sawdust on the concrete, covered it with perforated plastic sheeting, and watered it all day. I suppose the concrete will harden slowly due to the low temperature: about 15-17g during the day, and less than 10g at night. Tomorrow I will moisten the surface and check the hardness.
03/24/2016 18:08:32 Maxim Gvozdev
Victor, thanks for the detailed answer. Did you count with a calculator? And in the input data, you did not specify the brand of concrete and mobility. Well, if I understand correctly, then the mobility is of the order of P3. Concrete, most likely M200. But still I wanted to clarify. According to your proportions C:P:G:Water=10:25:42:8 is this given from the calculator or did you all have to change the composition?
03/24/2016 18:09:00 Victor
We continue the dialogue. P3, m200. I am making an adjustment to W / C \u003d 9/10, instead of 8/10 (I checked the buckets for displacement), i.e. C:P:G:W=10:25:42:9. Taking into account the humidity of the sand, the W / C ratio corresponds to the calculator. Further more difficult. The output of the finished mixture of 120 l declared according to the passport (I just bought a 180 l concrete mixer and was guided by this indicator) corresponds only to light bulk materials, although it is called a concrete mixer. The real output for heavy concrete, alas, is about 60 liters. With an increase in the volume of the finished mixture, the engine stops by 800 W when the concrete is unloaded. There was no calculator at hand, time did not wait, so I used the table of approximate proportions for a concrete mix on M400 cement, designed for 10 liters of cement. The output of finished products 1 batch = 60l. P.S. The calculator is very useful for a novice developer if you implement the formula: Vout. without reference to the volume of the concrete mixer drum. After the first loading, the owner himself will determine how much ready-made concrete the concrete mixer can digest, depending on the capacity of the drum, engine power, gear ratio, etc.
03/24/2016 18:09:40 Maxim Gvozdev
Victor. See. On your concrete mixer, according to your passport, two volumes are indicated - nominal and working. Nominal is the displacement when the pear is strictly vertical. The worker is the volume of the finished mixture that can be obtained at the exit, provided that the pear has a slope at which it can mix the mixture. Of course, concrete mixer manufacturers are chasing high parameters and indicate the smallest slope at which the mixture can supposedly be mixed. But how much will good quality mixing at their minimum slope? Perhaps just to mix the concrete mix, you need a greater inclination of the pear. About the calculator. When I calculated it, I understood that for the calculation in a concrete mixer, you should not use only the output parameters of the concrete mixture declared by the manufacturers. Therefore, I collected a sample based on the answers of people (about 20 options) who mixed concrete on different concrete mixers with different nominal volumes. On average, the coefficient was in the range of 0.39 - 0.47. For the calculator, I took 0.44. That is, if you have a 180l concrete mixer, then it turns out: 180 x 0.44 = 79 liters. In the calculator, I made 2 options for the output of the concrete mix. The first one is more suitable for containers with vertical loading (bucket, trough). The second is just for concrete mixers. This is the very bottom of the calculator: "Real values in relation to the volume of the concrete mixer to the finished mixture at the exit."
03/24/2016 18:11:17 Victor
I agree with you about the uselessness of stirring with the drum upright. In my case, the working volume of the finished mixture according to the passport is 120 liters. With dry filling of the components, I mixed and poured 105l (P + Gr) without stopping the drum, at any tilt of the drum. 105 liters of concrete at the exit would suit me, but in reality it’s 60 liters (P + Gr + C + V)! The concrete was unloaded immediately into the formwork and in small portions, and flopped with a swing - the engine did not pull when the drum was in a horizontal position (max moment). A little harder concrete stopped. The reason is that the 800W motor is small for a 180L unit. When it burns out, I will put 1 kW and get my 105 liters at the exit. You implemented in the calculator the average statistical coefficient on a small sample of 20 hours, with ambiguous initial data (including crafty passport data), averaged the mistakes made and deviated from the goal of getting "ideal" concrete in "handicraft" conditions. In my opinion, if we exclude the volume of the concrete mixer in the initial data of the calculator (we automatically exclude the average coefficient and the errors associated with them), and lay the output volume of the finished mixture in accordance with the standards, and calculate the fractional volume of the components for 1 batch, then as a result we get: 1 .On any concrete mixer we can knead any required volume that it will "pull". 2. We will increase the accuracy of the fractional laying, therefore, the quality of the concrete. P.S. Taking into account the error, my case on the calculator is realized with a volume of 115-120 l (in the original data)
03/24/2016 18:11:45 Maxim Gvozdev
Victor, good afternoon. I agree that a sample of 20 people is not considered large. But the answers were all in the same range with a slight difference. I will try to increase it over time. I'm adding your result. When I increase the data, I will change, if necessary, the yield ratio of the concrete mixture. You got it 60/180 = 0.33, provided that an 800W motor was used. When using 1 kW at the output, your coefficient will be 105/180 = 0.58 according to your data. We return to the calculator. Thanks for the criticism) I'll clarify a little. Crafty data from manufacturers are not included in the calculator. I wrote about this in a previous post. The coefficient was calculated only from the responses of people who kneaded concrete in their concrete mixers in real life. You wrote that it is better to remove the calculation for the concrete mixer from the calculator, and make a calculation according to the normative data for the output of the concrete mixture according to the bulk density of the components of the concrete mixture. This indicator is implemented in the calculator. This calculation is called “Calculated values by coefficient. output of concrete mix. This calculation is just according to the normative data. It can also be used in practice if we mix concrete in a container with a vertical load (bucket, trough, mason's box, etc.). I described all the calculations and formulas under the calculator. But, I agree, it is not very clear, perhaps displayed in the calculator. I will improve. With a concrete mixer, more or less everything is clear. I will increase the sample. I'm very interested in the composition of concrete. You wrote that there were nail marks on the concrete after the first day. How are things going on this moment?
03/24/2016 18:12:26 Victor
Concrete is gaining strength - "sharpen" the nail. Regarding the “Calculated values for the coefficient. output of concrete mix. It is very useful to keep this calculation at hand as an independent unit without connection with the volume of the concrete mixer in the initial data of the entire calculator. Sketch, briefly. I have a 180l b-ka, I need 50l of concrete at the output. In the line of the "concrete mixer" section, I add 50l and get the volumes of the VTsPShch in l. Without affecting the other sections.
