Expanded clay, whose thermal conductivity is largelydetermined by raw materials, it also has a low specific weight, as well as high strength. It is these qualities that cause a wide range of use of this material in construction.
Thermal conductivity
For those materials that are designed to performprotective function, thermal conductivity characteristic is particularly important. Expanded clay acts as a natural material, which is why this parameter depends on many qualities.
Among the first should be the size of the granules.The more impressive the fraction will be, the more insulation will be needed. Porosity and moisture content of claydite will also affect the thermal conductivity. The average coefficient of thermal conductivity is quite difficult to determine, because there are many deviations. Expanded clay, the thermal conductivity of which in reference books is specified in the range of 0.07 W / m, has a high hygroscopicity. But it would be fair to indicate the maximum value of thermal conductivity - it reaches the level of 0.16.
It is important to choose the right material.If the coefficient of thermal conductivity is higher, the amount of heat that passes through the insulator layer will be impressive. This indicates that thermal protection is reduced. You should also pay attention to the porosity of expanded clay, which affects the density and thermal conductivity. The higher the first parameter, the lower will be the last two.
What influences the main characteristic of expanded clay
Studies show that thermal conductivityhaydite is determined by the absence of quartz, but only at a single stage of production. Technologists should take into account the features of production. After all, silica contained in expanded clay increases thermal conductivity, while other oxides lower this value.
This does not apply to gases that form when heated to the expansion temperature. It has been established that if the pores contain H2 + CO in an amount greater than 55%, thenthermal conductivity of expanded clay will be 2 times higher than in the case if the fullness will be air. Thermal conductivity can also affect micropores. The smaller they are, the lower the thermal conductivity will be, however, the porosity does not affect this characteristic.
Basic properties
Expanded clay, thermal conductivity of which was mentioned above, has certain properties, among them:
- high strength;
- frost resistance;
- durability;
- refractoriness;
- optimum ratio of quality and cost.
Considering this material, it is impossible not to distinguishgood thermal insulation, acid resistance and chemical inertness. Expanded clay is considered a natural material and is an environmentally friendly heat insulator.
Key Features
Expanded clay, the thermal conductivity of which you want to learnbefore purchasing this material, has excellent qualities. It is made of slate and clay and is suitable for environmentally friendly and modern house building.
Claydite is also used for decorative purposes, andat home it is suitable for solving problems of growing cultivated plants. With the help of this material it is possible to eliminate the increased evaporation of moisture, which helps to control the water balance of plants.
Specifications
Thermal conductivity coefficient of expanded clayestablished by state standards 9757-90, like the rest of the technical characteristics, among them should be allocated fractional composition. On sale you can find the material in three fractions:
- 5-10;
- 10-20;
- 20-40 mm.
Not to mention another category.fractions, which is quite rarely used in construction works. These include crushed clay and expanded granules, the sizes of which vary from 2.5 to 10 mm. Quite often when buying a consumer is interested in bulk density, in this matter 7 values are set by brands:
- up to 250 kg / m3 - mark 250;
- from 250 to 300 kg / m3 - mark 300;
- similarly, the brands 350, 400, 450, 500, 600.
Для широкой продажи следующие две марки не produced, they are made only with the consent of the consumer. Expanded clay, characteristics, thermal conductivity of which is mentioned in the article and should be interesting to the consumer, has a certain compaction factor, which is individually agreed, but this value does not exceed 1.15. An important parameter that determines the behavior of claydite when exposed to moisture, is water absorption. It can vary from 8 to 20%.
Comparison of thermal conductivity of expanded clay with some other materials
Expanded clay, thermal conductivity (comparison ofcharacteristics with other materials should also be carried out before making a choice of material) which has already been mentioned above, is quite often preferred by consumers of mineral wool or expanded perlite. In the first case, the coefficient is 0.04, which indicates that at the same thickness, the cotton will release less heat compared to expanded clay.
Another alternative is expanded perlite. Its water absorption is lower than that of expanded clay and is only 5%, while the coefficient of thermal conductivity is only 0.04.
Expanded clay, properties, thermal conductivity of whichmake it sometimes an indispensable material during the work, sometimes even compared with exfoliated vermiculite. It is the best option that could replace the expanded clay, and is produced from the rock, which makes it environmentally friendly. The thermal conductivity of expanded vermiculite is 0.08, which is 2 times less than mineral wool. If you use this material, you can form a thinner layer of backfill, which will load the floor less. This suggests that this insulation can also be used as a basis for screed.
Conclusion
Thermal conductivity acts as one ofimportant characteristics of claydite. But it does not greatly depend on the mode of production. If you use the usual technology, then change the quality of expanded clay is not particularly work. However, when using modern techniques such as joint firing or plastic method, it is possible to increase the insulating properties of expanded clay.
