LIGNACITE LTD
NORFOLK HOUSE
HIGH STREET
BRANDON
SUFFOLK IP27 0AX
Tel: 01842 810678
Fax: brandonsales@lignacite.co.uk
Suppliers of: Concrete Blocks Masonry Blocks Dense Concrete Blocks lightweight blocks building Blocks Concrete Blocks Concrete Soffit Blocks concrete
Lignacite are a leading manufacturer of concrete and masonry products and have one of the most efficient and modern manufacturing sites in the U.K.
Sustainable and Environmentally Sensitive Manufacturing
Lignacite sets the standards for sustainable and environmentally sensitive manufacturing. Our curing chambers re-use heat given off by the exothermic reaction between cement and water and when additional heat is needed, gas emissions are pumped back into the chambers, where blocks absorb CO2.
All water used at Brandon comes from a on site borehole, and is recycled at up to 5000 gallons / hour. Sand and aggregate quarried on land adjacent to the plant saves around 36,000 lorry journeys over the period of extraction. The land is then restored on an annual basis for wildlife conservation.
Main Product Ranges:
Concrete Blocks
All our products are Kitemarked as conforming to BS EN 771-3 Aggregate Concrete Masonry Units. They comply with category 1 Masonry Units and are manufactured under a quality assurance scheme assessed and certified to BS EN 9001:2000 by the British Standards Institute.
Lignacite concrete blocks comprise a range of medium density loadbearing units, used in internal or external walls. Lignacite blocks contribute to sound environmental practices as they contain graded wood particles, a selected waste wood product as an alternative aggregate. They also provide exceptional sound reduction qualities.
Concrete Blocks - Lignacite Ash GP:
Ash GP is a medium density concrete block which is robust, durable and suitable for a range of walling applications. Typical uses include the inner leaf of cavity walls when used with cavity insulation, separating or partition walls, and infill blocks in beam and block flooring systems. Ash GP can also be used externally where rendering or cladding is to be applied to the wall. Ash GP blocks provide a strong background for holding fixings. Ash GP is produced using at least 35% of recycled aggregate (by volume) thereby conserving valuable sources of primary material.
Concrete Blocks - Fibo850 Blocks:
Fibo850 is an excellent light weight house builder block. The block is manufactured from expanded clay lightweight aggregate, and contains up to 24% recycled aggregates by volume.
Lignacrete is a robust and durable block that provides a good background for fixing, and that has excellent acoustic properties and thermal capacity. Lignacrete blocks are used in internal or external walls and manufactured from cement, sand and dense aggregates, and contains up to 20% recycled aggregates by volume.
Further technical information is available to download from the BPi download Library or directly from the manufacturer’s own website.
An introduction to medium dense blocks: their properties, benefits and uses
We take a closer look at medium dense blocks and how they could be used in your next building project. Read on to learn more.
Looking for a strong and durable concrete block for your building project? A dense concrete block isn’t your only option! In this article, we’ll introduce you to the medium dense block and demonstrate why it could be the perfect alternative for your build.
What is a medium dense block?
A medium dense concrete block is a popular construction material that offers builders strength, durability and excellent sound and thermal insulation. They are lighter than standard dense blocks, which makes them easier to handle and reduces the overall load on a structure. Typically, they have a density that ranges from 1,100 to 1,600 kg/m³.
Medium dense blocks can be used in both load-bearing and non-load-bearing walls, partitions and other structural elements in residential, commercial and industrial buildings.
What's the difference between dense and medium dense blocks?
The difference between dense and medium density blocks is their weight and density. Dense blocks are heavier due to their composition, which features dense, tightly packed aggregates. This gives them impressive strength, which makes them ideal for heavy-duty structural applications.
Medium dense blocks, on the other hand, are lighter. Their composition includes a proportion of lightweight aggregates but they retain many of the qualities of dense blocks. In addition, they also have good thermal and excellent acoustic insulating qualities.
Read more: Learn more about the properties of dense blocks.