03/24/2016 18:12:56 Maxim Gvozdev
Victor. Your idea is clear. But the main thing is not to confuse the user. Now I will correct some details and write a small instruction. I would appreciate a follow up test. I think I'll post the corrected version by tonight.
03/24/2016 18:13:13 Maxim Gvozdev
Made some changes in the design of the calculator. The principle of operation is the following. As Viktor wrote, it is necessary to select the composition of the concrete mixture for the manufacture of 50 liters of concrete when using a 180-liter concrete mixer. Principle of operation: we select the volume of concrete 0.05 m3. At the output, we have two calculations: 1 - calculation for one batch in a vertical container (bucket, trough), 2 - calculation for one batch in a concrete mixer. Under the calculator I made explanations of what you should pay attention to when calculating.
03/24/2016 06:13:41 PM Tatiana
Hello. Ivan, please tell me after pouring the foundation on what day you can mount the walls.
03/24/2016 18:14:43 Maxim Gvozdev
Tatiana. After 7 days the concrete is gaining approximately 70% strength, after 28 days 100% of the design strength, then the strength is very slow for a very long time. The ripening rate depends on the ambient temperature and air humidity. The main thing is not to let the concrete dry out. So see for yourself. If I flooded in the summer at an average air temperature of 20-30 C, I would withstand about 10 days, if I flood now at an average daily temperature of 10-15 C, I would still withstand 28 days. The main thing is to observe the technology of pouring and caring for concrete in the early days.
03/24/2016 18:15:07 Sergey
It would be nice if there was a PRINT or COPY button.
03/24/2016 18:15:42 Maxim Gvozdev
Sergey, thanks. I'll tweak the "Print" button then. Also thought about it.
03/24/2016 18:15:58 Maxim Gvozdev
Made a button to print the result. Can be saved as a pdf file.
03/24/2016 18:16:25 Sergey
Hello developers! Very cool program. Is it possible to take into account the moisture content of the components - sand and gravel - in the calculation of the composition? After all, in practice it turns out that the sand is unevenly dry, because it lies in a pile. And the quality of concrete depends on the purity of the crushed stone. Therefore, it is recommended to rinse it before backfilling. Thanks in advance!
03/24/2016 18:17:07 Maxim Gvozdev
Sergey, thanks! I'll see if there is something in Sizov's book about this. Like it was. Or in SNiP, GOSTs. In any case, it can be implemented by making it possible to choose wet or not sand (crushed stone). If wet, reduce the amount of mixing water while maintaining the W/C ratio.
24.03.2016 18:17:44 Sergei, Belgorod
03/24/2016 18:18:03 Maxim Gvozdev
Sergei Belgorod. If you have a Google Chrome browser, then it's very simple. Click on the "Print" link and select "Save as Pdf" in printers. If this is not possible in your browser, then you can install any virtual printer. For example Solid Pdf Creater, Abobe PDF and select it in printers. The file will be saved on your computer in pdf format.
03/24/2016 18:18:46 Dmitry
Add cement M800 to the calculation
03/24/2016 18:19:09 Maxim Gvozdev
Dmitry, I'll take a look at high-quality cements. There is a peculiarity there: when using high-activity cements for concretes of low strength grades, it is necessary to use additives. This is according to the book of Sizov.
03/24/2016 18:19:31 Anatoly
The thing is good. In the results of the calculation, you need to give one decimal place, because. when calculating small volumes (<=50 л.) очень большая погрешность по В/Ц, вместо 0,75 реально получится 0,83. Параметры: 25л, Б20, П4, М500. Результат 5л воды и 6л цемента, что явно не 0.75. По расчету наверное воды 4.5 л, но при выводе округляется до 5л. Это не придирка, расчитывал для корыта, а лопатой 50л. ворочать не очень просто:).
03/24/2016 18:19:59 Maxim Gvozdev
Anatoly. Now I checked according to your input data 25l, B20, P4, M500, medium sand, crushed stone 20mm. It turned out water 6kg cement 8kg. W / C 0.75 If you look at the liters: 6 liters of water and 6 liters of cement. W/C is calculated by weight. But I agree with you. There will be an error on small volumes. I will think. I can make decimal values when calculating for small volumes. Thank you for your helpful comment.
03/24/2016 18:20:24 Victor
Good day. Tell me, I just can’t understand, for the brand of concrete M200 from cement M400 I met a lot of proportions 1 / 2.8 / 4.8, but here I see 1 / 2.1 / 4.2. why is that? Thanks for the calculator, it's very handy!
03/24/2016 18:20:45 Maxim Gvozdev
Victor, I didn’t understand much in your proportions. The calculator has proportions by mass and by volume. Many here are confused. Also, methods for calculating proportions may vary. Well, in addition, in addition to the brand of concrete and cement, the proportion will be influenced by fractions of coarse and fine aggregates.
03/24/2016 18:21:10 Victor
It seems that I didn’t mess up anything, I look at everything by mass, and not by volume. For example, if you type something like "table of proportions for concrete" in a search engine, then in them for concrete M200 from cement M400 the ratio of cement / sand / crushed stone is 1 / 2.8 / 4.8. In the calculator, I choose the brand - M200, mobility - P3, Cement brand - M400, fine filler - 2-2.5mm, large - 20mm, there is no plasticizer, and as a result I get a proportion of 1 / 2.1 / 4.2. I tried to choose different fractions of fillers, different mobility, and still I don’t get 1 / 2.8 / 4.8. It’s just that the numbers, as for me, are very different, so I don’t understand how to do it all the same :(
03/24/2016 18:21:30 Maxim Gvozdev
Victor, on the Internet it's just a general formula. As well as for the preparation of the mortar, there is a generally accepted proportion of 1: 3 (cement: sand). On specialized forums, it is recommended to use proportions from Finer's book http://www..pdf There is truth with a plasticizer. The calculator works according to the method described in Sizov's book, which is also in demand. Here you decide. Try a test batch to make and check the concrete for strength. I would appreciate it if you post the results.
03/24/2016 18:21:48 Maxim Gvozdev
With a crushed stone fraction of 40 mm, the proportions are already 1: 2.4: 4.6
03/24/2016 06:22:36 PM Alexsandr
Good afternoon. I can’t understand: Concrete B15 per 1 m3 goes 221 liters of cement, and a concrete mixer 180 liters - 17 liters. Very strange. Or a jamb somewhere or I do not understand something. Today I will experimentally calculate the proportions. the proportion seems to be true!
