Design and experimental testing of the bundled glass column

Abstract

Glass columns are a promising solution for transparent structural members, capable of transferring the compressive loads in a building while allowing for light and space continuity. Several different types of all-glass columns have been explored in the past, nevertheless, they are seldom applied in construction. Reasons include complications in fabrication, lack of adequate strength data but foremost the decreased safety due to the inherent brittleness of glass. This work presents the engineering steps towards the realization of the bundled glass column, from its fabrication method to the experimental testing of series of prototypes in several lengths. Composed of multiple adhesively bonded standardized extruded borosilicate rods, this column can be manufactured relatively easily, achieving a high visual result and sufficient load-bearing capacity. Initially, compressive testing is conducted on series of small-scale prototypes to evaluate the degree of coupling of the rods and the influence of spliced joints along the length of the individual components. Based on the findings, prototypes on a scale relevant to buildings are produced and experimentally tested. Finally, prototypes with post-tensioning are also tested in compression and evaluated, in an attempt to transform the sudden, brittle mode of failure into ductile. The results demonstrate that the designed bundled column can perform monolithically under loading and has sufficient load-carrying capacity to be considered a structural element. Post-tensioning of the column can contribute to a consistent failure but further development is necessary so that sufficient cooperation between the glass and the steel tendon is achieved.