The properties of medium dense blocks
Medium dense blocks tend to have densities that range from 1,100 to 1,600 kg/m³. The exact weight of each block will depend on this density, along with the block’s size and its mix. For instance, our 140mm Lignacite SP blocks have had their mix optimised to produce a solid block that weighs less than 20kg per unit.
Medium dense blocks are known for their strength and durability. For example, our Lignacite solid block and Ash GPmedium dense blocks have loadbearing strengths of up to 10.4N/mm². This makes them an excellent choice for substantial structures.
Another key feature of medium density blocks is their insulative properties. These blocks have a relatively low thermal conductivity, which means that they can help to keep buildings warm. For example, our 100mm Lignacite blocks (with a moisture content of 3%) have thermal conductivity of 0.90 W/mK while our 140mm SP blocks have an even lower conductivity score of 0.79W/mK.
They have excellent sound-insulating properties too. Their relatively high mass with low levels of porosity helps to block external and internal sound effectively. Walls built with our 140mm Lignacite SP blocks can therefore give sound insulation in excess of 50db (Rw).
Read more: Find out more about the sound insulation properties of Lignacite blocks.
What are medium dense concrete blocks used for?
The strength and durability of medium density blocks makes them very versatile. They can be used to build homes, shopping centres and stadiums, and you can use them for internal and external applications. You can even use them below ground!
Here are just some ideas of what you can use medium density concrete blocks for:
Inner and outer leaves of external cavity walls
Internal walls (including fire break walls)
Separating or partition walls
Below ground
Infill for block and beam flooring
You can find out more about how different blocks can be used with our Application Locator tool.
The benefits of using medium dense blocks
There are several advantages to using medium density blocks in your building projects.
Durability: The strong durability and impact resistance of medium dense blocks means that they can be used in structures for commercial, leisure and academic use.
Excellent sound insulation: Medium density blocks can ensure the comfort of inhabitants and can help to protect them from excess noise pollution thanks to their fantastic sound insulation.
A1 fire rated: Medium density concrete blocks make no contribution towards fire and are completely non-combustible.
Air tightness: Medium dense blocks, such as our Lignacite product, have very low air permeability, particularly if their surface is painted.
Find the right medium dense block for your project
If you're looking for the right medium density blocks for partition walls, external walls or cavity walls, get in touch with our friendly Quoting Team by calling 01842 778485 today.
You can also visit our dedicated web pages on our Lignacite and Ash GP medium density blocks to see if they fit your specifications.
Lignacite - The thermal performance of concrete: an introduction
Learn all about the thermal performance of concrete, from thermal conductivity to resistance, in this helpful article.
Concrete is a popular construction material because it has some fantastic properties. In terms of thermal performance, it can also outshine many of its competitors. To showcase this more clearly, we’ve pulled together a roundup of concrete’s thermal performance. Read on if you’d like to learn more about its insulative abilities and its conductivity.
What are the thermal properties of concrete?
Concrete blocks are excellent thermal insulators, which is one of the many reasons why they are such a popular material in construction. Their thermal heat capacity also means that they can contribute towards a building’s thermal mass, a feature that will become increasingly important in sustainable construction.
To give you the best overview of the thermal properties of concrete, let’s take a more in-depth look at conductivity, insulation, expansion rate, resistance and thermal capacity.
The thermal conductivity of concrete
Thermal conductivity is the measure of a material’s ability to transfer heat by conduction. The lower the conductivity of a material, the less energy is transferred and the better it is as an insulator.
It is usually defined as the amount of heat (watts or W) transferred through a square area of material. It is measured in watts per metre kelvin (W/mK), which can also be expressed as λ.
The thermal conductivity of concrete blocks can be found in BS EN 1745 Masonry and Masonry Products. Methods For Determining Thermal Properties. Typically, the thermal conductivity of medium-dense blockwork is 0.51W/mK. This rises up to 1.33W/mK in dense blocks.
The thermal conductivity of concrete is therefore reasonable, although it is relatively low when compared to materials such as steel or glass. This is because concrete blocks have a more porous structure, which acts as an insulator.
