Expanded concrete is a modern building material related to lightweight concrete. Blocks and other elements are produced from it, which are used for the construction of internal and external walls of houses and engineering structures for various purposes. It is also used to fill monolithic frames as a heat-insulating material.
Composition and production
Expanded concrete blocks are produced by mixing expanded clay, Portland cement, sand and water by semi-dry vibrocompression. Sometimes, if necessary, permitted plasticizers are added. Depending on the place of application, the composition may vary: to increase the thermal insulation properties, the amount of sand and cement may decrease, while the volume of expanded clay increases, reducing the mass of products and the weight of the finished object. At the same time, heat and sound insulation indicators increase.
Expanded clay is a specially processed burnt clay, which looks like porous oval pebbles. Depending on the production method, they may have an angular shape,such material is called expanded clay gravel. For the production of blocks, a filler with a fraction of 5-10 mm is used.
Since clay is a cheap natural material, a house made of such blocks will be environmentally friendly and the total cost of materials will be lower than buying more traditional and common building stones (gypsum concrete, foam concrete).
Classifications
As a composition, the size of expanded clay blocks and characteristics can be different, they are divided into groups according to several parameters:
1. By appointment:
- Constructive. The heaviest and most durable blocks. They are used for the construction of independent supporting elements of buildings, bridges, overpasses. The specific weight of such blocks is from 1400 to 1800 kg/m3.
- Structural and heat-insulating are involved in the construction of walls, mostly single-layer. Specific weight of blocks from 600 to 1400 kg/m3.
- Thermal insulation is used as a heater of various designs. The lightest elements with the lowest content of cement and sand. Specific gravity 350-600 kg/m3.
2. By Application:
- Wall. For interior and exterior masonry of varying degrees of responsibility.
- Partition walls for separating the interior space and, in some cases, the inter-apartment space.
3. By form. All blocks are parallelepipedal differ only in the degree of filling:
- Full-bodied.
- Hollow.
4. In laying order:
- Facial.
- Private.
Standards
In terms of properties and technical parameters, expanded clay concrete blocks must comply with the requirements established in GOST 6133-99 "Concrete wall stones". The document spells out various parameters for quality control, determines the grades of stones, the characteristics of raw materials for their production, the rules for transportation and storage.
GOST defines the specific dimensions of the gas block, foam block, expanded clay block:
The document also indicates the allowable deviations from the main dimensions:
General parameters
The dimensions of the claydite block according to GOST are clearly defined, for clarity, let's simplify and translate them into the form we are used to and get the following table:
| Name of blocks | Size, mm |
| Wall |
390x190x188 288x288x138 288x138x138 290x190x188 190x190x188 90x190x188 |
| Septal |
590х90х188 390х90х188 190х90х188 |
According to these values, you can always calculate the amount of materials needed for construction. These figures apply to blocks of all types of concrete.
The standard size of the expanded clay block can be changed according to specific wishesat the production stage for a specific batch or for an entire product line. Then the seller must indicate that the product is manufactured according to the specifications and has personal sizes that are different from the accepted ones.
The standard specifies not only the size of expanded clay blocks, but also the main shape of the stones - a parallelepiped. The element can have flat ends, as well as tongue-and-groove joints.
The shape of stones (polyhedra, semicircles, etc.) can be changed for the device of architectural elements of structures.
Specifications
Note that the size of expanded clay blocks does not affect the performance.
1. Expanded clay blocks differ in strength depending on the area of application:
| Destination | Indicator, kg/cm2 |
| Thermal insulation | 5-35 |
| Structural and thermal insulation | 35-100 |
| Constructive | 100-500 |
2. Dimensional weight:
| Destination | Indicator, kg/cm3 |
| Thermal insulation | 350-600 |
| Structural and thermal insulation | 600-1400 |
| Constructive | 1400-1800 |
3. The thermal conductivity of blocks of expanded clay concrete ranges from 0,14-0.66 W/(mK). The indicator depends on the amount of sand and cement in the composition of the stone - the smaller they are, the higher the block's ability to retain heat. Hollow elements have the highest value, and the structure of them will be the warmest.
4. Frost resistance depends on the severity of the block - the greater the weight, the greater the number of cycles the material withstands.
| Destination | Number of cycles |
| Thermal insulation | 15-50 |
| Structural and thermal insulation | 150 |
| Constructive | 500 |
5. Water absorption for a standard expanded clay block - up to 10%. The indicator can be reduced by adding special plasticizing additives and improvers to the composition.
6. Vapor permeability increases along with porosity - 0.3-0.9 mg / (mhPa). Accordingly, lightweight insulation blocks perfectly pass moisture.
7. Sound insulation depends on the degree of porosity of the block. 90 mm baffle provides protection up to 50 dB.
8. Fire resistance. Expanded clay concrete is able to withstand 180 minutes. at an exposure temperature of 10500С.
9. Shrinkage corresponds to 0.3-0.5 mm/m.
10. Permissible number of storeys of the building - 12.
Application
Blocks of expanded clay concrete are universal - they are used for the construction of different parts of buildings and engineering structures. For foundations, massive elements are produced that canwithstand significant loads, the body is additionally reinforced. For walls, there are both independent and insulating blocks. The difference lies in the design and composition: elements for support and load-bearing structures have greater weight and density, while insulating elements are more porous and light.
Partitions made of expanded clay concrete isolate sound indoors well. These suit in houses and buildings for various purposes. The size of the partition claydite block allows you to assemble the wall quickly with minimal labor.
Advantages over other materials
+ Produced expanded clay blocks, the dimensions of which are standardized, are easy to install: their porous structure allows the mortar to penetrate into the body of the stone, thereby ensuring reliable bonding of the masonry.
+ Walls built from hollow blocks are easy to reinforce: reinforcing reinforcement is inserted into the through holes, creating a frame. This is especially true for multi-storey construction.
+ The size of claydite blocks saves on the amount of mortar for masonry, and also reduces labor costs for the construction of structures.
+ The low weight of the elements does not require a strong foundation for the base.
+ Opportunity to save money without additional insulation.
+ "Breathable" walls allow you to maintain an optimal indoor climate without condensation.
+ Expanded clay concrete surface can be finished with various buildingmaterials, and its structure will ensure reliable adhesion of the layers.
+ Solid stones withstand various hanging items (cabinets, shelves, appliances).
+ Minimal shrinkage will have little effect on finish and structural integrity.
Flaws
- Compared to heavy concrete, expanded clay is less durable, therefore its use for foundations is possible only with low-rise construction and careful calculation.
- High-rise buildings require high-density blocks, which increases the load on the foundation and requires a more powerful structure, which can increase the cost of the project.
- It happens that expanded clay blocks are not ideal in size due to their structure, it is necessary to carefully lay them. But if the deviations are within the limits allowed by GOST, there are no problems.
Features of application and selection
If, when choosing a building material for the house, you settled on expanded clay concrete, you need to consider some nuances:
- In order not to create additional insulation, it is necessary to arrange the thickness of the walls at least 40 mm. Then living in the house will be comfortable, and the microclimate is always optimal.
- Laying should be done by carefully measuring the thickness of the seams. There should be no protrusions or drops.
- A strip foundation is suitable for a house made of expanded clay blocks, if a basement is not provided. After its precipitation, you can start building walls.
SizeThe standard clearly defines the expanded clay block, and therefore, if your project is designed according to such parameters, be careful when buying material: the manufacturer must indicate the dimensions according to GOST or TU. They may differ.
