Thin Glass as Cold Bent Laminated Panels in Architectural Applications

Abstract

Glass has been used for centuries. Originally to create weapons, jewellery and decorative ceramics. Nowadays as windows, reagent bottles and electronic devices. It’s only in the last two centuries that there has been substantial development of float glass. The resulting products provide comfort, protection, energy reduction, security and transparency. It is for this reason that glass in modern architecture grew very rapidly in the past decade. Glass panels increased in size and with that growth, the thickness of glass panels has increased from a modest 8 mm to a currently more regular thickness of 32 mm. On top of this, the required insulation values of glass constructions also increased. Future glass panels can include triple or more layers to provide for the required insulation, creating even heavier panels. At a time where we strive to make ever larger and heavier glass panels, shouldn’t we investigate new ways of pushing technological boundaries in order to save material rather than using more of it?

Where regular float glass is a rather thick, hard and brittle substance that can break easily when subjected to large stresses, thin glass can be found on the other side of the spectrum with its flexibility, clarity and higher strength. Thin glass has rarely been used for architectural applications, mainly because technologies for manufacturing thin glass in construction element sizes were not available or were often too expensive. This product however shows large potential provided sufficient interest is shown from different sectors to lower the price and stimulate innovation. This research will therefore focus on how to implement thin glass on a larger architectural scale and embrace its features to create thinner and stronger load-bearing glazing elements in areas where regular float glass doesn’t work. Several design configuration are proposed, of which the thin glass as cold bent laminated panels is the chosen principle to further explore. The main goal of this research is then to gain insight in the structural and post-breakage behaviour of cold bent laminated thin glass panels. Two layers of Leoflex glass from AGC are to be cold bent into a sinusoidal shape with Saflex DG41 provided by Qdel and SentryGlas provided by Trosifol as the interlayers. From the moment the panels are released from their mould, a certain spring back can be observed. Afterwards, the relaxation phase is initiated. Additionally, experiments are performed on a smaller scale panel for a point load applied in the middle of the upper bent surface.