HeBerlinWall: Hebel Research Part 2 (History, Manufacturing Process & Product Range)

The History of Hebel

The Hebel story began over 45 years ago in West Germany, when a building contractor named Josef Hebel decided to develop a more cost-effective building system.

From the initial success of the first Autoclaved Aerated Concrete (AAC) products, Josef Hebel was encouraged to set up a mixing, moulding and cutting plant at Emmering near Munich. Architects and builders quickly saw the advantages of this strong yet lightweight material, and were soon utilising its range of properties in all types of construction.

In 1961 the first home was built from Hebel and in the next year a further division, Hebel House, was formed to specialise in residential projects throughout Germany. Hebel’s German success was soon noticed by overseas interests, and in 1967 the first joint manufacturing licence was signed with Asahi Chemicals of Japan. That partnership now accounts for six factories and supplies a major share of Japan is masonry requirements. In addition, Hebel now manufactures in 10 countries worldwide.

The Manufacturing Process of Hebel

Diagram 01. Hebel Manufacture Process

Hebel AAC is manufactured from sand, lime and cement, to which is added a gas forming agent. Sand is ground to the required fineness in a ball mill and stored. Cement and lime are stored in silos.

The raw materials are then automatically weighed and measured in the mixer. To this mixture is added water and aluminium paste (the gas-forming agent). After mixing, the cement slurry is poured into a mould. The aluminium paste reacts with the alkaline elements in the cement and forms hydrogen gas.

The liberated gas expands the mixture forming extremely small, finely dispersed air spaces. The product is removed from the moulds after a few hours and transported to a cutting machine. The cutting machine cuts the moulds using cutting wires, into the required size building elements.

The final curing of the product takes up to 12 hours under steam pressure in an autoclave. The blocks, panels and lintels are removed from the autoclave and are packed, ready for transport to site. In the case of reinforced panels and lintels, corrosion protected steel reinforcing mesh is placed in the mould before the cement mixture is added. The process is then the same as for unreinforced products.

The Benefits of Hebel

Hebel is produced in blocks, panels and lintels, for both loadbearing and nonloadbearing uses. The material has a number of unique properties, providing the following benefits:

1) Rapid On-Site Assembly

The product’s lightweight and easy workability means that it is very quick to install on site.

2) Excellent Acoustic Performance

Hebel has excellent acoustic performance and can be used as an effective sound barrier, e.g., inter-tenancy walls.

3) Easily Worked

Hebel blocks and panels can be sawn, drilled, nailed and machined using off the shelf tools.

4) Fire Resistant

Hebel is totally inorganic and is incombustible. The product is especially suited for fire-rated applications.

5) Accuracy of Manufactured Panels and Blocks

The accurate manufacturing process ensures that Hebel panels and blocks are always produced to size as they leave the factory. This results in less on-site trimming and reduced quantities of mortar and finishing materials use.

6) Non-Toxic

Hebel products do not contain any toxic gas substances. The product does not harbour or encourage vermin.

7) Versatility

Hebel building systems can be used for all applications including walls, roofs, floors and balconies, in both load-bearing and non-load-bearing applications.

8) Long Life

Hebel products are not affected by harsh climatic conditions and will not degrade under normal atmospheric conditions.

9) Lightweight

Hebel blocks are one-fifth of the weight of concrete and are produced in easily handled sizes.

10) Energy Saving

The remarkably good insulation properties of Hebel mean a pleasant interior environment is achieved. In most cases the need for supplementary insulation can be avoided.

The Product Range of Hebel

Hebel products are available in either blocks or reinforced panels, lintels and stair treads in a range of strength grades. The diversity of the CSR Hebel product range is designed to cater for the large range of applications in Australian and overseas building industries.