Flexible Forms

Biocomposites Experimental Pavilion

8 November 2019

The “Flexible Forms” pavilion of the BioMat Group at the ITKE in Stuttgart is a double-curved, parametrically designed segment shell made of light, one-sided curved wood and bio-composite elements. The pavilion is a double-curved, parametrically designed segmental shell of light, single-curved wood and biocomposite elements supported by three curved crossed wooden beams. All elements can then be separated and reused to form various other designs and constellations. The holistic geometry of the shell resembles a 3D fabric in which the curved elements are connected with nodes in all directions in space. This allows us to express new aesthetic architectural features of the future made possible by the use of digital manufacturing technologies and data flow management.

121 parametrically optimized curved elements

The 3.6 m height, 9.5 m span research bio-composite pavilion is an interconnected segmented shell construction consisted of 121 parametrically optimized curved elements prepared by a vacuum-assisted veneer-reinforcement lamination process. Natural-based core of each element was reinforced by long wooden-fibres in the form of veneer, then coated with UV-resistant resin to resist against weathering conditions.

The research focus was a flexible board made from natural fibres mixed with bioplastic, manufactured by an extrusion process. The natural fibres, such as straw, are waste coming from agricultural production, which find its second life as material for architectural use. One of the main advantages of this board in comparison to, for example, MDF, is exceptional elasticity which allows for forming even extremely double-curved surfaces, without heat or water treatment. The CNC cut fibre-board cores are later laminated from both sides with pre-cut 3D veneer sheets – a kind of veneer which can be bend in 2 directions at once. The processes of lamination and forming happen in a mold inside a vacuum press bag. Lamination not only allows to form a flexible flat core board into a stiff 3d bent element, but also allows to create a composite panel with mechanical properties higher than core material itself. For example, during bending test specimens reached Elastic Modulus of over 5,5 GP which is equal to MDF. Simultaneously, another variation of a similar wooden composite plate was developed, in which a flexible wooden board with single direction fibres is used as a core. This variation achieved identical mechanical properties as the first one and finally, due to logistic reasons, was used in this pavilion.

image: Construction in detail

All 121 components were later connected together on-site into 4 fragments, using screws, and pulled on top of the crossed wooden beams, where the final connections were realized. Such approach allows for elements to be separated later and reused to form various other designs and constellations. Foundations of the beams are located at different height levels, allowing the structure form for visual and functional adaption to the local landscape. Within the structure, components interweave with each other, creating a segmented shell which resembles a 3D fabric in which the curved elements are connected to common nodes in all directions in space.

BioMat Research Pavilion demonstrates the architectural and structural potential of novel building materials made from natural material. BioMat department focuses on a mission of examining different sustainability aspects in architecture. This built work is the result of 10 months of intensive work, following many years of work in the field of applications of bio-based materials and diverse approaches towards future-oriented sustainable architecture. It is the direct result of cooperation between experienced architects, around 40 architecture students over two semesters, with support from the University of Stuttgart, the German Agency for Renewable Resources (FNR) under the Ministry of Food and Agriculture (BMEL), the Baden-Württemberg Foundation and multiple industrial funding.


images: Biomat, ITKE