Building with Pressure
Inflatable Concrete Formwork

Related Staff : Christian Lange, Olivier Ottevaere

Student: Pang Leong Luigi

Thesis Abstract

Casting a concrete slab with an inflatable formwork is essentially carving out excessive material from the bottom of the slab with air pressure. This idea of removing material resonates with Pier Nervi’s waffle slab, as well as Robert Maillard’s mushroom slab. This thesis, however, also extends beyond the structural and construction realm, and becomes a design tool which uses the ceiling to articulate the spaces below.

The design of the inflatable formwork was inspired by the technique of upholstery; a method to provide structure to a sheet of PVC by pinning it down to a checkered grid and applying air pressure. The grid is defined by the position of the columns, and the sheet of PVC provides the concrete with a form active structure. Because of the nature of the fabric like material, ribs are formed around the columns and capitals, behaving as a second layer of structural supports against buckling. With increasing height, pressure, and corrugation in the formwork, a Gothic imagery emerges and the slab has the potential to become a vault-like structure.

This thesis begins with a building method that is both material and cost efficient. And as it progresses a style emerges, it acts as a tool to help us rethink the ceiling as an architectural form, using its arrangement, depth and weight to convey the spaces beneath it.