03/24/2016 18:23:02 Maxim Gvozdev
Alexander, there is no mistake here. The only thing that can be an error in the coefficient. output of concrete mix for a concrete mixer, which depends in particular on the human factor. Now I will explain. We consider ... 221 liters of cement per 1000 liters. Therefore, for 180 l it will turn out 221/1000 * 180 \u003d 39.78 l But this amount of cement is for 180 l of ready-mixed concrete. We are dealing with a concrete mixer, in which the yield of concrete mixture is much lower. To find the amount of ready-mix for a concrete mixer, I collected a sample of the results of people who mixed concrete in various concrete mixers. As a result, I found an average concrete mix yield of 0.44. Of course, it can be different and depends largely not only on the design of the concrete mixer, but also on the skill of working with it. Someone kneads concrete with one angle of inclination, someone with another. As a result, we have 39.78 * 0.44 \u003d 17.5 liters
03/24/2016 18:23:22 Daniel
Thank you for your hard work! It was urgently required to estimate consumables for 0.064 cubic meters. concrete. Helped out. Bookmark site - algorithm in notepad;)
03/24/2016 18:27:06 sir24
What data should be entered into the calculator when using 0-10 screenings for concrete? Fine fraction 1.8mm, and coarse aggregate up to 10mm? Or does he count when there is both sand and gravel?
03/24/2016 18:27:24 Maxim Gvozdev
Yes, the calculator only counts in the presence of crushed stone and sand of certain fractions. Well, purely logically, you can take it as you wrote: crushed stone is 10mm, and it is better to take coarse sand more than 2.5mm. As a result, after calculating in the calculator, you will need to add up the mass of crushed stone and sand. This will be the mass of dropouts.
03/24/2016 18:27:58 Kovylin
In what proportions is C3 taken? The instructions on the canister say that 1.5-2.5 liters per 100 kg of cement, but do you have 0.7 liters per 100 kg of cement for P4?
03/24/2016 18:28:29 Maxim Gvozdev
As I understand it, C-3 is in liquid form. The calculator comes with C-3 in dry form. I made an explanation about it there. The concentration should be indicated in the instructions on the canister (average 30-40%).
24.03.2016 18:28:58 Kerulen
The most advanced calculator ever! However, an unexpected W/C ratio is observed. For example, for concrete 200 on cement 500, the calculator gives a value of 0.86, which is expected for concrete 100. Similarly, the W / C ratio for concrete 250 is shifted by a notch (0.75 instead of the expected 0.64) https://yadi.sk/i /6j_Q6A_FhjrQS https://yadi.sk/i/H_EUHQlkhjrU4 The lines in the A/C ratio table didn't "go" for an hour?
03/24/2016 18:29:17 Maxim Gvozdev
Kerulen, let's watch. Under the calculator there is a calculation algorithm and formulas. We take the first formula for finding V / C. W/C=/=/=0.86
03/24/2016 18:29:59 Sergey
In principle, the humidity of the components is not so important. It is only necessary to pour water 80% of the calculated volume. And then add if necessary, if the crushed stone and sand are dry. Wet and not required at all. Here another task is interesting in everyday life. All components are loaded with shovels. And the exact dosage is not always successful. What if we calculate the grade of concrete from the number of poured components in volume equivalents. Let's say B:C:P:Sch+C3=1:1:3:5, then what brand and plasticity will be obtained? Calculations will show that somewhere between M150 and M200. I am more than sure that the majority of the inhabitants will be satisfied with the M179-P3 brand for their designs.
03/24/2016 18:30:17 Maxim Gvozdev
Sergey, because there is a volumetric meter, taking into account the bulk density of the material. The calculator calculates both in kg and in liters. A shovel as a measuring container is not very suitable :) Someone is gaining with a slide, someone has a large shovel, someone has a small one. But buckets can even be measured (you need to know the volume of the bucket in advance). That is, with shovels we collect in a bucket, and then we pour it out of the bucket into a concrete mixer.
03/24/2016 18:30:37 Victor
To obtain the result, you need to set the required volume of concrete and the required grade - an indicator of its strength.
03/24/2016 18:30:59 Kovylin
Together with my son, I fill the floor of the first floor using this M350 calculator with a concrete mixer of 120 liters, the output is somewhere around 48-49 liters (21 batches per cube), but I make a fair slope for better mixing, then my coefficient is 0.4- 0.41, which, in principle, is not far from what is used in the calculator. Well, since this is the overlap of the first floor and the delivery of materials to the top is done manually by a wheelbarrow, and each wheelbarrow is an additional adventure that could be dispensed with, the selection of the amount of filler is quite accurate and helps a lot in work, thank you. Although in reserve I raise a couple of wheelbarrows of filler, just in case.
03/24/2016 18:31:19 Vadim174
Great calculator. I have used a concrete mixer several times. I did 1 to 2, I realized that the brand was about 200. But the question arises - with medium sand (grains are mostly 1 - 2.5 mm) when using a plasticizer and a VIBRATOR (required), you can achieve a brand of almost increased grade by 100, that is, not 200, and 300, with the same batch data. There is a video somewhere where they measured how much sand, cement was needed with buckets and pushed off the rubble. I don’t understand what is the point of adding more cement if, when using a vibrator, the cement completely fills the sand (if we compare the amount needed P, C, D for concrete mixing), but the rise in price is significant between grades 150 and 300. I’ll tell you how I did the batch - water + diluted plasticizer - - crushed stone 5 - 20 fractions (4 parts) - crushed stone is completely moistened with a slope with a concrete mixer (about 20 seconds) - cement (1 part) is poured (slope is small) - I set the slope more, I wait for the crushed stone to be saturated with liquid cement (1 minute) - I remove the slope - sand (2 parts) - more slope (3 - 5 minutes) If I didn’t make a lot of mistakes (thick or liquid) - I add water or cement.
03/24/2016 18:31:47 Dmitry V.
