Engineering and Applications of the Bundled Glass Column

This paper presents the engineering steps towards the realisation of loadbearing bundled glass columns, composed of adhesively bonded standardized extruded borosilicate rods. The possibilities and constrains during the design and fabrication phases, and the potential architectural applications of such structural elements are evaluated. Previous experimental work conducted in 0.5m and 1.5m long prototypes has demonstrated the strength and typical failure behaviour of this type of element. Specifically, the 0.5m long specimens fail under compression when the stresses due to expansion in the perpendicular to the load direction exceed the tensile strength of the applied adhesive. Until this stress level, the adhesive allows the bundle to function as one monolithic unit. Due to their high slenderness ratio, the 1.5m long specimens fail after visible buckling at lower stress values. Based on these results, prototypes on a scale relevant to building applications are made and tested in compression to further evaluate the performance of the column and its feasibility in practice. To increase the safety of the column, different safety measures for a gradual and controlled failure behaviour are assessed. Based on these results, a final design is proposed, including the detailing of the top and bottom connections.