Freeform masonry shell construction using segmental post tensioning to eliminate the use of falsework

Abstract

The use of masonry shell structures has all but vanished in the construction industry. Yet this is not owed to the lack of knowledge or inefficiency of the structure, but purely due to the complexity and expense of the construction process. This dissertation investigates numerous ways in which falsework can be reduced or eliminated in the construction of freeform masonry shells to render such structures a viable solution once again. A construction system utilising segmental post-tensioning is proposed for the assembly of freeform masonry shells with a complete elimination of falsework. The proposed system was successfully applied to a large scale coralline limestone prototype, demonstrating the viability of the proposed system. A comprehensive description of how the proposed segmental post-tensioning system works and its implementation into freeform masonry shells is presented, along with a step-by-step account of how the system was applied and tested on the scaled prototype, from design to assembly. Experimentation with the latest digital form-finding techniques, namely ‘Trust Network Analysis’ (TNA), and digital fabrication methods were employed to realise the envisioned prototype. Observations of the proposed system, as well as possible improvements are outlined in the concluding chapters.