Design of a demountable structural glass pavilion

Abstract

Glass is a fascinating material that has also been used as a primary construction material in various remarkable buildings since the last century. Unfortunately, a lot of carbon dioxide is released during the production of glass because of the extreme heat required. The construction industry accounts for ten per cent of global CO2 emissions. If a focus in this sector is put on recycling, reducing and reusing, emissions can be drastically reduced because of less needed new building material. However, structural glass is currently hardly reused. A second challenge arises with existing demountable structures made of glass like the LocHal: these are not weatherproof, thus unsuitable as sheltered accommodation.

In response to the absence of adequate standardised structural glass building systems, this research project proposes a preliminary design for a modular, transportable art pavilion with an appropriate structural verification. The research question is therefore: ’How can glass be applied as load‐bearing material in temporary modular building units to realise easy‐to‐ (dis)assemble, transparent and transportable structures?’.

A case‐study is introduced to find an answer to the main research question. The fictive scenario is sketched to design a temporary art pavilion which stands for one to three months in a city centre in the Netherlands. After this period, the pavilion should be demounted and transported to the next destination. The information described here determines the boundary conditions for the design and calculations. The imaginary pavilion is 24 m in length, 10 m in width and 2.5 m in height. The inner walls in the pavilion are retained to create a natural walking path inside. On the short side of the pavilion, doors are inserted as an entrance and an exit. From the available literature, the transportability of the building elements and the requirement for thermal insulation appear to be important preconditions for the final design.

The design is based on four different types of prefabricated building elements: roof panels, wall panels, floor panels and base profiles. The roof panels are of 220 mm thick cross‐laminated timber (CLT), in length six or three metres and have a width of 2.5 m. The wall panels are of laminated glass, 2.5 m in height and come in two types. Insulated glass units (IGU’s) of 6 or 5 m long function as exterior walls. These consist of an outer sheet of 10 mm fully tempered glass, a 15 mm cavity of 90% argon gas and a triple laminated inner panel of 5.10.5 mm heat‐strengthened glass. The inner walls are of a composition of 5.10.5 mm heat‐strengthened glass. The glass is laminated with a SentryGlas® interlayer of 1.52 mm. CLT is also used for the floor panels, now with a thickness of 210 mm and lengths of 6 and 3 m. The base is defined by steel ’cap’ (RHSFB, lengths of 6 and 5 m) and ’hat’ (THQ, length of 4.25 m) profiles. Both profiles are 265 mm in height.

Roof connections, wall connections and base connections were designed and dimensioned, in total seven different types. The most innovative and structurally interesting joints are two wall connections. These connections consist of a so‐called ’coffee‐ cup‐hand’ system; titanium elements laminated 30 mm into the middle sheet of the wall panels. The wall panels are checked on maximum deflection and tensile stress, as well as the local tensile stress in the glass and in the SentryGlas® interlayer around the laminated titanium elements. All checks comply with the maximum allowable values described in the Eurocodes and in literature.

The conclusion is that the proposed design, with some enhancements to be made, satisfies the structural‐, building physics‐ and practical requirements as a transportable and a relative transparent building system for structural glass. With this building system, glass can be integrated as a load‐bearing material for designs of temporary structures.

Engineers who wish to apply this building system in practice are advised to first enhance the roof connections. For transportation means, the grid‐measurements should be decreased by 8% to fit the components in a regular container. For practice, it is also advised to deal with factors such as installations and drainage systems, which were not included in this study. Follow‐up research could focus on the adaptability of the building system when the building is used with a more permanent function. In addition, it is mechanically interesting to further investigate how the wall connections interact with each other in a 3D analysis and lab experiments.