The majority of glass used in load-bearing structures is as planar elements. Some projects exist that use linear glass elements. This paper discusses in broad terms the design, engineering, and fabrication of a unique vector active glass structure consisting of glass bundles and partly printed steel connections. A structure was conceived that utilizes the glass bundles in a way that can be directly experienced by the users: a swing. To create a non-standard form for the swing, a structural optimization procedure was used. To realize the structure, a novel steel node was developed and produced using an additive manufacturing technique in steel. These novel applications have made the project innovation heavy, particularly considering the limited timeframe for its development and construction. Description is given of the several optimization techniques incorporated in the digital process, the assembly and testing of the glass bundles, and the manufacturing of the steel nodes by Wire and Arc Additive Manufacturing.

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The majority of glass used in structures is as planar elements. Some projects exist that use linear glass elements. This paper discusses in broad terms the design, engineering and fabrication of a unique vector active glass structure.

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Der Einsatz von Glas als Konstruktionswerkstoff in der Architektur nimmt stetig zu. Die Glass & Transparency Research Group an der TU Delft befasst sich mit diesem Bereich und entwickelt neuartige strukturelle Glaslösungen mit verbesserter Leistung. Hauptthemen sind die Entwicklung neuer Glasrezepturen, Gussglaskonstruktionen, Glasbrückenkonstruktionen, Glassäulen und Dünnglasanwendungen. The application of glass as a structural material in contemporary architecture is ever increasing. The Glass & Transparency Research Group at TU Delft addresses this domain and develops novel structural glass solutions with enhanced performance. Primary topics are the development of new glass recipes, cast glass constructions, glass bridge constructions, glass columns and thin glass applications.@en

A Glass Truss Bridge has been constructed on the Green Village on the campus of Delft University of Technology (TU Delft) by the Glass & Transparency Research group (faculties of Architecture and CiTG). The bridge has been fitted with as many glass components as was structurally feasible, showcasing the group’s research into the structural application of glass in the built environment. The diagonals in the truss are glass bundle struts and the nodes of the truss are cast glass components. The lenticular truss will serve as a temporary bridge. Because of the experimental nature of the truss, with its unusual and novel applications of structural glass, a number of demonstrative proof loadings were performed to ease concerns about the safety of the structure. The glass bundles have been proof-loaded to twice their maximum expected load just prior to their installation in the structure. The whole bridge, once installed, has then been proof-loaded for several critical load combinations (static and dynamic) just after installation. During the proof-loading the strains in the glass diagonals have been measured. These lie well within the acceptable limits. In the paper the structural design of the bridge, in particular the glass node connector and the glass bundle diagonals will be explained. Then the proof-loading of the bridge will be described and the results of the proof-loading are presented and discussed.@en

The construction has started of an entrance bridge, spanning 14 m, to the Green Village; a sustainable development for the Delft University of Technology (DUT). This bridge will be constructed with massive glass blocks, in a shallow arch, with no adhesives: just interlocking blocks under pressure. The massive glass blocks method of building was already tested in a shop for Chanel in Amsterdam.

The glass arch gives considerable horizontal forces on the foundations. Taking just the characteristic dead load of 300 kN of glass blocks leads to a horizontal force of 480 kN on the abutments of this bridge. If we add to this the loads resulting from live load; a maximum vertical load of 443 kN and a maximum horizontal load of 718 kN results.

The glass arch bridge is designed and engineered by the DUT: the two abutments by the engineering firm RHDHV. The DUT was also involved in the execution of the abutments. The following structure was worked out for each abutment: two vertical concrete piles at the support side and behind it six inclined concrete piles, inclination 1:5. All concrete piles; 400 × 400 mm, length 24 m, were driven into the ground. On top of all piles a reinforced concrete plate was cast of 5650 × 3300 × 800 mm.

