How squares become curves

For centuries, vaulted brick constructions were an established method of bridging large rooms and spans without columns. Due to the great effort involved in their manufacture, this type of supporting structure is no longer used today. A research team at Darmstadt Technical University has now developed a process that enables the cost-effective production of multiple-curved brick shells from flat prefabricated parts.

Thin load-bearing constructions are called planar structures. If these are additionally curved, one speaks of shells. Shell structures made of bricks are highly load-bearing, aesthetic and can cover large spans with small cross-sections. However, their manufacture is material- and personnel-intensive, above all because a substructure in the form of a full-surface so-called falsework is required for construction. This determines the curvature and can only be removed after complete completion, as brick shell structures are only fully load-bearing with the last stone. This type of load-bearing structure is therefore practically never used.

In a research project of the Institute for Constructive Design and Building Construction (KGBauko) at the Department of Civil and Environmental Engineering at the TU Darmstadt, a team led by Alexander Pick within the framework of the ZukunftBau research initiative has investigated whether and how brick shells can be produced economically – for example by using prefabricated parts. The work was carried out in two stages: first digitally on the computer, then with bricks in field trials. The design and calculations of the brick shell were carried out with the aid of a computer model. A prototype 15 meters long and 11.5 centimeters thick with multiple curved geometry was designed on the computer as a 3D model. A complex, static and constructionally rather unfavourable geometry was deliberately chosen in order to prove the efficiency of the principle.