On Friday, October 24, 2025, Dyckerhoff invited guests to a special event marking a significant moment in the company's history: the ceremonial inauguration of the 94-year-old, newly restored Dywidag Test Shell.

This historically important structure, made of white cement, was built by the former company Dyckerhoff & Widmann AG (Dywidag) using cement from the Portland Cement Factory Dyckerhoff & Söhne—today’s Amöneburg plant. It is a shell construction, built specifically to test the load-bearing capacity of white reinforced concrete and the shell building method. The well-known photograph from 1931, showing 50 Dywidag employees standing on the test shell, impressively documents the stability of the structure.

Together with representatives from politics, industry, and long-standing companions, the unique history of the Dywidag Test Shell was honored. Over nearly a century, the shell has occupied various sites and even came close to being scrapped. Now, the shell shines in new splendor and has found its permanent home on the premises of Dyckerhoff GmbH.

After its initial construction, the shell stood for more than 40 years at the Dywidag company site in Wiesbaden-Biebrich. When the company moved its headquarters to Wiesbaden-Erbenheim, the shell remained in place and thus ended up on the premises of the chemical company Kalle AG, which used it as an inconspicuous storage building. In 1974, the entire warehouse building, which had incorporated the shell, was set to be demolished. With support from the city of Wiesbaden, the historic preservation authorities, and the cement and concrete industry, the shell was ultimately saved and relocated to Wiesbaden-Erbenheim, the new headquarters of Dywidag.

Following the insolvency of Dywidag in 2005, the future of the shell was uncertain. Thanks in large part to the special commitment of the beautification and transport association Verschönerungs- und Verkehrsverein Biebrich am Rhein e.V., the test shell was saved and finally transported to the Amöneburg plant in 2010. Restoration and installation at its current location took place in 2025.

The event opened with speeches by Patrick Klein (Managing Director, Dyckerhoff GmbH), Martin Möllmann (Head of White Cement Sales, Dyckerhoff), and Gert-Uwe Mende (Mayor of the City of Wiesbaden). Afterwards, the inauguration of the shell was celebrated together with Luigi Buzzi, Chief Technology Officer of the parent company Buzzi S.p.A., by ceremoniously cutting a ribbon.

Further information about the Dywidag Test Shell can be found here: https://www.dyckerhoff.com/weissbeton-schale

Photos: Title, 1-5: Dyckerhoff/Christoph Mertens; 6: Dyckerhof