bio-host glass

Abstract

Dense urbanization increases the demand on the building sector who is responsible, on the one hand for producing large amounts of landfilled glass waste, and on the other for consuming the earth’s natural resources and release additional CO2 emissions, for the manufacture of new architectural glass. These unfavorable conditions together with the already apparent effects of climate change, demand resourceful solutions for adaptive and resilient cities, that utilize current waste and require low maintenance and low costs, to be implemented universally.

This, can only be ensured by letting nature to take over. Unexploited urban facades have a key role to provide this new ground that can be colonized by microorganisms, creating a microclimate by forming an outer green layer growing on its own. Aiming this, materials covering our urban facades need to be transformed to porous hosts by retaining rainwater and providing the right environment for bio-growth to take place.

This research aims to discover new ways that unutilized glass waste can be upcycled into bioreceptive applications, that form a promising set of criteria. By shedding light firstly on the specific material properties needed, the method of glass foaming is chosen to be investigated, as the means to provide an open porous network that can incorporate large amounts of waste into its recipe.

An experimental approach has been designed to explore the parameters related to the mixture, manufacturing process affecting the glass foam’s microstructure and potential biofilm formation by producing a total of 22 samples in the Glass lab in Stevin lab, TU Delft. These specimens were not foamed at once, but gradually being tested first of all, microscopically, to reveal the porosity network and secondly, with a series of quick tests related to their hydraulic performance, providing feedback for the next batch of samples regarding the most promising recipes to be further explored. All the samples were tested for their water absorption, evaporation rate and frosting resistance, while only the higher-scored specimens were put under test for moss-growth and compressive strength.

Apart from the experimental analysis, the next steps towards a product development were also explored by setting the bioreceptive design principles for manufacturing the meso-scale surface. Limitations in adjusting these guidelines to the way glass-foam is produced are addressed with possible solutions as suggestions for further experimentation. In addition, an application catalogue was composed as schematic recommendations to showcase the potential of bio-host glass. Combining this idea to the material science, these applications were also approached from an engineering view to analyze the material properties’ specific demands per product. This tool, can prove to be beneficial both in the hands of the future designer and material researcher to have a starting point on what needs to be further developed, depending on the chosen product out of bioreceptive glass-foam.

Taking the most immediately feasible example of a façade tile, based on the findings of the aforementioned analysis, during the last part of this project, a methodology for designing and implementing the new material into the urban environment is proposed. By informing the design of the macro-scale with weather data, precipitation levels can be exploited, in order to provide the maximum water content for the benefit of bioreceptivity.
Therefore, the novelty of this thesis, aspires by providing a holistic approach, based on the knowledge obtained both in the literature review and the conducted experiments, to stir not only bio-growth on our cities, but also innovative thinking and exploration on ways to combat the increasing landfill waste.