The thermal insulation of concrete
Thermal insulation is a broad term that refers to the reduction of heat transfer. A thermally insulative material will therefore help to prevent heat from transferring from one space to another, such as from outside to inside or between rooms.
Concrete blocks, such as those in our Lignacite range, boast excellent thermal insulation. This is because concrete blocks have tiny pockets of air within them. Air is a poor conductor, which means that less heat is transferred. As a result, denser concrete blocks are less thermally insulative than low-density products.
The thermal expansion rate of concrete
Thermal expansion is the likelihood of a material to change its area, shape, volume and density as a result of a change in temperature. This is a key consideration when designing buildings, as designers must take into account any possible movement by construction and building materials when subjected to very cold weather or elevated temperatures.
When concrete gets hot, it can expand. And if the weather is very cold, it can contract. The exact thermal expansion rate of concrete can vary depending on factors such as its composition, moisture content and temperature range. However, the typical coefficient of linear expansion (CTE) of a dense concrete block (such as Lignacrete) is 10x10 -6 /℃.
This is equivalent to 17mm of thermal expansion for every 30.5m of concrete that is subjected to a rise or fall of 38℃.
What is the thermal expansion test for concrete?
To find out the thermal expansion of concrete, samples are subjected to temperature changes. Changes in the length of the samples are then measured. The CTE is calculated from the measured length change / original specimen length / measured temperature change.
The thermal resistance of concrete
Thermal resistance is the ability of a material to prevent heat flow and is usually expressed as m2K/W. It is used to determine the performance of different thicknesses of materials because thermal conductivity measurements do not take this into account (for example, a 100mm block would be given the same λ-value as a 190mm block).
Working out the thermal resistance, or R-value, is therefore key.
The thermal resistance is found by dividing the thickness of the material by its thermal conductivity. The higher the thermal resistance, the better as it means the material has greater resistance to heat transfer.
Designers can then use the R-value in their calculations for U-values, which measure how effective something is as an insulator.
The specific thermal heat capacity of concrete
This refers to the heat energy per unit of mass (usually 1kg) that is needed to raise the temperature of a material by 1℃. The higher the heat capacity of a material, the more energy is needed in order to increase its temperature.
Typically, the specific heat capacity of a concrete block is 800-1,000 J/kg°C.
Taking the specific heat capacity into account when designing a building is useful because it can help you to assess the benefits of the finished building’s thermal mass. Thermal mass refers to the ability of construction materials such as concrete to protect against temperature changes within buildings by absorbing and releasing heat. This can improve the thermal comfort of future residents.
Materials that have a high specific heat capacity, a high density and reasonable thermal conductivity offer a useful level of thermal mass. Concrete blocks have these properties, which makes them a practical material to consider for thermal mass.
Which factors influence the thermal performance of concrete?
Several factors influence the thermal properties of concrete, impacting its ability to conduct, store and resist heat.
Types of aggregates
Firstly, the composition of the concrete mixture plays a crucial role. Aggregates and other cementitious materials significantly influence the thermal conductivity of concrete due to their composition, size, shape, crystallinity and distribution within the mixture. For instance, lightweight aggregates such as expanded shale or clay can reduce thermal conductivity due to their lower density and thermal resistance.
Additionally, the size and shape of aggregates impact the distribution of voids within the concrete, affecting the pathways for heat transfer. Coarse aggregates may create more air voids, increasing insulation, while finer aggregates can improve contact between particles, potentially enhancing thermal conductivity.
Moisture content
The moisture content within the concrete also affects its thermal performance, with higher moisture levels being linked with higher thermal conductivity. This is because water is a good conductor.
Concrete density and porosity
The density and porosity of concrete also influence its insulating properties. This is because the presence of air voids within concrete blocks can enhance insulation by reducing thermal conductivity. Concrete blocks with lower densities therefore have better thermal resistance.
Find the right concrete block for your project
If you’d like to find the right concrete product for your next build, try out our interactive Product Selector tool.
Alternatively, get in touch with our friendly Quoting Team by calling 01842 778485 today.
