Gridshell as formwork: Proof of concept for a new technique for constructing thin concrete shells supported by gridshell as formwork

This paper documents an empirical experiment conducted in August 2014 as proof of concept for a new method of constructing concrete shells. An idea initially presented by the first author in 2012, it uses redeployable gridshells onto which fabric is midstressed and concrete applied. Primarily, this system addresses key issues that led to their decline in use: construction methods/form work systems were not reusable, nor were they easily customizable to create different shapes. Employing 27 man-hours over seven days, two concrete shells were achieved using the same reusable and reconfigurable form work. Lightweight (0.6 kg) PVC grid shell form work supported 106.92 kg of concrete to create a concrete shell that covered 1.11 m2 (floor area). The construction verifies a low-cost (£6.06/m2) efficiency and material utilization in the construction of very strong wide-spanning thin concrete structures. Detailed analysis of form work behavior during construction and detailed measurements of resultant shell results prove this new method of deployable grid shells as a reusable and reconfigurable formwork to construct very strong concrete shells very quickly. Whilst the emphasis of the research focused on the construction process, the vaults were tested and sustained a failure load of 4.2 kN (4.32 times their dead weight), applied as a point load at the crown. DOI: 10.1061/(ASCE)AE.1943-5568.0000430. © 2020 American Society of Civil Engineers.