Almost any construction cannot be done without using mortar in its process. Except when it comes to wooden structures, and they must be installed on a well-organized foundation, the basis of which, as you know, is cement mortar.
No yard can do without convenient paths, which you can make yourself.
Concrete can be used not only to construct the foundation of a house, but also for monolithic pouring of walls, floors and in road construction. Concrete is also made for pouring. In any case, there are pouring rules that are considered unique by professional builders. This means that in order to learn how to pour the solution correctly, you need to study and practice the acquired knowledge on some specific example. For example, if you learn how to fill the driveway to your house with a mixture or understand, then making a foundation with your own hands in the future will not be difficult.
For work, be it pouring a road or the foundation of a house, certain rules must be followed.
The technology or foundation involves several practically similar stages. The first step is to prepare the site for construction and excavate the ground. This is followed by the following stages: creating a cushion of sand and gravel, installing formwork, reinforcing the object, for example, floors created using mortar, which will significantly increase the level of strength and durability of the floor. Understanding the importance of the upcoming work, you must first prepare a schematic plan, supported by some calculations, for example, you need to determine how much building material will be required for a properly organized project, calculate the floor area or what dimensions the gutter will have. Take care in advance of the tools that will be used to fill the floors or roads - a shovel and a mixer.
Installation of tracks
When the concrete has already been poured into the place prepared for the path, a special flat board it is necessary to smoothly move along the edges of the formwork to remove excess and compact.
Before you begin directly pouring the object, you should carefully prepare the site for it. In the case of a road, we will talk about soil compaction. This is done by leveling the ground. After this, you need to make an embankment of fine sand, approximately 15 cm in height. The sand must be compacted tightly under the slab that will be formed in the future. In the case when a foundation or base of floors is being created, you need to dig out the ground of the required depth and width under the gutter, at the bottom of which an embankment of sand or crushed granite is also made. If you have gravel, you can use that too. After which formwork should be placed on this cushion. The mixture of sand and gravel for the foundation does not have to be done using a mixer.
Formwork installation
After compacting the soil and base to create roads that a car can drive on, you should move on to the next stage, that is, arranging the formwork. Pay attention here Special attention on what thickness of slab you plan to create for the road. After all, it will directly determine what cross-section of lumber will have to be used in the work. If, for example, you are creating a slab 100 mm thick, then you will have to construct the formwork from boards with a cross-section not exceeding an area of 50 x 100 mm. Provided that the layer is thicker, 150 mm, you will need boards with a section of 50 mm by 150 mm. They can also be suitable for laying floors. If the boards themselves have cracks, they can be easily repaired using ordinary polyethylene. This will seriously strengthen the formwork, because the concrete will not be able to escape through the cracks.
The formwork must be secured very firmly, using metal poles.
The reinforcement process consists of laying a metal mesh in the formwork on top of the prepared base.
The lumber must first be coated with a special chemical composition, through which easy separation from the dried concrete will be ensured. After successfully strengthening the formwork, you can safely move on to strengthening the structure being prepared. Why put in the gutter, in the formwork, reinforcement, the dimensions, strength level and quality of the bond of which will allow you to increase the reliability standards of the solution at least twice. The reinforcement that is recommended to be used for pouring into the foundation should be a ready-made mesh made of metal steel, the cell area of which is approximately 15 square meters. cm. You can build such a mesh yourself using metal wire. It must be tied together into a frame with your own hands, which is placed in the formwork groove: on the ground (platform) and in the prepared sand and gravel base.
To prevent concrete from cracking, this type of reinforcement is necessary. If the foundation is not strengthened with reinforcement, cracks will appear not only in it, but also in the walls of the existing building. In order for the wire or metal grid fits more comfortably and does not get in the way when pouring the solution, experts advise using clamps that will make your work much easier. Formwork is also used when constructing floors.
Preparing for pouring
You can make your own road construction mortar using a mixer or concrete mixer.