Thanks a lot for your work! There are a couple of questions: 1. Is it possible to additionally indicate the volumetric W / C ratio (and not just the weight ratio). Often this is necessary, and to obtain this coefficient you have to calculate it yourself, based on the data from your calculator. Few people weigh bulk materials, most often they use some kind of dosing containers. Also, the final volume of the required concrete is not always clear .. Then the volumetric W / C ratio is needed. You can specify it in the line "Ratio C:P:SCH, in l", modifying the line to the form "Ratio C:P:SCH:V, in l". 2. The version for Android has not appeared yet?
03/24/2016 18:33:36 Maxim Gvozdev
Dmitry.V. Why do you need W/C ratio? It's some official information. I just displayed his references. After all, the calculation of components in volumetric form is given in the calculator already in finished form. That is, for the preparation of 1m3 of concrete, so many liters of cement, water, sand, gravel are needed. 2. I haven’t done it for Android yet, but I plan to. Now just busy with other construction calculators.
03/24/2016 18:34:06 Dmitry V.
A simple example: I start pouring window lintels. Volume 0.05-0.06 m3. Work for 3 hours. I did not calculate the required volume of concrete, I just started working, and that's it. Mixes by hand in a trough in small batches. It makes no sense to dirty the concrete mixer. I took the first bucket that came across, and began to dose all the components with it. With cement, sand and gravel, everything is clear - volumetric ratios are indicated in your calculator. But how much water to pour is not clear. In the case of weight ratios, for example, for M250 P3, W / C is 0.86, and in the case of volumetric ratios, it is also 1.12. That is, I have to calculate this coefficient for a specific brand of concrete, and then pour 1.12 of the above bucket into the trough. Did you manage to substantiate?
03/24/2016 18:34:42 Maxim Gvozdev
Dmitry V. yes, I understand what you are talking about. You use only the ratios of the components according to the calculator. And why don't you want to take ready-made dosages at the bottom of the calculator there is a calculation called "Calculation for 1 batch in a container with vertical loading (bucket, trough, box, etc.)". You have a trough. Indicate it not the nominal volume, but the smaller one. Let's say a trough displacement of 50 liters. And you indicate in the calculator 30 liters in the "Concrete mixer" field (well, provided that you do not want to fill up the components to the eyeballs of the container). The input and output data for the concrete mix indicate those that you need. Well, as a result, you can see how much water, cement, sand and gravel are needed for 1 batch. True, for such small volumes of containers, I wanted to calculate the proportions of the components in decimals, otherwise everything seems to be rounded up to a whole number. Well, I'll do it.
03/24/2016 18:35:33 Dmitry V.
Yes, you are right, you can use dosages for small containers, but as long as there is a large error due to rounding, this is not an option. Also, the volume of the dosing container is not always known, then we use not the absolute values of the dosages, but their volumetric ratios. So it is: more often we take one bucket of cement, three buckets of sand, five buckets of gravel. That is, we don’t think about how much it is in kilograms or liters. And, accordingly, we measure the water with the same bucket in a certain proportion. And the proportion is not explicitly indicated, it needs to be calculated ... Nevertheless, I will ask you to additionally display the "volumetric" V / C, in some cases it is necessary. In my opinion, it would be correct as follows: Weight ratio C:P:Sch,V 1 3.1 5.6 0.86 kg Volumetric ratio C:P:Sch,V 1 2.7 4.9 1.12 l I I do not insist on anything, this is your product, and you decide. I'm just trying to participate in the improvement of the product, which I myself will be happy to use. Laziness is the engine of progress :-)
03/24/2016 18:36:48 Maxim Gvozdev
Dmitry V. Yes, I agree with you. That can be done, of course. Today or tomorrow I will post a new version of the calculator with revision.
03/24/2016 18:37:13 Dmitry V.
Thank you so much! Forgive me for importunity, is it possible now to solve the issue with rounding to one decimal place for a batch in a small container and to two decimal places for W / C (weight and volume)? Actually, earlier V / C was rounded up to two decimal places. p.s. The previously displayed V/C can be hidden, it is now duplicated. Thanks again!
03/24/2016 18:37:33 Maxim Gvozdev
Dmitry V. did. I won't clean up the A/C yet. There, the algorithm will not have to be changed much. In general, it doesn't interfere much. If you have any other requests, please write. Thank you for participating!
03/24/2016 18:37:58 Andrey56
Either the skis don’t go, or I’m a fool ((I calculated concrete M300 for a warm floor screed in the calculator: the volume of pouring is 1.2 cubic meters, I make it from a fraction of 0-5mm, that is, screening, I interfere in the trough 200l, I use the Thermoplast plasticizer and the additive D- 5, which also plasticizes the mixture. Since I did not find screenings in the calculator, I chose the smallest fractions in the windows of aggregates. The calculator gave out 27 liters of water per batch. The ratio of cement to screenings was approximately 1: 4. In practice, at 27 liters per batch , the consistency of the mixture is like that of asphalt before laying ... I had to pour almost twice as much water to get normal concrete.
03/24/2016 18:38:45 Maxim Gvozdev
Andrei56, I can’t say for sure. It may be difficult to achieve a homogeneous mixture by mixing in a trough. After all, you add a plasticizer and, due to it, reduce the consumption of water and cement. Most likely, mixing in a concrete mixer would have a different effect. In any case, the ratio of cement and water must be observed. Add water, add cement. Otherwise, there is a loss in the strength of concrete.
03/24/2016 18:41:49 Dmitry V.
Andrei56, in my opinion, such a consistency should be. As soon as you touch the mixture with a vibrator, it will flow. Without a vibrator, it is difficult to lay such inactive mixtures.
03/24/2016 18:46:07 Leonid
Used your calculator twice. Both times the water turned out to be 20 percent more than concrete of a given mobility could actually "accept". The proportions for the concrete mixer differ too much from the calculated proportions per 1 cubic meter. And yet, recently, cement has increasingly been designated not by brand, but by strength class. I buy cement in Voskresensk of class 42.5, which corresponds to about M400+. I think it's worth putting classes into the calculator too.
03/24/2016 18:47:33 Maxim Gvozdev
Leonid, thanks for the comment. Was the sand not saturated with water? If water-saturated, then of course you need less water. This is not taken into account in the calculator. Regarding the proportions, there may be slight deviations when comparing 1m3 and the proportions in a concrete mixer. There is a rounding error as a result. I'll fix it. Regarding the class of cement, it is not difficult to do. I think I will too.
