618 spun concrete columns for the third largest mosque in the world

Djamaa El Djazair - The Great Mosque of Algiers

Around six kilometres from the historic heart of the Algerian capital Algiers, a temple of magnificence soars into the sky. On a site measuring a good 26 hectares directly on the Bay of Algiers, the Jemma el Djazair, the third-largest mosque in the world, is under construction. Only the two pilgrimage sites in Mecca and Medina are larger. The load-bearing elements of the imposing structure are 618 spun concrete columns, produced in the concrete pole factory at FUCHS Europoles headquarters in Neumarkt. The spun concrete columns up to 36 m high are a distinguishing feature of a 'building for eternity' that is in a class of its own.

A multifunctional complex

At a height of 265 m, the minaret of the Great Mosque of Algiers will be the tallest in the world. It rises above the gigantic complex that extends over an area of 375,000 m2 with just under 1.8 million m3 enclosed space. The principal ANARGEMA (Agence Nationale de Réalisation de Gestion de la Mosquée d’Algérie) is investing over €1 billion to build it. There is room for 120,000 people in the complex, which apart from the house of worship itself also incorporates a large number of cultural and religious establishments. For example there will be a museum and a library with over a million works, as well as apartments and a kindergarten.

Special measures for a special project

Despite its enormous size, the overall concept by architects KSP Jürgen Engel is airy and delicate. This impression is evoked above all by the white colour and the slender columns in spun concrete, which are the responsibility of the specialists from FUCHS Europoles.

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The production and delivery for the largest single order in the history of FUCHS Europoles calls for special measures,” says Michael Biederer, the Technical Project Manager at FUCHS Europoles. “For the mosque columns we set up a separate storage yard directly next to the plant and we fitted the production facility with new cranes and a new concrete mixing facility.


Michael Biederer

Technical Project Manager

FUCHS Europoles GmbH

Dispatched to their destination in three sections

The largest 32 of the 618 octagonal spun concrete columns made from high-quality white concrete in material class C50/60 are produced in three parts for easier transportation and then assembled together on the construction site using pole insertion joints. The columns are 36 metres long and 1.62 metres in diameter. “The production of a column of this scale takes around three days including the subsequent finishing process,” explains Biederer.

Spun concrete process makes all the difference

To be able to satisfy the client's requirements for load-bearing capacity and visual appearance of the columns in fair-faced concrete quality, they are produced using the spun concrete process, a production technique that FUCHS Europoles has been using and constantly improving for over 50 years. “For the production of the columns we installed a unique conveyor belt. While the mould is rotating, the concrete is filled gradually to ensure even distribution. Afterwards, the concrete in the steel mould rotates around the longitudinal axis at about 800 rpm,” says Michael Biederer, describing the process. The fresh concrete is pressed against the wall of the steel mould with 20-fold gravitational acceleration and densely compacted. This produces the extremely smooth, uniform and non-porous surface required. The spun concrete process is also responsible for giving the columns for the mosque their sharp corners which also enhance the aesthetics of the architectural elements.

Expertise as success factor

However, the production process doesn't just create a visually appealing surface. During the production process itself the star-shaped reliefs, which adorn around a third of all columns for the mosque, can be incorporated by inserting patterned rubber matrices. In addition, the centrifugal forces that occur in the process create a hollow space in the middle of the column.

This free space is put to excellent use in the fire and earthquake resistant columns for the mosque (the region around Algiers is regarded as at high risk from earthquakes). Because the drainage of the entire roof of the mosque is effected via these cavities in the core of the columns. This was one of the reasons why FUCHS Europoles managed to win this major contract, says the technical project manager: “Combined with our in-house engineering expertise, the production technology benefits and special features were ultimately what were behind the decision to award us the order.”

A logistical master-stroke over a distance of 4,377 kilometres

The completed columns, some of the tops of which are flared for connection to the impressive roof structure of the mosque, go directly from Neumarkt on the long 4377 km journey to Algiers. Packed in special film to protect them against dirt and wetness, the columns are loaded by crane into freight cars while still at the plant. The train then rolls out of the factory grounds towards the port in Bremen, where the columns are removed, completely packed again and then transported by ship to Algiers, to be integrated “just-in-time” directly into the assembly work flow. Following a production time of a good year and ten months, the last spun concrete column set out on its journey in September 2015, to support the roof of the third largest mosque in the world in Algiers.

Technical details


Project duration spun concrete columns

November 2013 to September 2015


Scope of supply

618 octagonal spun concrete columns in three diameters


Details

  • Lengths: 3.5 to 36 metres
  • Diameter: 0.81 to 1.62 metres
  • Weight: Total 22,248 metric tons of white concrete
  • High-quality fair-faced concrete executed as white concrete in C50/60
  • Integration of drainage pipes in the cavity at the core of the column
  • In some cases, flaring of column heads to meet architectural specifications
  • Integration of inspection ports in identical fair-facing concrete quality
Columns