Lightweight autoclaved aerated concrete

Hebel is a lightweight autoclaved aerated concrete (AAC) that is a completely cured, inert and stable form of calcium silicate hydrate. It is a structural material, approximately one quarter the weight of conventional concrete, composed of minute cells which give the material lightweight and high thermal insulation properties. It is available as blocks and pre-cast reinforced units, i.e. floors, roofs, walls and lintels.

Everite is the supplier and manufacturer of Hebel (AAC).

installing AAC blocks

Autoclaved Aerated Concrete (AAC) is made from sand, lime, cement, water and aluminium powder acting as a foaming agent to form a homogenous cellular structure known as calcium silicate hydrate.

This porcelainic reaction results in a unique and extremely stable tobermorite chemical structure. The mixing results in a chemical reaction that expands the mixture to form small, finely-dispersed air spaces. The mix is poured into moulds and allowed to set for a few hours while the chemical reaction continues.

The semi-solid material is removed from the moulds and then cut to shape in various lengths and profiles. The final phase in the production process is high-pressure steam curing in autoclaves for up to 12 hours. It is this autoclaving process that gives this material its unique and superior performance characteristics over any other.

Hebel reinforced elements, such as slab panels and wall panels, contain specially coated steel to prevent corrosion and give the material both dimensional accuracy and stability. The steel reinforcing is placed in the moulds before the mix is added. The manufacturing process is then the same as described above for unreinforced elements.

Features and Benefits

The following impressive attributes of AAC make Hebel an innovative, sustainable and proven building material and are summarised by the following qualities:

High speed of construction for an economical building process Hebel panels is faster to construct and require significantly less labour when compared to traditional masonry construction techniques leading to substantial savings and reduced on-site costs depending on the finish required.

  • Building with Hebel also means a cleaner safer work area during construction and less clean-up at the completion of the building.
  • Fast installation and easy workability with simple tools result in lower construction costs.
  • Can be cut and shaped like wood with simple hand tools.
  • The chasing of walls can be done by hand or with a wood router.
  • A smooth finish can substantially remove plastering trades.
  • Load-bearing capacity for the most unexpected situations

Being a masonry product, Hebel blocks and panels provide the attributes of being solid, strong and secure – all of these normally only associated with traditional bricks. Our 600 kg/m density product has a 5 MPa compressive strength and is rated for building up to 4 stories and in earthquake zones due to its high strength to weight ratio.

Outstanding fire resistance for maximum protection and safety. Non-combustible and renowned for its highly fire-resistant properties.

For example, a 150 mm thick AAC Hebel wall withstands direct fire exposure for up to 6 hours.

A standard 100 mm thick Hebel wall can withstand temperatures for 4 hours.

Thermal insulation in winter and summer for long-term reduction in energy consumption

The enhanced insulation performance is 5 times that of brick of the same thickness.

The thermal efficiency reduces the reliance on heating and cooling appliances and provides up to 60% reduction in heating and cooling costs.

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