03/24/2016 18:46:23 Leonid
Deviations in the calculations of the components in the concrete mixer reach 10%, this is too much.
03/24/2016 18:47:51 Maxim Gvozdev
Leonid, can you give an example? Maybe we're talking about different things
03/24/2016 18:46:47 Leonid
It would be nice to supplement the calculator with the calculation of sand concrete. The solution calculator is not quite suitable, as there is a limited choice of mobility.
03/24/2016 18:48:20 Valery
Good day. I join all the thanks for your work on the calculator. I have questions and a suggestion. Please tell me by what criteria you chose the literature (because there is a lot of it) for calculating the composition of concrete (to create a calculator). How to choose the "correct" digital values, in the range, when calculating the composition yourself, for example, coefficients or C-3 from 0.4 - 1%, etc. is it necessary to round the results of the calculation of the parameters ..... or all this is not critical ...... Well, the suggestion ..... I read the comments .... but what if you don’t bother with the concrete mix output coefficient and install a concrete mixer drum ( who has, or will acquire in the future) to the "favorite" angle of inclination, pour in portions (10 liters each, then 1 liter each) to an acceptable level - the result will be the displacement of the working mixture, then "hammer" the parameters of the required grade of concrete into the calculator, without bothering with the volume of the concrete mixer, and take only the results per 1 m3, and each parameter C.P.Gr.V. recalculate to the "displacement" of your concrete mixer for 1 batch. Or divide the required volume of concrete into equal parts, so that each part "fits" into the "displacement" ....... or am I mistaken in something ?. Sincerely, Valery.
03/24/2016 18:48:49 Valery
How do you deal with interpolation if it occurs in composition calculation manuals, by the nearest parameter or calculation? if there is a formula please indicate the source. Thank you, good luck, strength and health!!!
03/24/2016 18:49:42 Maxim Gvozdev
Valery, thanks for the detailed comment! If where interpolation was needed, then it was taken according to the nearest parameters. I used Sizov's book because of the good reviews on specialized forums about it. Regarding the coefficients, I apologize, I did not understand the question. If you are talking about rounding, then I wanted to finish it so that the calculator makes more accurate calculations with small volumes. About your proposal. It is possible, of course, and so, but it will be necessary to explain to users why this is so, and not as it is now. In general, you can simply set the “favorite” volume of concrete mix for your concrete mixer in the volume of concrete volume field. And see the results for 1 batch in the column "Specified concrete calculation". That is, look at the calculation for 1 batch without using coefficients.
03/24/2016 18:49:11 Vladimir
Thank you for the calculator, the calculator has already helped on two objects. Now I have begun to design an underground structure. I would very much like to see in the calculator, concretes of classes B50 - B90, I think that this is not difficult ?!
03/24/2016 18:49:59 Maxim Gvozdev
Vladimir, it's not hard to do. Wrote down the finishing touches on the calculator.
03/24/2016 18:50:18 Valery
Forgive me, I didn’t explain about the coefficients, I’m interested if I try to calculate the composition of concrete myself. And in reference books, for example: coefficient. 0.55.....0.75. You can apply anyone in this range, but then the result (in the end) will turn out to be different, I mean if you count with one and then with another (coefficient) or is it not critical? ... and also, is there a superplasticizer 0.5% in the calculator? and in reference books from 0.4 to 1.2%, it may turn out that 0.5% or a lot or a little, the mixture will either delaminate or not react with the plasticizer, it seems to me that here it is necessary to somehow individually approach the calculations. by batch: - did a trial calculation, on a calculator for 125 liters of mixture, b.m. for 130 l. total: (for example, water) total - 27 liters, 3 batches in b, m, 12 liters each. in 1 batch - total 36 l.? as I understand it, the 3rd batch needs to be recalculated, so I suggested the required displacement of the mixture, according to the calculator, divided into equal parts that fit into the b / m drum. Sincerely, Valery.
03/24/2016 18:50:52 Maxim Gvozdev
Valery, hello! First of all, thanks for the detailed comments. I also apologize to everyone for the delay in responding. If I don’t answer questions on the site for a long time, you can ask questions on the forum for this calculator https://www.forumhouse.ru/threads/269324/ There, if not me, then someone else will definitely answer. Regarding the plasticizer, I took this one from the book by Yu.P. Chernysheva: "Plastic concrete". Of course, you need to make a trial batch and find a middle ground. I will also think about your proposal, I made a note. A little later I will look through all the entries and I will already make adjustments to the calculator. Thank you all in advance for your contribution to the development of the calculator!
03/24/2016 18:50:34 Victor
The Betonokomplekt company offers a convenient concrete calculation calculator. We are the largest supplier, we have our own production of building mixtures and offer the highest quality products at the best prices with delivery in the shortest possible time. We accept applications for the transportation of the required amount of solution.
03/24/2016 18:51:17 Valery
Please explain what parameters are included in the calculator for the separation of grains and voids (literature, author) and why, with different modules of sand size (everything else is the same), the calculator gives the same water flow?
03/24/2016 18:53:30 Maxim Gvozdev
Valery, everything is according to the calculation algorithm presented under the calculator.
03/24/2016 18:53:58 Alexander
Is it planned to calculate the I-beam deflection and bending calculator. Like with a channel and a corner?
03/24/2016 18:54:08 Maxim Gvozdev
Alexander hasn't planned yet.
04/04/2016 15:49:23 GLEB
First of all, thank you so much for the calculator. As for the output of the finished mixture (the working volume of the concrete mixer), it has been experimentally verified: on the Skiper B-140c concrete mixer - the volume of the finished mixture is 50 liters (M150 B12.5 using a plasticizer). now the actual questions and wishes: * is it possible to make an additional option for recalculating the plasticizer, given that most people (self-builders), I think, use a ready-made solution in cans. just an additional option with a pre-installed calculation algorithm. * the question with V / C is not entirely clear, although you say that this is "official" information, but on the Internet I constantly come across recommendations on the need to comply with V / C in the aisles of 0.5-0.6, and here are completely different values. can make an additional option, where the calculation was made from V / c, as from a given value? or am I confusing something? does this only apply to cement mortars? * Recently, numerous additives have appeared on the market, such as microsilica and microfiber. Is it possible to add options for introducing these components? thank you, good luck.
