High up with Dyckerhoff WEISS
12 November 2019

High up with Dyckerhoff WEISS

In a demanding project, the new bell tower for the Kreuzkirche in Freiburg was built with white cement from Dyckerhoff.

It can already be seen from a distance – the newly erected tower of the Evangelical Church in Freiburg, Baden-Württemberg in Germany. With its bright white color, it clearly stands out from the surrounding buildings.

On July 31, 2019, the 21 meter high building was assembled on site from prefabricated parts. The contractor was Egenter Betonfertigteilwerk GmbH. For the company based here, which also produced the precast elements, this project was unique in its company history of more than 45 years.

The tower consists of 5 elements: each 4 meters high and 16 tons heavy. They each contain approx. 1.4 tons of steel and have 120 differently sized, tapered recesses that look like small windows. The wall thickness is 20 centimeters. Each of the elements was concreted in four stages. Once one side was finished, the mould was rotated by 90 degrees. The individual sides are linked by a connecting reinforcement. Two elements are screwed together with 16 threaded rods each. The 30 centimeter thick base was also installed as a precast element and anchored approx. 4 meters deep in the ground with a kind of foundation piles.

The challenge in this project was the complex, complicated formwork construction – especially with regard to the 120 differently sized recesses. On the other hand, a suitable building material had to be found for this formwork, with which the brilliant white could also be achieved.

Formwork and mixture of the white concrete were developed in advance in a series of tests. The decision was made to use white cement of the grade CEM I 42.5 R (Dyckerhoff Weiss FACE) from the cement plant in Wiesbaden-Amöneburg as binder. High-quality admixtures (super-plasticisers and deaerators) were also used.

After the bell cage, spiral staircase and electrics had been installed, the bell was able to resume service at the beginning of September 2019.

(Photos 1 to 8: Egenter Betonfertigteilwerk)