Current research conducted at TU Delft focused on utilizing structural Topology Optimization (TO) for designing large monolithic cast glass structures with maximum stiffness and minimum mass. These structures demonstrated improved manufacturability in terms of time, energy, and cost efficiency due to their mass efficiency, which results in shorter annealing times. However, the complex geometries and customization of these forms posed challenges in terms of fabrication.

The manufacturability of intricate glass structures is explored by analysing and comparing three possible fabrication methods for three-dimensional glass structures with complex and customized geometries. The methods examined are:

(i) Kiln casting in disposable moulds,
(ii) Waterjet cutting and lamination of float glass panes,
(iii) Additive manufacturing of glass.

The assessment of these methods is based on a set of criteria related to structural performance, visual quality, fabrication limitations, and sustainability. This comparative study act as a guide to the design of a case study and the selection of the preferred fabrication method. An all-glass topologically optimized bridge observatory in Vikos Gorge, Greece, is chosen as the design case. Based on the comparative study and a set of soft criteria, casting in disposable moulds is selected as the preferred fabrication method.

However, glass casting currently faces major drawbacks that restrict its potential. The two main drawbacks that this thesis tries to address are:

Rough and opaque surface quality (main focus): This issue is tackled through laboratory experimentation with the aim of achieving good surface quality immediately after demoulding. The experiments involve the use of different types of disposable 3D printed sand moulds (3DPSM) and application of refractory coatings and coating combinations at various maximum firing temperatures.

Lack of redundancy: Redundancy is explored though research by design and the implementation of design strategies (segmentation, zoning, fabrication methods combination) to ensure the feasibility of the structure.

The end result of this thesis is a comprehensive study on how an all-glass structure with complex and customized shape can be realized. The experimental part of the research yielded improved results, indicating that the combination of refractory coatings and 3DPSM has the potential to bring such glass components to life, reduce the need for post-processing, and simplify the fabrication process.

Given the limitations of time and knowledge within a master’s thesis, further research is suggested to validate and evaluate the results obtained.