04/14/2016 03:59:58 AM Maxim Gvozdev
Gleb, thank you for your feedback. W / C calculates according to formulas taken from Sizov's book. All formulas and graphs brought out under the calculator. I made a note about your wishes. And so, in general, I used data from books or regulatory documents. So plasticizer in dry matter.
04/18/2016 21:57:28 Andrey
I thought, I thought, I didn’t understand, the data differ from other sites)) I need the M350 brand for support pillars, and perkladin, a 180l mixer, how to knead for high-quality concrete?)
05/08/2016 09:36:25 Maxim Gvozdev
Andrey, so consider on the calculator. You have the input. If the data differs from other sites, then the fact is that everywhere there is a different calculation method. Many do according to the Finer table (I have a link to the file below the work algorithm).
05/08/2016 21:05:14 Andrey
Thanks for the answer! To be honest, I thought so, I decided to clarify, because you have less sand than on other sites, and I will be responsible for filling, so I’m interested! I wrote above that I need a mixture of 350, but I think to do 400, is it necessary? I'm afraid of losing the brand, will I have an examination to make buildings, or if I strictly observe the proportions, will I keep the brand? There will be kneading in the mixer
05/10/2016 02:36:32 PM Maxim Gvozdev
06/02/2016 19:21:14 sergey
Thanks for the calculator.
06/11/2016 11:52:49 AM Roman D.
The day before yesterday and yesterday I did the first batches in my life. I used yours and several other calculators as a basis, including various tables with cement and plasticizer. As a result, I came to such a ratio for the convenience of work, for 25 kg of cement I take ~ 48 kg of sand (3 buckets of 12 liters each) ~ 108 kg of crushed stone (6 buckets of 12 each) I check the dosage every time for every occasion, I trust weight more than volume. Here I pour 3-4 liters less water, otherwise a very mobile mixture is obtained with a plasticizer, since I use a vibrator with a hard one, it is clearer to me when it has condensed. The sequence of kneading was always different, but now I decided first sand, then water, then crushed stone and, as soon as possible, cement immediately after it. I tried to mix the dry mix as advised first, the result - dry sand with cement stuck to the concrete mixer, crushed stone flopped near the hole, I had to stop and mix it manually with a shovel and then turn it on again, and this was with an almost horizontal slope. I plop the plasticizer at the last moment 180-200 ml per eye when the mixture is already beginning to mix. In general, I hope that it will stand, and the brand will not be lower than m200. Thank you for the handy calculators)
06/11/2016 05:52:04 PM Maxim Gvozdev
Please, and thank you for your feedback.
06/13/2016 21:23:05 Andrey
A week ago, I filled in the first columns, they are still getting stronger, on the street during the day +30, I removed the formwork after 2.5 days, everything seems to be beautifully even) I interfered with the M400 brand with a plasticizer, vibrated, it only turned out 3-4 batches more in a cube approximately, a little more poured water, seizes very quickly, but I had to carry it with buckets of 4m, in general, thanks for the calculator, everything is clear and convenient in the chain, we are waiting for branded strength)
06/13/2016 21:29:17 Andrey
By the way, I interfered, water, crushed stone, c3 dry, crushed stone, sand, cement, it interferes well, the mixer is 180l, I took the output of the finished mixture by 80l, it interferes faster and better)
07/18/2016 21:58:44 Vadim
Thank you! Great tool! Still, exporting the calculation to a spreadsheet or text document would be very useful.
07/25/2016 00:40:13 Stas
It would be nice to get the results of the examination from the laboratory on prescriptions from this calculator. So that it doesn’t turn out that I chose m300 in the calculator, but it turned out 200 ...
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The foundation is the foundation of the house, on which the durability, reliability and safety of the structure depend. Therefore, before starting its pouring, it is necessary to conduct a study of the soil of the land. The choice of the type of foundation and the preparation of a cost estimate for its laying depend on the composition and indicators of the soil. The online calculator for calculating the foundation will allow you to correctly design the foundation of the house from an engineering and technical point of view.
How to calculate the foundation yourself?
In order to determine the required volume of concrete (V) for the foundation of the house, a special formula is used, which involves the multiplication of the following design indicators:
- P - foundation perimeter;
- H - foundation heights (underground and aboveground parts);
- B - the width of the foundation.
When calculating the proportion of the concrete mixture, it is necessary to take into account the brand of cement, the fractionation of sand and crushed stone, as well as the degree of their density. The calculator for calculating concrete for a foundation for a house will give the required volume of concrete in cubic meters. It also provides for online calculation of materials (rebar, cement, sand, crushed stone, formwork boards) for the foundation. At the same time, the amount of required reinforcement is indicated in meters, sand and crushed stone in tons.
Calculation of the strip foundation
The tape base is the most popular type of foundation, which is explained by its technical characteristics and economic benefits.
Effective design of the foundation will allow you to properly distribute external loads along its perimeter, which is an important step in the subsequent construction work. Handwritten calculation of the foundation has a high probability of making mistakes, which, over the years of operation of the house, are fraught with the destruction of the structure. A specially designed strip foundation calculation calculator takes into account the engineering subtleties of its device.
The result of specifying the requested parameters in the corresponding input fields implies obtaining data regarding:
- foundation reinforcement;
- formwork material;
- volume of concrete, cement, sand and gravel.
A convenient and simple online calculator is designed to significantly simplify the process of calculating the strip foundation.
The house must have a solid foundation - a guarantee that at one fine moment your home will not begin to sag and become covered with cracks in the entire wall. One of the best options in such a situation is a strip foundation - a reinforced concrete structure closed along the contour, on which the building box is being erected.
This is a fairly versatile element, on the basis of which you can build diverse structures. A strip foundation is suitable for a house made of foam blocks, log cabins, brick boxes. Its use can significantly reduce the amount of preparatory excavation, construction time and total cost.
There are two types of such a foundation used in mass construction:
- Monolithic. A bonded reinforcing cage, which is poured with concrete into a specially prepared formwork.
- Made. A foundation that is closed along the contour, laid out from ready-made concrete blocks fastened together.
The first one contains the following elements:
1. Sand cushion. This is the lowest part, which is placed at the bottom of the trench prepared in advance. The thickness of the ball should be within 20-30 cm.
2. Large-fraction pillow. Intermediate base layer up to 10 cm thick of crushed stone, gravel or finely chipped old bricks.
