Robustness of a full-scale precast building structure after edge column failure

A full-scale purposely built precast concrete building, designed to comply with robustness requirements in current building codes, was subjected to two different scenarios of sudden edge-column removal under the accidental load combination established by the codes. The main aim of this study was to assess how the structural system can prevent collapse initiation after the removal of a single edge column at different locations. This building was later subjected to a larger initial failure with the aim of arresting collapse propagation as part of another piece of research and outside the scope of this specific study. The building was highly instrumented providing unique data at a building system level for the understanding of the development of alternative load paths after the column removals. This work is novel since existing tests of edge-column removal from precast systems correspond mostly to simplified beam-column-slab subassemblies where the interaction with the rest of the building is neglected. The results obtained from this work are particularly relevant towards understanding the role of tying systems used in precast concrete buildings under different accidental scenarios using typical load combinations defined in building codes. The structure was able to redistribute the loads after each column was removed due to a combination of Vierendeel and compressive arching and membrane actions, leading to very small deflections. The role of vertical, horizontal, and floor tying systems in providing continuity between prefabricated and hybrid members was analysed in view of the experimental results obtained. The response obtained differed significantly from design assumptions commonly adopted for tying systems that rely on tensile catenary action at large deflections. This research is timely considering the push to adopt prefabricated components in building construction driven by Net Zero targets while maximising robustness of buildings subjected to more extreme events exacerbated by climate change. • Two tests were carried out on a purposely built full-scale PC building structure. • Different edge columns were suddenly removed. • Alternative load paths were identified at low deformations. • The role of vertical, horizontal and floor tying systems was analysed.