Xella: 100 years of cellular concrete

The Xella group, the largest producer of cellular concrete and silico-lime, has been able to diversify its offering to cover all market needs and thus offer construction solutions for structural work, passive fire protection and development. . Through its 5 brands – Siporex, Ytong, Hebel, Silka and Multipor – it can respond to all housing, tertiary and industrial building projects, both new and renovated.

Combining thermal performance and presenting a good carbon footprint during the manufacturing process, Xella construction solutions also contribute to improving the summer comfort of buildings.

From tobermorite… to cellular concrete

The discovery of tobermorite at the end of the 19th century in Scotland inspired cellular concrete. Its composition, a mixture of limestone and silica, naturally pressurized and called “hydrated calcium silicate”, gives this ore extraordinary properties in terms of strength, durability and insulating qualities. But as it is only present in very small quantities in nature, engineers have sought an alternative to this rock.

In 1880, German engineer W. Michaelis mixed lime, sand and water with saturated water vapor under high pressure. It creates water-resistant hydrated calcium silicates. From this material, the engineer E. Hoffmann developed the technique of mortar expansion in 1889, then in 1914, the Americans J. W. Aylsworth and F. A. Dyer improved the process by introducing aluminum powder and zinc.

After the First World War, the formidable thermal properties of this material propelled it into the industrial era to, in particular, improve the insulation of buildings.
Thus in 1923, the Swedish engineer and architect J.A. Eriksson, who was looking for a construction material with the same appreciable properties as wood (insulation, resistance and machinability values) without the disadvantages (flammability and instability), combined all manufacturing processes. He brought a mixture enriched with lime and silica into contact with aluminum powder which he steamed in an autoclave. He had just reproduced tobermorite, this light, insulating material, resistant to compression and fire, and which nature took years to generate. This is how cellular concrete was born!

The birth of Ytong, a pioneering company

In 1929, a period when Sweden lacked raw materials, the first production of aerated concrete was launched in Yxhult by the entrepreneur Carl August Carlén. The name “Yxhults Anghärdade Gasbetong” was the first registered trademark in construction and the Haniel group, a seller of building materials, marketed the blocks.

Aerated concrete began its global career in 1940 when Ytong manufactured it industrially from cement, lime, gypsum, sand and aluminum powder cooked at low temperature but under very high pressure in an autoclave to form the air bubbles which make up 80% of the material. In 1958, different sizes of aerated concrete blocks were standardized.

The German group Haniel Bau-Industrie GmbH acquired Ytong AG in 2002 and Fels-Werke GmbH (raw materials manufacturer). The merger of the 3 entities will give birth to the Xella group in 2003, the year in which the German group acquired Hebel (manufacturer of cellular concrete since 1943 and in France under the name Siporex-Hebel) in order to become the leading European manufacturer of construction materials. Today, the Ytong brand remains known worldwide for its economical and sustainable building solutions.

In France, the production of cellular concrete blocks began in 1988 on the Saint-Savin site (38), which became the head office of Xella France.

Cellular concrete: a natural and virtuous material

Aerated concrete has unique and remarkable characteristics in terms of insulation and thermal comfort, insensitivity to humidity and fire resistance. Load-bearing and insulating, cellular concrete walls ensure perfect airtightness as well as excellent treatment of thermal bridges.

This mineral material is ecological and economical in terms of raw materials because it is made up of 80% air enclosed in thousands of cells and the solid parts represent only 20% of the volume, which makes it very light.

Free of Volatile Organic Compounds (VOC), it is Excell Green Zone certified. The life cycle analysis of Xella construction systems highlights its high level of environmental quality at all stages of its existence (manufacturing, transport, implementation, life of the structure, destruction).

The environmental performance of Xella constructive solutions is also validated by FDES (Environmental and Health Declaration Sheet).

A low carbon solution

Because they are made from natural raw materials, Xella construction solutions reduce the carbon footprint of production, limit resource extraction and fit perfectly into the concept of circular economy.

In fact, the Xella cellular concrete manufacturing process, which requires few raw materials, consumes between 60 and 70% less energy than other common construction materials.

The autoclaves used to harden the blocks are particularly energy efficient, and all aerated concrete waste can be recycled, crushed and reused in production instead of sand. This is how nearly 25% of the original raw materials are revalued.

Xella products contribute to the energy efficiency of buildings and to building in a carbon-free manner. They are part of RE2020 which aims to reduce the energy consumption of new constructions and reduce carbon emissions throughout the construction process.

They support developments in the building sector in terms of sustainable development and ecological commitment.

A material of the future

Renovation and rehabilitation occupies an increasingly important place both in the residential construction sector and in that of industrial and tertiary construction. Due to their lightness and thermal performance, Ytong solutions adapt perfectly to all these types of projects: extensions, renovation or even infill walls. They allow flexible renovation, energy savings, improved living comfort and increased fire safety.

Xella solutions, and in particular Ytong cellular concrete blocks, also meet the 3 fundamental pillars of RE2020 in terms of energy saving, summer and winter comfort, and carbon footprint. This regulation imposes on all builders a more sustainable vision of the constructions of tomorrow.

Finally, the exceptional properties of cellular concrete mean that Ytong and Hebel solutions are particularly popular for the construction of public buildings and HQE or BREEAM* labeled projects. They meet current standards in terms of thermal insulation and fire safety, and the issues of today’s construction.

*Building Research Establishment Environmental Assessment Method, a British certification standard relating to the environmental assessment of buildings.

Xella Group: an offer for all structural or energy renovation projects, extension and rehabilitation

With more than 5 employees, the Xella group today has 200 factories in 75 countries and sales departments in 16 countries. Leader in many markets, it is one of the main international suppliers of construction and insulation materials solutions, and one of the world's largest manufacturers of cellular and sand-lime concrete.

Its success is based on its five strong brands: Siporex, Ytong Hebel, Silka, Multipor whose specific properties guarantee a high quality result.

Offered in the form of blocks, tiles, prefabricated panels and custom-made elements, Xella construction solutions are suitable for all types of construction, are easy to implement and retain their properties over the very long term.