In three parts to the goal

The largest 32 of the 618 octagonal spun concrete columns made of high-quality white concrete of the material quality C50/60 are manufactured in three parts for better transport and only put together on the construction site using a socket joint. Its dimensions: 36 meters long and 1.62 meters in diameter. "The production of a support of this size, including the final finishing, takes about three days" explains Biederer.

Spun concrete process makes the difference

In order to be able to achieve the load capacity and appearance of the columns in high-quality fair-faced concrete required by the client, they are manufactured using the spun concrete method – a production technique that FUCHS Europoles has been using for over 50 years and has continuously improved. “We installed a unique conveyor for manufacturing. As the mold rotates, the concrete is gradually poured in, ensuring even distribution. The concrete of the steel mold then rotates around the longitudinal axis at around 800 revolutions per minute." Michael Biederer describes the procedure. The fresh concrete is pressed against the formwork wall with 20 times the acceleration due to gravity and is extremely compacted. In this way, the required extremely smooth, even and non-porous surface is created. The mosque supports also owe their sharp-edged corners to the spun concrete process, which contribute to the aesthetic shaping of the architectural elements.

Know-how as a success factor

However, the production process not only creates a visually appealing surface. The star-shaped reliefs, which adorn around a third of all the supports for the mosque, can already be incorporated during the production process by inserting appropriately patterned rubber matrices. In addition, the centrifugal forces involved in spinning create a void in the center of the support.

The free space can be used excellently with the fire and earthquake-proof mosque supports – the region around Algiers is considered to be at high risk of earthquakes. Because: The drainage of the entire mosque roof takes place via this cavity in the support core. One of the reasons why FUCHS Europoles was able to win the major order, says the technical project manager: "Together with our in-house engineering expertise, the production-technological advantages and special features were ultimately the deciding factor in the award of the contract."

4,377 kilometers of a logistical masterpiece

For the finished supports, the heads of which are partially widened so that they can be connected to the impressive roof construction of the mosque, the 4377-kilometre journey to Algiers starts directly from Neumarkt. Packed in a special film to protect against dirt and moisture, the supports are loaded onto railway wagons by crane in the factory. The train then rolls out of the factory premises in the direction of the port of Bremen. There, the supports were removed, completely repackaged and finally transported by ship to Algeria, where they were integrated directly into the assembly process just-in-time. After a total production time of a year and ten months, the last spun concrete column is on its way in September 2015.