Hybrid Glass Block

Abstract

The wide application of glass in buildings is due to its innate transparency and durability. This quality has led to the development of hollow glass blocks during the industrial revolution. These blocks are durable, fire-resistant, exhibit heat resistance, and sound deadening properties. In recent years, new explorations have begun to uncover the structural potential of glass. It is no longer just a cladding material but is also being used for load-bearing applications due to its high compressive strength. One of the most significant drawbacks of cast glass bricks’ current systems is the unsatisfactory thermal performance due to the absence of a cavity and the thick cross-section, which acts as one thick single glazed unit. On the other hand, hollow glass blocks are non-load-bearing due to their thin cross-section of the inner wall which results in buckling under a load and thus, the system is susceptible to failure. A promising solution to these problems is to develop a block that can exhibit structural strength and thermal insulating properties. To do this, design guidelines were developed by carefully studying both the systems followed by different design options which were analysed for their thermal performance. It was observed that the incorporation of cavity, inert gas and coatings greatly influences the thermal property. Also, the presence of continuous glass cross-section is important for structural integrity which generates thermal bridges that negatively impacts the thermal performance of the system. This analysis resulted in two different design options; the fusion block and the lattice block. To fabricate these blocks, careful consideration was taken in the design of the moulds and the chosen glass type. For the two designs, two separate connection systems are employed; one an embedded connection and the other an interlocking pattern. Both connections generate a dry assembly system which is reversible, easy to assemble and easy to maintain. To understand the feasibility of the proposed design solutions, a case study of Ports 1961 store in Shanghai was considered. The blocks were applied on the façade of the building and this was then analysed based on the developed design criterions. The proposed blocks have better thermal performance values, optical and aesthetical qualities. The installation process is much simpler and reversible. The fabrication process is however complex but that is due to the absence of standardized manufacturing system for cast glass bricks. The present research does not conclude in a single suitable design option but rather two concepts. The exploration of different concepts for thermal performance, it’s fabrication and installation results in a general understanding of the parameters that affect the development of this technology. To realize the proposed system, structural verification, fire safety and acoustics still need to be carefully considered and additionally this need to be validated experimentally to derive statistical data for its safe application. Nonetheless the performance values indicate a great potential in the technology.