The quality of concrete used in construction will depend not only appearance the structure being created, but also how long the structure can last without additional preventive and decorative repairs. Quality of ready-mixed concrete supplied construction companies, are calculated according to a strictly defined and internationally accepted scale of measurements, the quantitative indicators of which vary from 1 to 12. One corresponds to a dry mixture based on concrete, and as the numbers increase, the level of humidity increases. In the case of creating a track, the number should be four or five. This option suggests quite fast work with him, because on outdoors it dries out quickly. And adding water to an already used mass is not permissible. Even very small volumes of liquid in the solution, added in excess, can seriously reduce the level of strength initially guaranteed by the concrete grade.
One part cement, three parts sand and five parts gravel are the dry components of the future solution.
You can make the solution yourself. To do this, you need to use a mixer or concrete mixer. First, the dry components of the solution are poured into the mixer sequentially: one norm of cement, three norms of sand, preferably with small grains of sand, and five norms of gravel or granite crushed stone. After these ingredients are thoroughly mixed using a mixer, you can gradually add water to it. Try to pay special attention to the resulting consistency at this moment. To lay the path in the gutter, stop adding water when the consistency becomes like curd. Delivery of a mixer, by the way, involves hiring equipment.
Selection of materials
The strength and durability of the future path depends on the quality of the components.
When preparing, it is advised to carefully select components. For example, cement must be of a certain brand, and the higher the brand indicated as a number on the packaging, the higher the strength of the mortar that will be made on the basis of such cement. The crushed stone should not be too large, since too large stones often lead to the formation of voids inside the structures being poured. What negatively affects them? functional features and service life. Sand should also be first prepared for work by cleaning it from additional impurities, for example, silt and clay, which are very often found in the structure sand mixtures. You should also pay attention to the quality of the water, since stale, opaque-colored water will not sufficiently mix and dissolve the components of the solution. This can cause numerous cracks to form.
When the concrete is ready, it can be manually distributed along the constructed formwork using a shovel, carefully closing all cracks and compacting the spread concrete layer by layer using a vibrator or some kind of handy lath. The best way is the technology of raking to the highest point of the formwork or foundation, since from here the solution can independently advance to all areas that have cracks, which must be filled with solution.
Experts themselves recommend adding to the solution not a large number of a plasticizer, which will speed up the drying process of the solution and help remove excess moisture from it after the facility is put into operation. Filling according to existing rules must be done within one day, otherwise the foundation may crack.
Concrete mortar is the most important component in the construction of foundations, and the durability of the entire structure depends on its quality. It is not always possible to order ready mixture, and therefore it is advisable to know how to make concrete with your own hands. Here it is important not only to maintain proportions, but to select the components correctly, otherwise the strength of the solution will not be high enough.
Characteristics of concrete
Strength
Concrete mortar is a mixture of cement, sand, filler and water in certain proportions, which vary depending on the purpose of the concrete and the brand of cement. If necessary, plasticizers are added to the solution. The most important characteristic concrete is its compressive strength, which is measured in MPa (mega pascals). It is based on this indicator that concrete is divided into classes. But the grade of concrete indicates the amount of cement in the solution.
| Concrete class | Average strength of this class, kg s/sq.cm | Nearest brand of concrete |
|---|---|---|
| AT 5 | 65 | M 75 |
| B 7.5 | 98 | M 100 |
| AT 10 | 131 | M 150 |
| At 12.5 | 164 | M 150 |
| At 15 | 196 | M 200 |
| IN 20 | 262 | M 250 |
| At 25 | 327 | M 350 |
| At 30 | 393 | M 400 |
| At 35 | 458 | M 450 |
| At 40 | 524 | M 550 |
| At 45 | 589 | M 600 |
| At 50 | 655 | M 600 |
| At 55 | 720 | M 700 |
| At 60 | 786 | M 800 |
M100 and M150 (B7.5 and B12.5) are most often used as a layer under the main foundation, for the manufacture of screeds, and concreting paths. Concrete M200-M350 is most in demand: it is used in the construction of foundations, for the manufacture of screeds, concrete stairs, blind area. Mortars of higher grades are used primarily in industrial construction.
Plastic
An important characteristic of concrete is its plasticity. The more plastic the solution, the better it fills the formwork structure. When the mobility of concrete is low, unfilled areas remain in the screed or foundation, which leads to gradual destruction concrete slab. For standard structures, concrete with plasticity P-2 or P-3 is used, for formwork complex shape and in hard to reach places It is recommended to use solution P-4 and higher.
Waterproof and frost-resistant
Water resistance depends on the amount and brand of cement in the solution. The higher the grade, the more resistant the concrete is to moisture. Frost resistance of concrete is achieved by adding plasticizers to the composition. It should be noted that these set very quickly; if you incorrectly calculate the amount of the mixture or use it at a low temperature, the concrete will turn into a monolithic block right in the container.
Concrete components
Cement performs a binding function for all other components concrete mortar and the strength of the concrete itself directly depends on its quality. In private construction, cement grades M400 and M500 are most in demand. When purchasing cement, you should be aware that it loses its qualities if stored for a long time or improperly. Already a month after production, the binding properties of cement decrease by 10%, after six months - by 50%, after a year it is not recommended to use it at all. But even fresh cement will become unsuitable for use if it becomes damp, so it must be stored in a dry place.
Sand is the second most important component of concrete mortar. In rare cases, it is replaced with slag, while standard concrete is always mixed with sand. It is best to use coarse grain river sand without various impurities. If only ordinary fine sand is available, it should not contain clay, earth or silt, which reduce the adhesion of the solution to the filler. Before mixing, the sand must be sifted to remove all excess.
Aggregate
The best aggregate for concrete mortar is considered to be sizes from 5 to 35 mm. Often crushed stone is replaced with gravel, and a little less often with expanded clay. It is very important that the surface of the aggregate is rough, then its adhesion to the cement will be as strong as possible. To compact the mixture, you need to take aggregate of different fractions. Like sand, the aggregate must be clean, so it should be poured onto a prepared and compacted area or on a spread tarp.
Supplements
To give concrete frost resistance, water resistance and other beneficial properties plasticizers are used. They ensure the setting of the solution at low temperatures, increase its plasticity or, conversely, impart viscosity. They should be used only if it is really necessary, and you should strictly adhere to the instructions for their use and observe the proportions.
If a thin or unstable screed is required, reinforcing fibers are mixed into the concrete solution. They are made of polyvinyl chloride and polypropylene; they have low strength, but are excellent at avoiding cracking of concrete. In standard foundations and screeds, reinforcing substances are not needed.
Prices for cement and basic mixtures
Cement and base mixtures
Solution proportions
To make high-quality concrete yourself, you need to know in what proportions to mix the components. Most often, the ratio of cement, sand and crushed stone is used as 1: 3: 6; At the same time, they take half as much water as total weight dry ingredients. It is recommended to add water not all at once, but in several portions, this makes it easier to control the density of the solution. The humidity of the sand also has its own meaning - the higher it is, the less water required. All components must be measured in one container, for example, a bucket. When using containers of different sizes, it will not be possible to achieve the desired proportions.
When mixing, the purpose of the solution should be taken into account. For the substrate under the screed, lean concrete is made without adding crushed stone; for concreting paths and blind areas, crushed stone of medium and fine fractions is used; for the foundation of a house, medium-fraction crushed stone and high-quality cement are used. The table will help you find out the exact different brands.
Manual method of mixing concrete
Mixing the concrete solution is carried out manually or in a concrete mixer. If you need to fill large area, the first method is not suitable, as it will take too much time and physical effort. If you need a little solution, it is more convenient to knead it by hand.
Step 1. Preparation
To prepare the solution, you will need a low, wide container, for example, a large metal trough, a picking shovel, a bucket and a regular hoe.
Step 2: Dry Mixing
A bucket of cement is poured into the container, then 3 buckets of sifted sand and 5 buckets of crushed stone. The dry ingredients are thoroughly mixed with a hoe. The proportions may be different, depending on the required brand of solution.
Step 3: Adding Water
If all ingredients are mixed evenly, you can add water. First, pour out 7-8 liters and begin to intensively stir the contents with a hoe. This process will require effort, but you need to stir it very well. It is advisable to lift the bottom layer and run the hoe into the corners where dry lumps may remain. If the solution is very thick and sticks to the hoe, you need to add a little water. Properly prepared concrete slides off the shovel slowly and does not delaminate.
There is another mixing option: first, water is poured into the container, then cement is poured. For 2 buckets of water you need 2 buckets of cement. Thoroughly mix the cement with water and add 4 buckets of sand. Mix well again until smooth. Lastly, add crushed stone in the amount of 8 buckets and mix again. There is no clear opinion on which method is better, so it’s worth trying both and determining the most optimal one for yourself.
Find out the correct proportions, how to make them yourself, from our new article.
If the resulting concrete is too thick, add a little cement to the remaining water, mix well and pour into a concrete mixer. It is not recommended to stir the solution for more than 10 minutes, otherwise the cement will begin to set. Ready concrete is poured directly onto the site or into a wheelbarrow if the concrete mixer is located at a distance. It is advisable to pour out the entire solution at once, but if this does not work, leave part of the mass in the turned on concrete mixer. It should be used as soon as possible.
Prices for popular models of concrete mixers
Concrete mixers
Video - How to make concrete with your own hands
Independent preparation of concrete mortar for pouring the foundation is a very responsible and labor-intensive process. In many ways, the quality of construction depends on the foundation.
In order to obtain a high-quality solution mixture, it is necessary to use the right materials and make an exact proportion. If during construction the most common strip foundation, increased demands must be placed on the quality of concrete.
When preparing concrete, the following factors affecting its strength must be taken into account:
- the amount of cement contained in the mixture;
- level of reaction with other substances (the higher the level of cement reaction (activity), the larger the structure can be installed on it);
- the ratio of water and cement in the composition of the substance (the lower, the better);
— quality of fillers (the use of fine-grained fillers reduces the strength of the composition);
— degree of compaction.
Necessary materials
The main component for preparing the solution is cement. When choosing it, you need to pay attention to the main indicators. Currently, there is a large assortment of cement types on the construction market, so it is important to choose quality material. The quality guarantee is the material class with an error level of 13.5% (variation coefficient).
for the foundation it is better to use cement grades 400 or 500
Strength is indicated on the packaging with the letter “M” and numbers ranging from 400 to 1000. This indicator indicates how much weight the concrete will withstand after hardening per 1 cm. It is best to use cement grade M400-M500 (depending on the density of the soil and the load on foundation). Before making a purchase, it is advisable to find out the name of the manufacturer, reviews about the manufacturer, as well as in what packaging the products are packaged. On the packaging you must pay attention to the series and number; they should not be duplicated. These simple precautions will help you avoid buying counterfeits.
Also, to prepare concrete you will need sand, water and crushed stone (gravel). When choosing these materials, it is also necessary to take into account their properties. Sand for concrete must first of all be clean. Sticks, leaves and debris are not allowed in it. Also, it should not contain clay, the permissible error is no more than 5% of the total mass.
the ideal crushed stone for concrete is granite
The presence of crushed stone or gravel is allowed if percentage of the total mass it does not exceed 0.5. In addition, it is necessary to take into account the size (fraction) of sand. Not every building material fits this parameter. Perfect option fractions - in the range of 2-2.5. When making a solution for the foundation, the sand must be dry. If the sand used is wet, it must be dried, or in the future, when preparing concrete, use less water.
It is better to use fine gravel or crushed stone. The crushed stone must be clean, without foreign impurities. The most durable crushed stone is granite, but it is more expensive than others and has a higher background radiation. It is better to choose lime or gravel material. Under no circumstances should river pebbles be consumed.
Exact proportions of the solution
Before preparing the solution, you first need to calculate how much concrete will be needed. The calculation is carried out using a simple formula: the product of the length of the tape, width and height. You can also use ours for calculation. Having decided on the volume and materials for pouring the foundation, it is necessary to maintain the correct proportion of the mixture. The process of drawing up proportions must be strictly followed, otherwise the foundation will be unreliable.
As a rule, the ratio of sand and cement in concrete is 1:2, and the amount of crushed stone is 4 parts. Based on this proportion, you can easily prepare concrete mixture. If the solution turns out to be too dense, it must be diluted with water. The resulting consistency should be stirred with a shovel with little effort. In this case, the solution should not quickly drain from the shovel.
You can mix the components different ways. but if possible. It is better to do this using a concrete mixer.
with the help of such a device the mixture is better mixed
Pouring concrete - instructions
After the concrete is prepared, it must be poured into reinforced formwork. The ideal temperature for pouring is from +5° to +15° C. If the air temperature is below 0° C, the poured foundation must be covered with film. Do not remove the formwork until the concrete has completely dried.
If the street is above +15° C, the foundation must be watered once a day and also covered with film to avoid cracking. The formwork can be removed the next day.
The foundation can be poured in warm weather
Complete drying occurs within 2 days. Pouring should occur calmly, in layers of 25 cm. The time between pouring layers should be from 30 minutes to 1.5 hours, depending on the type of cement in the concrete.
Air must be released from each filled layer. To do this, you can use conventional reinforcement, lowering its parts into concrete at a short distance from each other.
Also, each layer must be leveled. If pouring occurs in one layer, then it is necessary to use a vibration-shrinking tool. If you follow everything according to the instructions and do not skimp on materials, then a house built on such a foundation will delight its owners for many years.
The choice of concrete proportions used for the foundation is influenced by many factors: soil parameters, expected loads, type of foundation. The basis cement mortar consists of cement, sand, crushed stone or gravel and water, its properties directly depend on the quality and uniformity of mixing of the components. Changing the regulated ratios is unacceptable; the slightest errors lead to a decrease in the strength of the foundation and, as a result, the risk of destruction load-bearing structures building.
- Required brand
- Proportions for preparing the solution
- What are the requirements for the components?
- Description of the concrete preparation process
Choosing a concrete grade
The main criteria include the geological conditions of the site (relief, level and partial pressure groundwater on foundation elements, climate, freezing depth), type of foundation, presence or absence of a basement, building height and other weight loads. The limiting factor is the work budget; using high-quality types of concrete for the construction of light buildings on summer cottages is not economically feasible. The recommended minimum is:
- M400 – for houses over 3 floors.
- M200-M250 – for frame and panel buildings.
- M250-M300 – for buildings made of wooden beams.
- M300 - for low-rise buildings made of expanded clay, gas silicate or cellular blocks.
- M350-M300 – for brick construction or pouring load-bearing walls made of monolithic concrete.
The specified gradations are relevant when constructing one- or two-story houses, when adding another floor, it is advisable to choose a higher grade. The same applies to ready-made purchased solutions, especially if purchased from an unverified manufacturer. In general, the minimum permissible strength when concreting the foundations of residential buildings on slightly heaving soils is M200; when building on less stable soils, it increases.
When preparing solutions, the working measure is the mass or volume fraction of the binder; the most common and convenient ratios include 1:3:5 (cement, sand, gravel, respectively). The regulated proportions, depending on the required strength of concrete, are:
The strength of concrete is primarily affected by the ratio of sand and cement, but in addition to strict control over the proportion of dry components, the amount of water introduced is monitored. When using Portland cement, the W/C proportions are:
| Binder grade | Concrete strength grade | ||||
| 150 | 200 | 250 | 300 | 400 | |
| M300 | 0,65 | 0,55 | 0,50 | 0,40 | |
| M400 | 0,75 | 0,63 | 0,56 | 0,50 | 0,40 |
| M500 | 0,85 | 0,71 | 0,64 | 0,60 | 0,46 |
| M600 | 0,95 | 0,75 | 0,68 | 0,63 | 0,50 |
When building a foundation on dry soils, it is allowed to add lime or clay to the cement mortar; these components increase its plasticity. The recommended proportions when using Portland cement M400 are:
In private construction, it is inconvenient to separately determine the mass of all poured ingredients; a bucket is usually used as a measuring tool. In this case, all fillers are pre-weighed in a dry state. The W/C ratio largely depends on the moisture content of the sand; experienced developers add no more than 80% of the recommended proportion of water during mixing and then, if necessary (the consistency is not sufficiently plastic), pour it in portions. Fiber, PAD and other plasticizers are added to concrete at the very end along with the liquid; their share usually does not exceed 75 g per 1 m3.
Component Requirements
To prepare cement mortar for pouring the foundation, the following is used:
- Fresh Portland cement, ideally the release date does not exceed 2 months before the start of concreting. The recommended brand is M400 or M500.
- River sand with particle sizes ranging from 1.2-3.5 mm with admixtures of silt or clay not exceeding 5%. It is recommended to check its cleanliness (fill with water and monitor the change in color and sediment), sift, and, if necessary, rinse and dry.
- Pure crushed stone or gravel with fraction sizes from 1 to 8 cm, with flakiness within 20%. When preparing concrete for the foundation, hard rock screenings are used; limestone is not suitable due to its low strength.
- Water: tap water, free of impurities and foreign particles.
- Additives: antifreeze, plasticizing, reinforcing fiber. The introduction of such impurities is carried out in strict compliance with proportions.
It is important to understand the principle: coarse filler is introduced into the solution not only to replace a more expensive binder, it is precisely this that imparts the necessary rigidity. Minimum compressive strength of gravel or granite screenings is 800 kgf/cm2; in its absence, concrete simply will not withstand the weight load. A mixture for a foundation without crushed stone is prepared only when constructing it from individual blocks or slabs, and sometimes for quickly pouring pile supports.
Recommended proportions of cement and sand for masonry mortars– 1:3 or 1:2. The first ratio is considered universal, the second is chosen when constructing foundations on unstable soils. In practice, this means that for one bucket of cement with a grade not lower than M400 (M500 for increased loads), take 2 or 3 sifted quartz sand and no more than 0.8 parts of water. A properly prepared mixture has a consistency similar to toothpaste, to increase workability per 1 m3, 75-100 g of plasticizers are introduced ( liquid soap or other PADs).
How to make cement mortar for the foundation?
The process begins with the preparation of components and a concrete mixer; the presence of the latter is mandatory when mixing concrete for underground structures. The amount of building materials is calculated in advance according to the volume of the foundation and is purchased with a small margin. It is extremely important to carry out the filling on the same day, when self-cooking solution, all components are washed and dried in advance. Next, they are poured into buckets into a concrete mixer in the following sequence: part of the water → sand and cement → dry additives and fiber (if necessary) → coarse filler → the remaining liquid in small portions. After adding the new ingredient, the drum is turned on for 2-3 minutes, and no more than 15 minutes later the finished solution is unloaded.
There is a time-tested method for selecting the correct proportions, chosen in the absence of data on the size of crushed stone. In this case, the bucket is filled with coarse filler, shaken several times and completely covered with water. The resulting volume of water corresponds to the required proportion of sand in the solution. After that, sand is poured into the bucket and filled with water again to determine the proportion of cement. But some consider this approach complex and outdated; the standard method of recalculation is considered more correct mass fraction into the volumetric and pouring the components into the concrete mixer.
In order to independently prepare cement mortar for pouring the foundation, it is important to select the right components, observe required proportions materials and take into account some of the nuances of mixing and pouring.
Its quality and durability depend on how correctly and in what proportions the components for the foundation mortar are selected.
Materials for the mixture
In order to make concrete for the foundation, you will need:
- water;
- sand;
- cement;
- crushed stone;
- additives (if necessary).
Water for preparing cement mortar should, if possible, not contain chemical substances(fuel oil, gasoline and others). Ordinary running water is what you need.
The sand should not be silty or clayey. Fatty substances create films that prevent the components from adhering to each other. Ideally, washed sand goes into the solution, the cleaner the better.
Cement is distinguished by its brand. The most common are M300, M400 and M500. The higher the grade of cement, the higher the quality of the resulting solution, that is, such specifications, such as compressive and fracture strength.
According to the construction goals and the size of the foundation, a specific brand of cement is selected.
In order to prepare a solution for the foundation, you will need water, sand, cement, crushed stone, and, if necessary, various additives.
Crushed stone should not be limestone. You should also not add gravel as a filler for cement mortar. It is better to take crushed stone. Its sharp corners and uneven edges cling to each other and thereby increase the strength of the concrete for the foundation. Cement-sand, as well as mortar based on gravel, expanded clay, and other fillers will be less durable and therefore not used in the manufacture of concrete for foundations.
Additives are needed if you want to make a solution in special conditions. For example, when you need to make a solution in frosty weather, or the finished foundation will be partially or entirely in water and exposed to aggressive environment. Additives are mixed with water according to the instructions on the package. It is worth remembering that any additives lower the grade of concrete.
Cooking methods
There are 2 main methods of kneading: mechanical (using electric concrete mixer) and manual. Let's look at each separately.
Mechanical method
This method involves the purchase of a rather expensive tool - an electric concrete mixer. Since pouring the foundation is usually the very beginning of construction, purchasing a concrete mixer at this stage is economically justified. So, the object should have:
Diagram of a monolithic foundation on a sand and gravel bed
- buckets;
- shovels;
- water barrel or hose;
- concrete mixer;
- extension cord (carrying).
Buckets are convenient for carrying sand and crushed stone and loading cement into a concrete mixer. In addition, buckets make it easy to measure the required amount of each component and maintain the correct proportions. Shovels are used to throw materials into buckets.
The capacity of the concrete mixer depends on the size of the building under construction and varies between 50-300 liters. To build a private house, a single-phase 220 volt concrete mixer will be sufficient. Larger projects, as well as industrial facilities, may require 380 volt three phase. To operate the concrete mixer itself, you may need an extension cord to supply electricity to it.
All prepared components (water, cement, sand, crushed stone) in the required quantities are loaded into the concrete mixer bowl and the apparatus is turned on. The mass is brought to a homogeneous creamy state. The solution for pouring the foundation is ready.
Manual method
To knead manually you will need:
- buckets;
- shovels and bayonets;
- capacity;
- water barrel or hose;
- hoe.
You need to pour water into the container for mixing the components (already with additives, if needed), then add sand and cement. It is convenient to mix the solution manually in a trough or old bath using a hoe or bayonet shovel. The mass needs to be made homogeneous, similar to sour cream. At the very end, all that remains is to add crushed gravel and mix everything again. The solution is ready.
It’s good if it is possible to pour the foundation directly from a concrete mixer or trough - this way you can save money great amount time and effort. If this is not possible, then the ready-made cement mortar is poured into buckets using a shovel and the foundation is poured from them.
Proportions
Cement and sand are mixed in a ratio of 1:3. The amount of crushed stone is not strictly standardized, but usually they take the same amount as sand. Thus, for 1 bucket of cement there are 3 buckets of sand and 3 buckets of crushed stone.
The amount of water is selected experimentally each time, as it depends on many factors. For example, from the humidity of sand and air. It is important to achieve the desired consistency (like sour cream) and not to overdo it with water. The thinner the solution, the lower the grade, and, accordingly, the worse the strength of the resulting concrete.
Fill
Concrete does not set well at temperatures below +8 degrees Celsius (unless frost-resistant additives were included in it), so it is better not to pour in cold weather. The quality of such concrete will be worse than that of ordinary concrete, and, alas, nothing can be done about it.
The process of concrete setting has nothing to do with drying! If pouring occurs in hot, sunny, dry weather, then add to the solution extra water no need. In this case, the only the right decision The foundation will be watered for several days simply from a hose, from above, to prevent the concrete from drying out. If it dries out, it begins to burst and crack.
When building a house or gazebo on summer cottage, every owner is faced with the need to lay a foundation. This process is complex and responsible, because you need to choose the right material and calculate the ratio of components. Therefore, before starting work, you should carefully study the stages of foundation construction.
Due to its low cost and exceptional durability, concrete is considered the most popular material for pouring foundations. In this article we will look in detail at the intricacies of working with it, so that even a novice master can build a base on his own.
The composition is prepared taking into account certain proportions of crushed stone (or gravel), sand and cement. What ratio of components is required depends on the result to be obtained. Crushed stone and sand serve as fillers, cement is needed as a binder that holds the components together into a single block. If too many cavities are formed between sand and crushed stone, then the need for cement increases. To keep them to a minimum, it is important to use crushed stone different sizes: small particles will fill the cavities between large ones, and sand will fill between small ones.
Concrete hardens within a month, but this process is most intense during the first week.
Types of concrete for pouring the base
To prepare a solution for the foundation, sand is suitable, the particle size of which varies from 1.2 to 3.5 mm. Use bulk material without foreign impurities. A five percent clay and silt content is allowed, but this makes the concrete less durable.
The following experiment will help determine the quality of the composition: pour sand into a container, dilute it with water and shake the resulting solution thoroughly. If the water remains clear or loses a little transparency, it means the raw material is of high quality, and if it becomes very cloudy, it contains impurities. You can also leave the container to stand for a while. If clay sediment eventually appears above the sand, it is better not to use such bulk material for construction.
Thematic material:
- Proportions of concrete for the foundation in buckets
- Foundation concrete recipe
There should also be no impurities in the crushed stone composition. The particle size is 1-8 cm.
IN construction field The following types of cement are distinguished:
- Portland cement (the most common option, which is used in the construction of various structures).
- Slag Portland cement (has high moisture resistance and frost resistance, but hardens more slowly).
- Pozzolanic Portland cement (used for the construction of structures under water and underground due to its exceptional moisture-resistant properties; in conditions air environment gives strong shrinkage and loses strength).
- Fast-hardening cement (hardens in about 2 weeks; it is necessary to work with such material without delay, as it sets instantly, so this is not the best option for novice builders).
Thus, the most suitable material Portland cement is used to independently pour a monolithic foundation for a house or other structure.
The following grades of cement are distinguished: ... PTs 500, PTs 500 D20, PTs 400 D20, PTs 400, etc. In accordance with the brand, the value of its compressive strength changes, which is determined for a concrete cube with sides of 20 cm and is measured in kg/cm2 .
Preparing the right solution
To obtain the composition of the desired viscosity, certain proportions are observed during its preparation. The ratio is 1/3/5, where 1 is cement, 3 is sand, 5 is crushed stone.
The use of additives will allow you to obtain a certain type of cement mortar: quick-hardening, hydrophobic, pozzolanic, colored, sulfate-resistant, plasticized, etc. In this case, they are used different brands from M 100 to M 600. But to get, for example, a mixture of M 400, it is not necessary to use cement of the same brand.
Below is a table of ratios that will help in the calculations:
If you dilute cement M 400 with four buckets of water in a ratio of 1:4, you get a mixture of M 100, and to prepare a solution of M 100 from M 500, add five buckets, that is, 1:5.
To prepare concrete grades M 300 and M 400, the weight of the components must exceed the weight of water by half.
If you need to get 1 cube of concrete (this is V cube, each side of which is 1 m), then the ratio should be as follows: half a cube of sand, 0.8 crushed stone and filler. The amount of the latter depends on the purposes for which concrete is required. Please note that the less cement the solution contains, the more mobile it will be. It is important to know that you cannot put more than 350 kg of cement on one cube (that’s 7 bags), increasing the norm can provoke destruction.
The price per cubic meter of cement varies; the higher the grade, the higher the cost.
To make concrete, use a concrete mixer, a wooden box, an iron bath or wood flooring. It is important to ensure that no debris or other impurities get into the solution. To begin with, pour in the dry ingredients - sand, crushed stone, cement, mix them thoroughly to obtain a homogeneous composition. Then slowly add water, stirring until evenly moistened. And only after that they start pouring.
Keep in mind that cement does not store for long; over time, its grade decreases under the influence of moisture. After the first month, about 10% of strength is lost, after 3 – 20%, in six months this figure reaches 30-40%.
When pouring a foundation, the most popular unit of measurement is a bucket, so few people accurately observe the correct proportions. It is not recommended to stir the mixture with a shovel, as the concrete will be inhomogeneous. Thus, losses may occur and eventually the M 100 grade will be released. But this will be enough for construction small house or gazebos.
Even if you deviate greatly from the standards for pouring a foundation, it will still be durable and will withstand heavy loads, so it will be suitable for building a house. But, according to official standards, you should take cement M 300 or M 400 to get a grade of 200 or more.
Pour the foundation in warm weather, negative temperature provokes the emergence of some difficulties. For example, you will have to heat the water and the composition itself, since they may freeze before hardening begins. And when hardening begins, without heating the concrete will begin to freeze due to the water contained in it, and the resulting ice crystals will begin to destroy the foundation from the inside.
If you follow the proportions and prepare the composition according to standards, even at home the solution will be homogeneous and as close as possible to the correct option, so don't worry about its durability.
Now you know what ratio of components is needed to prepare 1 cube of concrete. The main thing is to accurately calculate the proportions and try to follow the technology. Concrete is an easy-to-prepare composition, so the knowledge gained will help even a novice builder to easily build a foundation for a house or gazebo.