3D printed concrete beams as optimised load carrying structural elements – The Minimass beam

3D printed concrete structures have not been widely developed outside the realms of compression-only cases such as walls and columns. The Minimass beam is proposed as an approach to design and manufacture beams, which resist bending primarily through axial compression and tension. This is achieved using 3D printing of concrete for compression elements and external steel cable reinforcing for tension elements but without traditional reinforcement in the concrete itself. This paper presents the justification and benefits of such an approach. It also presents a series of load tests on physical prototypes, describing the performance and results. The different failure modes are discussed, with suggestions for improvements and a focus on the outlook for the future.