Dywidag Test Shell (1931)
Over the years, it has been given many names, such as the “Dywidag Dome,” “Concrete Temple,” or “Dyckerhoff (White) Temple.” The Dywidag Test Shell, built in 1931 and now a listed monument, documents the early history of German reinforced concrete shell construction.
A photo that made construction history: On August 17, 1931, fifty employees of Dyckerhoff & Widmann AG (Dywidag) stood on the dome structure in Wiesbaden-Biebrich, thereby confirming the load-bearing capacity of the test shell, made of white reinforced concrete, which was only 1.5 centimeters thick at the center and 2.5 centimeters at the edges. Scaled down, this is roughly the thickness of an eggshell.
Already in its early years, Dywidag relied on intensive experimental and research work, supported by a team of highly qualified professionals.
The driving force behind the further development of shell construction in the 1920s—and thus the starting point for the industrial monument presented here—was the demand from Carl Zeiss, the renowned company from Jena, for dome structures to serve as projection surfaces for the most advanced planetariums of that era. Accordingly, it was also known as the “Shell Vault System Zeiss-Dywidag”. This was followed by the development of a series of different shell structures for various construction tasks, such as a column-free roof structure for a modern wholesale market hall in Dresden.
For these purposes, a test shell made of white reinforced concrete was built on the Dywidag plant grounds in 1931 at a scale of 1:5, which at the time represented a milestone in shell construction. This double-curved shell construction was the first to use the white Portland cement Dyckerhoff Weiss, which was introduced to the German market that same year with wide public attention. This cement had been newly developed by the Portland-Cement-Fabrik Dyckerhoff & Söhne, the company now known as Dyckerhoff GmbH.
Such experimental structures were aimed not only at testing new construction techniques but also at using spectacular trial images to convince clients and building authorities of new, barely tried concrete constructions. The "load test" with employees, shown in the photo above, was for example preceded by a test with sandbags. Both full-area and partial loads of 300 kg/m² were tested—an amount that far exceeded the combined weight of the 50 people.
The History of the Test Shell:
- 1931: Construction and initial installation on the then Dywidag plant site on the Biebrich Rhine bank (now Infraserv)
- built using a custom-fabricated wooden formwork
- Reinforcement: 3 mm wire mesh, with additional iron reinforcement at the corners
- Corner supports: 20x20 cm; clear height: 2 m
- No planned use of the space beneath the shell
- 1937: Dywidag relocates its headquarters to Wiesbaden-Erbenheim; the test shell remains on the property, now owned by the chemical company Kalle, and is repurposed as the roof of a Kalle storage building in Wiesbaden-Biebrich
- 1974: Due to Kalle’s redevelopment plans, separation of shell structure from its supports and relocation to the Dywidag premises at Berliner Straße in Wiesbaden-Erbenheim
- only the shell itself could be moved
- new supports manufactured for the new location
- financing provided by the historic preservation authority, City of Wiesbaden, and the cement and concrete industry
- 1975: Surface of the shell strengthened with epoxy resin mortar
- 1990: Extensive repairs carried out for Dywidag’s 125th anniversary
- 2010: After Dywidag was dissolved and the former Dywidag site was redeveloped as residential and commercial space, the shell was transported to the Dyckerhoff works at Biebricher Straße in Mainz-Amöneburg (City of Wiesbaden), where it was stored out of public view
- 2025: The test shell is reinstalled at a publicly accessible, pedestrian location on newly constructed supports
Since autumn 2025, the test shell on display in front of the Dyckerhoff Info Center has been one of the few experimental reinforced concrete structures to have survived permanently. Because of its significance in the history of structural engineering, the State Office for Historic Preservation has entered this unique, historically valuable structure into the State of Hesse’s official list of monuments.