Design of a Reusable Float Glass System

Abstract

The environmental impact of construction materials, particularly in structural applications, has become a pressing concern in the building industry. A key strategy to reduce this impact is the transition to a circular economy, in which reuse is considered the most effective way to extend the lifespan of a product or component (Platform CB’23, 2019).

Float glass has increasingly been used as a primary load-bearing material in recent decades, driven by the fascination of architects and engineers with its aesthetic and structural qualities (Rammig, 2022). This interest has contributed to significant advancements in its technical development (Giese et al., 2024). Nevertheless, despite the material’s inherent durability and its widespread use in both historic and modern contexts, the reuse potential of float glass remains largely underexplored.

This research explores how a reusable float glass system can be designed, enabled by spatial adaptability and modularity. By creating a practical system design, the study encourages designers and researchers to go beyond traditional recycling and consider other circular strategies. In doing so, it explores a potential pathway to extend the functional lifespan of structural glass, reducing waste, conserving resources, and limiting unnecessary energy use.

The study combines theoretical, computational, and experimental research methods. A literature review laid the groundwork for the conceptual design of structural elements and connections and identified key design principles for structural float glass. Using parametric design experimentation, various spatial configurations were explored based on a selected concept: bent laminated glass modules that dry-interlock, allowing for reconfiguration and straightforward assembly. This parametric exploration showed that a system based on two standardized bent float glass modules - each around one meter in length and with two variable heights of up to half a meter to reduce weight and allow manual handling - enables the creation of variable spans of several meters. This is achieved by interlocking the modules at both positive and negative angles and by varying the assembly sequence of the two standardized heights.

Based on these findings, a parametric tool was developed to generate compression-driven forms using the system. These forms are tailored to the span and shape requirements of a specific location, while optimizing both structural weight and ease of assembly.

In the final phase, structural analyses and laboratory testing demonstrated that the adaptable system, made from 2×6 mm fully toughened glass, is structurally feasible when loaded in compression via the slots. A single slot was experimentally shown to withstand at least 2.5 times the design load of 3 kN, accounting for a worst-case configuration of 70 stacked modules - corresponding to a maximum span of approximately 8 meters. If 2×5 mm heat-strengthened glass is to be used, additional testing will be required to verify its structural performance.