3. Waterproofing. Most often, a polyethylene film is laid on the gravel - a universal barrier that prevents direct contact between the foundation concrete and the soil.
4. Reinforcing mesh. It consists of two rows of special rods Æ10 mm, arranged vertically in increments of up to 30 cm. They are interconnected with intermediate jumpers Æ6 mm. This is a kind of skeleton of a strip foundation that holds the mass of concrete within the designated boundaries.
5. Concrete tape. A ball, which in a liquid state is poured into the prepared formwork. After hardening, it is used as a base for placing load-bearing walls.
A typical prefabricated concrete foundation contains the following elements:
- Sand pillow. A compacted embankment at the bottom of the trench, wider than in a monolithic type, 10-15 cm thick.
- Foundation plate. Finished concrete product with a trapezoidal profile.
- Reinforced belt. Reinforced concrete layer up to 50 mm thick.
- Main ball. Several rows of building blocks stacked in a checkerboard pattern. A gap of at least 2 cm is maintained between adjacent elements, which is poured with liquid concrete.
What should be taken into account in the calculation process?
After a clear idea of \u200b\u200bthe design has been formed, it's time to start calculating using a calculator or a personal computer. They can be conditionally divided into technical and material stages.
The result of the first stage are the following main parameters:
- General dimensions in cross section and along the perimeter (length, width, depth of the underground part, height above the soil level).
- Profile and required dimensions of the trench under the base of the house.
- Volumes and component structure of the cushion for the concrete belt (sand, gravel, etc.).
At the second stage, according to the known parameters of the trench, the required flow rate is determined:
1. Volumes of preparatory earthmoving works.
2. The amount of bulk materials for the pillow.
3. The consumption of the main mass of concrete according to the size of the tape and, as a result, the ability to calculate the content of the components.
4. Length, diameter and total number of reinforcing bars for linking the tape carcass.
5. Square sheets for waterproofing.
6. Volumes of lumber for the arrangement of surface formwork.
How to do the calculations correctly?
If you have already matured with the idea of \u200b\u200bbuilding your own house and have come close to the construction of a strip foundation, then you can choose one of three calculation options:
1. Entrust the work to a professional designer.
2. Carry out calculations on your own on a calculator, based on your own experience (if any), available information and advice from colleagues.
A trained person knows exactly what, when and how to take into account when calculating sizes and materials, based on the current regulations:
- SNiP 2.02.01-83 "Foundations of buildings and structures" using the recommendations of the design manual.
- SNiP 2.08.01-85 "Designs of residential buildings", completed with relevant methodological materials.
Even a professional needs to perform one or two recalculations in order to eliminate possible inconsistencies and achieve a loss factor of 1.12-1.15. For this, special software is used. Naturally, you will have to pay at least 5000 rubles for this.
If the customer does not want to spend extra money on attracting experienced designers, then he can try to calculate the materials on his own, on a calculator, based on the already mentioned standards and recommendations for them. You will have to take into account a lot of different coefficients and conditions that cannot be chosen at random.
The number of iterations in this case can reach five times. In addition, it is recommended to play it safe and conduct parallel calculations of concrete volumes for a strip foundation in several hands, as they say.
Approximate cost of filling turnkey
About 80% of the strip foundations of private houses sooner or later become covered with cracks and require regular maintenance. This happens because even at the stage of independent calculations gross errors are made or obvious facts are simply ignored to reduce the cost of the finished product.
Professionals approach the issue responsibly, with a real understanding of the required scope of work, calculation tactics and the cost of pouring a turnkey foundation. Of course, it can differ significantly depending on the region, materials and services of the contractor, but on average, a classic tape-shaped base will cost the customer 14,000 - 16,000 rubles per cubic meter.
A comparative table of the cost of performing work on pouring the foundation of the most commonly used sizes in the plan will look like this:
| Foundation size in plan, m | Price of works, rubles | Cost of materials | Turnkey filling price |
| 4×6 | 55 000 | 80 000 | 130 000 |
| 6×6 | 60 000 | 90 000 | 140 000 |
| 6×8 | 70 000 | 105 000 | 165 000 |
| 6×10 | 100 000 | 130 000 | 215 000 |
| 8×8 | 105 000 | 140 000 | 230 000 |
| 9×9 | 110 000 | 150 000 | 245 000 |
Calculations on the online calculator
If the future owner of the house does not have a desire to use the services of professional designers, and he himself is not able to master the upcoming amount of work, then you can turn to another option - an online calculator for calculating foundation concrete.
The use of such calculators that calculate materials for pouring a strip foundation can significantly reduce the time of the preparatory stage. Nevertheless, it is desirable to double-check the obtained result manually for safety net.
Private construction, which is carried out with one's own hands, does not cancel accurate calculations. This approach helps to optimize costs and speed up the progress of work. The calculation of concrete for the foundation with a calculator will allow you to buy the exact amount of the required material, without huge unrealizable balances.
The choice of reinforced concrete for strength is based on the features of the future design. If the load on the base is small, as from country houses or frame-panel structures, you can use the M200 brand material.
More massive buildings, including two-story ones, with attics, made of timber, logs, foam blocks, require the arrangement of stronger bases on grades M 250/300. Brick, reinforced concrete walls withstand systems made on the basis of materials M350 / M400. Using the brand of the working solution, you can calculate the volume of concrete for the foundation, the calculator will allow you to get all the data.
Of key importance is the density of concrete used for the construction of load-bearing structures. It varies from 1300 to 2500 kg/m³
concrete calculator
The service is designed to calculate the dimensions of the base, formwork, diameter and quantity of reinforcement and the volume of the working solution, which is used to equip the supporting structure.
The calculation of concrete for the foundation (calculator) is based on building codes and regulations governing the construction of structures made of concrete and reinforced concrete (SNiP) 52-01-2003, state standard GOST R 52086-2003, SNiP 3.03.01-87.
Calculation of materials for a strip foundation
The load-bearing structure of this type is a closed monolithic reinforced concrete strip, which is placed under the load-bearing walls of the facility, distributing the load over the entire area of the belts.
The system blocks the change in the shape of the building and its subsidence, which occurs due to swelling of the soil, high loads are transferred to the corners. This is the most popular type of foundation used in private housing construction., which is due to the optimal ratio of cost and characteristics obtained.
