Aerated Blocks

What Are Aerated Blocks?

Unlike regular bricks and blocks, aerated concrete blocks are produced by incorporating air or gas, making them lightweight and enhancing their insulating properties.

These blocks are made from a mix of quartz sand aggregates, calcined gypsum, lime, Portland cement, pulverised fuel ash (PFA), water, and aluminium powder. The inclusion of aluminium powder creates tiny air bubbles within the blocks, contributing to their low density and excellent thermal insulation.

Once the materials are combined, the mixture undergoes autoclaving, a process that subjects it to high heat and pressure. This step is crucial in developing the blocks' final properties, ensuring durability and strength.

The resulting aerated concrete blocks vary in density and compressive strength, typically ranging from 3 to 8 N/mm². Their lightweight nature makes them easier to handle and transport, while their insulating properties help improve Energy Performance Certificate (EPC) ratings, thereby enhancing the overall value of your property.

For competitive prices and top-quality products, explore our extensive range of aerated blocks and building materials.

Aerated Blocks Applications

Aerated blocks (AAC) offer both structural support and insulation due to their unique composition and manufacturing process.

This highly versatile material can be applied in both load-bearing and non-bearing designs. AAC blocks can be utilised as a foundation laying material as well as in above-ground construction. 

Aerated blocks are not just limited to structural applications in low-rise constructions or partitions, but can also be employed as part of curtain walling for taller buildings.

Aerated Block Uses Include: 

• Foundations
• Inner Cavity Wall Leaves
• Cavity Walls Below DPC
• Partition Walls
• Internal and External Walls
• Fire Walls
• Suspended Beam and Block Floors

Specific Use Cases: 

• Inner Levels of Cavity Walls
• Dwelling Partition Walls
• Panels Joined with Thin-Bed Mortar
• Strengthening with Steel as Needed

To increase the durability of aerated blocks, consider using finishes like natural or engineered stone, polymer-modified stucco, or siding, depending on their purpose.

When using these blocks in basements, it’s important to cover the outer surface with a thick layer of damp-proofing membrane. For the interior surface, you have the option to leave it uncoated or finish it with plaster, drywall, or tile, based on your preference.

Aerated Concrete Block Benefits

• Quick and cheap to install – cost-effective and reduces build time
• Bigger blocks with fewer joints than non-autoclaved aerated concrete blocks
• Highly versatile
• Class A1 Fire
• Offers a combination of water resistance, frost resistance and insect resistance
• Excellent thermal properties - reduces thermal bridging with low thermal conductivity values 
• Uses industrial waste (PFA) as a prime constituent - helping to minimise waste
• Lightweight composition ensures blocks are easier to lift than traditional concrete – quicker load movements
• Higher thermal performance – reduced insulation costs 

Composition and Manufacturing Process

Aerated concrete blocks are made from a mixture of:

• Quartz sand aggregates
• Calcined gypsum
• Lime
• Portland cement
• Pulverised fuel ash (PFA)
• Water
• Aluminium powder

Once the materials are combined and mixed, the mixture is then autoclaved under extreme heat and pressure. 

This process involves heating the material in an autoclave, a machine which elevates temperature and pressure, resulting in the creation of air bubbles within the blocks. These air bubbles provide excellent thermal insulation, moisture resistance, and strength.