During execution all dimensions were monitored and measured: loading tests will be executed on the completed bridge and control of deformation: also in the long run, will take place. It is important to know the state of deformation of this highly experimental bridge to assure its safety, or to be able to take preventive measures when deformations become too large.@en

On the campus of Delft University the Glass and Transparency Research Group is preparing to build a pedestrian bridge as a low arch consisting of dry-stacked glass blocks. As temporary support for the arch, a lens-shaped truss has been constructed and placed on location. This truss has been fitted with as many glass components as was structurally feasible. The diagonals in the truss are glass bundle struts and the nodes of the truss are cast glass components. The lenticular truss will serve as a temporary bridge during the time the team needs to prepare for construction of the eventual Glass Arch Bridge. Due to the experimental nature of the truss, with its unusual and novel applications of structural glass, a number of demonstrative proof loadings were performed to ease concerns about the safety of the structure. The glass bundles have been proof-loaded to twice their maximum expected load just prior to their installation in the structure. The whole system has then been proof-loaded for several critical load combinations (static and dynamic) just after installation. During the proof-loading the strains in the glass diagonals have been measured. These lie easily within the acceptable limits. In the paper the structural design of the bridge, in particular the glass node connector and the glass bundle diagonals will be explained. Then the proof-loading of the bridge will be described. Then the results of the proof-loading are presented and discussed.@en

In the last decade there has been an increased usage of cast glass as structural element. Within this respect, a 14 m span glass masonry arch bridge is planned to be constructed at the TU Delft Campus. This paper focuses on part of the experimental analysis that was executed to develop the concept of this bridge. Since it is an arch, the applied loads will be transferred as compressive forces, hence the suitability of glass. Adhesive bonding is not required, since the arch is in compression under its own weight. Application of cast glass bricks in a bridge is a new concept, therefore several aspects with respect to the structural behavior are unknown. Two experimental tests are presented in this paper. First, an experiment with a stacked glass column with varying interlayers is loaded to investigate the stiffness of the interlayer. For PVC interlayers the time-dependent behavior is significant, whereas for polyurethane it is minimal. Furthermore the interlayer’s equivalent modulus of elasticity is dependent on the thickness, due to a difference in the occurring contact areas. Second, a small-scale glass masonry arch is loaded till collapse to investigate the failure behavior and the stresses distribution. It was concluded that a certain robustness is present in the system. Furthermore the brick geometry and the occurrence of sliding are the main aspects that determine the stress distribution. Therewith a stiffer interlayer results in higher stresses in the glass.@en

The purpose of this paper, as part of a MSc graduation project, has been to explore to which extent the kinematic potential of folded geometries can benefit from the structural and architectural properties of glass plates. Using as a case study the covering in an adjustable way an outdoor swimming pool area, the course of this paper consists of form evolution based on structural performance and development of a dual purpose connection and deployment principle developed through experimental testing. Both aspects are examined independently, in parallel processes, and the findings are combined and further evaluated. This study has shown that it is possible to create a self-supporting structure made out of plate elements which is also directionally deployable, without compromising the system’s stability and thus provides an important beginning to implementing complex structures that make use of the benefits of glass.@en

A pedestrian glass bridge, located at the TU Delft campus site, is being designed by the TU Delft Glass & Transparency Lab. Specifically, the arch-formed bridge consists of cast glass, dry-assembled, interlocking components. To validate the shape of the components, glass mock-ups in 1:2 scale are kiln-cast and tested. This paper follows the elements’ production process from the 3D milled MDF model and the construction of disposable moulds via the lost-wax technique, to the kiln-casting at 940ºC with the “flowerpot method”. Steps are taken towards the refinement of the production technique, with emphasis in minimizing the occurrence of air bubbles, surface flaws and internal stresses that can reduce the load-bearing capacity of the components. Polarisation techniques are employed to define the residual stress distribution of the cast elements as well as to map the consolidated flow of molten glass and the areas of inhomogeneity or non-cohesion. The structural performance of the components and their interlocking behaviour are studied by conducting shear tests on three series comprising three glass bricks with a transparent PU interlayer in-between. The fracture patterns of the specimens are analysed and correlated with the flaws and internal stresses resulting from the kiln-casting process.@en

Inspired by the glass masonry façade advanced by the Delft University Glass and Transparency Group for the Crystal House in Amsterdam, a 14 meter span structural glass pedestrian bridge is developed, also consisting of cast glass elements. In contrast to the Crystal House project, which employs an adhesively
bonded glass block system, here dry assembly of the glass elements is proposed to allow for a demountable structure. A number of exploratory experiments are carried out to investigate the structural behaviour of the system. These include compression tests on the glass blocks with a PVC interlayer. With the physical properties obtained from the experiment the bridge can modelled in a finite element program. The results are compared to analytical and numerical calculations and discussed.@en