What is the thermal conductivity of expanded clay concrete blocks and how to calculate it?

Expanded clay concrete blocks are a common option in building because of their ability to withstand heat and being lightweight. Cement or lime binder is mixed with expanded clay aggregate to create these blocks. The resultant material is easier to handle during construction because it is strong but much lighter than conventional concrete blocks.

Thermal conductivity, or the ability of expanded clay concrete blocks to conduct heat, is one of the most important factors to take into account. This characteristic is essential for preserving cozy interior temperatures and cutting down on energy use for heating and cooling. Builders and designers can maximize energy efficiency in buildings by having a thorough understanding of the thermal conductivity of these blocks.

A number of factors must be taken into account when calculating expanded clay concrete blocks’ thermal conductivity. The density of the blocks, the kind and quantity of materials used in their construction, and any additional insulating layers or coatings applied are the main factors affecting thermal conductivity. Blocks with higher densities typically have lower heat conductivity, though this can also be influenced by the particular combinations of binders and expanded clay.

In order to determine the thermal conductivity of expanded clay concrete blocks, builders frequently utilize established guidelines and formulas that consider the block’s dimensions and composition. The design of energy-efficient buildings is aided by these computations, which help predict how much heat will transfer through the blocks under particular circumstances. Building codes and standards for thermal performance require that structures be precisely calculated.

Practically speaking, building experts can choose insulation tactics and overall building energy efficiency by being aware of the thermal conductivity of expanded clay concrete blocks. Modern construction practices can enhance comfort and sustainability by minimizing heat gain in the summer and reducing heat loss in the winter by selecting materials with lower thermal conductivity.

What does the concept mean??

Expanded clay concrete stones refer to a value that describes a material’s ability to transfer heat from one surface to another through the thickness of its composition. The material’s transfer potential gradient is what gives it this ability. The inverse of this value, thermal resistance, is frequently used to describe it.

Certain raw materials transfer heat very quickly, while other materials transfer heat more slowly. For instance, thermal insulation materials take longer to transfer heat than metal, so metal is frequently used in addition to other materials to keep heat in a home. With the exception of solid stones, expanded clay concrete stone has little solid particle content, which results in low thermal conductivity.

Expanded clay concrete blocks stand out for their effective insulation capabilities when it comes to understanding the thermal properties of building materials. This article defines thermal conductivity for these blocks and gives a simple calculation method for them. Homeowners and builders can improve the energy efficiency of their building and renovation projects by taking a close look at how these blocks control heat transfer.

What does it depend on?

This stone parameter is dependent on multiple factors:

• emptiness;
• dimensions;
• compound;
• porosity.

It is well known that a product’s capacity to insulate against heat increases with the number of voids in it. Solid products have the highest thermal conductivity coefficient because they are completely void-free, or have a voidness of 0%. Nevertheless, since these materials cannot hold heat inside the home, you will require extra thermal insulation if you construct walls out of them.

This parameter is also influenced by the material’s porosity. A specific volume of expanded clay is added to the product in a specific dispersion as part of the stone. These indicators also have an impact on heat conductivity because a material’s mass and density decrease with the number of pores in it.

Crucial! Additionally, the composition of the block—more specifically, the proportion of the brand to the building materials—determines this indicator.

Odds table

You can look at the table below to learn what the expanded clay concrete stone indicator is. The product’s density determines this. The thermal conductivity of stones both during operation and in a dry state is displayed in two columns.

How does wall thickness affect?

After the heat conductivity has been established, the structure’s thickness must be computed.

The value of heat transfer resistance, which varies depending on the kind of building and the climate of the area where the house is being built, is also used for this purpose.

The wall’s thickness has an impact on the parameter as well. The ability of a wall to conduct heat increases with thickness. Furthermore, since there is no air inside and the walls’ capacity to insulate against heat loss, masonry composed of void-free blocks will require additional insulation.

Requirements for expanded clay stones

Certain standards apply to expanded clay and concrete blocks in terms of their thermal conductivity and other qualities. The GOST 33126-2014 document governs this. Separate specifications apply to non-load-bearing partitions as well as load-bearing external and internal walls.

For load-bearing external and internal walls

It is advised to use expanded clay concrete stones with medium density and thermal conductivity indicators of 0.1–0.2 W (m°C) when building load-bearing exterior and interior walls.

These blocks are both thermal and structural insulators, and because of their favorable solid-to-void ratio, they can be used to build exterior walls. Additionally, this material can be used to insulate exterior buildings.

Non-load bearing partitions

A unique kind of heat-insulating partition stone is appropriate for non-load-bearing walls and partitions, or it can be used for structural and thermal insulation. Because this kind of block isn’t meant to support a large weight, it can only be used indoors and isn’t used to support the floor slab.

Because hollow blocks have a lot of holes or cracks in them, they retain heat the best possible. However, these characteristics suggest that their thermal conductivity is just 0.1 W (m°C), which is low.

How to calculate?

The walls’ thermal conductivity needs to be suitable for the various climatic conditions.

You can find your region and learn what parameters should match the weather at the construction site by referring to a number of tables available online. After that, you can use the formula to perform your own calculations.

For instance, when planning a project, it’s important to figure out how thick the walls will need to be in order to create a future home that will be comfortable to live in. The thermal conductivity coefficient of the walls for the area is always included in the formula; the heat transfer resistance value is also used for this.

The formula is as follows: wall thickness for a given region = δx Rreg.

For instance, the thermal conductivity of an expanded clay concrete block with a density of 600 will be equal to 0.15 W (m °C), and the heat transfer resistance coefficient in Moscow is 3.28 kW.m x °C/W. As per the equation 3.28×0.15=0.492 m. This means that if expanded clay and cement stones are used, the average wall thickness for Moscow, assuming normal indoor temperatures, should be at least 49 cm.

Consequences of choosing the wrong indicator

The occupants of the house may soon experience issues if you use stone with inappropriate indicators and fail to promptly calculate the correct thermal conductivity of an expanded clay concrete block. First of all, even with heating devices, the house will take a very long time to heat up. If the stone is chosen properly, the house will warm up completely in two hours, even though it was cold before.

An additional issue is the requirement for more insulation. Money will unavoidably be wasted on this procedure. It is imperative that you handle the insulation process correctly, which means hiring experts and incurring costs. As a result, it is preferable to ascertain beforehand the required thermal conductivity of the expanded clay concrete block material and to base your construction upon it.

For construction, expanded clay concrete blocks are a common option because of their good thermal insulation qualities and lightweight design. These blocks’ thermal conductivity, which is commonly represented by λ (lambda) values, indicates how quickly heat moves through the substance. Compared to conventional concrete or bricks, expanded clay concrete blocks have a lower conductivity, which helps them retain interior temperatures and minimize heat loss.

The density and composition of the blocks are among the variables that must be taken into account when calculating the thermal conductivity. Lower λ values are generally associated with lower densities and higher proportions of insulating materials such as expanded clay. As a result, the blocks will be able to better withstand heat flow, which is essential for energy-efficient construction. These values are used by engineers and architects to create buildings that satisfy thermal codes and offer cozy living and working spaces.

Knowing the thermal conductivity of building materials, such as expanded clay concrete blocks, can help with energy efficiency and insulation selection during the planning stages of a construction project. Builders can help cut down on energy use and greenhouse gas emissions related to heating and cooling buildings by choosing materials with lower λ values.

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