Reusable inflatable formwork for complex shape concrete shells

By sealing two membranes according to a pattern, this system allows the construction of complex inflated shapes. The sealing pattern is designed such that, once inflated, the planar metric becomes not uniform and generates a 3D surface following Gauss's Theorema Egregium, a classical result of differential geometry. This design of the seal pattern is guided by a numerical tool capable of accurately predicting the inflated shape. The simulations are compared to physical models made of fabrics, before manufacturing inflatable formwork prototypes in composite membranes from about 1 to three metres wide. Support is set up to pour concrete on the inflatable formwork without damaging it for reuse. The resulting thin concrete shell and its fabrication method are eligible for wider-scale application in the AEC industry.