Non-rectangular Concrete Beams Produced from Bent Planar Molds
James Roney
Aalto University, Helsinki, Finland
Supervisors
Professor of Practice, Jouni Punkki
Univ.Prof. Günther H. Filz
ended 2018
Abstract. Active-bending structures are structures which use controlled elastic bending of components to produce structural forms. Such structures are created from panels or rods bent and restrained against each other, so that a stable structure is created.
Concrete, on the other hand, is a monolithic building material which is cast as a liquid into a molded shape that is not altered once cured. Although the theoret-ical shapes cast from the concrete are limitless, the realities of constructability dic-tate prismatic elements, which sacrifice material efficiency for ease of construction.
This research attempts to adapt the concepts of active bending structures, namely the feasibility of a shape deployed from bent planar or straight elements being used as a mold with which concrete could be cast into a structural element. The use of active bending would allow the mold to exist as a flat “packet” prior to being “inflated” with concrete. Such molds could be quickly transported and erected, and with proper preparation, reused multiple times. The curved section geometries realized from the bent sections could produce a savings of material over more-traditional rectangular section beams. To test this, a variety of potential mold designs were explored before finalists were realized as mid-scale test castings.
These castings revealed the potential for material savings and exhibited some of the transportability benefits originally hoped for, while also exposing some aspects which would require additional revision in future research.
Keywords: Active Bending, Concrete, Molds, Curved Concrete