Prefabrication experiments - 261 - Connectors - 02 - Abstracta building system

 

Transferring know-how from object, product or commodity production to large-scale building construction has motivated a spectrum of potential building systems both in theory and in practice. Volumetric modular stacking as an approach to industrialized building has been compared to modular toy assembly sets. Toys, from Lego blocks to Lincoln Logs and the infamous Erector Set, were cited as procedural models for simplifying onsite assembly. Modular kits composed of controlled, standardized and compatible parts, still fairly marginal in building, have been successfully applied in furniture assembly. Elements are categorized, bundled and packaged according to predetermined formal or functional objectives. 

 

Scaling the modular kit from furniture to building was at the core of Poul Cadovius’ Abstracta reticulated structural frame system. The Danish born inventor, designer and producer conceived the system in the late 1950s and filed for a patent in 1964. The Abstracta system is composed of a formed cast steel connector joint with a varying number of specially profiled appendages ending in a spherical bulge that fits and locks into tubular struts of varying lengths. The connectors are designed on the same principle as Cadovius’ modular furniture kit with one key difference: the size and thickness of the tubular struts have a minimum diameter of 45mm and a wall thickness of 3mm. The straight member spokes are manufactured with an internal globular pocket for the connector spigot, lodging it in place and resisting compression and tension. The same connector and struts can be assembled into 3d structural matrices to make exhibit structures, scaffolding or even large scale dome and freeform structures.

 

The Abstracta system was awarded the Gold medal in 1961 at the International Inventor’s Congress in Brussels. Its application in building remained negligible. Casting a connector with varying limbs both in terms of spigot angles and a specific shape demands production processes and tolerances that have not been the norm in building construction. Further, the design of hub connectors in general architectural systems has not tackled requirements to coordinate systems other than structure and it is difficult to imagine one connector capable of attaining such universality. Cadovius’ Abstracta system’s ongoing application in furniture still inspires the longstanding intention of assembling architecture with the simplicity of a toy. 

Patent drawing for the connector