Tape bases can be prefabricated or monolithic, deep and shallow. The choice of the type of construction is based on the characteristics of the soil layer, the design load and other parameters considered individually. The system is suitable for all types of buildings and is used in the arrangement of the basement and basements.
Calculations based on specified inputs:
- brand of reinforced concrete;
- tape width, in meters;
- tape length, in meters;
- tape height, in cm;
- tape thickness, in cm;
Indicative calculation of concrete on a monolithic foundation (calculator)
If a strip base is equipped on a solution of brand M300, class 22.5, with the following linear design parameters:
- width - 6.00 m;
- length - 8.00 m;
- height - 70.00 cm;
- thickness - 40.00 cm, then the required volume of concrete will be 7.4 m³ with a total mass of 18500 kg (with a material density of 2500 kg / m³).
Calculation of concrete on the foundation - general information on decoding the results
It is easy to determine the amount of material in kg. It is enough to multiply the volume indicator m³ by the density kg/m³
Using a calculator, you can get the indicated data. Their interpretation is as follows:
- the total length of the tape is the perimeter of the base;
- area of the sole of the tape - indicates the area of \u200b\u200bsupport of the base on the ground. The parameter corresponds to the required waterproofing dimensions;
- side surface area from the outside - indicates the area of the required insulation for the outer side of the base;
- calculation of the volume of concrete - the calculator allows you to determine the cubic capacity of the material required to pour the entire base with the initial parameters. When mixing the solution, it is recommended to exceed the resulting volume by 10%;
- the amount of solution - the approximate weight of the material at an average density;
- calculation of the load on the foundation - the calculator allows you to determine the load parameters for the entire area of \u200b\u200bthe support, in kg / cm²;
- formwork board thickness - GOST R 52086-2003 for a given support spacing and initial parameters of the supporting structure;
- number of boards - the number of boards for formwork of the original size.
The calculation of concrete for a strip foundation, taking into account all construction parameters, is ready.
Calculation of concrete on a columnar foundation calculator
When calculating the amount of materials for a columnar foundation you need to know the parameters of the specified initial parameters:
- brand of concrete;
- number of poles, pcs;
- column diameter, cm;
- height, cm;
- diameter of its base, cm;
- base height, cm;
- grillage width, m;
- grillage length, m;
- grillage height, m;
- grillage thickness, m;
The structural elements of such systems - pillars - are located in the ground. The tops of the pillars are interconnected by a monolith (reinforced concrete tape, which is called a grillage). The calculation of concrete cubes for a foundation (calculator) of this type allows you to obtain the required data, in accordance with current building codes and regulations.
Approximate calculation
The exact determination of reinforcement and its quantity is made on the basis of complex engineering calculations of the foundation for strength
Initial data:
- the system contains 12 pillars;
- diameter of each - 30 cm;
- height - 300 cm;
- diameter of the base of the column - 40 cm;
- base height - 20 cm;
- grillage width - 6m;
- length - 8 m;
- height - 70 cm;
- thickness - 40 cm.
To equip the foundation, you will need 10.2 m³ of material (M300), weighing 24059 kg.
Calculation of the cubature of concrete for a monolithic slab
The development of such bases allows you to get a rectangular base. Calculations are based on the specified initial data:
- plate length;
- width;
- height.
An approximate calculation of the amount of concrete for the foundation of a house (calculator) looks like this: initial data - grillage dimensions 12.0 x 10.0 m, slab height 0.40 m. Calculation per cube of material - 12.0 x 10.0 x 0.40 \u003d 48.0 m³, which corresponds to 120.000 kg
Foundation reinforcement (monolithic slabs)
The calculation allows you to determine the following parameters:
- min allowable diameter of longitudinally and transversely located rods, mm;
- min number of rows in the upper and lower belt, pcs.;
- the amount of overlap, in cm;
- total length, m;
- total weight, kg.
Calculation of formwork for a monolithic slab
The calculator allows you to determine the minimum thickness of the board, when installing the formwork in increments of 1 m, in mm and the number of boards of the original size, in pieces.
Calculation of cement per cube of concrete
The grade of the material should be 1.5-2 r higher than the required grade of the working solution. For example, to obtain M 200, you need a binder M400.
To determine the required amount of cement per m³ of reinforced concrete, it is necessary to divide the amount of water used by the water-cement ratio.
Table - water consumption depending on the aggregate fraction
| Required ductility of reinforced concrete | Fluid consumption, l/m³ | |||||||
| gravel, mm | Crushed stone, mm | |||||||
| 10.00 | 20.00 | 40.00 | 80.00 | 10.00 | 20.00 | 40.00 | 80.00 | |
| high | 215.00 | 200.00 | 185.00 | 170.00 | 230.00 | 215.00 | 200.00 | 185.00 |
| Medium | 205.00 | 190.00 | 175.00 | 160.00 | 220.00 | 205.00 | 190.00 | 175.00 |
| Low | 195.00 | 180.00 | 165.00 | 150.00 | 210.00 | 195.00 | 180.00 | 165.00 |
| Non-plastic concrete | 185.00 | 170.00 | 155.00 | 140.00 | 200.00 | 185.00 | 170.00 | 155.00 |
The choice of water-cement ratio is based on the maturation period of reinforced concrete (according to the conditions of construction) and the brand of cement. If crushed stone is used to prepare the mixture, 0.05 is added to the indicator indicated in the table
| Cement, M | Curing time 28 days | |||
| Reinforced concrete grades | ||||
| 200.0 | 250.0 | 300.0 | 400.0 | |
| 300.0 | 0.550 | 0.500 | 0.400 | — |
| 400.0 | 0.630 | 0.560 | 0.500 | 0.400 |
| 500.0 | 0.710 | 0.640 | 0.600 | 0.460 |
For example, with a given volume of liquid equal to 205 liters and VC equal to 0.61, 336 kg of cement (205.0 / 0.610) will be required for mixing.
Price
By implementing the calculation of concrete for the foundation (online calculator), you can determine the cost of construction. The higher the brand of material, the higher the level of costs. On average, 1 m³ of the most popular solution of the M300 brand is estimated at 3100-3300 tr. If the material is fed through a concrete pump, there is a slight increase in cost.
This video explains how the calculation of the amount of concrete for the foundation with a calculator exposes the fraud of concrete suppliers:
