Expanded clay concrete is one of the types. It has found its application in various construction work. For example, during thermal insulation, structural thermal insulation and when creating a structure. to perform each of these types of work will be different. What they have in common is that the recipe for this material is very simple.
Expanded clay concrete is a type of lightweight concrete designed for thermal insulation and construction of various structures.
The prepared solution is used for the production of expanded clay concrete blocks, which find their further use in construction. The preparation of mortar for blocks can be carried out on concrete units or directly on the site where construction is taking place. But it should be borne in mind that when producing expanded clay concrete blocks on a construction site, you will not be able to achieve the same level of material quality as in industrial production. This is due to the fact that in construction conditions it is difficult to correctly observe all the proportions of the components for the solution, and also to ensure that all technical requirements in the absence of special equipment.
Raw materials used
The main difference between expanded clay concrete and other types of concrete is the expanded clay included in its composition.
Expanded clay concrete differs from concrete in that it contains expanded clay, moreover, it is an environmentally friendly product.
This material is characterized primarily by the fact that it is an environmentally friendly product. It is foamed and fired clay, which in structure becomes frozen foam. During the production of expanded clay, granules with such a structure are obtained, the shell of which gives them strength. That is why expanded clay is the main type of porous filler. The advantages of expanded clay concrete over conventional concrete are determined by its resistance to moisture and chemical exposure, as well as sound and heat insulation properties.
The use of expanded clay concrete blocks during construction makes it possible to reduce the consumption of mortar by more than 2 times, increase the installation speed by approximately 4-5 times and reduce the mass of material used per 1 m² of masonry by 1.5 times.
The thermal insulation properties of expanded clay concrete allow it to be used in both cold and hot climates. Thanks to the porous structure of the material, the humidity in the room is regulated. Buildings made from this material do not require additional care. Expanded clay combines the positive characteristics of stone and wood. It does not rot, does not rust and does not burn.
Expanded clay concrete has the following advantages over brick: expanded clay concrete blocks contain less cement, the weight of such masonry is less than brick, expanded clay concrete block replaces 7 bricks, the speed is much higher than brick. Replacing bricks with expanded clay concrete can reduce construction costs by 30-40%.
Expanded clay concrete has excellent thermal insulation properties; it can reduce the heat transfer of a room by 75%.
Preparation of expanded clay concrete
If the construction site is located far from industrial production expanded clay concrete blocks, optimal solution their production will begin directly at construction site.
To do this you will need:
- concrete mixer with a volume of about 200 liters;
- a container into which the solution will be placed after mixing (a tub or trough with a volume no less than a concrete mixer);
- vibrating machine for the production of expanded clay concrete blocks.
The expanded clay concrete recipe includes the following ingredients:
- expanded clay;
- concrete;
- cement;
- water;
- washing powder.
The ratio of components in the solution must be observed in the following proportion: 8/3/1 (expanded clay/sand/cement), required quantity water is determined depending on the moisture content of the materials, approximately 200-300 liters per 1 m³ of solution, washing powder is used in an amount of 50 g per concrete mixer.
The recipe for expanded clay concrete is quite simple, so making it on a construction site will not be difficult for you. First of all, prepare an astringent solution. To do this, pour the required amount of water into the turned on concrete mixer. Add cement to the water first and then sand. After the solution is thoroughly mixed, add expanded clay. The mixing process must be carefully monitored. The solution will be ready when it reaches the consistency of thick sour cream. If necessary, water can be added to the solution. If the solution, on the contrary, is too liquid, then it is necessary to let it settle and then continue stirring.
The recipe for preparing the solution allows for dry mixing. When using this preparation method, all components are mixed dry, and after that water is added and the components are mixed in a concrete mixer. Using this recipe, you can achieve greater homogeneity and the required consistency of the solution.
Using this recipe, you can prepare a solution that must be used as quickly as possible, so that the fractions of the solution components do not have time to settle. Then the viscosity of the solution will remain required.
If you are using mortar to cast floors, walls or slabs, it is best to prepare the formwork in advance. If you plan to make blocks, place the molds on a pallet and pour the solution into them using a bucket or shovel. The solution should remain in the formwork or forms for some time without the use of mechanical force. Typically, the required time is about two days.
Making blocks
Blocks made on a vibration machine have higher heat and sound insulation qualities. If you use a vibrating machine to make blocks, then place a steel plate in the mold and fill in the required amount of solution. After this, turn on the engine and remove excess solution. Turn the machine handle to remove the block on the steel plate from the mold. Let it dry, this will also take about two days. After the block has dried, remove the steel plates from it. Now you can start laying blocks.
When making expanded clay concrete and blocks from this material yourself on a construction site, you should remember that building materials, obtained in this way may not fully meet all the requirements put forward to them. This is due to the fact that it is very difficult to maintain the exact proportion and manufacturing technology in such conditions.
Knowing the specifics of preparing the solution and making structures from expanded clay concrete, you can easily take advantage of all the advantages of this material.
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Leveling the subfloor while simultaneously insulating it makes it easy to expanded clay concrete screed. It’s not difficult to do it yourself, the main thing is to follow correct proportions mixtures. This will require the same ingredients as for cooking. ordinary concrete, only expanded clay – that same expanded clay – will serve as a coarse aggregate instead of crushed stone.
Expanded clay for screed can be taken in any size up to 40 mm. However, to level the floor, it is better to take expanded clay sand with a grain size of 0-5 mm. It has high strength, and due to its small size it gives the solution looseness and facilitates the installation process. On the other hand, the larger the size of the clay granules, the lighter and warmer the concrete will be. But high quality one cannot expect from such a composition.
To solve this problem, you can perform a two-layer fill. After the screed is ready, it is brought to zero finishing layer cement-sand mortar. In this case, the coating will be not only warm, but also perfectly smooth, with a more durable surface.
The thickness of the finishing fill does not exceed 30 mm, but you need to have time to do it before the main layer of expanded clay concrete sets so that they adhere firmly to each other. To do this, it is enough to divide the surface into separate areas, filling them in turn with both compositions.
Proportions
Expanded clay concrete is divided into grades from M50 to M250. But for the screed device, M100 is considered optimal. Brand identity is determined by the composition of the solution, that is, the ratio of all its components.
When calculating proportions, you should start from the volume of expanded clay, but based on the final strength concrete covering the quantity and brand of cement used will affect. Only very strong material is suitable - M400 or M500 without additives (marked D0). And the more there is, the stronger the floor surface will be. However, here it is worth observing the golden mean, since with an increase in the ratio of binder to other components, the thermal insulation properties expanded clay concrete.
For floor insulation residential buildings The following composition of expanded clay concrete mixture is considered a classic:
- 1 part cement and water;
- 3 parts sand;
- 2 – expanded clay.
But by varying the number of components, you can get a screed with different strength indicators. The mass ratio C:P:C for the main grades of expanded clay concrete looks like this:
| C:P:C ratio, kg | M75 | M100 | M150 |
| 220: 300: 600 | 330: 320: 630 | 430: 420: 720 |
For rooms with high traffic of sand cement, take 30 kg for every 25 kg of expanded clay. This screed has greater strength and wear resistance.
Depending on the size of the selected expanded clay, the composition and proportions of expanded clay concrete per 1 m3 may differ slightly. The density of the clay aggregate will also have an impact - the lighter the expanded clay granules, the more cement will be required to obtain concrete of the required strength.
To determine the amount of materials, you will need to calculate the cubic capacity of the future screed. To do this, simply measure the floor surface area and multiply it by average height alignment. Naturally, the thickness of the fill cannot be less than the maximum piece of expanded clay.
The ratio of expanded clay concrete components in volumetric terms does not differ from the proportions for classic heavy concrete. But due to the low density of the filler (400-600 kg/m3), the weight of the screed will be significantly less.
When pouring expanded clay into the mixture, it is first soaked in water. To do this, the granules are poured into a separate container and left until their surface pores are saturated with moisture. You can speed up soaking by stirring. This is done so that the granules do not take water from the solution, which is needed to hydrate the cement, and thereby weaken the concrete.
After some time, the remaining water from the container is drained, and cement pre-mixed with sand is added to the expanded clay. It is not advisable to fill them separately. But if it is not possible to prepare or buy dry sand cement, proceed as follows:
- The binder is poured into the expanded clay and the mixture is stirred until it dissolves.
- Add sand and mix thoroughly again.
- Add water.
When mixing expanded clay concrete with water, it is important not so much to observe the selected proportions for the screed, but to monitor the viscosity. Excess water will wash cement particles into the lower layers of the fill, weakening the floor surface. A rigid composition that does not contain enough moisture will be impossible to stir or lay down properly.
You can determine whether the screed solution is mixed well enough by the color of the aggregate. Normally, it should not differ from the main gray mass. Absence brown spots on the surface of the granules indicates that cement-sand mixture completely envelops them, and the adhesion in the screed will be strong.
If you don’t want to bother with preparing a solution of expanded clay concrete, then when large volume screed installation work can be purchased ready mixture. It will cost, depending on the brand, relatively inexpensively:
- M75 – 3100 rub/m3;
- M100 – 3200 rub/m3;
- M150 – 3400 rub/m3.
When performing various construction works, it often becomes necessary to make a concrete solution directly at the construction site. If you have the necessary equipment, this is not difficult to do, however, it must be taken into account that its quality depends on compliance with the proportions of the components, as well as on a number of other factors. Therefore, below we will consider this process in detail, and also give the proportions for preparing different types of concrete.
Brand
The main parameter of concrete is strength, which is reflected in its grade. The brand number indicates the maximum load in kilograms per square centimeter area that the material can support. For example, M200 concrete can withstand a load of 200 kg per square centimeter.
Thus, before you start preparing the solution, you need to decide on its brand. To do this, calculate the load on concrete structure. True, builders rarely accurately calculate the required grade, since they can use material with a margin of safety.
The only thing is that this stock should be reasonable, since the higher the brand, the higher the price of the material. Therefore, excessive strength leads to an unreasonable increase in construction costs.
Proportions
M100
This brand is widely used in repair, construction and restoration work.
In particular, the material is used for the following purposes:
- To perform the foundation substrate;
- When making roughings on the ground;
- When arranging parking lots and various sites;
- During production reinforced concrete structures that will not be subject to excessive loads.
In the photo - crushed stone for preparing the solution
Table of proportions for preparing M100 concrete per 1m3:
For , i.e. without crushed stone, the proportions are as follows:
M200
For cooking concrete mortar grade M200 per 1m3 mix the components in the following proportions:
This brand is the most popular, since its scope is very wide.
Most often the material is used for the following purposes:
- When constructing foundations;
- For the construction of staircases;
- When screeding floors and other structures.
Pay attention! Thanks to excellent technical specifications, this brand is the most favorable in terms of price/quality ratio.
M300
The proportions for preparing M300 concrete are as follows:
The M300 grade is even more durable, which is why it is used in the construction load-bearing structures, which are expected to bear a large load. In particular, they often fill the foundations of heavy buildings, make floors, etc.
Pay attention! To prepare the solution, it is necessary to use fresh cement, since its quality deteriorates over time. So in a year it can lose up to 40 percent of its strength.
Proportions of expanded clay concrete
Separately, it should be said about such a material as expanded clay concrete. Its difference from ordinary concrete is that expanded clay is added to it as a coarse filler. These are light and porous granules, which at the same time have good strength.
The use of expanded clay in the solution makes the material lighter and “warmer”. Due to the strength of expanded clay, expanded clay concrete can be used in the construction of walls and even in the foundations of small light buildings, for example, garages or outbuildings. In addition, it has found wide application in insulating flat roofs.
The proportions for preparing expanded clay concrete are as follows:
These proportions will make it possible to create expanded clay concrete grade M200.
To prepare a concrete solution, you will definitely need a concrete mixer, since it is very difficult to mix concrete manually, especially if the composition contains crushed stone or gravel. Therefore, it is unlikely that it will be possible to obtain a high-quality homogeneous mixture.
It should also be noted that performing the solution requires following a certain sequence:
- First of all, you need to pour the dry ingredients – sand and cement – into the concrete mixer with your own hands.
- After the components are mixed into a homogeneous mixture, they should be gradually poured into water, and care must be taken that it is clean. Experts recommend preparing a solution based on drinking water.
- After obtaining a homogeneous mass, the filler, cleared of clay or other contaminants, is poured into the concrete mixer.
Pay attention! To improve the quality of the material, a plasticizer and other additives can be added to the composition. They should be added to the composition at the stage of pouring water, in accordance with the instructions from the manufacturer.
This completes the process of preparing the solution. It must be said that expanded clay concrete is prepared in the same sequence.
Conclusion
If the above proportions and concrete preparation technology are observed, you can get quality material and at home. The only thing is that you need to pay attention to the quality of the components, since even dirty water or sand with admixtures can significantly reduce the strength and other properties of the composition.
From the video in this article you can get additional information on this topic.
Expanded clay concrete is a very popular material in the construction industry. It has a lot of positive properties that help make the building suitable for use in accordance with all operating rules, and is in no way inferior in this regard to other types of concrete. What does it represent this material? What components are included in expanded clay concrete? In what proportions are the ingredients mixed per 1 m3? The answers can be found below.
How to choose ingredients for expanded clay concrete composition?
It is not difficult to prepare expanded clay concrete mortar. This building material contains high quality cement and fine expanded clay, made from exclusively natural raw materials. For greater density, sand is mixed into the solution. Sawdust or ash can also be added.
The proportion of the material can be compiled directly on the construction site. Professionals in this matter give several recommendations that should not be neglected:
- when making the mixture, take into account the quality characteristics of the raw materials used: humidity, grain size;
- If you want to increase the strength and elasticity of the future building material, add quartz sand during mixing. At the same time acceptable expanded clay gravel without expanded clay sand and moisture-sensitive cement, the addition of which usually contributes to vulnerability finished design before moisture;
- as a binder, as a rule, Portland cement with a minimum marking of M400 is used, which does not have plasticizing components that provoke a decrease in the strength of the finished product at the initial stages;
- The strength of the finished product can be increased by adding cement to the composition of expanded clay concrete. However, this leads to an increase in the volumetric mass of the building mixture;
- if heat treatment of expanded clay concrete material is planned, then preparation should be made from alite cement;
- to work with solid expanded clay concrete, more expanded clay is added inside the solution.
The density and structure of the finished blocks, which are:
- large porous;
- with intergranular pores;
- coarse- and fine-grained;
- quite dense;
- with medium thickness.
For a mixture with moderate density, coarse expanded clay is used. Such a solution often acts as a heat insulator. Small expanded clay is used in the construction of load-bearing structures and interior walls. It is used to produce expanded clay concrete monoliths of various sizes, marked M50, M75, M100.
The smaller the expanded clay granules, the denser and heavier the finished material will be. In this case, its thermal insulation properties are lost. Therefore, in order to achieve a golden mean, manufacturers of expanded clay concrete building materials often combine small and large expanded clay.
Approximate ratio of ingredients
When producing expanded clay concrete mixtures for the construction of private houses, the following generally accepted proportions of added components, calculated for the M400 cement grade, are practiced:
- expanded clay - 4-5 buckets (depending on the grain size);
- sand - 3-4 buckets;
- cement - 1 bucket;
- water - 1.5 buckets (approximately);
- plasticizer - based on the instructions for this ingredient.
The finer the expanded clay, the more it is added, and the higher the density of the solution will be.
If the plasticizer is liquid soap, then 2-3 caps of a five-liter bottle are mixed with the above amount of cement. plastic tank– it comes out to about 100 g.
When pouring water, be guided by the condition and appearance solution. It should be buoyant and at the same time viscous. You can check the condition of the mixture like this. Grab it. If a fairly stable mound has formed on the shovel, the solution is good; if the mound spreads quickly, the material is too liquid.
Floor mixture recipe
Depending on the pouring method, flooring can be dry, semi-dry, or wet. For wet screed gender apply following proportions expanded clay concrete: 4:3:1 – expanded clay/sand/cement. Expanded clay concrete mixture brand M100 is made with this proportion.
Expanded clay concrete blocks, which have long conquered the Western construction market, find adherents in our country. The popularity is due to the fact that the source material for making blocks has many advantages compared to brick, gas and foam concrete. The ratio of components in expanded clay concrete directly affects its density and performance qualities.
Expanded clay concrete is a porous composite that is used in block or monolithic construction. Compared to other concretes, the material has a special composition. In addition to cement and sand, the mixture includes expanded clay - foamed baked clay. In appearance, the filler resembles crushed stone, gravel or sand - it depends on the size of the fraction. Read more about the characteristics of expanded clay blocks and reviews from developers.
Here are the main properties of the composite:
- resistance to low and high temperatures;
- anti-corrosion properties;
- resistance to chemically aggressive environments;
- small specific gravity.
Thanks to its universal qualities, the scope of application is quite wide. A special feature of the material is the ability to adjust the composition of the expanded clay concrete mixture depending on the required density of finished blocks, panels or floors.
1. Construction of low-rise walls.
Blocks and panels are formed from lightweight concrete and poured into formwork. With a density of 1000 kg/cube, it can withstand loads of at least 7 MPa. To produce a cubic meter of wall blocks, you need the following composition of the expanded clay concrete mixture: Portland cement (grade 400) - 0.43 t; sand – 0.32 t; expanded clay fractions from 5 to 10 mm – 0.8 m3; water – 250-400 l. More durable material obtained by using river or quartz sand. If part of it is replaced with expanded clay (particle size up to 5 mm), the strength is somewhat reduced, but the walls will better accumulate and retain heat. In order for expanded clay concrete blocks to have a density of 950 kg/m3, the grade of expanded clay (indicator bulk density) must be no lower than M400-M500.
2. Making a screed.
Screed composition for residential buildings something like this: 2 parts expanded clay plus 3 parts sand plus 1 cement to 1 water. Such proportions ensure sufficient strength of the concrete layer and its rapid hardening.
3. Production of floor slabs.
The casting method produces lightweight products that are moisture-resistant, durable, and retain heat well. The only negative is the fragility of the material. It can be minimized by reinforcement, increasing the proportion of cement, and reducing the size of the expanded clay fraction. The ratio of components in the solution is selected as follows: 1 part M400 cement, 3-4 sand, 4-5 expanded clay, 1.5 water, plasticizing additives - according to the instructions.
Under production conditions, it is necessary to adjust the proportions of expanded clay concrete due to the use of different filler fractions (gravel or crushed stone). If the composition is set correctly, the same brand of expanded clay concrete can be obtained, despite different proportions of ingredients. In this case, the ratio of cement and water can vary from ½ to 1/1.
Types and brands of expanded clay concrete
The main characteristics include grade M (strength, kg/cm2) and density D (kg/m3). These are complex indicators that depend on the composition of expanded clay concrete blocks (and other products) and fractionation starting materials. Each brand is used for its intended purpose:
- M50 – for filling load-bearing walls internal partitions in residential buildings;
- M75 – for the manufacture of load-bearing structures in residential and industrial buildings using monolithic technology;
- M100 – for pouring screeds;
- M150 – for the production of blocks;
- M200 – for blocks and light floors;
- M300 – for road surfaces and bridges.
Depending on the density, there are 3 groups of expanded clay concrete.
1. Sandless (large-porous). To obtain it, gravel, Portland cement and water are mixed. Sand is not included. The advantage of this material is its low price; it is used to form walls, floors, and ceilings in low-rise construction.
2. Porous. For the manufacture of blocks, there are 3 subtypes with different levels of density:
- thermal insulation – D400-600, used for an additional layer of wall insulation;
- thermal insulation and structural – from D700 to D1400, it is used as insulation or for laying internal walls;
- wall (structural) – D1400-2000, for various engineering structures.
3. Dense. It is characterized by a high cement content and combines the characteristics of sandless and porous options. The cost of dense expanded clay concrete is high; it is rarely used in private construction.
There is another classification composite material– in terms of volumetric mass. Based on this criterion, the following types of expanded clay concrete are distinguished:
- heavy: its volumetric mass is 1200-1400 kg/m3, strength is 25 MPa;
- light: a cubic meter weighs 800-1000 kg/m3, natural expanded clay with a low specific gravity is added to the composition of lightweight expanded clay concrete;
- especially light: the cube weighs from 600 to 1800 kg/m3, strength – from 7.5 to 40 MPa; Artificially sintered expanded clay, agloporite, ash gravel, and slag pumice are used as fillers.
Pros and cons
Developers often decide to purchase expanded clay concrete blocks in an effort to reduce the overall cost of construction. But won't the quality of the structure deteriorate, taking into account the long-term perspective? The time has come to briefly list the advantages and disadvantages of the material in question. Except affordable price on expanded clay concrete, its advantages include:
- good body-saving characteristics - due to this, it is possible to reduce the calculated thickness of the walls (compared to brick) and reduce the pressure on the foundation (floors);
- vapor permeability – thanks to it, the level of humidity in the rooms is regulated;
- high rates of sound insulation and noise absorption;
- sufficient level of strength - walls made of expanded clay concrete do not experience deformation, shrinkage is minimal;
- increasing the pace of construction - if you buy lightweight large-sized blocks, this will help significantly speed up the masonry process;
- environmental friendliness.
The main disadvantage of a porous composite is its low moisture resistance, which requires waterproofing. External walls lined or cast from expanded clay concrete cannot be left without a facing layer for a long time, otherwise the life of the house will be reduced. The material has other disadvantages:
- the need for thermal insulation - if it is neglected, cold bridges are formed through which heat leaks;
- impossibility of using for laying foundations, plinths, garden paths;
- walls require powerful installation strip foundation– despite its relatively low specific gravity, expanded clay concrete is heavier than similar building composites.
Prices
The cost for one cube of expanded clay concrete depends on the brand of material, density, and design of the products (they can be solid or hollow). Buying blocks in bulk from a manufacturer will be cheaper than buying small quantities through an intermediary. To purchase a quality product, it is advisable to familiarize yourself with the certificate of conformity (it confirms that the manufacturing technology has been followed), and then find out what the cost is.
| Brand/density | Class | Price, rub/m3 |
| M50/ D800 | V 3.5 | 3100 |
| M75/ D1000 | B 5.0 | 3150 |
| M100/ D1200 | B 7.5 | 3200 |
| M150/ D1400 | At 12.5 | 3400 |
| M200/ D1600 | At 15.0 | 3500 |